Simultaneous quantification of Curcumin, Piperine and Capsaicin by HPTLC in Rasam, a polyherbal soup

Abstract

Traditionally rasam is consumed for the treatment of cold and cough. The major chemical constituents present in the spices required to prepare the rasam are known but, the chemical composition of the prepared rasam are unknown. The preparation involves, boiling the spices in water and oil, this may create an opportunity for an altered chemical profile of the prepared rasam. As a part of our chemical investigation in rasam, curcumin, piperine and capsaicin were chosen as marker compounds based on their literature for exhibiting potent activity against upper and lower respiratory tract infections (URTI & LRTI). The current work was planned to identify and quantify curcumin, piperine and capsaicin simultaneously by HPTLC in rasam. Silica gel 60F₂₅₄ TLC plates were used for the study. The optimized mobile phase used was toluene and ethyl acetate (7:3, v/v) and the densiometric scanning was done at 254 nm. The R_f values of curcumin, piperine and capsaicin were found to be 0.26, 0.40 and 0.47 respectively. The calibration graph of peak area versus concentration graph of curcumin, piperine and capsaicin was found to be linear in the range of 2 to 7 μg spot^-1. The amount of curcumin, piperine and capsaicin in 100 mL of rasam was found to be 0.49, 0.66 and 0.41% w/v respectively. The developed method was validated as per ICH guideline parameters. The current study shows that the developed TLC method is simple, precise, specific, robust and accurate. This method will also be useful to identify or quantity any polyherbal formulation containing curcumin, piperine and capsaicin as chemical constituents.