A Validated HPTLC Densitometric Method for Determination of Lupeol, β-Sitosterol and Rotenone in Tephrosia purpurea: A Seasonal Study

Tephrosia purpurea (L.) Pers., commonly known as "sarpunkha" and "wild indigo", is being used in traditional systems of medicine to treat liver disorders, spleen and kidney. In the present study, a validated High Performance Thin Layer Chromatography (HPTLC) method was established for the estimation of lupeol, beta-sitosterol and rotenone in various extracts of T. purpurea with the aim to see the effect of seasons on the quantity of aforesaid phytoconstituents. The plant material was collected in summer (April), rainy (August) and winter (December) during 2013-2014 from Lucknow, India. The method was validated in terms of precision, repeatability, specificity, sensitivity linearity and robustness. The method permits reliable quantification and showed good resolution on silica gel with toluene-ethyl acetate-formic acid (9:1:1 v/v/v) as mobile phase, and characteristic bands of beta-sitosterol, rotenone and lupeol were observed at Rf 0.38, 0.45 and 0.52, respectively. The content of aforesaid phytoconstituents varies from season to season and extract to extract. Our finding indicated that winter season (December) may not be appropriate for collection of T. purpurea for the preparation of therapeutic formulations because of the high content of rotenone, a known insecticide that is responsible for Parkinson's disease and associated with heart failure, fatty liver and liver necrosis.