In vitro anti-ageing activities of ethanolic extracts from Pink rambutan (Nephelium lappaceum Linn.) for skin applications

Skin ageing is characterized by features such as wrinkles, loss of elasticity, laxity, rough-textured appearance, melasma and freckles. Several researches have focused for preventing, and treating skin ageing by many natural ingredients. This study aimed to assess the anti-ageing activities for anti-skin ageing of the ethanolic extracts of Pink rambutan (PR) (Nephelium lappaceum Linn.) from leaves (L), branches (B), seeds (S), and peels from ripe (R) and young (Y) fruits. The extraction yields of all Pink Rambutan (PR) extracted by the Maceration (M) and the Soxhlet extraction (Sox) using 95% ethanol as a solvent, ranged from 10.62% to 30.63%. Flavonoids were found as the main phytochemicals in almost all the PR extracts. The PR-Y-M and PR-Y-Sox extracts gave the highest total phenolic contents by the Folin-Ciocalteu assay of 67.60 ± 4.38 mgGAE/g, and total flavonoid contents by the modified aluminum chloride colorimetric assay of 678.72 ± 23.59 mgQE/g, respectively. The PR-L-M extracts showed the highest three anti-oxidative activities; the free radical scavenging (SC50 of 0.320 ± 0.070 mg/mL), the lipid peroxidation inhibition (LC50 of 0.274 ± 0.029 mg/mL), and the metal chelation activity (MC50 of 0.203 ± 0.021 mg/mL). All the PR extracts at 0.01 and 0.1 mg/mL showed no cytotoxicity on B16F10 cells, and human skin fibroblasts, respectively. Likewise, the PR-R-Sox extract exhibited the highest anti-melanogenesis on B16F10 cells (52.7 ± 0.9%) and, the mushroom tyrosinase inhibition activity (IC50 of 0.04 ± 0.02 mg/mL), which was significantly comparable to kojic acid (p