ABSTRACT:
The present study emphasizes on the need and importance of novel bioactive compounds from natural sources for reatment of infections with HSV type I and HSV type 2, a major opportunistic disease in immunocompromised patients. Plumbagin (PZEA-I), a naphthoquinone and the mixture of flavonoids (PZFF) isolated and characterized from the most promising ethyl acetate fraction of Plumbago zeylanica roots, a traditional medicinal plant, were assessed for anti-viral activity to find out the lead molecules effective against HSV-2 on Hep 2 cell line by in vitro method. The viability of cells treated with the isolated compounds were observed microscopically for morphological changes and evaluated by MTT assay and the non toxic dose of PZEA-I, PZFF and curcumin was calculated which was found to be 0.4ug/ml, 12Spg/mi and 100ugml. Further, TCID values of HSV-2 at vVarying dilutions showing complete cytopathic effect was estimated using kaher's formula and antigen dose (1 TCIDS0) was estimated which was found to be 10" that is to be used for antiviral assay The antiviral assay was then carried out with the non toxic concentration of the test samples against 1, 10, 100 TCID, virus. It was found that the Complete Cytopathic Effect (CPE) inhibition was observed in 100 TCID of virus with the flavonoid fraction showing significant antiviral activity at a concentration of 0.048ug/ml similar to the standard curcumin when compared to plumbagin with only parital activity at concentration of 0.4ug/ml. It was observed that the flavonoids identified as nutin, quercetin, orientin and kacmpferol, were the lead molecules responsible for significant anti-viral activity whereas plunhagin (PZEA-I) had only partial activity. Attempts are being made to perform the plague assay to find out the extent of percentage inhibition in the effective flavonoid fraction (PZFF) and the determinate effect of anthraquinones isolated from the Plambago zeylanica roots might focus on the efficacy in the traditional system of medicine.