Chamuangone‑Enriched Garcinia cowa Leaf Extract with Rice Bran Oil: Extraction and Cytotoxic Activity against Cancer Cells

Objectives: Some vegetable oils were determined as an alternative green solvent for extraction of an anticancer compound, chamuangone from G. cowa leaf. The chamuangone‑enriched extract was standardized and evaluated for cytotoxic activity against human cancer cell lines. Materials and Methods: Microwave‑assisted extraction and high‑performance liquid chromatography were used for extraction and standardization. The cytotoxic activity was determined using a sulforhodamine B assay. Results: The chamuangone‑enriched extract was obtained using rice bran oil as the alternative green solvent and standardized to contain 1.97 mg/mL chamuangone. The extract exhibited cytotoxic activity against human lung adenocarcinoma, human breast adenocarcinoma, and human colorectal adenocarcinoma cell lines, with IC50 values of 15.3, 15.9, and 12.8 µg/mL, respectively, but was nontoxic to human gingival fibroblasts, a normal cell line, at a concentration of 50 µg/mL. Moreover, the extract contained several natural antioxidants, including α‑tocopherol (76.7 mg/100 g), γ‑oryzanol (cycloartenol ferulate: 67.1 µg/mL and 24‑methylenecycloartanol ferulate: 85.6 µg/mL), and antioxidant capacity determined as ascorbic acid (258.7‑mM ascorbic acid equivalent per gram). Conclusion: Based on these findings, the chamuangone‑enriched extract may be considered as a novel functional food in cancer chemopreventive action.