ABSTRAK
Penelitian terdahulu menunjukkan bahwa ekstrak metanol 80% daun Cassiafistula L. serta fraksi-fraksinya berpotensi sebagai antitirosinase sehingga dapatmenghambat pembentukan melanin. Penelitian ini bertujuan untuk memperolehsediaan krim yang mengandung fraksi nonpolar, yaitu fraksi n-heksana dariekstrak etanol 96% daun trengguli, yang mempunyai aktivitas antioksidan danantitirosinase, stabil dan aman. Metode untuk menguji aktivitas antioksidanadalah metode DPPH, sedangkan untuk pengujian aktivitas antitirosinasedilakukan dengan mengukur penurunan intensitas warna yang menunjukkanpenghambatan pembentukan dopakrom dalam reaksi tirosinase-L-DOPA.Parameter adanya aktivitas ditunjukkan oleh persentase inhibisi dan nilai IC50. Ujistabilitas fisik terhadap krim dilakukan selama 12 minggu dan uji keamanankepada sukarelawan menggunakan metode single application closed patchepicutaneous test under occlusion. Hasil uji aktivitas antioksidan menunjukkanekstrak etanol 96% daun trengguli dan fraksi n-heksana memiliki nilai IC50sebesar 70,196 μg/mL dan 141,459 μg/mL secara berurutan. Pengujian aktivitasantitirosinase menunjukkan nilai IC50 ekstrak etanol 96% daun trengguli 393,264μg/mL dan nilai IC50 fraksi n-heksana 188,239 μg/mL. Konsentrasi fraksi nheksanadalam krim dibuat menjadi 3 macam, yaitu 0,1; 0,5; dan 2,5%. Hasil ujistabilitas terhadap krim selama 12 minggu menunjukkan ketiga konsentrasi krimbersifat stabil. Uji keamanan ketiga konsentrasi krim terhadap sukarelawan tidakmenimbulkan reaksi iritasi sehingga aman diaplikasikan ke kulit.

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ABSTRACT
Previous study reported that methanol 80% extract of Cassia fistula L. leaves andits fractions have potency as antityrosinase which can inhibit melanin production.This research was conducted to obtain nonpolar fraction (n-hexane fraction)-containing cream from ethanol 96% extract of Cassia fistula L. leaves, which wasconsidered potent as antioxidant and antityrosinase, stable, and safe. DPPHmethod was used to determine antioxidant activity, while antityrosinase activityassay performed by measuring the decreasing in color intensity which inhibitdopachrome formation resulted in tyrosinase-L-DOPA reaction. Parameter foridentifying activity were determined by inhibitory percentage and IC50. Physicalstability test was done for 12 weeks and safety test in human used singleapplication closed patch epicutaneous test under occlusion method. The result ofantioxidant activity test showed that ethanol 96% extract of Cassia fistula L.leaves and n-hexane fraction had IC50 values 70,196 μg/mL and 141,459 μg/mL,respectively. Antityrosinase test showed that IC50 value of ethanol 96% extract ofCassia fistula L. leaves was 393,264 μg/mL, while IC50 values of n-hexanefraction was 188,239 μg/mL. Fraction of n-hexane was formulated into cream for3 concentrations, which are 0,1; 0,5; and 2,5%. The stability test of the creams for12 weeks indicated that creams were stable. The result of safety test of creamsshowed that creams have no irritation effect so it was safe for topical applicationin human skin.