Antiproliferative activity of longan (Dimocarpus longan Lour.) leaf extracts

Longan (Dimocarpus longan Lour.) belongs to the Sapindaceae family. We examined the antiproliferative activity of longan leaf extracts against cancer-derived cell lines in vitro. The tested samples were water extract, ethanol extract, n-hexane fraction, ethyl acetate fraction, and water fraction of longan leaf. Cytotoxicity test is against brine shrimps that were screened using Brine Shrimp Lethality Test. Antiproliferative activity assay on WEHI-164 cells (mouse fibrosarcoma cancer cell), THP-1 cells (human peripheral blood acute monocyte cell), and Vero cells (non-cancer or normal cell) that was conducted using a hemocytometer with Trypan Blue Dye exclusion. The 50% lethality concentration (LC50) value of water extract, ethanol extract, n-hexane fraction, ethyl acetate fraction, and water fraction were 854.64, 305.81, 446.55, 1313.44, and 1621.8 μg/ml. Ethanol extract exhibited significant cytotoxic due to the lowest LC50 value. The ethanol extract was then used for further examination. The highest antiproliferative activity was achieved 44.93% by 600 μg/ml ethanol extract on WEHI-164 and 57.45% by 500 μg/ml ethanol extract on THP-1. It was significantly equal to doxorubicin antiproliferative activity. Ethanol extract dose had a low effect on Vero cells. This present study confirmed that the longan leaf ethanol extract possesses marked antiproliferative activity on cancer-derived cell lines.