María Adelina Jiménez-Arellanes

Antitubercular Activity and the Subacute Toxicity of (−)-Licarin A in BALB/c Mice: A Neolignan Isolated from Aristolochia taliscana

BACKGROUND AND AIMS Tuberculosis remains a worldwide health problem and requires long-term treatment with several antibiotics; therefore, compliance problems and the emergence of multidrug resistance (MDR) are involved. (-)-Licarin A (LA) was isolated from diverse plants such as Aristolochia taliscana and possesses antimycobacterial, antiinflammatory, trypanocidal, and neuroprotective activities. The aim of the study was to determine the antitubercular and subacute toxicity of LA isolated from A. taliscana in BALB/c mice. METHODS The antitubercular activity of LA was tested in a TB murine model inducing disease with M. tuberculosis H37Rv or MDR. Mice were treated with LA (5 mg/kg) for 30 and 60 days; post/treatment, lung bacilli loads and pneumonia percentage were determined. The subacute toxicity of LA (21 days) was evaluated in healthy mice. After treatment, biochemical and hematological parameters were determined and main organs were analyzed histologically. RESULTS In animals infected with drug-sensitive or MDR strains, LA produced a significant decrease of pulmonary bacillary burdens at day 30 of treatment, and a significant pneumonia reduction at days 30 and 60 of treatment. Regarding subacute toxicity, LA administration during 21 days showed no abnormalities in main-organ macro- and microarchitecture. Biochemical and hematological parameters analyzed showed no statistical differences between control and treated groups. CONCLUSIONS (-)-Licarin A reduces pneumonia of mice infected with both mycobacterium strains. Also, subacute toxicity of LA exhibits no major signs of damage. Biochemical and hematological parameters and histological analyses indicate that LA caused no significant changes at the doses assayed.

Anti-inflammatory and toxicological evaluation of Moussonia deppeana (Schldl. & Cham) Hanst and Verbascoside as a main active metabolite.

ETHNOPHARMACOLOGICAL RELEVANCE Moussonia deppeana, known as Tlachichinole, is a Mexican medicinal plant used for treatment of inflammatory diseases, influenza, diarrhea, gastrointestinal disorders and arthritis. AIM OF THE STUDY In this paper the antioxidant and anti-inflammatory activities as well as the acute and sub-acute toxicological effects were evaluated for the ethanolic extract from aerial parts of M. deppeana, also its phytochemical analysis is described. MATERIALS AND METHODS Phytochemical analysis and compound isolation were performed with thin layer chromatography. The chemical identification of the main compound was performed by (1)H NMR (COSY, NOESY, HSQC and HMBC) spectra. In vitro antioxidant capacity and total phenolic content for the ethanolic extract and its primary fractions was determined by DPPH and Folin-Ciocalteu reagent. Acute and subacute toxicity tests were evaluated on Balb/C mice. Finally acute anti-inflammatory evaluation was tested for a local (TPA) and systemic (carrageenan) murine model. RESULTS The main compound isolated from the ethanolic extract of M. deppeana was Verbascoside, which was isolated from F3 and was identified by (1)H NMR and COSY data. Furthermore oleanolic and ursolic acids were isolated from primary fractions F1 and F2. Ethanolic extract showed IC50 = 6.71mg/mL for DPPH test and 664.12µg QE/mL for the total phenolic content. The LD50 value was >2g/kg by i.g. route in male and female mice. Sub-acute administration (28 days) of the ethanolic extract (1g/kg) did not cause lethality or alter any hematological and biochemical parameters, in addition, histological analysis of the major organs exhibited no structural changes. Anti-inflammatory activity of the ethanolic extract showed an ED50 = 1.5mg/ear and 450mg/kg for TPA and carrageenan test, respectively. Primary fractions generated moderate local and systemic anti-inflammatory activity. CONCLUSION The ethanolic extract from the aerial parts of M. deppeana did not cause any lethality or adverse effect in either of the acute and sub-acute toxicity tests. This exhibited an important local and systemic anti-inflammatory activity and also moderate antioxidant capacity. Moreover, the primary fraction F2 was more active for the TPA model while the primary fraction F3 was most active in the carrageenan model in vivo. The main compound isolated from F3 was verbascoside; on the other hand also ursolic and oleanolic acids were isolated from F1 and F2.

Medical plant extracts and natural compounds with a hepatoprotective effect against damage caused by antitubercular drugs: A review

Drug-induced liver injury encompasses a spectrum of diseases ranging from mild biochemical abnormalities to acute liver failure; example of this scenery is hepatotoxicity caused by the first-line antituberculous drugs isoniazid, rifampin and pyrazinamide, which are basic for treatment of drug-sensible and drug-resistant tuberculosis. In the search for pharmacological alternatives to prevent liver damage, antitubercular drugs have been the subject of numerous studies and published reviews, a great majority of them carried out by Asian countries. At the same time, hepatoprotectors from plant source are now emerging as a possible alternative to counteract the toxic effects of these therapeutic agents. The present review aims to highlight the most recent studies on the subject, based information published in scientific databases such as Scopus and PubMed.

Medicinal Plants, an Important Reserve of Antimycobacterial and Antitubercular Drugs: An Update

Background: Tuberculosis is a global and serious Public Health problem due to the increase of multidrugresistant and extensively drug-resistant cases; as a result, diverse research groups worldwide are focusing their efforts on finding novel antituberculous agents that can provide greater effectiveness, less toxicity and having a specific mechanism of action, possibly being coadjuvants in the treatments currently prescribed. Methods: The present review covers the literature published concerning secondary metabolites of those Mexican medicinal plants and secondary metabolites isolated from them showing in vitro antimycobacterial activity with MIC <50 μg/mL against sensitive and MDR M. tuberculosis strains as well as against NTM strains. The review also includes a special section for those natural compounds or plant extracts with antitubercular activity evaluated an in vivo experimental tuberculosis model. Results: Some pure compounds with MIC<25 μg/mL are: 2-oxo-14-(3´,4´-methylenedioxyphenyl) tetradecane, 2- oxo-16-(3´,4´-methylenedioxyphenyl)hexadecane, 5,6-dehydro-7,8-dihydro methysticin, cepharanone B and piperolactam A (from Piper sanctum), suberosin (from Arracacia tolucensis) and leubethanol (from Leucophyllum frutescens). In addition, (-)-licarin A (from Aristolochia taliscana) was active against M. tuberculosis H37Rv, 12 MDR M. tuberculosis clinical isolates and four non-tuberculous mycobacteria. On the other hand, the antitubercular activity of (-)-licarin A, ursolic acid and oleanolic acid has been determined in a TB murine experimental in vivo model; (-)-licarin A reduces the bacterial lung load and the percentage of pneumonia in animals infected with M. tuberculosis H37Rv and MDR M. tuberculosis. The mixture of ursolic and oleanolic acids showed a significant reduction of bacterial loads and pneumonia in animals infected with M. tuberculosis H37Rv and MDR M. tuberculosis. Conclusion: Since (-)-licarin A, ursolic acid and oleanolic acid have been evaluated as antitubercular compounds, these metabolites are candidates proposed feasible to be proposed for development of antituberculosis drugs.

In vitro and in vivo cysticidal activity of extracts and isolated flavanone from the bark of Prunus serotina: A bio-guided study

Currently, neurocysticercosis treatment involves two drugs: albendazole and praziquantel; however, their efficacy is suboptimal and new cysticidal drugs are needed. The present paper reports the cysticidal activity of extracts of the bark from Prunus serotina against Taenia crassiceps cysts and the isolation and identification of the main components of the most active extract. Results showed that all extracts displayed in vitro cysticidal activity (EC50=17.9-88.5μg/mL), being the methanolic the most active and selective. Also, methanolic extract exhibited in vivo efficacy at 300mg/kg which was similar to that obtained with albendazole. Bio-guided fractionation of methanolic extract led the isolation of 2,3-dihydro-5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (naringenin, NGN), 3,4,5-trimethoxybenzoic acid and 1,3,5-trimethoxybenzene. NGN exhibited in vitro activity, in a time-concentration-dependent manner (EC50=89.3μM]. Furthermore, NGN at a dose of 376.1μmol/kg displayed similar in vivo efficacy than those obtained with albendazole at 188.4μmol/kg. NGN also caused a high level of damage in all parasite tissue in a similar manner than that observed with the methanolic extract. This study represents the first report of the cysticidal properties of the bark of P. serotina. NGN was identified as the main active compound of this specie and other studies are required to explore the potential of this flavanone as cysticidal agent.