HPTLC Densitometric Analysis for Quantification of Sennocide-B and Rhein in Leaf Extracts of Senna alexandrina Mill. and Their Commercial Formulations.

Abstract

The leaf extract of Senna alexandrina Mill., a plant from the Fabaceae family, contains bioactive anthraquinones sennoside-B and rhein, traditionally used in Indian medicine for various health issues. However, standardizing the quality of S. alexandrina and its commercial products is challenging. To address this, we established two high-performance thin-layer chromatography (HPTLC) methods for accurate analysis of these biomarkers in S. alexandrina leaf extract and its commercial formulations. For sennoside-B, a mobile phase combination of solvent for example, butanol, water, and glacial acetic acid (6:3.5:0.5, v/v/v) was used, with detection at 254 nm, producing spots at an Rf value of 0.37 ± 0.006. The method showed linearity between 100 to 2000 ng/spot (R² = 0.9983 ± 0.0017), with a limit of detection (LoD) of 22.84 ± 0.554 ng/band and a limit of quantitation (LoQ) of 69.22 ± 0.859 ng/band. For rhein, a mobile phase combination of solvent toluene, ethyl acetate, and glacial acetic acid in the ratio (7:2.5:0.5, v/v/v) was utilized and was also detected at 254 nm. The obtained spots had Rf value of 0.67 ± 0.004. The linearity was confirmed within the same range (R² = 0.9985 ± 0.0005), with an LoD of 15.49 ± 0.645 ng/spot and an LoQ of 46.94 ± 1.172 ng/spot. Herein, the methods have followed the guidelines of ICH (Q2) R1. These developed HPTLC methods are selective, simple, sensitive, accurate, and economical, making them suitable for everyday assessment of these bioactive markers in S. alexandrina and its commercial products. This study supports the quality control of S. alexandrina, ensuring product consistency, efficacy, and safety.