Chemical composition and antiproliferative activity of supercritical CO₂ extracts from citrus fruits

Supercritical CO₂ extract from fruits of Citrus hassaku Hort ex Tanaka, Citrus iyo Hort. ex Tanaka, and Citrus grandis Osbeck, locally known as phalsak, yeagam, and dangyuja, respectively, in Korea, were analyzed by gas chromatography-mass spectrometry (GC-MS). In total, 70, 79, and 76 compounds were identified in fruits of phalsak, yeagam, and dangyuja respectively. (Z)-9-Octadecenoic acid was the major compound in phalsak, whereas limonene prevailed among the others. α-Terpineol, (E,E)-2,4-decadienal, hexadecanoic acid, pentacosane, stigmasterol, and γ-sitosterol were prominent in all species. Antiproliferative activity of the fruit extract was revealed through the colorimetric MTT (tetrazolium) assay against human glioblastoma U373MG, SNU-16 gastric cancer cells, HeLa cervix adenocarcinoma cells and AGS gastric adenocarcinoma cells. Although all tested fruit extracts exhibited antiproliferative effects toward cancer cells, different cell lines varied in their sensitivity to the same plant fruit extract.