Relative estimation of beta-sitosterol in alcoholic extracts of roots and small branches of oroxylum indicum (L.) Kurz by HPTLC for plant part substitution, medicinal uses and conservation

Abstract

Beta-sitosterol is a common and useful ‘phytosterol’, present in roots and small branches of Oroxylum indicum (L.) Kurz It has mainly cholesterol-lowering, anti-inflammatory, anti-cancer, and dietary properties. O. indicum is a rare medicinal plant in the traditional medicine system. This study comparatively identified and estimated beta-sitosterol in the methanolic extracts of roots and the small branches of O. indicum by the development of a validated HPTLC method. Chromatographic separation was performed on precoated TLC plates by toluene: ethyl acetate: formic acid: water (6:3:1:0.2, v/v/v/v) with standard procedures using HPTLC assembly. Marker was identified at RF 0.60 as prominent bands and quantified at 540 nm with sharp peaks corresponding to beta-sitosterol by calibration method. The method was validated as per ICH guidelines with a good linear relationship i.e. r2 = 0.9973 ± 0.000405 in 100 – 500 ng band−1 with respect to the peak area. The LOD and LOQ were calculated as 35.22 and 106.73 ng/band, respectively. The quantity of marker in extracts of roots and the small branches was found to be 268.7% w/w and 208.5% w/w respectively in 0.5 g of the sample. The method was simple, accurate, and reproducible for rapid screening and quantification of beta-sitosterol in roots and aerial parts of O. indicum. The study may helpful for plant part substitution study, medicinal practises, sustainability, and conservation of such vulnerable plant species. It may useful to establish the quality and efficacy of plant in traditional applications and in routine standardization (quality control) of different commercial preparations of O. indicum.