Phytochemical profiling and bioactivity assessment of Caesalpinia pulcherrima (L.) Sw. extracts using HPTLC, LC-MS, and in vitro studies.

Abstract

Caesalpinia pulcherrima (L.) Sw. contains diverse phytoconstituents with potential biological activities. This study evaluated the phytochemical profile and antioxidant and cytoprotective activities of leaf and flower extracts. An ICH-compliant High-performance thin-layer chromatography (HPTLC) method was developed and validated for gallic acid and quercetin, while LC-QTOF-MS was used for tentative phytochemical profiling. The HPTLC method showed satisfactory linearity over 100-600 ng/spot, with R2 values of 0.986 for gallic acid and 0.982 for quercetin. Gallic acid contents were 0.55%, 0.066%, 0.14%, and 0.16%, while quercetin contents were 0.62%, 0.12%, 1.07%, and 0.89% in methanolic leaf, aqueous leaf, methanolic flower, and aqueous flower extracts, respectively. CPLF2 showed the strongest DPPH radical-scavenging activity (IC50 = 51.7 µg/mL) and comparatively higher cell viability under CCl4-induced oxidative stress. Overall, the findings indicate an association between phytochemical composition and the observed biological activities. Gallic acid and quercetin served as analytical markers, and their individual contribution to biological effects cannot be established from the present study.