CHIANG MAI UNIVERSITY JOURNAL OF NATURAL SCIENCES

Volume 19, No. 02, Month APRIL, Year 2020, Pages 235 - 251

In vitro biological activities of the anti-aging potential of dimocarpus longan leaf extracts

Pimjai Doungsaard, Sunee Chansakaow, Jakkapan Sirithunyalug, Lue Shang-Chian, Lin Wei-Chao, Liang Chia-Hua, Lee Kuan-Ha and Pimporn Leelapornpisid

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The longan (Dimocarpus longan Lour.) leaves, which are the underutilized part of trimming longan trees to increase their fruit productivity, were of interest in this study. They have been reported to contain phytochemical components which might be used for anti-aging purposes. In this study, longan leaves were extracted using two different solvents including 95% ethanol and 50% ethanol, named ethanolic extract (ET) and hydroethanolic extract (HE), respectively. The extracts were investigated for antioxidation properties, inhibition of hyaluronidase, collagenase, MMP-2 and MMP-9 together with the determination of their total phenolic and flavonoid content. Additionally, HPLC-fingerprinting of the extract was performed. The results revealed that HE had a higher yield with the remarkable property of superior in vitro biological activity compared with ET. HE showed radical scavenging activity on DPPH and hydrogen peroxide with IC50 of 30.03 ± 7.64 and 71.40 ± 15.30 μg/ml, respectively. Moreover, it showed inhibition of lipid peroxidation with IC50 of 537.01 ± 42.32 μg/ml. For inhibition against hyaluronidase and collagenase, HE was detected with IC50 of 234.80 ± 21.52 and 314.44 ± 62.14 μg/ml, respectively. The extract also demonstrated MMP-2 and MMP-9 inhibition, which is more potent than gallic acid as determined by zymography at 1.0 mg/ml. In conclusion, hydroethanolic extract (HE) of longan leaves presented high potential as in vitro antioxidant and inhibitor of enzymatic activities. It might be a promising approach to the further development of anti-aging products.

Keywords

Longan leaves, Antioxidant activity, Anti-hyaluronidase activity, Anti-collagenase activity, Inhibition of MMP-2 and MMP-9 assay

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