Green Chromatographic Methods and in Vitro Pharmacological Analysis of Varronia curassavica Leaf Derivatives

Varronia curassavica displays anti-inflammatory, antiulcerogenic, and antioxidant activities. Herein, we employed new UHPLC -UV green chromatographic methods for the analysis of in vitro antioxidant and anti-inflammatory activities of V. curassavica and its embryotoxicity in Zebrafish. Cordialin A, brickellin, and artemetin were purified from the ethanol (EtOH) extract of V. Curassavica leaves and identified using spectrometric techniques. In line with Green Analytical Chemistry principles, the proposed UHPLC methods involve the use of ethanol as organic modifier with low mobile phase consumption, and without sample pretreatment (OLE-UHPLC-UV). The application of the Agree and HPLC-EAT tools for greenness assessment yielded this pattern: HPLC-UV (reference)<UHPLC-UV<OLE-UHPLC-UV. Zebrafish assay results showed that 70 % EtOH extract of V. Curassavica leaves exhibited lower toxicity compared to 100 % EtOH extract, with LC50 of 164.3 and 122.9 μg/mL, respectively, in 24 h post fertilization. Some embryos exhibited malformation phenotypes in the heart, somites, and eyes, mainly in higher extract concentrations. Extracts and brickellin exhibited higher antioxidant activity in the DPPH⋅ assay, while brickellin+artemetin displayed higher antioxidant activity compared to the extracts and isolated flavones in the O2 ⋅- and HOCl/OCl- scavenging assays. Cordialin A and brickellin exhibited low COX-1, COX-2, and phospholipase A2 inhibition.