ABSTRACT
The present study aimed to develop pharmacognostical and phytochemical descriptors (HPTLC) of Calotropis procera and Calotropis gigantea. β-sitosterol which is one of the common terpene content and a potent antioxidant, purgative, antispasmodic and expectorant, has also been studied through a simple and high-precision method using high performance thin layer chromatography (HPTLC). This may be utilized by pharmaceutical industries for quality evaluation, ensuring successful commercial exploitation of this drug. From the present study it has been observed that both Calotropis procera and C. gigantea have similar microscopic characteristics, physico-chemical parameters showed a little variation as total ash components and extractive values are little less in C. gigantea. HPTLC studies also showed similar qualitative profile with some quantitative variations in total β-sitosterol, which was higher in C. gigantea (2.79%).
ABSTRACT
Background & objectives: Banaba (Lagerstroemia speciosa L.) extracts have been used as traditional medicines and are effective in controlling diabetes and obesity. The aim of this study was to evaluate the anti-HIV property of the extracts prepared from the leaves and stems of banaba, and further purification and characterization of the active components. Methods: Aqueous and 50 per cent ethanolic extracts were prepared from leaves and stems of banaba and were evaluated for cytotoxicity and anti-HIV activity using in vitro reporter gene based assays. Further, three compounds were isolated from the 50 per cent ethanolic extract of banaba leaves using silica gel column chromatography and characterization done by HPLC, NMR and MS analysis. To delineate the mode of action of the active compounds, reverse transcriptase assay and protease assay were performed using commercially available kits. Results: All the extracts showed a dose dependent inhibition of HIV-1-infection in TZM-bl and CEM-GFP cell lines with a maximum from the 50 per cent ethanolic extract from leaves (IC50 = 1 to 25 μg/ml). This observation was confirmed by the virus load (p24) estimation in infected CEM-GFP cells when treated with the extracts. Gallic acid showed an inhibition in reverse transcriptase whereas ellagic acid inhibited the HIV-1 protease activity. Interpretation & conclusions: The present study shows a novel anti-HIV activity of banaba. The active components responsible for anti-HIV activity were gallic acid and ellagic acid, through inhibition of reverse transcriptase and HIV protease, respectively and hence could be regarded as promising candidates for the development of topical anti-HIV-1 agents.