Tyrosinase, elastase, hyaluronidase, inhibitory and antioxidant activity of Sri Lankan medicinal plants for novel cosmeceuticals

The search for natural cosmeceuticals has gained an increasing demand due to its fewer side effects and become more prevalent in cosmetic formulations. Plant sources contain numerous natural compounds which can be used as whitening, anti-aging anti-wrinkle ingredients and also for the treatment of dermatological disorders. Ethanol extracts of 15 Sri Lankan medicinal plants were investigated for their tyrosinase, elastase and hyaluronidase enzyme inhibitory and antioxidant activities for the purpose of identifying anti-aging and skin-whitening ingredients with the potential for use as materials in cosmetics. Eleocarpus serratus bark extract showed highest elastase inhibitory activity (IC50 27.27 ± 2.74 μg/mL) while Curcuma aromatica rhizomes exhibited marked elastase (IC50 252.7 ± 6.8 μg/mL) and hyaluronidase inhibitory activities (95.0% inhibition at 500 μg/mL). Artocarpus altilis and Artocarpus nobilis bark extracts are good source of tyrosinase (IC50 27.47 ± 0.45 μg/mL, 53.23 ± 2.65 μg/mL), hyaluronidase (68.59%, 44.78% inhibition at 500 μg/mL), and elastase inhibitors (23.87%, 30.96% inhibition at 500 μg/mL). Eleocarpus serratus extracts exhibited highest antioxidant activities compared to other tested plants. Tyrosinase inhibitory activity positively correlates with the Total Flavonoid Content (r = 0.711) and DPPH free radical scavenging activities (r = 0.891). These results suggest that medicinal plants showing biological activities may be potent inhibitors of tyrosinase, elastase and hyaluronidase and could be useful for application in cosmetics. This is the first report of tyrosinase elastase, and hyaluronidase inhibitory activity of ethanol extracts of A. nobilis and E. serratus bark, leaves and fruit and M. ferrea leaves, petals and stamens.