The H37Rv strain of MTB was grown in modified Sauton’s medium till mid-log phase. Peripheral blood mononuclear cells (PBMC) were isolated by density gradient sedimentation on Ficoll-Paque separation medium. Adherent monocytes obtained from PBMC’s were infected with H37Rv for 90 min. in the ratio of 1:1 (1 bug: 1 cell). Thereafter, after washing, infected cells were co-cultured with varying doses of neem extract for 24 hrs, and harvested subsequently. Modulation of secreted TNF-[alpha], iNOS and MTB Ag85 complex expressions in culture supernatants was estimated by ELISA.
We report the high basal expression of secreted tumor necrosis factor-[alpha] (TNF-[alpha]), inducible nitric oxide synthase (iNOS) and MTB Ag85 complex in MTB-infected monocytes was suppressed by neem extract in a dose-dependent manner (P<0.001 for all). A concentration of 1ug/ml of neem extract showed a suppression by ~ 2.5-fold (P<0.001), 1.7-fold (P<0.001) and 1.8-fold (P<0.001) in the expressions of
secreted TNF-[alpha], iNOS and MTB Ag85 respectively in 24 hr culture supernatants of MTB-infected monocytes.
Thus, neem extract seems to be a potential future adjunct for in-depth studies in the management of tuberculosis
