Characterization of the aqueous extract of the root of Aristolochia indica: Evaluation of its traditional use as an antidote for snake bites

Ethnopharmacological relevance

The aqueous extract of the roots of Aristolochia indica is used as a decoction for the ailment of a number of diseases including snake bite treatment. Though the alcoholic extract of the different parts of the plant are well studied, information on the aqueous extract is limited. We have estimated aristolochic acid, different enzymes, enzyme inhibitors and anti-snake venom potency of its root extract.

Materials and methods

Reverse phase–HPLC was used to quantify aristolochic acid. Zymography, DQ-gelatin assay and atomic force microscopy were done to demonstrate gelatinase and collagenase activities of the extract. SDS-PAGE followed by MS/MS analysis revealed the identity of major protein components. Toxicity of the extract was estimated on animal model. Interaction of the extract with Russell's viper venom components was followed by Rayleigh scattering and enzyme assay.

Results

The aristolochic acid content of the root extract is 3.08±1.88×10⁻³ mg/ml. The extract possesses strong gelatinolytic, collagenase, peroxidase and nuclease activities together with l-amino acid oxidase and protease inhibitory potencies. Partial proteomic studies indicated presence of starch branching enzymes as major protein constituent of the extract. The extract did not show any acute and sub-chronic toxicity in animals at lower doses, but high dose causes liver and kidney damage. The extract elongated duration of survival of animals after application of Russell's viper venom.

Conclusions

Considering the low aristolochic acid content of the extract, its consumption for a short time at moderate dose does not appear to cause serious toxicity. Strong inhibition of l-amino acid oxidase may give partial relief from snake bite after topical application of the extract.     

Ipomoea asarifolia neutralizes inflammation induced by Tityus serrulatus scorpion venom

Ethnopharmacological relevance

Envenoming caused by scorpion sting is a serious public health problem. In Brazil, 13,038 accidents caused by venomous animals have been reported. Of this total, 53% of the cases and 14 deaths were caused by scorpions. Furthermore, Tityus serrulatus (Buthidae) is the most dangerous scorpion due to the high toxicity of its venom. The treatment is the common supportive therapy and the serum therapy, but some people do not have access to both therapies and seek healing through the use of medical plants.

Aim of the study

This study evaluated the ability of the crude extract and fractions from the leaves of Ipomoea asarifolia in neutralizing the main biological effects caused by Tityus serrulatus envenoming in mice.

Materials and methods

BALB/c mice were pretreated (i.v.) with 100 μλ of aqueous extracts and fractions dichloromethane, ethyl acetate, and n-butanol (CH₂Cl₂, EtOAc, and n-BuOH, respectively) of Ipomoea asarifolia, rutin or saline. Then, the animals received 100 μλ (i.p.) of venom of Tityus serrulatus (0.8 mg/kg). After six hours, the peritoneal lavage was performed with PBS and the number cells were determined using a Neubauer chamber. The supernatants were collected for determination of cytokines, such as IL-6, IL-12, and IL-1β.

Results

The aqueous extract, fractions and rutin, at all doses, significantly reduced cell migration, which was endorsed by the reduction of the levels of certain cytokines.

Conclusion

This is the first study that demonstrated the potential effect of Ipomoea asarifolia against inflammation caused by Tityus serrulatus venom, suggesting that these extracts and/or their bioactive molecules, especially the flavonoid rutin, have potential use in the therapy of this envenomation.     

Estrogenic and serotonergic butenolides from the leaves of Piper hispidum Swingle (Piperaceae)

Ethnopharmacological relevance

Our previous work has demonstrated that several plants in the Piperaceae family are commonly used by the Q’eqchi Maya of Livingston, Guatemala to treat amenorrhea, dysmenorrhea, and pain. Extracts of Piper hispidum Swingle (Piperaceae), bound to the estrogen (ER) and serotonin (5-HT7) receptors.

Aim of the study

To investigate the estrogenic and serotonergic activities of Piper hispidum extracts in functionalized assays, identify the active chemical constituents in the leaf extract, and test these compounds as agonists or antagonists of ER and 5-HT7.

Materials and methods

The effects of the Piper hispidum leaf extracts were investigated in estrogen reporter gene and endogenous gene assays in MCF-7 cells to determine if the extracts acted as an estrogen agonist or antagonist. In addition, the active compounds were isolated using ER- and 5-HT7 receptor bioassay-guided fractionation. The structures of the purified compounds were identified using high-resolution LC–MS and NMR spectroscopic methods. The ER- and 5-HT7-agonist effects of the purified chemical constituents were tested in a 2ERE-reporter gene assay in MCF-7 cells and in serotonin binding and functionalized assays.

Results

Three butenolides including one new compound (1) were isolated from the leaves of Piper hispidum, and their structures were determined. Compound 1 bound to the serotonin receptor 5-HT₇ with IC₅₀ values of 16.1 and 8.3 μM, respectively, and using GTP shift assays, Compound 1 was found to be a partial agonist of the 5-HT₇ receptor. The Piper hispidum leaf extracts, as well as Compounds 2 and 3 enhanced the expression of estrogen responsive reporter and endogenous genes in MCF-7 cells, demonstrating estrogen agonist effects.

Conclusions

Extracts of Piper hispidum act as agonists of the ER and 5-HT₇ receptors. Compound 1, a new natural product, identified as 9,10-methylenedioxy-5,6-Z-fadyenolide, was isolated as the 5-HT₇ agonist. Compounds 2 and 3 are reported for the first time in Piper hispidum, and identified as the estrogen agonists. No inhibition of CYP450 was observed for any of these compounds in concentrations up to 1 μM. These activities are consistent with the Q’eqchi traditional use of the plant for the treatment of disorders associated with the female reproductive cycle.     

Cytochrome P450 inhibitory potential and RP-HPLC standardization of trikatu—A Rasayana from Indian Ayurveda

Ethnopharmacological relevance

Trikatu is a very well known ‘Rasayana’ in Ayurveda and widely used as a polyherbal ayurvedic formulation in India. It consists of three well known plants, viz., Piper longum (PL), Piper nigrum (PN) and Zingiber officinale (ZO) in equal ratio. Trikatu has been prescribed for cough, cold, fever, asthma, respiratory problems and improvement of digestive disorders. The aim of the present study was to investigate the effect of individual ingredients of trikatu namely PL, PN, and ZO and formulations [Marketed formulation (MF) and laboratory formulation (LF)] on drug metabolizing enzymes (CYP3A4 and CYP2D6), to assess its herb–drug interaction potential through cytochrome P450 inhibition assays. Further this work was aimed to develop an RP-HPLC method for the identification and quantification of piperine and 6-gingerol in the crude drug trikatu.

Materials and methods

Enzyme inhibition effect of LF, MF, PL, PN and ZO was explored through CYP450–CO complex assay using rat liver microsomes (RLM) and a fluorescence screening method using individual isoenzymes (CYP3A4 and CYP2D6). The RP-HPLC method was developed for the identification and quantification of piperine and 6-gingerol in LF, MF and individual plant materials at the concentration of 1 mg/mL.

Results

RP-HPLC analysis confirmed the presence of piperine and 6-gingerol in LF and MF [Piperine: 7.89±2.12% (w/w) (MF), 6.70±2.13% (w/w) (LF)]; [6-gingerol: 5.3±1.21% (w/w) (MF), 4.95±2.34% (w/w) (LF)]. Inhibitory potential of MF and LF in CYP450–CO complex assay was found to be 37.54±3.12% (MF) and 35.12±2.31% (LF) and against CYP2D6 and CYP3A4 was estimated to be IC₅₀ 251.30±3.98 and 245.23±1.92 μg/mL and IC₅₀ 225.50±1.02 and 223.254±0.92 μg/mL respectively.

Conclusions

Different concentrations of the trikatu formulation and its individual components showed significantly (p<0.001) less inhibitory activity on individual isoenzymes as compared to the positive control. The crude drug exhibited inhibitory potential against the CYP450 enzymes in a concentration dependent manner. Outcome of the present study demonstrated that trikatu has less interaction potential with drug metabolizing enzymes.     

Antiulcer and gastric antisecretory effects of dichloromethane fraction and piplartine obtained from fruits of Piper tuberculatum Jacq. in rats

Ethnopharmacological relevance

Piper tuberculatum Jacq. (Piperaceae) is medicinally used as an analgesic and as a treatment for gastric complaints. Thus, the current study aimed to investigate the gastroprotective and antisecretory properties of the dichloromethane fraction of the fruit of Piper tuberculatum (DFPT) and piplartine, a compound isolated from the DFPT, in rats.

Materials and methods

Gastric ulcers were induced in fasted rats by oral administration of absolute ethanol and then mucus content and glutathione (GSH) levels were measured. Mechanisms underlying the antisecretory action were studied through gastric H⁺,K⁺-ATPase activity of highly purified rabbit gastric microsomes and pylorus ligature method in rats.

Results

In the acute toxicity test the values of estimated LD₅₀ for oral and intraperitoneal administration of DFPT were 1.6266 and 0.2684 g/kg, respectively. The DFPT (ED₅₀=29 mg/kg, p.o.) and piplartine (4.5 mg/kg, p.o.) promoted gastroprotection against acute lesions induced by ethanol, effect that could be related with the maintenance of GSH levels in the gastric mucosa. However, only DFPT stimulated gastric mucus secretion. In vitro, the DFPT and piplartine inhibited the H⁺,K⁺-ATPase activity and, in vivo DFPT and piplartine also reduced basal gastric acid secretion, as well as that stimulated by pentagastrin.

Conclusions

These results demonstrate that DFPT and piplatine cause marked gastroprotective effects accompanied by the increase and maintenance of gastric mucus and GSH levels, as well as a reduction in gastric acid secretion through the gastrinergic pathway.     

Involvement of the L-arginine-nitric oxide pathway in the antinociception caused by fruits of Prosopis strombulifera (Lam.) Benth

Ethnopharmacological relevance

Prosopis strombulifera (Lam.) Benth. is a rhizomatous shrub that grows in the north and central zone of Argentina. In folk medicine, the fruits of this plant have been used as an astringent, anti-inflammatory and odontalgic agent and anti-diarrheic.

Aim of the study

To investigate the antinociceptive effect of ethanol (EE), chloroform (CE) and ethyl acetate (EtOAcE) extracts of Prosopis strombulifera fruits and the involvement of the l-arginine-nitric oxide pathway in this effect.

Materials and methods

The antinociceptive effects of the EE, CE and EtOAcE of Prosopis strombulifera fruits were evaluated in vivo using the formalin-induced pain test in mice with aspirin and morphine as reference antinociceptive compounds. The participation of the l-arginine-nitric oxide pathway in the antinociceptive effect was investigated in the same animal model using l-arginine as a nitric oxide (NO) precursor. The in vitro inhibitory effect of the extracts on LPS-induced nitric oxide production and iNOS expression was investigated in a J774A.1 macrophage-derived cell line.

Results

CE (300 mg/kg), in contrast to EE and EtOAcE, caused significant inhibition (p < 0.05) of the in vivo nociceptive response. Moreover, CE (100–1000 mg/kg, p.o.) produced a dose-dependent inhibition of the neurogenic and the inflammatory phases of the formalin test with inhibition values (at 600 mg/kg) of 42 ± 7% and 62 ± 7%, respectively. CE inhibition was more potent in the inflammatory phase, with an ID₅₀ of 400.1 (252.2–634.8) mg/kg. The antinociception caused by CE (600 mg/kg, p.o.) was significantly attenuated (p < 0.05) by i.p. treatment of mice with l-arginine (600 mg/kg). In addition, CE (100 μg/mL) produced significant in vitro inhibition (p < 0.001) of LPS-induced NO production, which was not observed with EE and EtOAcE at the same concentration. The inhibition of NO production by CE (10–100 μg/mL) was dose-dependent, with an IC₅₀ of 39.8 (34.4–46.1) μg/mL, and CE significantly inhibited LPS-induced iNOS expression in J774A.1 cells.

Conclusions

This study supports, in part, the ethnomedical use of Prosopis strombulifera fruits by showing that its CE produces moderate antinociception in vivo. The findings also provide scientific information for understanding the molecular mechanism involved in the analgesic effect of this plant.     

Evaluation of the antinociceptive, anti-inflammatory and gastric antiulcer activities of the essential oil from Piper aleyreanum C.DC in rodents

Ethnopharmacological relevance

Piper aleyreanum is a small tree that is widely distributed in tropical and subtropical regions, mostly in North and South America, and is used as an immunomodulator, analgesic and antidepressant in folk medicine.

Aim of the study

This study was designed to investigate the antinociceptive, anti-inflammatory and gastric antiulcer activities of the essential oils from the aerial parts of Piper aleyreanum (EOPa) in rodents.

Materials and methods

The antinociceptive and anti-inflammatory effects of orally administered EOPa were evaluated in mice subjected to the formalin and pleurisy models, respectively. We also pretreated the rats with EOPa before acute ethanol-induced gastric lesions and measured gastric lesion extension and mucus and glutathione (GSH) levels in the gastric mucosa. Finally, we performed a phytochemical analysis of EOPa.

Results

The chemical composition of EOPa was analyzed by gas chromatography and mass spectrometry (GC/MS), which identified 35 compounds, representing 81.7% of total oil compounds. Caryophyllene oxide (11.5%), β-pinene (9%), spathulenol (6.7%), camphene (5.2%), β-elemene (4.7%), myrtenal (4.2%), verbenone (3.3%) and pinocarvone (3.1%) were the major oil constituents. The oral administration of EOPa (10–1000 mg/kg) significantly inhibited the neurogenic and inflammatory phases of formalin-induced licking, with ID50 values of 281.2 and 70.5 mg/kg, respectively. The antinociception caused by EOPa (100 mg/kg, p.o.) was not reversed by naloxone (1 or 5 mg/kg, i.p.) in the formalin test. EOPa (100–300 mg/kg, p.o.) did not affect animal motor coordination in an open-field model. In carrageenan-induced pleurisy, EOPa (1–100 mg/kg, p.o.) significantly decreased the total cell count, neutrophils and mononuclear cells with mean ID50 values of 53.6, 21.7 and 43.5 mg/kg, respectively. In addition, EOPa (1–30 mg/kg, p.o.) protected the rats against ethanol-induced gastric lesions with an ID50 value of 1.7 mg/kg and increased the mucus and GSH levels of the gastric mucosa to levels similar to those of the non-lesioned group.

Conclusions

These data show for the first time that EOPa has significant antinociceptive and anti-inflammatory actions, which do not appear to be related to the opioid system. EOPa also has interesting gastroprotective effects related to the maintenance of protective factors, such as mucus production and GSH. These results support the widespread use of Piper aleyreanum in popular medicine and demonstrate that this plant has therapeutic potential for the development of phytomedicines with antinociceptive, anti-inflammatory and gastroprotective properties.     

In vivo anti-nociceptive and anti-inflammatory activities of the aqueous extract of the leaves of Piper sarmentosum

Ethnopharmacological relevance

Piper sarmentosum (Piperaceae) is a medicinal plant traditionally used by the Malays to treat headaches, toothaches, coughs, asthma and fever.

Aim of the study

In order to establish the pharmacological properties of the leaf of this plant, studies were performed on anti-nociceptive and anti-inflammatory activities.

Materials and methods

The aqueous extract of Piper sarmentosum (AEPS) was prepared in the doses of 30, 100 and 300 mg/kg. Anti-nociceptive activity of AEPS was evaluated by abdominal constriction and hot-plate tests. AEPS was also pre-challenged with 5 mg/kg naloxone to determine the involvement of opioid receptors. Anti-inflammatory activity was evaluated using carrageenan-induced paw edema assay.

Results

Subcutaneous administration of AEPS exhibited anti-nociceptive activity (P < 0.05) in a dose-dependent manner in the abdominal constriction and hot-plate tests. Pre-treatment with naloxone completely (P < 0.05) diminished the extract anti-nociceptive activity in both tests. The AEPS, at all doses used, exerted significant (P < 0.05) anti-inflammatory activity in a dose-dependent manner.

Conclusions

The AEPS exhibits opioid-mediated anti-nociceptive activity at the peripheral and central levels, as well as anti-inflammatory activity, which confirmed the traditional uses of the plant in the treatment of pain- and inflammatory-related ailments.     

Anti-inflammatory effect of bee venom on antigen-induced arthritis in rabbits: Influence of endogenous glucocorticoids

Aim of the study

This study assessed the involvement of endogenous glucocorticoids (GCs) in the anti-arthritic properties of bee venom (BV) on antigen-induced arthritis (AIA) in rabbits.

Materials and methods

BV (1.5–6 μg/kg/day) was injected for 7 days before AIA induction, whereas the control group received sterile saline. The total and differential leukocyte count, PGE₂ levels in synovial fluid and synovial membrane cell infiltrate were evaluated. The contribution of GCs to BV action was assessed in rabbits treated with BV plus metyrapone, an inhibitor of GC synthesis, or RU-38 486, a steroid antagonist.

Results

Treatment with BV (1.5 μg/kg/day) reduced the leukocyte count and PGE₂ level (18571 ± 1909 cells/mm³ and 0.49 ± 0.05 ng/mL, respectively) as well as the cellular infiltrate compared with the control group (40968 ± 5248 cells/mm³ and 2.92 ± 0.68 ng/mL, p < 0.05). The addition of metyrapone to BV treatment completely reversed the inhibition of AIA, whereas RU-38 486 was ineffective.

Conclusion

Our data show that bee venom treatment prevents the development of antigen-induced arthritis in rabbits through the action of GCs.     

Cytotoxicity and modes of action of four Cameroonian dietary spices ethno-medically used to treat Cancers: Echinops giganteus, Xylopia aethiopica, Imperata cylindrica and Piper capense

Ethnopharmacological relevance.

Echinops giganteus, Imperata cylindrica, Piper capense and Xylopia aethiopica are four medicinal spices used in Cameroon to treat cancers.

Aim of the study

The above plants previously displayed cytotoxicty against leukemia CCRF-CEM and CEM/ADR5000 cell lines as well as human pancreatic MiaPaCa-2 cells. The present study aims at emphasizing the study of the cytotoxicity and the modes of action of the above plants on a panel of ten cancer cell lines including various sensitive and drug-resistant phenotypes. The study has been extended to the isolation of the bioactive constituents from Echinops giganteus.

Materials and methods

The cytotoxicity of the extracts was determined using a resazurin reduction assay, whereas the caspase-Glo assay was used to detect the activation of caspases 3/7, caspase 8 and caspase 9 in cells treated with the four extracts. Flow cytometry was used for cell cycle analysis and detection of apoptotic cells, analysis of mitochondrial membrane potential (MMP) as well as measurement of reactive oxygen species (ROS).

Results

The four tested extracts inhibited the proliferation of all tested cancer cell lines including sensitive and drug-resistant phenotypes. Collateral sensitivity of cancer cells to the extract of Echinops giganteus was generally better than to doxorubicin. The recorded IC₅₀ ranges were 3.29 µg/mL [against human knockout clones HCT116 (p53^−/−) colon cancer cells] to 14.32 µg/mL (against human liver hepatocellular carcinoma HepG2 cells) for the crude extract from Echinops giganteus, 4.17 µg/mL (against breast cancer cells transduced with control vector MDA-MB231 cells) to 19.45 µg/mL (against MDA-MB-231 BCRP cells) for that of Piper capense, 4.11 µg/mL (against leukemia CCRF-CEM cells) to 30.60 µg/mL (against leukemia HL60AR cells) for Xylopia aethiopica, 3.28 µg/mL [against HCT116 (p53^−/−) cells] to 33.43 µg/mL (against HepG2 cells) for Imperata cylindica and 0.11 µg/mL (against CCRF-CEM cells) to 132.47 µg/mL (against HL60AR cells) for doxorubicin. The four tested extracts induced apoptosis in CCRF-CEM cells via the alteration loss of MMP whilst that of Piper capense also enhanced the production of ROS.

Conclusion

The studied plants are potential cytotoxic drugs that deserve more detailed exploration in the future, to develop novel anticancer drugs against sensitive and otherwise drug-resistant phenotypes.     

Efficacy evaluations of Mimosa pudica tannin isolate (MPT) for its anti-ophidian properties

Aim of the study

Evaluations of the anti-snake venom efficacy of Mimosa pudica tannin isolate (MPT) obtained from root of the plant.

Materials and method

MPT was investigated in vitro and in vivo for its efficacy against the venom of Naja kaouthia snake.

Results

In vitro: (1) mice injected i.p. with MPT pre-incubated with Naja kaouthia venom at concentrations as low as 0.625 mg/ml showed 100% survival after a 24-h observation period. (2) In the proteomics study, mice injected with MPT pre-incubated with the Naja kaouthia venom showed down-regulation of five serum proteins. (3) In the protein-dye-binding study, the percentage of Bradford dye-protein binding showed a reduction relative to the decrease in MPT concentration used to incubate with the venom. In vivo: the results from the animal studies showed that MPT had no in vivo protection against the Naja kaouthia venom (0.875 mg/kg) in four different rescue modes and in an oral pre-treatment experiment.

Conclusion

The study indicated the promising ability of MPT to neutralize the Naja kaouthia venom in in vitro experiments but fell short in its in vivo potential. As such, the use of Mimosa pudica (Mimosaceae) as therapeutics for snake bites is questionable as all the possible in vivo rescue studies and pre-treatment of the active constituents showed no protection against the affected mice.     

Jiawei-Yupingfeng-Tang,a Chinese herbal formula,inhibits respiratory viral infections in vitro and in vivo

Ethnopharmacological relevance

Jiawei-Yupingfeng-Tang (JYT) is a Chinese herbal formula that is widely used to treat respiratory tract illness. However, the effect of JYT on respiratory viruses remains unknown. The influenza virus (IFV) and the human respiratory syncytial virus (HRSV) cause millions of cases of severe illness per year, and many of these illnesses develop into lethal pneumonia. The aim of this study is to evaluate whether JYT can be used to treat these infections.

Materials and methods

The effect of JYT against IFV and HRSV was tested using a plaque reduction assay in the lower respiratory tract cell line A549. The expression of ICAM-1 was determined by real-time RT-PCR and western blotting. A mouse model infected with lethal influenza developing into interstitial pneumonia was used to evaluate the effect of JYT in vivo.

Results

JYT extract inhibited both IFV and HRSV in a dose-dependent manner when given before, during and after a viral infection. JYT was effective in blocking the entry of the virus. Furthermore, pre-treatment with JYT reduced the susceptibility of cells to the invasion of HRSV by inhibiting the expression of ICAM-1. Importantly, JYT extract increased the survival rate of lethal influenza-infected mice, prolonged the survival time and alleviated the virus-induced lung lesions, which is comparable with the effects of ribavirin treatment.

Conclusions

These data support JYT as an alternative modality to be used in the treatment of respiratory viral infection induced by HRSV and IFV.     

Antinociceptive effect of Mirabilis jalapa on acute and chronic pain models in mice

Ethnopharmacological relevance

The infusion or decoction of Mirabilis jalapa leaves is used in traditional medicine in Brazil to treat inflammatory and painful diseases. Thus, the present study was designed to investigate whether the leaf ethyl acetate (Eta) fraction from Mirabilis jalapa exhibits antinociceptive effect in clinically relevant pain models in mice. Furthermore, we have investigated the role of cholinergic system in the antinociceptive action produced by Eta in mice.

Materials and methods

The effect of Eta administered orally (10 mg/kg, p.o.) in mice was verified on the painful hypersensitivity (mechanical allodynia) in models of chronic inflammation (subcutaneous injection of complete Freund’s Adjuvant—CFA in the plantar surface of the right hind paw), postoperative (paw surgical incision) and neuropathic (partial sciatic nerve ligation) pain. In the chronic inflammation model, we further verified the effect of Eta treatment on paw edema and interleukin-1β (IL-1β) levels. We also investigated the role of muscarinic and nicotinic receptors in the antiallodynic action produced by Eta as well as the possible action of Eta on in vitro and ex vivo acetylcholinesterase activity in CFA treated animals. Furthermore, we verified the effect of Eta treatment on the parameters of liver and kidney lesion (level of urea, and activity of aspartate aminotransferase and alanine aminotransferase).

Results

Eta produced marked reduction in the allodynia caused by CFA, surgical incision and partial sciatic nerve ligation. However, Eta did not alter the paw edema or the increase of IL-1β levels produced by CFA. The antinociceptive effect of Eta was reversed by the pre-treatment of animals with the antagonists of muscarinic (atropine, 5 mg/kg, s.c) or nicotinic (mecamylamine, 0.001 mg/kg, s.c.) receptors. Eta did not alter in vitro acetylcholinesterase activity in blood or spinal cord samples, but it reversed the increase in the acetylcholinesterase activity observed in the spinal cord samples from mice injected with CFA. Moreover, Eta did not alter the indicators of liver or kidney lesion.

Conclusions

Based on its use in traditional medicine, the results of the present study confirmed the antinociceptive properties of Eta in clinically relevant pain models. Also its effect on the CFA-induced chronic inflammation seems to be related to acetylcholinesterase inhibition and cholinergic system.     

Isolation and characterization of a novel antihyperglycemic protein from the fruits of Momordica cymbalaria

Aim of the study

A new antihyperglycemic protein was identified in the aqueous extract of fruits of Momordica cymbalaria by bioassay-guided fractionation. The study was aimed at isolation and characterization of this protein.

Materials and methods

The active principle was purified to homogeneity by ammonium sulphate precipitation, gel filtration column chromatography on Sephadex G-50 followed by reverse phase HPLC. Its N-terminal amino acid sequence was identified and compared in the protein data bank. Optimum dose and route of administration of the active principle was determined in STZ induced diabetic rats.

Results

A 17 kDa protein with an isoelectric point of 5.0 was identified as the active principle of antidiabetic action present in the aqueous extract of fruits of MC. It is named as M.Cy protein and found to be a novel protein by comparing its N-terminal amino acid sequence with those in the protein data bank. It did not produce any hypoglycemia in either normal or diabetic rats.

Conclusions

The results suggest that ‘M.Cy protein’, present in the fruits of Momordica cymbalaria is an effective antihyperglycemic active principle in STZ induced diabetic rats at a dose of 2.5 mg/kg b.w.     

Assessment of in vitro pharmacological effect of Neotropical Piperaceae in GABAergic bioassays in relation to plants traditionally used for folk illness by the Yanesha (Peru)

Ethnopharmacological relevance

A previous pilot ethnobotanical and ethnopharmacological study with the Q‘echi? Maya identified the family Piperaceae, as an important taxonomic group traditionally used for the treatment of epileptic and culture-bound anxiety disorders and possessing activity in the GABA system. Following that lead, a botanical survey was conducted in Peru, where 47 species of Piperaceae were collected including 21 plants traditionally used for folk illnesses by the Yanesha of Peru, an indigenous Amazonian group.

Materials and methods

Two high throughput bioassays were used to quantify the in vitro activity of botanical extracts on the GABA system.

Results

Plant extracts demonstrated moderate to high affinity to the γ-aminobutyric acid benzodiazepine (GABA-BZD) receptor. In addition, extracts demonstrated low to moderate activity in the inhibition of the GABA-transaminase, with select plants exhibiting significant activity. Plants indicated by the Yanesha showed comparable activity to the other Piperaceae plants collected. Piper cremii was the most active plant in the GABA-BZD receptor assay, and Drymaria cordata (Caryophyllaceae) in the GABA-T assay.

Conclusion

The study provides evidence that there is a pharmacological basis behind the use of plants in the treatment of susto and mal aire in both Central and South America, and we propose that the possible mechanism of action includes an interaction with the GABA-T enzyme and/or the GABA_A-BZD receptor.     

Evaluation of antinociceptive effects of Crassocephalum bauchiense Hutch (Asteraceae) leaf extract in rodents

Ethnopharmacological relevance

The leaves of Crassocephalum bauchiense have long been used in traditional Cameroonian medicine for the treatment of epilepsy, pain, inflammatory disorders, arthritis and intestinal pain.

Aim of the study

In this study, we attempted to identify the possible antinociceptive action of the aqueous extract and the alkaloid fraction prepared from the leaves of Crassocephalum baucheiense.

Materials and methods

Using acetic acid induced abdominal constrictions, formalin-, capsaisin- and glutamate-induced nociception, and hot plate assay procedures, the antinociceptive effects of the aqueous extract and the alkaloid fraction was assessed after oral administration in mice. Morphine sulfate was used as reference analgesic agent. Mice were submitted to the rota-rod task and open-field test in order to assess any non-specific muscle-relaxant or sedative effects of the extracts of Crassocephalum bauchiense. Male and female Swiss mice were used to assess acute toxicity of these extracts.

Results

The aqueous extract and the alkaloid fraction of Crassocephalum bauchiense produced a significant antinociceptive effects in the acetic acid, formalin, glutamate, capsaicin and hot plate tests. These antinociceptive effects of Crassocephalum bauchiense were significantly attenuated by pretreatment with naloxone. The extracts of Crassocephalum bauchiense did not alter the locomotion of animals in the open-field or rotarod tests, which suggest a lack of a central depressant effect. The animals did not exhibit any acute toxicity to the aqueous extract and the alkaloid fraction, so it was not possible to calculate the LD₅₀.

Conclusion

The results confirm the popular use of Crassocephalum bauchiense as an antinociceptive, and contribute to the pharmacological knowledge of this species because it was shown that the aqueous extract and the alkaloid fraction of Crassocephalum bauchiense produced dose related antinociception in models of chemical and thermal nociception through mechanisms that involve an interaction with opioidergic pathway.     

Inhibition of venom serine proteinase and metalloproteinase activities by Renealmia alpinia (Zingiberaceae) extracts: Comparison of wild and in vitro propagated plants

Ethnopharmacological relevance

The plant Renealmia alpinia has been used in folk medicine to treat snakebites in the northwest region of Colombia. In addition, it has been shown to neutralize edema-forming, hemorrhagic, lethal, and defibrin(ogen)ating activities of Bothrops asper venom. In this work, extracts of Renealmia alpinia obtained by micropropagation (in vitro) and from specimens collected in the wild were tested and compared in their capacity to inhibit enzymatic and toxic activities of a snake venom metalloproteinase isolated from Bothrops atrox (Batx-I) venom and a serine proteinase (Cdc SII) from Crotalus durissus cumanensis venom.

Materials and methods

We have investigated the inhibition capacity of Renealmia alpinia extracts on enzymatic and toxic actions of isolated toxins, a metalloproteinase and a serine proteinase. The protocols investigated included inhibition of proteolytic activity on azocasein, inhibition of proteolytic activity on fibrinogen, inhibition of pro-coagulant activity, inhibition of hemorrhagic activity and inhibition of edema-forming activity.

Results

Colorimetric assays detected the presence of terpenoids, flavonoids, tannins and coumarins in Renealmia alpinia extracts. Renealmia alpinia extracts inhibited the enzymatic, hemorrhagic and fibrinogenolytic activities of Batx-I. Extracts also inhibited coagulant, defibrin(ogen)ating and edema-forming activities of Cdc SII. Results highlight that Renealmia alpinia in vitro extract displayed comparable inhibitory capacity on venom proteinases that Renealmia alpinia wild extract. No alteration was observed in the electrophoretic pattern of venom proteinases after incubation with Renealmia alpinia extracts, thus excluding proteolytic degradation or protein denaturation/precipitation as a mechanism of inhibition.

Conclusions

Our results showed that Renealmia alpinia wild and in vitro extracts contain compounds that neutralize metallo- and serine proteinases present in snake venoms. The mechanism of inhibition is not related to proteolytic degradation of the enzymes nor protein aggregation, but is likely to depend on molecular interactions of secondary metabolites in the plant with these venom proteinases.     

Pharmacological evaluation of sedative–hypnotic activity and gastro-intestinal toxicity of Rhizoma Paridis saponins

Ethnopharmacological relevance

Rhizoma Paridis saponins (RPS) have been well studied for antimicrobial, anti-hemorrhagic, and anticancer effects. However, scientific information on RPS regarding the toxic and neuropharmacological effects is limited. In this study, the acute oral toxicity, sedative–hypnotic activity and gastro-intestinal toxicity of RPS were investigated.

Materials and methods

The acute toxicity was carried out by administering single doses (800–5000 mg/kg) of RPS to adult mice. Rotarod test and sodium pentobarbital-induced hypnosis activity were used to evaluate the neuropharmacological effects on mice. Gastric emptying and intestinal transit were used to investigate the gastric–intestinal system effects.

Results

A single oral administration of RPS dose-dependently caused adverse effects on the general behavior and mortality rate of mice. LD₅₀ value of oral acute toxicity was 2182.4 mg/kg, with 95% confidence limit of 1718.4–2807.8 mg/kg. In the test of sleeping mice, RPS acted in synergy with sodium pentobarbital at doses 250 and 500 mg/kg while motor coordination was not influenced within 120 min after treatment with RPS. Regarding the gastric–intestinal toxicity, RPS (100, 250, and 500 mg/kg) significantly inhibited gastric emptying but did not affect the intestinal transit.

Conclusions

RPS, which is a hypotoxic anticancer drug, possesses the sedative–hypnotic activity and gastric stimulus side effect.     

Atropa acuminata Royle Ex Lindl. blunts production of pro-inflammatory mediators eicosanoids., leukotrienes,cytokines in vitro and in vivo models of acute inflammatory responses

Ethnopharmacological relevance

Atropa acuminata Royle Ex Lindl. has been widely used in folk medicine for several inflammatory disorders such as arthritis, asthma, conjunctivitis, encephalitis, pancreatitis, peritonitis, acute infections and neuroinflammatory disorders.

Aim of the study

Our aim was to evaluate Atropa acuminata for its anti-inflammatory properties and to delineate its possible mechanism of action on the modulation of the inflammatory mediators.

Materials and methods

We investigated the inhibitory action of ethanolic extract of Atropa acuminata (AAEE) on production of NO, TNF-α and IL-1β in lipopolysaccharide (LPS)-stimulated RAW264.7 cells and also assayed it for COX 1/2 and 5-LOX inhibitory activities. Next AAEE was tested in acute inflammatory animal models., carragenean induced rat paw edema, carragenean induce pleurisy in rats and vascular permeability in mice and the effects on NO, PGE₂ and LTB₄ production in the pleural fluid and paw exudates were evaluated. In addition the effects on leukocyte migration and exudation and vascular permeability were also observed.

Results

Our findings summarized novel anti-inflammatory mechanisms for Atropa acuminata based on dual in vitro cyclooxygenase 1/2/ and 5-Lipoxygenase inhibitory activities and also significant downregulation of nitric oxide (NO) and pro-inflammatory cytokin (TNF-α and Il-1 β) release in LPS-stimulated RAW 246.7 macrophage cell line. In acute inflammatory models in vivo (carragenean induced edema, carragenean induced pleurisy in rats and vascular permeability in mice), AAEE exhibited an extensive diverse mechanism for anti-inflammatory properties. This was indicated on the basis of dose dependent suppression of multi targeted inflammatory mediators., NO, TNF-α and IL-1β, eicosanoids., PGE₂ and leukotrienes., LTB₄ along with significantly decreased leucocyte migration, exudation and decreased vascular permeability. These effects were more potent and prolonged than traditional NSAIDS, thereby indicating fewer side effects. AAEE was found to be safe for long term administration, as confirmed by the results of acute toxicity studies and MTT assay. The complex mode of action of the herbs was attributed possibly due to the high polyphenolic, flavanol and flavonoid content present in the extracts as observed by means of quantitative screening for phytochemicals.

Conclusion

Our study provides scientific evidence to support the traditional anti-inflammatory uses of Atropa acuminata and is probably due to inhibitory effects on multiple inflammatory mediators which indicates a promising potential for the development of a strong anti-inflammatory agent from this plant.     

Antiophidic activity of the extract of the Amazon plant Humirianthera ampla and constituents

Ethnopharmacological relevance

Although serotherapy against snakebite has been discovered more than one hundred years ago, antivenom is not available all over Brazil. The use of plants from folk medicine is common mainly in the Brazilian Amazon area. One of these plants is named Humirianthera ampla (HA).

Materials and Methods

We have investigated HA extract and constituents’ antiophidic activity in different experimental protocols against some Bothrops snake venoms (Bothrops jararacussu, Bothrops atrox and Bothrops jararaca). The protocols investigated include phospholipase, proteolytic, pro-coagulant, hemorrhagic, edematogenic and myotoxic activities induced by these venoms in Swiss mice.

Results

All the venoms caused an increase in the rate of creatine kinase (CK) release from isolated muscles, indicating damage to the sarcolemma. The crude extract of HA decreased the myotoxic activity in a concentration-dependent fashion. The presence of HA 300 μg/mL decreased up to 96% of Bothrops jararacussu and 94% of Bothrops atrox myotoxicity after 90 min of exposure. In vivo myotoxicity of Bothrops atrox venom was decreased in 75% when the venom was preincubated with HA 500 mg/kg. Similar results were observed with lupeol against Bothrops jararacussu and Bothrops atrox venoms. The hemorrhagic activity was evaluated by intradermal injection of Bothrops atrox venom. Preincubation and oral pre- and posttreatment with HA decreased hemorrhage by 100%, 45% and 45%, respectively. Bothrops atrox venom also induced formation of edema, which was significantly inhibited by pre- and posttreatment with HA. All the venoms showed extensive pro-coagulating properties, and these activities were inhibited by up to 90% with HA, which presented concentration-dependent inhibition. Finally, proteolytic and phospholipase activities of the venoms were all inhibited by increasing concentrations of HA, lupeol and sitosterol. The inhibition of these activities might help explain the actions against in vivo myotoxicity and the in vivo effects observed, i.e., edema, myotoxicity, pro-coagulation and hemorrhage.

Conclusions

Altogether, our results give support for the popular use of HA extracts in cases of accidents with snakes, suggesting that it can be used as an adjunct in the management of venomous snakebites.