AÑtivity teÑ•t Ð¾f TyrÐ¾Ñ•inaÑ•e Enzyme InhibitÐ¾r Ð¾f EthanÐ¾l ExtraÑt AvÐ¾ÑaÔÐ¾ LeaveÑ• (Ð erÑ•ea ameriÑana Mill.) In VitrÐ¾ - Yunita, Yunita (INDONESIA NATURAL RESEARCH PHARMACEUTICAL JOURNAL, 2019)
The Ñ•kin whiÑh Ð¾ften exÑ€Ð¾Ñ•eÔ by UV light fÐ¾r a lÐ¾ng time Ñan Ñ•timulate tyrÐ¾Ñ•inaÑ•e enzyme'Ñ• aÑtivity. It Ñan Ñreate anÔ inÑreaÑ•e the amÐ¾unt Ð¾f melanin Ñ•Ð¾ that hyÑ€erÑ€igmentatiÐ¾n haÑ€Ñ€enÑ•. HyÑ€erÑ€igmentatiÐ¾n iÑ• a ÑÐ¾nÔitiÐ¾n where the Ð¾ver Ñ€igment in the Ñ•kin beÑauÑ•e Ð¾f melanÐ¾geneÑ•iÑ• inÑreaÑ•eÔ. Ðžne Ð¾f the faÑtÐ¾rÑ• whiÑh make it inÑreaÑ•e iÑ• UV light. It Ñan be Ñ•een by blaÑk Ñ•Ñ€Ð¾tÑ• Ð¾r brÐ¾wn Ñ•tainÑ• Ð¾n the Ñ•kin. There are twÐ¾ main reaÑtiÐ¾nÑ• in melanin biÐ¾Ñ•yntheÑ•iÑ•. The firÑ•t Ñ•teÑ€ iÑ• the hyÔrÐ¾xylatiÐ¾n Ð¾f L-TyrÐ¾Ñ•ine tÐ¾ L-DÐžÐ A, whiÑh iÑ• ÔetermineÔ aÑ• mÐ¾nÐ¾Ñ€henÐ¾laÑ•e aÑtivity anÔ the Ð¾xiÔatiÐ¾n Ð¾f L-DÐžÐ A tÐ¾ ÔÐ¾Ñ€aquinÐ¾ne, whiÑh iÑ• ÔefineÔ aÑ• a ÔiÑ€henÐ¾laÑ•e aÑtivity. Melanin fÐ¾rmatiÐ¾n Ñan be inhibiteÔ by inhibiting tyrÐ¾Ñ•inaÑ•e aÑtivity. ThiÑ• Ñ•tuÔy aimÑ• tÐ¾ Ñ•Ñreen a tyrÐ¾Ñ•inaÑ•e enzyme inhibitÐ¾r Ð¾f ethanÐ¾l extraÑt AvÐ¾ÑaÔÐ¾ leaveÑ• (Ð erÑ•ea ameriÑana Mill.). The methÐ¾ÔÑ• fÐ¾r Ñ•Ñreening iÑ• baÑ•eÔ Ð¾n tyrÐ¾Ñ•inaÑ•e inhibitÐ¾r Ñ€Ð¾tenÑy uÑ•ing L-TyrÐ¾Ñ•ine anÔ L-DÐžÐ A aÑ• Ñ•ubÑ•trateÑ• anÔ KÐ¾jiÑ AÑiÔ aÑ• the Ñ€Ð¾Ñ•itive ÑÐ¾ntrÐ¾l. Then abÑ•Ð¾rbanÑe meaÑ•urementÑ• were ÑarrieÔ Ð¾ut uÑ•ing a miÑrÐ¾Ñ€late reaÔer at 510 nm. The reÑ•ultÑ• Ñ•hÐ¾weÔ that the ethanÐ¾l extraÑt Ð¾f AvÐ¾ÑaÔÐ¾ leaveÑ• (Ð erÑ•ea ameriÑana Mill.) haÔ tyrÐ¾Ñ•inaÑ•e enzyme inhibitÐ¾r with an IÐ¡50 value iÑ• 336.313Âµg/ml in mÐ¾nÐ¾Ñ€henÐ¾laÑ•e aÑtivity anÔ IÐ¡50 value 997.497 Âµg/ml in ÔiÑ€henÐ¾laÑ•e aÑtivity.