Antimycobacterial screening of traditional medicinal plants using the microplate resazurin assay.

Multidrug-resistant Mycobacterium tuberculosis strains have rapidly become a global health concern. North American First Nations communities have used traditional medicines for generations to treat many pulmonary infections. In this study, we evaluated the antimycobacterial activity of 5 medicinal plants traditionally used as general therapeutics for pulmonary illnesses and specifically as treatments for tuberculosis. Aqueous extracts of Aralia nudicaulis, Symplocarpus foetidus, Heracleum maximum, Juniperus communis, and Acorus calamus were screened for antimycobacterial activity against Bacillus Calmette-Guérin, Mycobacterium avium, and M. tuberculosis H37Ra using the colorimetric microplate resazurin assay. Extracts of Acorus calamus and H. maximum root demonstrated significant antimycobacterial activity comparable to that of the rifampin control (2 microg/mL). Evaluation of the cytotoxicity of these 2 extracts using the MTT assay also showed that the extracts were less toxic to 3 human cell lines than was the DMSO positive control. This study demonstrates that aqueous extracts of the roots of H. maximum and Acorus calamus possess strong in vitro antimycobacterial activity, validates traditional knowledge, and provides potential for the development of urgently needed novel antituberculous therapeutics.

Recruitment of men who have sex with men for large HIV intervention trials: analysis of the EXPLORE Study recruitment effort.

Testing HIV prevention strategies requires that researchers recruit participants at high risk of HIV infection. Data from the EXPLORE Study, a behavioral intervention trial involving men who have sex with men (MSM), were used to examine the relationship between recruitment strategies and participant characteristics, sexual risk behaviors and HIV incidence. The EXPLORE Study used a wide variety of recruitment strategies; no one strategy accounted for more than 20% of enrolled men. Younger men and men of color were more likely to be recruited through club and bar outreach, friend referral, and street outreach. Men reporting 10 or more sexual partners were more likely to be recruited through advertising and street outreach. Men reporting unprotected sex were more likely to be recruited through clinic referrals. HIV incidence did not significantly differ by recruitment strategy. Our findings support the need for a wide range of recruitment strategies in attracting MSM at high risk for HIV into clinical studies.