INHIBITION OF TYROSINASE ACTIVITY BY VARIATION OF CARBOMER 934
CONCENTRATION AS GELLING AGENT IN GREEN TEA (CAMELLIA SINENSIS (L.) KUNTZE) LEAF EXTRACT GEL
“RESULT AND DISCUSSION
Organoleptic Test
The obtained extract of green tea leaves had organoleptic characteristics that were viscous, blackish brown, aromatic smell of tea, bitter taste on the tongue; referring to the relevant literature, the characteristics are thick extract, blackish brown, and bitter taste on the tongue (Ministry of Health of the Republic of Indonesia, 2011). The yield of the extract was 53,7626%, this was in line with the requirement of tea leaf extract yield that was not less than 7,8% (ibid).
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NTRODUCTIONThe formulation of melanin (Melanogenesis) is commenced by the stage of tyrosine oxidation into dopaquinone which is catalyzed by tyrosinase enzyme. This stage is very important, at a certain pH level, the process runs spontaneously converting do- paquinone into dopa and dopachrome which will further form melanin (Chang 2009).
Therefore, the process of melanogenesis can be inhibited.
One of the natural ingredients that have the efficacy of tyrosinase inhibitors is green tea
leaves (Camellia sinensis L.). The methanol extract of 50% tea leaf has an inhibition activity of tyrosinase enzyme with an IC50 value of 51,95μg/ ml (Sangsrichan and Ting, 2010). The main components of polyphenol from catechins derivatives can maximally inhibit the activity of tyrosinase that plays a role in the creation of skin pigmentation (Suhandi and Jafar, 2014).
Carbomer or acrylic acid polymer is a gelling agent in a polymeric form which is derived from a synthetic material (Rowe, et al. 2009).
Carbomer 934 has good properties in the release of active substances compared with other gelling agents (Madan and Singh 2010).
Carbomer 934 can be used as a single-form gelling agent at a concentration of 0.5-2% (Rowe, et al. 2009). The optimization of car- bomer 934 concentration as a gelling agent in every gel preparation is pivotal to be done for the sake of identifying the optimum val- ue of carbomer 934, which further generates a good gel physical stability parameters.
Hanifah Rahmi1, Tiara Julianti1, Naniek Setiadi Radjab1
1Department of Pharmacy and Science, Universitas Muhammadiyah Prof. DR. HAMKA, Delima II Street, Malaka Sari, Klender, Jakarta, Indonesia
Correspondence : hanifah_rahmi@uhamka.ac.id PP 32
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BJECTIVE This study aimed to determine activity of tyrosinase enzyme with different consentration of carbomer 934 in green tea leaf extract gel.METHODS
Extraction of the Green Tea Leaves
Screening of the Tanin Chemical Component
Formulation Development
Evaluation of the Gel’s Physical Stability
Inhibition Activity Test of Tyrosinase
Data analysis (% Inhibition)
100%
Tyrosinase Inhibition Test
The obtained value of IC50 from formula 1 was 49.62 ppm. The IC50 values indicated that the green tea leaf extract gel played a role as a tyrosi- nase inhibitor. These results indicated that it had a greater effectiveness in inhibiting tyrosinase en- zyme compared to the positive control of the ex- tract. This occurs because the gel base could in- hibit the works of tyrosinase enzyme even though the percentage was low (See Figure 1).
Figure 1. Tyrosinase inhibition value from variation extract concentration.
CONCLUSION
Based on the gel physical stability test, formula 1 with Carbomer 934 concentration of 0.5% was the optimum formu- la as a gelling agent for green tea leaf gel, compared to formula 2 (concentration 0.75%) and formula 3 (1%). Inhibition of the tyrosinase enzyme activity in formula 1 had an IC50 value of 49.62 ppm.
pH Testing (For 6 weeks)
Statistical analysis shows that the pH was not influenced by the concentration of the gelling agent. Whereas, the pH value could be affected by the timing aspect in each week .
Centrifugation Test
The result of the centrifugation testing shows that the whole formula did not experience phase separation, this indi- cates the whole formula was stable
Freeze Thaw Test
The results of this test show that the formula 1 was the most stable formula for temperature and it had a longer shelf life than any other formula. Formula 1 was selected to proceed the tyrosinase inhibition test based on the overall evaluation of its physical stability.
Viscosity and Fluid Properties Test
The higher carbomer 934 concentration, the greater the viscosity. In addition to the viscosity testing, the type of fluid properties was also examined. The formula 1 and 2 were discovered to had a plastic type of flow properties and a quite stable thixotropy, starting from week 0 to week 6. Whereas, the formula 3 had a viscoelastic type of flow properties.
ACKNOWLEDGEMENT
We are grateful to PT. Martina Berto, Tbk. for levodopa and tirosinase mushroom. This research was supported by Universitas Muhammadiyah Prof. DR. HAMKA.
