TLC-DENSITOMETRIC EVALUATION OF THREE MAJOR BIOACTIVE DITERPENE LACTONES IN ANDROGRAPHIS PANICULATA INTERCROPPED WITH MORUS ALBA

Industrially used and endangered listed medicinal plant Andrographis paniculata was cultivated between rows of ten-year-old Morus alba (mulberry) plantation, spaced at 10′ × 10′ under a Randomized Block Design, already existed for sericulture purposes, and evaluated for its performance in terms of content of its three major bioactive diterpene lactones 14-deoxy-11,12-didehydroandrographolide, andrographolide, and neoandrographolide to examine the effect of intercropping on these constituents. Matured plants were harvested and the aerial parts were shade dried, milled, defatted, and extracted with methanol. The extracts were analyzed using HPLTC method validated for linearity, precision, specificity, and accuracy in accordance with the ICH guidelines. Pure lactones required for quantitative determination were isolated from column chromatography of the ethylacetate fraction of the methanol extract obtained from the aerial parts of the plant. Densitometric quantification was performed on Silica gel 60F254 pre-coated glass plates with a mobile phase of chloroform:methanol (7:1, v/v) in a twin trough chamber saturated for 20 min. Statistical analysis revealed significant increase in the contents of these lactones in the A. paniculata when intercropped than grown as sole crops. Thus, suitability of intercropping of A. paniculata in mulberry based cropping system was demonstrated.