Abstract

• The aim of the present work is to investigate the total phenolic contents, antioxidant, cytotoxic, and anti-arthritic activities, and phytoconstituents of Dimocarpus longan Lour. (Longan) peel (LGP). The total phenolic content of ethanol and watery extracts from LGP was determined by the FolinCiocalteu Reagent (FCR) method. Total phenolic content was found to be the highest in ethanol extract (176.12 ± 0.15) μg/mL. The in vitro antioxidant activity of ethanol and watery extracts of LGP was assessed by the DPPH free radical scavenging assay. The IC50 values were found to be 70.52 μg/mL for the watery extract and 8.77 μg/mL for the ethanol extract of LGP. The cytotoxicity of the watery and ethanol extracts was evaluated by a brine shrimp lethality bioassay. From these results, the LD50 values of watery and ethanol extracts were found to be non- toxic at the 1000 μg/mL concentration. The anti-arthritic activity of watery and ethanol extracts screened by the egg albumin method. According to the data, the watery extract (IC50 = 97.77 μg/mL) is more potent than standard diclofenac sodium (IC50 = 57.57 μg/mL) in anti-arthritic activity. By silica gel column chromatographic separation technique, two steroids, one terpenoid and a steroidal carboxylic acid were isolated from petroleum ether extract of LGP and characterized by physico-chemical properties and the FT IR spectroscopic method.