Investigation of melanogenesis using neonatal normal human epidermal melanocyte treated with mawa young coconut water

• Main Author: Ansari, Sara
• Format: Thesis
• Language: English
• Published: 2015
• Online Access: http://psasir.upm.edu.my/id/eprint/67825/1/FPSK%28m%29%202015%2065%20IR.pdf; http://psasir.upm.edu.my/id/eprint/67825/
• Institution: Universiti Putra Malaysia

The actual color of skin is determined by the type, size and amount of melanin synthesized by melanocytes, and also deposition pattern of melanin in the surrounding keratinocytes. Melanin is synthesized through a series of oxidative reactions and by the enzyme called tyrosinase. Besides turosinase, other melanogenic enzymes including tyrosinase related protein-1 (TRP-1) and tyrosinase related protein-2 (TRP-2) also known as dopachrome tatumerase (DCT) are involved in melanin synthesis pathway. Overproduction and aggregation of melanin in the human skin, can cause dark-skinned and also aesthetics problems which encourage researches to develop cosmetic agents with high efficacy and less side effects. Hence, inhibition of tyrosinase activity or melanogenic pathways to have skin lightening are challenging subjects challenge for many researchers. Today, many famous whitening agents such as kojic acid and hydroquinone have been used commercially in whitening creams and other products such as lotion. Due to some adverse effects of theses whitening agents such as poor penetration and skin irritation, a natural tyrosinase inhibitor with less harmful side effects, and also low cost producer are always in demand. The objective of this study was to investigate the effect of young coconut water on melanogenesis using neonatal normal human epidermal melanocytes. In this study, cell viability assay was performed to investigate a safe concentration of young coconut water on neonatal normal human epidermal melanocyte. In addition, young coconut water evaluated for in vitro cellular tyrosinase activity and melanin content in neonatal normal human epidermal melanocyte. In the present study, the protein levels of tyrosinase and other tyrosinase enzymes including tyrosinase related protein-1 (TRP-1) and tyrosinase related protein- 2 (TRP-2) also called dopachrome tatumearse (DCT) which are involved in melanogenesis pathway were determined using western blot method. In this study, skin melanocytes were treated with different concentration of young coconut water and compared with untreated cells. The result from MTT assay showed that young coconut water exhibited no cytotoxicity on melanocytes at 10 mg/ml and half-maximal cytotoxicity concentration (CC50) was 13.12 mg/ml. This study indicated that young coconut water reduced the tyrosinase activity by inhibition of its activity with an IC50 (half-maximal inhibitory concentration) value of 10 mg/ml and also down regulated the protein level of tyrosinase. Results from western blot demonstrated that the protein level of tyrosinase related protein-2 significantly decreased at 8 and 10 mg/ml of young coconut water by 0.351 and 0.280 fold, respectively. There was no significant reduction in protein level of tyrosinase related protein-1 (TRP-1). Although, young coconut water at low concentrations did not significantly reduce tyrosinase activity. In conclusion, young coconut water at 8 and 10 mg/ml obviously reduced the protein level of tyrosinase and tyrosinase related protein-2 (TRP-2) with more that 80% viability. This result indicated that young coconut water might be considered as a potential whitening agent in cosmetics.