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Context: An ethnobotany-based approach in the selection of raw plant materials to study was implemented. Objective: To acquire raw plant materials using ethnobotanical field interviews as starting point to discover new bioactive compounds from medicinal plants of the Lao People's Democratic Republic. Methods: Using semi-structured field interviews with healers in the Lao PDR, plant samples were collected, extracted, and bio-assayed to detect bioactivity against cancer, HIV/AIDS, TB, malaria. Plant species demonstrating activity were recollected and the extracts subjected to a bioassay-guided isolation protocol to isolate and identify the active compounds. Results: Field interviews with 118 healers in 15 of 17 provinces of Lao PDR yielded 753 collections (573 species) with 955 plant samples. Of these 955, 50 extracts demonstrated activity in the anticancer, 10 in the anti-HIV, 30 in the anti-TB, and 52 in the antimalarial assay. Recollection of actives followed by bioassay-guided isolation processes yielded a series of new and known in vitro-active anticancer and antimalarial compounds from 5 species. Discussion: Laos has a rich biodiversity, harboring an estimated 8000-11,000 species of plants. In a country highly dependent on traditional medicine for its primary health care, this rich plant diversity serves as a major source of their medication. Conclusions: Ethnobotanical survey has demonstrated the richness of plant-based traditional medicine of Lao PDR, taxonomically and therapeutically. Biological assays of extracts of half of the 955 samples followed by in-depth studies of a number of actives have yielded a series of new bioactive compounds against the diseases of cancer and malaria. [ABSTRACT FROM AUTHOR]

The aim of this study was to apply receiver operating characteristic (ROC) analysis to the microplate Alamar blue assay, a recently developed alternative for drug susceptibility testing of mycobacteria. As this is a quantitative assay, its performance can be determined by ROC analysis, in which the area under the ROC curve represents a summary of test performance (the higher the area, the better the test's performance). Sixty isolates of Mycobacterium tuberculosis were tested by the microcolorimetric assay against six twofold dilutions of streptomycin, isoniazid, rifampin, and ethambutol. For each isolate, the susceptibility pattern was simultaneously established by the agar proportion method, the result of which represented the gold standard value for the ROC analysis. The critical concentration, area under the curve, and P value for each drug were determined by ROC curve analysis. The results of the assay were obtained in an average of 8 days of incubation. The performance of the assay was excellent for all four drugs: the area under the curves was >0.97, the P values were 0.000, and sensitivity was 94%, specificity 97%, predictive value for resistance ≥92%, predictive value for susceptibility 97%, and test efficiency 97%. According to ROC analysis, the microplate Alamar blue assay is a reliable method for determination of drug-susceptibility. Rapidity and cost efficiency are two additional qualities that make this test an excellent alternative for the drug susceptibility testing of Mycobacterium tuberculosis. The ROC curve analysis is a robust statistical approach for evaluating the performance of new quantitative methods for determination of drug sensitivity of Mycobacterium tuberculosis isolates. [ABSTRACT FROM AUTHOR]

Ethanol extracts from a group of 53 marine organisms, including a newly identified species, from Baja California Sur (México), were evaluated for their antimicrobial and antiparasitic activity. The activity against Staphylococcus aureus, Streptococcus faecalis, Bacillus subtilis (Gram +), Escherichia coli (Gram-) and Candida albicans (yeast) was determined by the diffusion agar method. Aplysina gerardogreeni (Demospongiae) was found to be the most active sample. In addition, A. gerardogreeni, Pacifigorgia media, and Pacifigorgia sp. possess significant activity against Mycobacterium tuberculosis H 37Rv and Pacifigorgia media and Geodia sp. against Mycobacterium avium. From this group, 15 ethanol extracts were tested in vitro against Entamoeba histolytica and Giardia lamblia. Litotamnium crassiussculum, Geodia sp., Pacifigorgia sp. showed significant activity against Entamoeba histolytica while Myxilla incrustans and Muricea appressa were active against Giardia lamblia. Litotamnium crassiussculum showed activity against both trophozoites. [ABSTRACT FROM AUTHOR]