Antituberculosis potential of some ethnobotanically selected Malaysian plants

Aim of the study

Many local plants are used in Malaysian traditional medicine to treat respiratory diseases including symptoms of tuberculosis. The aim of the study was to screen 78 plant extracts from 70 Malaysian plant species used in traditional medicine to treat respiratory diseases including symptoms of tuberculosis for activity against Mycobacterium tuberculosis H37Rv using a colorimetric microplate-based assay.

Materials and methods

Plant extracts were prepared by maceration in methanol (80%) and antituberculosis screening was carried out using Tetrazolium bromide microplate assay (TEMA) method to determine the minimum inhibitory concentration (MIC).

Results

Thirty-eight plant extracts from 36 plant species exhibited antituberculosis activity with MICs in the range of 1600-400 μg/ml. The leaf extract of Angiopteris evecta exhibited the highest activity with MIC of 400 μg/ml. Five other extracts, namely, Costus speciosus (stem and flower), Piper sarmentosum (whole plant), Pluchea indica (leaf), Pluchea indica (flower), and Tabernaemontana coronaria (leaf) exhibited antituberculosis activity, each with MIC of 800 μg/ml. To the best of our knowledge, this is the first report of in vitro high throughput screening of Malaysian medicinal plants for antituberculosis activity.

Conclusions

Antituberculosis activity of extracts of some plants justifies, to a certain extent their ethnomedicinal uses as remedies for symptoms of tuberculosis. These results also support the general view that, selecting the plants based on ethnobotanical criteria would enhance the probability of finding species with antituberculosis activity.     

Potential of medicinal plants from the Brazilian semi-arid region (Caatinga) against Staphylococcus epidermidis planktonic and biofilm lifestyles

Ethnopharmacological relevance

Medicinal plants from the Caatinga, a Brazilian xeric shrubland, are used in folk medicine to treat infections. These ethnopharmacological data can contribute to obtaining new antimicrobial/antibiofilm extracts and natural product prototypes for the development of new drugs. The aim of this study was to investigate the antibiofilm and antibacterial activities of 45 aqueous extracts from 24 Caatinga plant species.

Materials and methods

The effect of aqueous extracts on planktonic cells and on biofilm formation by Staphylococcus epidermidis was studied by the OD₆₀₀ absorbance and by the crystal violet assay, respectively. Scanning electron microscopy (SEM) was used to generate comparative images of extract-treated and untreated biofilms. Chromatographic analyses were performed to characterize the active extracts.

Results

The in vitro screening, at 0.4 mg/mL and 4.0 mg/mL, showed 20 plants effective in preventing biofilm formation and 13 plants able to inhibit planktonic bacterial growth. SEM images demonstrated distinct profiles of bacterial adhesion, matrix production and cell morphology according to different treatments and surfaces. The phytochemical analysis of the selected active extracts indicates the polyphenols, coumarins, steroids and terpenes as possible active compounds.

Conclusion

This study describes the first antibiofilm and antibacterial screening of Caatinga plants against S. epidermidis. The evaluation presented in this study confirms several ethnopharmacological reports and can be utilized to identify new antibiofilm and antibacterial products against S. epidermidis from traditional Brazilian medicine.     

Antioxidant, toxicological and antiproliferative properties of Canadian polyphenolic extracts on normal and psoriatic keratinocytes

Aims of the study

In a first attempt for establishing the possible utilization of polyphenolic extracts from barks of Canadian wood species in psoriasis treatment, we aimed to study (a) their antioxidant capacity, (b) their toxicological properties on normal human keratinocytes (NHK), and (c) their effect on the growth of normal and psoriatic keratinocytes (PK).

Materials and methods

Polyphenolic extracts were obtained by 90% ethanolic maceration and hot water extraction (HWE). Scavenging capacity was evaluated towards hydrogen peroxide, hydroxyl, superoxide, nitric oxide and peroxyl radicals. MTT assay and Trypan blue dye exclusion (TBDE) method were used for evaluating the initial toxicity of the most antioxidant extracts on NHK during 24 and 48 h. The effects of extracts on the growth of NHK and PK at non-toxic concentrations were determined after exposure for 48 h.

Results

Yellow birch extract obtained by maceration (YB_Mac) and black spruce extract obtained by HWE (BS_HWE) were determined to have the highest antioxidant capacity, but BS_HWE was less toxic on NHK. Toxicity of extracts on keratinocyte plasma membrane and mitochondria after 24 h was attributed to their content of hydroxycinnamic acids and proanthocyanidins. BS_HWE inhibited the growth of NHK and non-lesional PK, but was not selective for lesional PK.

Conclusion

Given that BS_HWE presented elevated content of total phenols and flavonoids and showed a low toxicity on NHK as well as an adequate chemical reactivity towards different radicals and some antiproliferative properties, it was considered as the most valuable extract obtained from barks of Canadian wood species.     

Plants used by native Amazonian groups from the Nanay River (Peru) for the treatment of malaria

Aim of the study

In order to evaluate the antimalarial potential of traditional remedies used in Peru, Indigenous and Mestizo populations from the river Nanay in Loreto were interviewed about traditional medication for the treatment of malaria.

Materials and methods

The survey took place on six villages and led to the collection of 59 plants. 35 hydro-alcoholic extractions were performed on the 21 most cited plants. The extracts were then tested for antiplasmodial activity in vitro on Plasmodium falciparum chloroquine resistant strain (FCR-3), and ferriprotoporphyrin inhibition test was also performed in order to assume pharmacological properties.

Results

Extracts from 9 plants on twenty-one tested (Abuta rufescens, Ayapana lanceolata, Capsiandra angustifolia, Citrus limon, Citrus paradise, Minquartia guianensis, Potalia resinífera, Scoparia dulcis, and Physalis angulata) displayed an interesting antiplasmodial activity (IC₅₀ < 10 μg/ml) and 16 remedies were active on the ferriprotoporphyrin inhibition test.

Conclusions

The results give scientific validation to the traditional medical knowledge of the Amerindian and Mestizo populations from Loreto and exhibit a source of potentially active plants.     

Consequences of subchronic exposure to ethanolic extract from fruits and leaves of Schinus molle var. areira L. in mice

Aim of the study

Several extracts of Schinus molle var. areira L. plant proved to be useful for the treatment of different pathologies and for the control of insect pest. Due to these potential uses, it is necessary to study their safety. In this work, we evaluated the effects of subchronic exposure to ethanolic extracts from leaves and fruits of Schinus molle var. areira in mice.

Materials and methods

The plant extract was added to the diet at 1 g/kg body weight/day for 90 days. At the end of the exposure, behavioral and functional parameters in a functional observational battery and motor activity in an open field were assessed. Finally, several biochemical and histopathological studies were realized.

Results

The exposure to extract from leaves produced an increase in the number of rearings in the open field and of urine pools in the functional observational battery. On the other hand, the exposure to extract from fruits produced an increase in the neutrophil count and a decrease in the lymphocyte count and in the total cholesterol levels. None of the exposures affected the different organs evaluated.

Conclusions

Our results suggest that subchronic exposure to ethanolic extracts from leaves and fruits of Schinus molle var. areira should be potentially useful in the treatment of lipid pathologies and safe to use.     

Antibacterial, antioxidant and fibroblast growth stimulation activity of crude extracts of Bridelia ferruginea leaf, a wound-healing plant of Nigeria

Aim of the study

Determination of pharmacological activity relevant to wound healing of Bridelia ferruginea leaf, a traditional medicine used to treat wounds in rural Nigeria.

Materials and methods

Aqueous and ethanolic leaf extracts were tested against bacterial species of relevance to wound infections: Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. The ethanolic extracts were assessed for their ability to stimulate the growth of human dermal fibroblasts (FS5) and protect against damage induced by hydrogen peroxide. Antioxidant activity was also assessed using the DPPH assay.

Results

Both aqueous and ethanolic extracts had weak antibacterial activity (MIC > 470 μg/ml). A significant effect (p < 0.001) on the growth of FS5 fibroblasts was observed only at a concentration of 5 μg/ml (28% increase), above which the extracts appeared toxic to the cells. The ethanolic extract offered the highest protection against H₂O₂ damage to FS5 cells, comparable with catalase (82% at 250 μg/ml). The DPPH assay revealed antioxidant activity of the ethanolic leaf extract with IC₅₀ 12.5 ± 0.3 μg/ml comparable to l-ascorbic acid (7.3 ± 0.1 μg/ml).

Conclusion

The antibacterial, modest fibroblast stimulation activity and relatively strong antioxidant activity lend some support to the topical use of Bridelia ferruginea leaf for wound-healing in the traditional medicine of South-western Nigeria.     

Evaluation of the anti-inflammatory properties of Dodonaea polyandra, a Kaanju traditional medicine

Ethnopharmacological relevance

Extracts of the medicinal plant species Dodonaea polyandra were investigated as part of a collegial research partnership between Northern Kaanju traditional owners represented by Chuulangun Aboriginal Corporation (centred on the Wenlock and Pascoe Rivers, Cape York Peninsula, Queensland, Australia) and university-based researchers. D. polyandra, known as “Uncha” in Kaanju language, is used in Northern Kaanju Traditional Medicine for relief from pain associated with toothache and related ailments. The species has a restricted distribution in Cape York Peninsula and there has been no previous Western scientific investigation of its pharmacology or chemistry.

Aim of the study

The current study investigates the anti-inflammatory effects of several extracts from D. polyandra.

Materials and methods

Phytochemical screening was conducted using TLC. Anti-inflammatory effects of leaf extracts were determined using an acute mouse ear oedema model induced by croton oil and 12-o-tetradecanoylphorbol-13-acetate (TPA) chemical irritants.

Results

Flavonoid and terpenoid secondary compounds were detected in leaf extracts of D. polyandra. Non-polar hexane and methylene chloride/methanol extracts showed potent inhibition of inflammation in TPA-induced mouse ear oedema by 72.12 and 79.81%, respectively, after 24 h at 0.4 mg/ear.

Conclusion

In a mouse model of acute inflammation, this study revealed that leaf extracts of D. polyandra possess significant anti-inflammatory potential. These results contribute to a Western scientific understanding of the ethnopharmacological use of the plant in Northern Kaanju Medicine for reducing tooth-related pain.     

In vitro antitrypanosomal and antileishmanial activity of plants used in Benin in traditional medicine and bio-guided fractionation of the most active extract

Ethnopharmacological relevance

The aim of the study was to evaluate the in vitro antitrypanosomal and antileishmanial activity of crude extracts of 10 plant species traditionally used in Benin to treat parasitic infections.

Materials and methods

For each species, dichloromethane, methanol and aqueous extracts were tested. Their antitrypanosomal and antileishmanial activities were evaluated in vitro on Trypanosoma brucei brucei (strain 427) (Tbb) and on promastigotes of Leishmania mexicana mexicana (MHOM/BZ/84/BEL46) (Lmm).

Results

The best growth inhibition was observed with the dichloromethane extracts of aerial parts of Acanthospermum hispidum DC. (Asteraceae) (IC₅₀ = 14.5 μg/ml on Tbb and 11.1 μg/ml on Lmm), twigs of Keetia leucantha (K. Krause) Bridson (syn. Plectronia leucantha Krause) (IC₅₀ = 5.8 μg/ml on Tbb), aerial parts of Byrsocarpus coccineus Schumach. & Thonn (syn. Rourea coccinea (Schumach. & Thonn.) Hook.f.) (IC₅₀ = 14.7 μg/ml on Tbb) and aerial parts of Carpolobia lutea G.Don. (IC₅₀ = 18.3 μg/ml on Tbb). All these extracts had a low cytotoxicity. It is not the case for the methanolic and water extracts of roots of Anchomanes difformis (Blume) Engl. (IC₅₀ = 14.7 and 13.8 μg/ml on Tbb) which were toxic at the same concentration range on WI38, human cells. A bio-guided fractionation of the most active extract of Keetia leucantha allowed to identify oleanolic acid and ursolic acid as responsible for the observed activities.

Conclusion

Our study gives some justification for antiparasitic activity of some investigated plants.     

Kaempferia parviflora, a plant used in traditional medicine to enhance sexual performance contains large amounts of low affinity PDE5 inhibitors

Aim of the study

A number of medicinal plants are used in traditional medicine to treat erectile dysfunction. Since cyclic nucleotide PDEs inhibitors underlie several current treatments for this condition, we sought to show whether these plants might contain substantial amounts of PDE5 inhibitors.

Materials and methods

Forty one plant extracts and eight 7-methoxyflavones from Kaempferia parviflora Wall. ex Baker were screened for PDE5 and PDE6 inhibitory activities using the two-step radioactive assay. The PDE5 and PDE6 were prepared from mice lung and chicken retinas, respectively. All plant extracts were tested at 50 μg/ml whereas the pure compounds were tested at 10 μM.

Results

From forty one plant extracts tested, four showed the PDE5 inhibitory effect. The chemical constituents isolated from rhizomes of Kaempferia parviflora were further investigated on inhibitory activity against PDE5 and PDE6. The results showed that 7-methoxyflavones from this plant showed inhibition toward both enzymes. The most potent PDE5 inhibitor was 5,7-dimethoxyflavone (IC₅₀ = 10.64 ± 2.09 μM, selectivity on PDE5 over PDE6 = 3.71). Structure activity relationship showed that the methoxyl group at C-5 position of 7-methoxyflavones was necessary for PDE5 inhibition.

Conclusions

Kaempferia parviflora rhizome extract and its 7-methoxyflavone constituents had moderate inhibitory activity against PDE5. This finding provides an explanation for enhancing sexual performance in the traditional use of Kaempferia parviflora. Moreover, 5,7-dimethoxyflavones should make a useful lead compound to further develop clinically efficacious PDE5 inhibitors.     

Vasoactive effects of different fractions from two Panamanians plants used in Amerindian traditional medicine

Ethnopharmacological relevance

Cecropia obtusifolia (Cecropiaceae) and Psychotria poeppigiana (Synonym: Cephaelis elata, Rubiaceae) are two Latin American plants broadly used in traditional Amerindian medicine. The former, together with many other species of the genus Cecropia, share the folk reputation of curing heart failure, cough, asthma and bronchitis. The latter is used in Panama by Kuna and Ngäbe Buglé (Guaymies) native Indians for the treatment of dyspnea.

Aim of the study

Based on screening of selected medicinal Panamanian plants by radioligand-binding techniques by Caballero-George et al. (2001), the present study was carried out in order to investigate the vasoactive effects of different fractions from both P. poeppigiana and C. obtusifolia on rat thoracic aorta and identify active fractions and their chemical constituents.

Materials and methods

Both acid and neutral methanol fractions (P-AMeOH and P-NMeOH) and acid and neutral dichlorometane fractions (P-ADCM and P-NDCM) were obtained from P. poeppigiana crude methanolic and dichlorometane extracts, respectively. Identical fractionation was carried out for C. obtusifolia (C-AMeOH, C-NMeOH, C-ADCM and C-NDCM. Vasorelaxant effect of all fractions, and their inhibition of contractile responses to angiotensin II were evaluated in isolated aortic rings.

Results

P-AMeOH, P-NMeOH and P-ADCM fractions induced a concentration-dependent relaxation (43.9 ± 1.8%, 35.3 ± 4.7% and 52.9 ± 3.5%, respectively) in the endothelium-intact aorta precontracted by phenylephrine (PE, 10⁻⁶ M). The relaxation produced by C-AMeOH and C-NMeOH (57.3 ± 2.5% and 53.3 ± 3.3%, respectively) was greater than the effect produced by C-ADCM and C-NDCM (42.2 ± 3.4% and 21.8 ± 0.8%, respectively). Only the incubation of the aortic rings with P-AMeOH reduced the maximum contraction induced by angiotensin II at 20.08 ± 0.55%.

Conclusions

The direct vasorelaxation effect observed could explain in part the ethnomedical use of these plants in Amerindian traditional medicine. The most active fractions contain phenolic and aromatic acid compounds. Furthermore, P-AMeOH, the only fraction that showed both vasorelaxant effect and inhibition of contractile responses to angiotensin II, is the most rich in aromatic acids compounds and the only one that contains scopoletin.     

Barakol-induced apoptosis in P19 cells through generation of reactive oxygen species and activation of caspase-9

Ethnopharmacological relevance

Barakol, an anxiolytic agent isolated from Senna siamea leaves which has been traditionally used for producing natural sleep, has been described as toxic to patients.

Aim of the study

The aim of current study was to investigate the molecular mechanism of barakol-induced toxicity in mouse embryonal carcinoma P19 cell model.

Materials and methods

XTT assay was used to determine cell viability in P19 cells treated with barakol. Apoptotic cells were detected by Hoechst 33342 staining. Intracellular reactive oxygen species (ROS) generation was analyzed by flow cytometry using a fluorescent dye, DCFH-DA. Detection of apoptotic protein expression in P19 cells was performed by Western blot analysis. Caspase-9 activity was measured using a fluorescent immunosorbent enzyme assay kit.

Results

Treatment with barakol decreased cell viability in a concentration- and time-dependent manner with an IC₅₀ value of 1.5 mM in 24-h treated cells. A Hoechst 33342 assay revealed that barakol cytotoxicity was due to a significant increase in the number of apoptotic cells. Different scavengers to characterize ROS were utilized and revealed that hydroxyl radicals played a major role in ROS-induced apoptosis in barakol-treated cells. Western blot analysis demonstrated that barakol-induced apoptosis was mediated by the increase in expression ratio of Bax/Bcl-2. Furthermore, increase in caspase-9 activity after exposure to barakol for 24 h was also observed. Pretreatment of cells with N-acetyl-l-cysteine (NAC) attenuated intracellular ROS generation, the Bax/Bcl-2 protein expression, and apoptosis.

Conclusions

The mechanism of barakol-mediated toxicity in P19 cells is mainly associated with the ROS generation, followed by the imbalance of the Bax/Bcl-2 ratio, and caspase-9 activation leading to apoptotic cell death. Pretreatment of cells with NAC could antagonize the toxicity produced by barakol.     

Vasorelaxation by extracts of Casimiroa spp. in rat resistance vessels and pharmacological study of cellular mechanisms

Aim of the study

Casimiroa spp. are Mexican plants traditionally used for treatment of hypertension. To study their antihypertensive action, we determined the arterial dilatation induced by extracts from leaves and seeds of Casimiroa calderoniae F. Chiang & Medrano, Casimiroa edulis Llave et Lex, and Casimiroa pubescens Ramirez.

Materials and methods

The vascular effects of Casimiroa spp. extracts were investigated on rat caudal and aortic arteries. In addition, the extracts were characterized by HPLC using heraclenol, isopimpinellin, heraclenin and phellopterin as external standards. The methanolic extract of Casimiroa pubescens seeds (Cp12) was also studied by H-NMR and LC-MS (ESI-TOF) for the determination of casimiroin and zapotin.

Results

The hexanic and methanolic extracts of Casimiroa spp. (20 μg/ml) showed vasorelaxation in arterial tissues precontracted by phenylephrine (0.5 μM); the extracts from seeds always caused a greater relaxation in comparison to those from leaves. The most active were the methanolic seed extracts of Casimiroa edulis (Ce8) and Casimiroa pubescens (Cp12). To study the pharmacological mechanisms of vasodilatation we used various inhibitors selective to different receptor subtypes or intracellular enzymes. The vasorelaxant effect of Ce8 (20 μg/ml) remained unaffected by the pretreatment with pyrilamine (10 μM), an antagonist of histamine H₁ receptors, but was inhibited by atropine (0.1 μM), a muscarinic receptor antagonist. Therefore, to determine muscarinic receptor subtypes, we used pirenzepine (1 μM), a selective inhibitor of M₁ receptor, and 4-diphenylacetoxyl-N-methylpiperidine methiodide (DAMP, 0.01 μM), a selective inhibitor of M₃ receptor. Only the latter reduced the vasodilatation by Ce8 and Cp12. To investigate the role of the nitric oxide synthase (NOS), we used N^G-nitro-l-arginine methyl ester (l-NAME, 10 μM), a selective NOS inhibitor, which decreased the dilatation induced by Ce8 and Cp12. Finally, we studied the action of (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one) (ODQ, 3 μM), a selective guanylyl cyclase inhibitor, which inhibited the dilatation by Casimiroa extracts.

Conclusion

The data show that methanolic seed extracts of Casimiroa edulis (Ce8) and Casimiroa pubescens (Cp12) induce vasorelaxation by M₃ receptor through the activation of cGMP-dependent NO signaling. These results support the traditional use of Casimiroa decoctions for antihypertensive treatments in the Mexican ethnomedicine.     

Anti-inflammatory effect of a methanolic extract of leaves of Dregea volubilis

Aim of study

The aim of this study was to establish the anti-inflammatory activity of the methanolic extract of Dregea volubilis leaves (MEDV) with its fractions and to delineate the possible mechanism of action for MEDV.

Materials and methods

The anti-inflammatory activities of MEDV along with its petroleum ether and chloroform fractions were evaluated in a carrageenan induced model of acute inflammation. The effect of MEDV on lipopolysaccharide induced production of nitric oxide (NO) in macrophages was also studied.

Results

MEDV (100, 200 and 400 mg/kg body weight) significantly reduced carrageenan induced paw edema; chloroform fraction was most potent (66%, p < 0.001). MEDV was non-toxic up to 125 μg/ml in mouse peritoneal macrophages wherein it (0-100 μg/ml) reduced lipopolysaccharide induced NO production.

Conclusion

MEDV possesses significant anti-inflammatory activity. Chloroform fraction of MEDV showed best anti-inflammatory activity.     

Mutagenicity, antimutagenicity and cytotoxicity evaluation of South African Podocarpus species

Ethnopharmacological relevance

Four species of Podocarpus are used in traditional medicine both in human and animal healthcare in South Africa. In vitro pharmacological screening of leaf and stem extracts of these species exhibited potent antimicrobial, anti-inflammatory, anti-tyrosinase, anthelmintic, acetylcholinesterase inhibitory and antioxidant activities.

Aim of the study

To investigate the mutagenicity, antimutagenicity and cytotoxicity effects of leaf and stem extract of South African Podocarpus species.

Material and methods

The mutagenicity and cytotoxic effects of extracts from four species of Podocarpus were tested using the Salmonella/microsome assay with and without metabolic activation, based on the plate-incorporation method and neutral red uptake (NRU) assay respectively. Five Salmonella typhimurium tester strains; TA98, TA100, TA102, TA1535 and TA1537 were used for mutagenicity testing. The relative cytotoxicity of the extracts was assessed by determining their NI₅₀ values (50% inhibition of NRU).

Results

The extracts did not show any mutagenic effects against all the tester strains with or without metabolic activation. All extracts demonstrated a strong antimutagenic effect on the mutations induced by 4NQO, decreasing its mutagenic effect in a dose-dependent manner. Strong cytotoxic effects were exhibited by petroleum ether extracts as compared to 80% ethanol extracts. When HepG2 cells were in contact with plant extracts in an increasing concentration, slopes of NRU decreased (highest-lowest %) following a concentration-dependent pattern. For 80% ethanol extracts, the most toxic extract in terms of percentage viability was leaves of Podocarpus falcatus whereby at 0.2 mg/ml, the viability of the cells was 38.9%. Stem extract of Podocarpus latifolius was the most toxic among PE extracts, giving a percentage viability of 46.4 at 0.1 mg/ml.

Conclusion

Absence of mutagenicity does not indicate lack of toxicity, as was observed from these extracts. These findings will help in assessing the safety measures to be considered in the use of these species and also the need to determine the cytotoxic potential of these species against various forms of human cancer cells.     

Evaluating pulmonary toxicity of Shuang-Huang-Lian in vitro and in vivo

Ethnopharmaocological relevance

Shuang-Huang-Lian (SHL) is a traditional Chinese formula and has been used for the treatment of respiratory tract infections by inhalation. However, the pulmonary toxicity via inhalation is largely uninvestigated.

Aim of study

: To evaluate the pulmonary toxicity of SHL following in vivo intratracheal spray to rats and in vitro exposures to A549 and Calu-3 cells.

Methods

: Calu-3 and A549 cells were exposed to SHL, chlorogenic acid, baicalin and forsythin solutions and in vitro cytotoxicity was evaluated using an MTT assay, whilst rats were subjected to intratracheal administration of SHL solutions and in vivo toxicity was indicated by assaying the LDH activity and total protein content in bronchoalveolar lavage fluid (BALF) and observing the histopathologic changes of the lungs. Secretion of inflammatory mediators, including IL-6, IL-8 and TNF-α, in cell culture media and BALF was quantified by ELISA.

Results

: The MTT cell viability data revealed the presence of minor toxicity to Calu-3 or A549 cells following exposure to SHL and its major ingredients for 24 h or 48 h. However, the cell cultural media showed no sign of inflammatory responses. The in vivo results showed that exposures to SHL at doses of up to 50 mg/kg did not significantly increase the total protein content, the LDH activity and the concentrations of IL-6, IL-8 and TNF-α in BALF. However, although intratracheal sprayed SHL at doses of up to 6 mg/kg for histopathologic study and up to 25 mg/kg for cell counts showed no sign of adverse effects, inhaled SHL at elevated doses appeared to induce alveolar fusion in the lung and significant increases in the cell number of monocytes and granulocytes in the BALF.

Conclusion

: The results demonstrated that the pulmonary safety of inhaled SHL was dependent on the administered dose. Inhalation therapy of SHL may be safely used when the inhaled dose was properly controlled.     

Neuroprotective effect of Momordica charantia in global cerebral ischemia and reperfusion induced neuronal damage in diabetic mice

Ethnopharmacological relevance

Momordica charantia L. (Cucurbitaceae) fruits have been used traditionally for centuries, especially for treating diabetes and associated complications.

Aim of the study

The present study was performed to evaluate neuroprotective effect of lyophilized M. charantia fruit juice against global cerebral ischemia and reperfusion induced neuronal injury in diabetic mice.

Materials and methods

Global cerebral ischemia induced by occluding both common carotid arteries for 10 min followed by 24 h reperfusion was used to induce neuronal injury. Ischemia-reperfusion induced neuronal injury was evaluated in terms of cerebral infarct size, generation of free radicals measured as thiobarbaturic acid reactive substances (TBARS), and neurological functions measured as short term memory and motor activity.

Results

The cerebral oxidative stress and damage, and neurological deficits were dose dependently attenuated by pre-treatment with the lyophilized M. charantia juice (200-800 mg/kg, p.o., o.d.). Moreover, M. charantia also exhibited dose dependent antihyperglycemic activity in diabetic mice.

Conclusions

These results suggest that M. charantia has potent neuroprotective activity against global cerebral ischemia-reperfusion induced neuronal injury and consequent neurological deficits in diabetic mice.     

Screening of Caesalpinia bonduc leaves for antipsoriatic activity

Ethnopharmacological relevance

Leaves of Caesalpinia bonduc (L.) Roxb. (Caesalpiniaceae) have been used by traditional Siddha healer of Malabar region for psoriasis treatment.

Aim of the study

To evaluate the Caesalpinia bonduc decoction (CBD), Caesalpinia bonduc hydroalcoholic extract (CBHA) for antipsoriatic activity.

Materials and methods

Mouse tail test for psoriasis was used for the evaluation of antipsoriatic activity. Extracts were tested at a dose of 500 mg/kg b.w. and fractions at 250 mg/kg b.w. in Swiss albino mice. Parameters studied in the mouse tail test were changes in epidermal thickness and percentage orthokeratotic values. In vitro antiproliferant assay on HaCaT cell lines and in vitro lipoxygenase inhibition were also carried out.

Results

Butanol fraction of Caesalpinia bonduc hydroalcoholic extract (CBHAB) and water fraction of Caesalpinia bonduc hydroalcoholic extract (CBHAW) produced significant orthokeratosis (p < 0.001). In relative epidermal thickness, a significant (p < 0.05) reduction with respect to control was observed in groups treated with retinoic acid, CBD, butanol fraction of Caesalpinia bonduc decoction (CBDB), water fraction of Caesalpinia bonduc hydroalcoholic extract (CBHAW). Maximum antiproliferant activity was shown by CBHA (IC₅₀, 77.5 ± 12.7 μg/ml). In lipoxygenase inhibition assay, water fraction of Caesalpinia bonduc decoction (CBDW) showed maximum activity with an IC₅₀ value of 164.71 ± 4.57 μg/ml.

Conclusions

Among all the tested samples only CBHAW showed good activity in the mouse tail test, antiproliferant activity in HaCaT cells and lipoxygenase inhibition assay. Other extracts and fractions showed varying degrees of activity. The present study supports the traditional use of Caesalpinia bonduc leaves for psoriasis treatment.     

Acute and subchronic oral toxicities of Pu-erh black tea extract in Sprague-Dawley rats

Ethnopharmacological relevance

Pu-erh black tea, which is obtained by first parching crude green tea leaves and then undergoes secondary fermentation with microorganisms, has been believed to be beneficial beverages for health for nearly 2000 years in China, Japan and Taiwan area. But its potential toxicity when administered at a high dose as concentrated extracts has not been completely investigated.

The aim of the study

The present study was aimed at evaluating potential toxicity of Pu-erh black tea extracts (BTE) from acute and sub-chronic administration to male and female Sprague-Dawley (SD) rats.

Materials and methods

A single BTE dose of 10,000 mg/kg of body weight was administered by oral gavage for acute toxicity in SD rats. Four groups (10 males and 10 females per group) of dose levels of 1250, 2500, and 5000 mg/kg/day of the test article, as well as controls (distilled water) were tested as the subchronic toxicity study.

Results

No deaths and signs of toxicity occurred during the 14 days of the study. There were no test article related mortalities, body weight gain, feed consumption, clinical observation, organ weight changes, gross finding, clinical or histopathological alterations during the 91-day administration.

Conclusions

The LD₅₀ of BTE can be defined as more than 10,000 mg/kg, and a dose of 5000 mg/kg/day was identified as the no-observed-adverse-effect-level (NOAEL) in this study.     

The effect of emodin, an anthraquinone derivative extracted from the roots of Rheum tanguticum, against herpes simplex virus in vitro and in vivo

Aim of the study

Herpes simplex viruses (HSV-1 and -2) are important pathogens for humans and the discovery of novel anti-HSV drugs with low toxicity deserves great efforts. Rhubarb is one of the oldest and best-known traditional Chinese medicines. We initiated this study to test if emodin is the active ingredients from Rheum tanguticum (R. tanguticum, one of the Chinese Rhubarb) against HSV infection and to investigate its antiviral activity on HSV infection in tissue culture cells and in a mouse model.

Materials and methods

Emodin (3-methyl-1,6,8-trihydroxyanthraquinone) was extracted and purified from R. tanguticum (cultivated at high mountainous area in Qinghai) and the purity was determined by high performance liquid chromatography. The antiviral experiments of emodin against HSV infection were performed in vitro and in vivo. In vivo, the HSV-infected mice were orally administered with emodin beginning at 24 h post-HSV exposures with dosages of 3.3 g/kg/day, 6.7 g/kg/day, and 11.3 g/kg/day, respectively, for 7 days.

Results

Emodin was found to inhibit the replication of HSV-1 and HSV-2 in cell culture at the concentration of 50 μg/ml with antiviral index of 2.07 and 3.53, respectively. The emodin treatment increased the survival rate of HSV-infected mice, prolonged survival time and showed higher efficacy of HSV elimination from brain, heart, liver and ganglion, compared to the viral controls. In addition, the antiviral activity of emodin was found to be equivalent to that of acyclovir in vivo.

Conclusions

Our results indicate that emodin has the anti-HSV activity in vitro and in vivo and is thus a promising agent in the clinical therapy of HSV infection.