Supercritical CO₂ extraction was applied to Heliotropium arbainense to evaluate how extraction pressure influences phytochemical composition and biological activity. Extractions of phenolic and flavonoid were performed at two pressures (200 and 550 bar), by using Supercritical CO₂. Phenolic and flavonoid compounds, were determined by HPLC analysis. Higher pressure extraction (550 bar) resulted in a greater extraction yield and a marked enrichment of phenolic and flavonoid compounds. Gallic acid (1496.01 µg/g) was the most prevalent component under SFE 1, followed by catechin (859.51 µg/g), rutin (824.55 µg/g), and coumaric acid (559.93 µg/g). Both extracts exhibited broad antimicrobial activity against Gram-positive and Gram-negative bacteria as well as Candida albicans, with consistently lower MIC and MBC/MFC values observed for the high-pressure extract. Cytotoxic evaluation against SKOV3 ovarian cancer cells revealed a clear dose-dependent reduction in cell viability. The calculated IC₅₀ values further confirm the greater cytotoxic potency of extract at 550 bar, with a lower IC₅₀ (153.04 ± 0.4 µg/mL) compared to extract at 200 bar (183.18 ± 2.29 µg/mL) against SKOV3 cells. However, flow cytometry revealed that extract at 200 bar produced slightly higher early apoptosis (43.79% vs. 43.39%) and greater necrosis (21.83% vs. 13.29%) in SKOV3 ovarian cells overall. Anti-inflammatory activity, assessed by protein denaturation inhibition, was observed for both extracts, with the lower-pressure extract showing slightly stronger inhibitory efficiency. Pressure-dependent supercritical CO₂ extraction significantly influenced the phytochemical richness and biological performance of H. arbainense. These findings highlight the importance of extraction conditions in maximizing the functional potential of plant-derived bioactive compounds and support further investigation of H. arbainense as a source of biologically active phenolics.
Selim et al. (Mon,) studied this question.