Assessment of environmental quantitative variation of diosgenin in fenugreek seeds via high-performance thin-layer chromatography method

Fenugreek is one of the oldest medicinal plants known by mankind. The aim of this study is to evaluate the effect of environmental conditions on the saponin contents of the plant. The amount of diosgenin in different samples of fenugreek was estimated by high-performance thin-layer chromatography (HPTLC). The developed method was validated, in accordance with the International Conference on Harmonization (ICH) guidelines for precision, accuracy, and robustness. HPTLC was carried out using hexane-acetone (8:2%, v/v) on 20 cm × 10 cm glass coated silica gel 60 F₂₅₄ plates. The developed plates were scanned and quantified densitometrically at λ = 430 nm. Linear regression analysis revealed a good linear relationship between the area under the peak and the amount of diosgenin in the range of 50-400 ng per band. The amount of diosgenin which reflects the total saponin contents varied according to the country of origin. The sample obtained from Yemen showed the highest amount of diosgenin followed by the Saudi sample. Both locations represent areas with the highest altitude (Yemen) and the highest temperature (Saudi).