Quantification of phenolic compounds in Leucas mollissima Wall. ex Benth through HPTLC and validation of its antioxidant potential

Abstract

The present study deals with quantification of phenolic compounds by a simple, rapid, sensitive and selective high-performance thin-layer chromatographic (HPTLC) method and evaluation of its traditional claims. A chromatographic separation was performed by using a combination of toluene: ethyl acetate: formic acid (70:30:10, v/v/v) as a mobile phase. A densitometric absorption mode has been used for the estimation of catechin and vanillic acid by comparing the peak area against the standard at wavelength 220 nm. The amount of catechin and vanillic acid was found to be 0.15% and 0.45% dry weight basis. The developed method was validated and found to be specific, linear, precise and accurate as per the International Conference on Harmonization guidelines. Antioxidant potential was evaluated by five different models having variable mechanisms of action viz., total phenolic and flavonoid content, reducing power assay, DPPH assay, deoxyribose assay and total antioxidant potential. In vitro potential data reveals that the species has significant potential and may be used as an alternative plant in future for the treatment of diabetic condition. However, identified bioactive compounds (catechin and vanillic acid) may be used as a reference tool for proper recognition and confirmation of right plant material and monitoring of batch-to-batch consistency of finished herbal products using Leucas mollissima as an ingredient.