Analgesic and anti-inflammatory activities of Cnestis ferruginea Vahl ex DC (Connaraceae) methanolic root extract

Ethnopharmacological relevance

Cnestis ferruginea Vahl ex DC (Connaraceae) is a shrub widely used in traditional African Medicine (TAM) for the treatment of various painful and inflammatory conditions.

Aim of the study

The objective of this study was to investigate the analgesic and anti-inflammatory properties of the methanolic root extract of Cnestis ferruginea.

Materials and methods

Analgesic activity was evaluated using the acetic acid-induced writhing, formalin, tail clip, and hot plate tests in mice. The carrageenan- and egg albumin-induced rat paw oedema, formaldehyde-induced arthritis inflammation, and xylene-induced ear oedema tests were used to investigate the anti-inflammatory actions of Cnestis ferruginea.

Results

The methanolic root extract of Cnestis ferruginea (100, 200, and 400 mg/kg; p.o.) produced significant (P < 0.05) dose-dependent inhibition of pain response elicited by acetic acid and formalin while also increasing the nociceptive reaction latency in the tail clip and hot plate tests. In respect of anti-inflammatory activity, Cnestis ferruginea caused significant (P < 0.05) dose-dependent inhibition of oedema development in the carrageenan, egg albumin, formaldehyde, and xylene-induced inflammation tests. The effects of the extract in the various models were generally comparable to those of the standard drugs used.

Conclusion

The findings in this study suggest that the methanolic root extract of Cnestis ferruginea possesses analgesic and anti-inflammatory activities possibly mediated through peripheral and central mechanisms involving inhibition of release and/or actions of vasoactive substances (histamine, serotonin and kinins) and prostaglandins. The results justify the use of the extract in TAM for the treatment of painful and inflammatory conditions.     

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.     

Gut and airways relaxant effects of Carum roxburghianum

Ethnopharmacological relevance

Carum roxburghianum is traditionally used in hyperactive gastrointestinal and respiratory disorders. The present study was carried out to investigate the possible gut and airways relaxant potential of Carum roxburghianum to rationalize its folk uses.

Materials and methods

Crude extract of Carum roxburghianum (Cr.Cr) was studied in in vivo and in vitro techniques.

Results

Cr.Cr exhibited protective effect against castor oil-induced diarrhea in mice at 100–1000 mg/kg. In rabbit jejunum preparations, Cr.Cr (0.03–3.0 mg/mL) caused relaxation of spontaneous and K⁺ (80 mM)-induced contractions at similar concentrations, like papaverine. Pretreatment of tissues with Cr.Cr (0.1–1.0 mg/mL) shifted Ca⁺⁺ concentration–response curves (CRCs) to right, like verapamil. Cr.Cr (0.03 and 0.1 mg/mL) caused leftward shift of isoprenaline-induced inhibitory CRCs, similar to papaverine. In isolated guinea-pig ileum, Cr.Cr (0.01 and 0.03 mg/mL) produced rightward parallel shift of acetylcholine-curves, like atropine. Cr.Cr (1.0–30 mg/kg) caused suppression of carbachol (CCh, 100 μg/kg)-induced increase in inspiratory pressure of anaesthetized rats. In guinea-pig trachea, Cr.Cr (0.03–1.0 mg/mL) relaxed CCh and high K⁺-induced contractions, shifted isoprenaline-induced inhibitory CRCs to left at 0.1 and 0.3 mg/mL and CCh-curves parallel to right (0.01 and 0.03 mg/mL). Cr.Cr did not cause any mortality of mice up to 10 g/kg dose.

Conclusion

These results indicate that Carum roxburghianum possess combination of antidiarrheal, antispasmodic and bronchodilatory effects, which provides pharmacological basis to its traditional use in the disorders of gut and airways hyperactivity, like diarrhea, colic and asthma.     

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.     

Aegiceras corniculatum extract suppresses initial and late phases of inflammation in rat paw and attenuates the production of eicosanoids in rat neutrophils and human platelets

Aim of the study

The present study is designed to explore the anti-inflammatory potential of Aegiceras corniculatum Linn. Blanco stems extracts and their mechanism of action against various pro-inflammatory mediators and to validate its traditional use against inflammatory diseases.

Materials and methods

Rat paw edema and peritonitis models were employed for in vivo studies. For in vitro studies human platelets and rat neutrophils were stimulated with Ca²⁺-ionophore A23187 leading to the production of various pro-inflammatory metabolites, i.e., 12-HTT, 12-HETE and LTB₄ and 5-HETE which were quantified by HPLC.

Results

The highly polar methanol extract (100 mg/kg) caused ∼90% reduction in the carrageenan- and prostaglandin E2-induced paw edema in rats. It also caused the inhibition of cycloxygenase-1 metabolite, 12-HHT (IC₅₀ 41.1 ± 1.5 μg/ml) with a concomitant rise in 12-lipoxygenase metabolite, 12-HETE in A23187 stimulated human platelets. Conversely, the non-polar hexane extract attenuated (IC₅₀ 0.36 ± 0.12 μg/ml) 12-HETE formation with a parallel rise in 12-HHT, thereby displaying a selectivity towards 12-lipoxygenase. Non-polar hexane extract also antagonized the production of 5-lipoxygenase metabolites, i.e., leukotriene B₄ and 5-HETE in the rat neutrophils. Furthermore, ethyl acetate extract inhibited both COX and 5-LOX with a marked decline in the production of 12-HHT (IC₅₀ 0.08 ± 0.002 μg/ml) and LTB₄ (IC₅₀ 0.86 ± 0.03 μg/ml), respectively. The anti-inflammatory effect of hexane and ethyl acetate extracts was also reflected by the diminution of carrageenan-induced cell infiltration in rat peritoneum. Additionally, plant extracts caused ∼60% suppression in dextran-induced paw edema implying that they also ameliorate histamine and serotonin release.

Conclusion

Hexane, ethyl acetate and methanol extracts derived from Aegiceras corniculatum possess significant anti-inflammatory activity via multiple mechanisms and validate their traditional use against inflammation-related diseases.     

Antiinflammatory, analgesic and antioxidant activities of Cyathula prostrata (Linn.) Blume (Amaranthaceae)

Ethnopharmacological relevance

Cyathula prostrata (Linn) Blume (Amaranthaceae) is an annual herb widely used traditionally in the treatment of various inflammatory and pain related health disorders in Nigeria. The aim of this study is to evaluate the anti-inflammatory, analgesic and antioxidant activities of the methanolic extract of Cyathula prostrata (Linn) Blume.

Materials and methods

The anti-inflammatory (phorbol 12-myristate 13-acetate (PMA)-induced reactive oxygen species (ROS), lipopolysaccharide (LPS) induced nitric oxide production in U937 macrophages, LPS-induced COX-2 expression, carrageenan-induced rat paw oedema, arachidonic acid-induced ear oedema and xylene-induced ear oedema), analgesic (acetic acid-induced writhing and hot plate tests) and antioxidant activities (DPPH [1,1-diphenyl-2-picrylhydrazyl] and lipid peroxidation assays) activities of the plant extract were investigated.

Results

The methanolic extract of Cyathula prostrata did not show inhibitory activity in the in vitro PMA-induced reactive oxygen species, LPS-induced nitric oxide production and LPS-induced COX-2 expression assays. In the in vivo anti-inflammatory assays, the extract (50, 100 and 200 mg/kg) showed a significant (P < 0.05) dose-dependent inhibition in the carrageenan, arachidonic acid and xylene-induced tests. Cyathula prostrata produced a significant (P < 0.05, 0.001) dose-dependent inhibition in the acetic acid and hot plate analgesic tests respectively. The plant extract did not exhibit any antioxidant activity in the DPPH and lipid peroxidation assays.

Conclusion

The results suggest that the methanolic extract of Cyathula prostrata possesses anti-inflammatory and analgesic activities and this authenticates the use of the plant in the traditional treatment of ailments associated with inflammation and pain.     

Anticonvulsant activity of the essential oil and methanolic extract of Bunium persicum (Boiss). B. Fedtsch

Ethnopharmacological relevance

Bunium persicum is an endemic plant to Iran which its seeds have a long history of medicinal uses.

Aim of the study

This work aimed to study the anticonvulsant effect of the essential oil and methanolic extract of the plant.

Materials and methods

The essential oil and methanolic extract of the plant were studied against pentylenetetrazole (PTZ) and maximal electroshock (MES) induced convulsions in mice in different doses. The neurotoxicity of the essential oil and methanolic extract was investigated using rotarod method.

Results

The essential oil and methanolic extract prolonged the onset of clonic and tonic seizures in PTZ. The tonic seizures were prevented by essential oil in both methods at dose of 1 mL/kg and higher doses. The methanolic extract inhibited PTZ-convulsions at dose 3 g/kg and was ineffective against MES induced convulsion.

Conclusions

The essential oil of the plant might be useful to control absence and grand mal seizures at dose 1 mL/kg. This activity might be due to its content of monoterpenes.     

Evaluation of the wound healing potential of Wedelia trilobata (L.) leaves

Ethnopharmacological relevance

Wedelia trilobata (L.) Hitchc (Asteraceae) leaves are used in the treatment of wounds by traditional healers. Despite the use of this plant in wound healing, there is a scarcity of scientific data to support its therapeutic application.

Aim of the study

To investigate the wound healing potential of Wedelia trilobata (L.) leaves commonly employed by traditional healers and to clarify its traditional use in a scientific investigation.

Materials and methods

An ethanolic extract of Wedelia trilobata leaves was subjected to column chromatography. Hexane, ethyl acetate (WEA) and chloroform:methanol (50:50) (WCM) fractions were obtained. The fractions were tested using relevant in vitro wound healing assays. Antioxidant activity was measured by the DPPH assay. The fibroblast proliferation, oxidative stress using hydrogen peroxide, an in vitro scratch assay, and increasing collagen content was determined using fibroblast L929. Minimum inhibitory concentrations (MICs) were determined against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, and Pseudomonas aeruginosa.

Results

WEA (3 μg/mL) promoted fibroblast L929 survivability up to more than 90% before and more than 85% after hydrogen peroxide induced oxidative stress. WEA (3 μg/mL) induced a 70% migration rate in the in vitro scratch assay and the collagen content was increased to 261 μg/mL compared to the control (57.5 μg/mL). WCM exhibited a scavenging activity for DPPH with an IC₅₀ value of 179.5 μg/mL comparable to BHT (139.3 μg/mL). WEA was active against Gram positive bacteria Staphylococcus aureus, Staphylococcus epidermidis with MIC values of 62.5 and 31.25 μg/mL, respectively.

Conclusion

These scientific findings of wound healing activity supports the traditional claims for Wedelia trilobata (L.) leaves. The WEA displayed antibacterial and fibroblast stimulatory activities while WCM exhibited antioxidant to indicate its potential wound healing properties. However further studies to isolate the antibacterial, antioxidant and fibroblast stimulatory compounds that contribute to the wound healing properties of this plant are needed.     

Effects of taraxasterol on inflammatory responses in lipopolysaccharide-induced RAW 264.7 macrophages

Aim of the study

Taraxasterol, a pentacyclic-triterpene, was isolated from the Chinese medicinal herb Taraxacum officinale. In the present study, we investigated the in vitro anti-inflammatory activity of taraxasterol in lipopolysaccharide (LPS)-induced RAW 264.7 murine macrophages.

Materials and methods

RAW 264.7 cells were pretreated with 2.5, 5, or 12.5 μg/ml of taraxasterol 1 h prior to treatment with 1 μg/ml of LPS. Nitric oxide (NO) level in supernatants from cells was examined by Griess reaction, the concentrations of prostaglandin E₂ (PGE₂), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) were measured by ELISA. Nuclear factor kappa B (NF-κB) activation was evaluated by immunocytochemical analysis.

Results

We found that taraxasterol inhibited NO, PGE₂, TNF-α, IL-1β and IL-6 production in LPS-induced RAW 264.7 macrophages in a dose-dependent manner. Further studies revealed that taraxasterol prevented the LPS-induced NF-κB translocation from cytoplasm into nuclear.

Conclusions

These results indicate that taraxasterol has anti-inflammatory effect by blocking NF-κB pathway.     

Antinociceptive activity of Mirabilis jalapa 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.

Aim of the study

The present study examined the antinociceptive effect of Mirabilis jalapa extracts from leaves and stems in models of pain in mice.

Materials, methods and results

The crude hydroethanolic extract from leaves (CrdL) was more potent than the crude extract from stems (CrdS) to inhibit abdominal constrictions induced by acetic acid, with ID₅₀ values of 5.5 (2.3–13.1) and 18.0 (11.3–28.5) mg/kg, respectively. Among the fractions tested, the Eta fraction from leaves (Eta) was more effective (maximal inhibition of 83 ± 8%) and potent (ID₅₀ of 1.1 (0.6–2.1) mg/kg) to induce antinociception. Eta and CrdL also possessed an antinociceptive effect in the tail-flick test. Pre-treatment with naloxone did not modify the antinociceptive effect of Eta, but co-administration with atropine completely prevented it. This suggests that the antinociceptive effect might depend on the cholinergic system. Instead, Eta was not able to alter the acetylcholinesterase activity in blood or spinal cord. Concerning side effects, Eta did not alter locomotor activity, body temperature, gastrointestinal transit and did not produce gastric lesions.

Conclusion

Our results demonstrate that Mirabilis jalapa presents antinociceptive activity in mice, which supports its folkloric use as an analgesic.     

Beneficial effects of the ethanol extract of Caesalpinia pyramidalis on the inflammatory response and abdominal hyperalgesia in rats with acute pancreatitis

Ethnopharmacological relevance

Caesalpinia pyramidalis Tul. (Fabaceae) is a plant found in the Northeast of Brazil that is popularly used to treat inflammation. Acute pancreatitis (AP) is an inflammatory disease for which abdominal pain is a relevant symptom. As there is no specific therapy for AP, we investigated the effect of the ethanol extract from the inner bark of C. pyramidalis (EECp) on the AP induced by common bile duct obstruction (CBDO) in rats.

Material and methods

AP was induced in male Wistar rats (200–250g, n=6–8) through laparotomy and subsequent CBDO. Animals were euthanized after 6 (G6h) or 24 h (G24h) of induction. In the G6h protocol, animals were pretreated with EECp (100–400 mg/kg, p.o.) or vehicle (Tween 80; 0.2%) 1 h before CBDO or sham surgery. For the G24h protocol, rats were pretreated with EECp (400 mg/kg, 1 h before CBDO or 1 h before and 12 h after CBDO) or vehicle. The following parameters were measured: inflammatory/oxidative (myeloperoxidase activity and malondialdehyde formation in the pancreas and lung, leukocyte counts in the blood and serum nitrate/nitrite), enzymatic (serum amylase and lipase levels) and nociceptive (abdominal hyperalgesia).

Results

Induction of AP by CBDO significantly increased all the parameters evaluated in both G6h and G24h protocols when compared with the respective sham group. In the G6h protocol, the EECp pretreatment (400 mg/kg) significantly reduced all these parameters, besides completely inhibiting abdominal hyperalgesia. The same profile of reduction was observed from two administrations of EECp in the G24h protocol, while one single dose of EECp was able to significantly reduce pancreatic MDA, serum lipase levels, leukocyte counts in the blood and abdominal hyperalgesia without affecting the other parameters in the G24h protocol. Furthermore, rutin was found in the EECp.

Conclusions

Our results demonstrated that EECp decreases inflammation, lipoperoxidation and hyperalgesia in CBDO-induced AP, making it of interest in future approaches to treat this condition.     

Evaluation of mechanism for antihypertensive action of Clerodendrum colebrookianum Walp., used by folklore healers in north-east India

Ethnopharmacological relevance

The present investigation was aimed to justify the pharmacological basis in traditional use of Clerodendrum colebrookianum as antihypertensive agent in north-east India.

Materials and Methods

The aqueous extract (AECc), its aqueous, n-butanol (nBFCc), Ethyl-acetate (EtFCc) and Chloroform fractions of C. colebrookianum leaves were evaluated for antihypertensive potential by using fructose-induced hypertension model in rats and in isolated frog heart. The ex-vivo muscarinic action in isolated rat ileum, in-vitro assay for Rho-kinase (ROCK –II), phosphodiesterase-5 (PDE-5) and angiotension converting enzyme (ACE) were also carried out to establish the mechanism of action of samples. The total phenolic and flavonoied contents in test samples were estimated to establish phyto–pharmacological relationship.

Results

The 100 μg/mL test samples were showed calcium antagonism in rat ileum and at 50 μg/mL and 75 μg/mL doses exhibited ROCK-II and PDE-5 inhibition respectively where, EtFCc was caused maximum 68.62% (ROCK-II) and 52.28% (PDE-5) inhibition, but none of the sample was exhibit effect in ACE at 100 μg/mL. The test samples also showed negative inotropic and chronotropic effect on isolated frog heart and significant (P<0.001) reduction in systolic blood pressure and heart rate in hypertensive rats compared to control. The total phenolic content maximum 80 μg gallic acid equivalents in nBFCc and flavonoids content maximum 69.57 μg Quercetin equivalent in AECc were estimated.

Conclusions

These observations established the traditional claim and thus C. colebrookianum could be a potent antihypertensive agent for use in future. The antihypertensive effect mediated by cholinergic action and following ROCK – II, PDE-5 inhibition of C. colebrookianum.     

A comparative study on the antinociceptive and anti-inflammatory activities of five Juniperus taxa

Ethnopharmacological relevance

Juniperus L. (Cupressaceae) species have been used to various inflammatory and infectious diseases such as bronchitis, colds, cough, fungal infections, hemorrhoids, gynecological diseases, and wounds in Turkish folk medicine.

Aim of the study

To evaluate this traditional information, anti-inflammatory and antinociceptive activities of the methanolic and aqueous extracts prepared from different parts (stem, fruit and leaves) of the five Turkish taxa under Juniperus section of the gender; J. drupacea, J. communis var. communis, J. communis var. saxatilis, J. oxycedrus subsp. oxycedrus, and J. oxycedrus subsp. macrocarpa growing were investigated.

Methods

For the anti-inflammatory activity, carrageenan-induced and PGE₂-induced hind paw edema models, and for the antinociceptive activity p-benzoquinone-induced writhing and hot plate tests in mice were employed.

Results

The methanolic extracts of fruit and leaves from J. oxycedrus subsp. oxycedrus and J. communis var. saxatilis exhibited notable inhibition in carrageenan-induced edema model at a dose of 100 mg/kg. The same extracts also displayed significant activity against PGE₂-induced edema model. While, the remaining extracts were found inactive against these edema models. A similar activity pattern was observed against p-benzoquinone-induced abdominal constriction test without inducing any gastric damage or apparent acute toxicity, whereas all extracts were inactive in hot plate test.

Conclusion

The experimental data demonstrated that J. oxycedrus subsp. oxycedrus and J. communis var. saxatilis displayed remarkable anti-inflammatory and antinociceptive activities; however, further studies are warranted to define and isolate the active anti-inflammatory and antinociceptive components from these active species which may yield safe and effective agents to be used in the treatment of inflammatory disorders.     

Endothelium-dependent and independent vasorelaxation induced by an n-butanolic fraction of bark of Scutia buxifolia Reiss (Rhamanaceae)

Ethnopharmacological relevance

Scutia buxifolia has been widely used in Brazilian folk medicine as an anti-hypertensive agent.We evaluated the vascular effects and mechanism involved in the relaxation of aorta induced by an n-butanolic fraction (BuOH) from Scutia buxifolia.

Materials and Methods

Rat aortic rings precontracted by phenylephrine (1 μM) were exposed to cumulative concentrations (3–3000 μg/ml) of crude extracts or fractions obtained from bark or leaves of Scutia buxifolia. Classical receptor antagonists, channel and enzymatic inhibitors were used to check the mechanisms involved.

Results

The crude extracts of both leaves and bark of Scutia buxifolia, as well as several fractions, were able to induce partial or total relaxation of rat aortic rings. The BuOH fraction of bark of Scutia buxifolia was the most potent in endothelium-intact (E+) preparations, and also induced a partial, but very significant relaxation in endothelium-denuded (E−) vessels. The non-selective nitric oxide synthase inhibitor L-NAME, as well as the soluble guanylate cyclase inhibitor ODQ, vanished the relaxation in E+. In E− preparations, K⁺ channel blockers, such as tetraethylammonium, glibenclamide, 4-aminopyridine, and the large-conductance calcium-activated K⁺ channel blocker iberiotoxin, were able to significantly reduce the maximum relaxation elicited by BuOH fraction.

Conclusion

Our results demonstrated that BuOH fraction obtained from barks of Scutia buxifolia induced both endothelium-dependent and -independent relaxation in rat aortic rings. The endothelium-dependent relaxation is fully dependent on NO/cGMP system, while direct activation of K⁺ channels may explain, at least in part, the endothelium-independent relaxation induced by BuOH fraction of Scutia buxifolia.     

Phytochemistry and in vitro pharmacological activities of South African Vitex (Verbenaceae) species

Aim of the study

The in vitro phytochemical and pharmacological investigation of the non-volatile extracts of five South African Vitex species (Verbenaceae); V. obovata ssp. obovata, V. obovata ssp. wilmsii, V. pooara, V. rehmannii and V. zeyheri were investigated in order to validate their traditional use to treat a wide range of ailments such as malaria, wounds, skin diseases and body pains.

Material and Methods

The antimicrobial activity was assessed using the minimum inhibitory concentration assay. Through bioactivity-guided fractionation, the fraction responsible for the antimicrobial activity was determined. The toxicity profile, anti-oxidant and anti-inflammatory activity was evaluated using the tetrazolium cellular viability, 2,2-diphenyl-1-picrylhydrazyl and 5-lipoxygenase assays respectively. The antimalarial activity of the extracts and isolated compound from V. rehmannii was also investigated on the chloroquine-resistant Gambian FCR-3 strain of Plasmodium falciparum using the tritiated hypoxanthine incorporation assay.

Results

Mostly good antimicrobial inhibition was evident against Grampositive bacteria (0.02–8.00 mg/ml) and lower activity against the Gramnegative bacteria and the yeast (0.50–8.00 mg/ml). The fraction responsible for antimicrobial activity of V. rehmannii was purified to give a labdane diterpene as an inseparable epimeric mixture of 12S,16S/R-dihydroxy-ent-labda-7,13-dien-15,16-olide. Cirsimaritin was also isolated and identified from V. rehmannii. All the species, apart from V. zeyheri, exhibited scavenging activity (IC50: 22.14 ± 1.74 to 33.06 ± 1.68 μg/ml) in the anti-oxidant assay. None of the species displayed any anti-inflammatory activity at 100 μg/ml. All the extracts and the labdane diterpene exhibited good antimalarial activity, with the labdane diterpene being the most active (IC50: 2.39 ± 0.64 μg/ml). The test extracts were shown to be highly toxic, displaying safety index values ranging from 0.53 to 2.59.

Conclusion

Of all the pharmacological investigations, the antimalarial and antimicrobial activity exhibited greatest activity and may provide a scientific basis for the ethnomedical use of Vitex species.     

Antinociceptive effectiveness of triterpenes from rosemary in visceral nociception

Ethnopharmacological relevance

Rosemary is a species used worldwide as a common spice, but also in folk medicine for their therapeutic properties against abdominal pain. The rationale of this study was to examine the involvement of triterpenes and to compare their effectiveness in the antinociceptive effect of an ethanol extract of Rosmarinus officinalis L. (Lamiaceae).

Material and methods

Fractionation and HPLC analyses allowed the identification of a mixture of micromeric (121 mg/g), oleanolic (64 mg/g) and ursolic (83 mg/g) acids as partial antinociceptive responsible in an ethyl acetate fraction of R. officinalis by using the acetic acid-induced abdominal constrictions model in mice.

Results

These triterpenes individually evaluated produced a significant and dose-dependent antinociceptive response with similar potency as follows: ED₅₀=1.1 mg/kg (0.9–1.3 mg/kg), 2.1 mg/kg (1.6–2.6 mg/kg) and 1.6 mg/kg (1.1–2.1 mg/kg), respectively, by using the intraperitoneal (i.p.) route of administration in mice. Their maximal antinociceptive efficacy resembled that produced by ketorolac (10 mg/kg, i.p.), a common clinic analgesic.

Conclusion

Our results provide evidence that these triterpenes participate in the antinociceptive activity of R. officinalis. In addition, each individual triterpene showed a similar potency to that observed with ketorolac, a non-steroidal anti-inflammatory drug, in this experimental model.     

The in vitro antiviral property of Azadirachta indica polysaccharides for poliovirus

Ethnopharmacological relevance

Azadirachta indica A. Juss, popularly known as neem, has been extensively used in Ayurvedic medicine by Indian population for over 2000 years. It is used traditionally for the healing of various diseases. Natural products and their derivatives provide an excellent source for new anti-viral drugs.

Aim of the study

The present study aims at evaluating the activity of two polysaccharides (P1 and P2) isolated from the leaves of Azadirachta indica and their chemical sulfated derivatives (P1S and P2S) against poliovirus type 1 (PV-1).

Materials and methods

The cytotoxicity of the compounds was analyzed by MTT and the antiviral effect was determined by plaque reduction assay in different protocols.

Results

The polysaccharides did not show any cytotoxic effects on HEp-2 cells at the highest tested concentration (200 μg/ml) and exhibited significant antiviral activity with inhibitory concentrations (IC₅₀) of 80 μg/ml, 37.5 μg/ml, 77.5 μg/ml, and 12.1 μg/ml for P1, P1S, P2 and P2S, respectively, and the selectivity indexes (SI) ranged from 18 to 131.9. The compounds demonstrated better inhibitory effect when added concomitantly with the virus infection with a dose-dependent curve inhibition. Lesser effect was observed when the compounds were added after viral infection and the least effect at pre-treatment.

Conclusions

We suggested that the polysaccharides obtained from Azadirachta indica act against PV-1 by inhibiting the initial stage of viral replication. Importantly, original polysaccharides showed better virucidal effect than their sulfated derivatives at all tested concentrations. This study provides a scientific basis for the past and present ethnomedical uses of this plant.     

Pharmacological evaluation of Ipomoea asarifolia (Desr.) against carbon tetrachloride-induced hepatotoxicity in rats

Ethnopharmacological relevance

Ipomoeaasarifolia (Desr.) Roem. and Schult. is used traditionally in some parts of Africa for the treatment of a variety of diseases. This study attempts to validate its hepatoprotective activity by evaluating the prophylactic and curative properties of the methanolic extract of Ipomoea asarifolia (IA) leaves.

Materials and Methods

Liver damage was induced by administering 0.5 ml/kg of an equal mixture of carbon tetrachloride (CCl₄) in olive oil intraperitoneally on alternate days, for 5 days and the plant extract was given orally daily, for 7 days at doses of 100, 200 and 400 mg/kg.

Results

Pre-treatment with the extract significantly (P<0.05) decreased CCl₄-induced elevation in serum levels of alanine transaminase, aspartate transaminase, alkaline phosphatase, triglycerides, bilirubin and cholesterol, better than the standard drug silymarin at 100 mg/kg. In the curative study, IA significantly (P<0.05) reversed CCl₄-induced liver damage, comparable to silymarin. Hepatoprotective potential was further supported by decrease in pentobarbitone sleeping time and improved hepatic tissue histopathology.

Conclusion

These results indicate that I. asarifolia leaves have potent hepatoprotective activity against CCl₄-induced hepatic damage in rats.