ABSTRACT
Physalis peruviana Linn in Indonesia was better known as ciplukan, based on information from urban people in Indonesia is as antidiabetic. In the previeous studies, the levels of blood glucose in animals experimental of Physalis peruviana quantified with glucometer and compared with oral antidiabetic drugs gliclazide, showed that Gliclazide was decrease more levels of glucose significantly than ethanol extract of Physalis peruviana. We have done molecular docking using Molegro Virtual Docker (MVD) on ethanol extract of Physalis peruviana and gliclazide to compare between in silico and in vivo studies. Based on studies before the main content of the ethanol extract of Physalis peruviana were withanolide, 4-OH-withanolide, and perulactone. In this study the results showed that gliclazide had been better bond in insulin tyrosine kinase receptor than main content of Physalis peruviana which can be seen from Moldock score 105.217 and Rerank score -68,2931 means that the energy was lower and more stable binding. Moldock Score of main content Physalis peruviana (withanolide, 4-OH-withanolide, and perulactone) were -93.5472; 70.5843; 88.7881, respectively. Rerank score of main content Physalis peruviana (withanolide, 4-OH-withanolide, and perulactone) were -61.5149; -67.5345; -65.7979, respectively. The hydrogen bonds of withanolide, 4-OH-withanolide, perulactone and gliclazide with amino acid of insulin tyrosine kinase receptor were Phe 1186 and Thr 1186. Finally, in the 3D MVD visualization between main content of ethanol extract of Physalis peruviana and gliclazide can be concluded that interaction of gliclazide was more harmonious than main content of ethanol extract Physalis peruviana.
ABSTRACT
Tyrosinase is one of the most important enzymes in melanin biosynthesis. Inhibition of tyrosinase activity will cause a decrease in melanin production. Tyrosinase inhibitory activity by ascorbic acid has been studied before. Based on reported experiments, ascorbic acid can inhibit tyrosinase activity in enzymatic reaction competitively. As an effort to find out a skin whitening agent which is effective, safe and have minimum adverse effect, the inhibitory activities of Psidium guajava extract was studied on tyrosinase activity. This is one of the fruits that contains high amount of ascorbic acid. To determine the efficacy of tyrosinase inhibition, L-tyrosine was used as the substrate, P. guajava ex-tract as inhibitor and ascorbic acid as positive control that was measured by spectrophotometry. The optimization of method was also performed. The inhibitory kinetics was determined by measuring the absorbance of dopachrome as the end product of the tyrosinase reaction. Michaelis-Menten constant (Km) and maximum velocity (Vmax) of the ty-rosinase were determined by Lineweaver-Burk’s plots. The Km and Vmax without the fruit extract were 0.315mM and 0.0265μmol/min. The Km value with the fruit extract of 1%, 2% & 3% w/v were 0.4824, 0.698 & 0.543mM, while the Vmax value were 0.0269, 0.0283 & 0.0255 μmol/min, respectively. Lineweaver-Burk’s plots in presence of P. guajava fruit extract showed that the extract inhibited tyrosinase competitively. From the plots, the IC50 of the fruit extract was determined as 0.26mM; the control in 0.26mM concentration inhibited 56.523%. Finally, P. guajava fruit extract showed higher effect than ascorbic acid on Tyrosinase activity.
ABSTRACT
Tyrosinase is one of the most important enzymes in melanin biosynthesis. Inhibition of tyrosinase activity will cause a decrease in melanin production. Tyrosinase inhibitory activity by ascorbic acid has been studied before. Based on reported experiments, ascorbic acid can inhibit tyrosinase activity in enzymatic reaction competitively. As an effort to find out a skin whitening agent which is effective, safe and have minimum adverse effect, the inhibitory activities of Psidium guajava extract was studied on tyrosinase activity. This is one of the fruits that contains high amount of ascorbic acid. To determine the efficacy of tyrosinase inhibition, L-tyrosine was used as the substrate, P. guajava ex-tract as inhibitor and ascorbic acid as positive control that was measured by spectrophotometry. The optimization of method was also performed. The inhibitory kinetics was determined by measuring the absorbance of dopachrome as the end product of the tyrosinase reaction. Michaelis-Menten constant (Km) and maximum velocity (Vmax) of the ty-rosinase were determined by Lineweaver-Burk’s plots. The Km and Vmax without the fruit extract were 0.315mM and 0.0265μmol/min. The Km value with the fruit extract of 1%, 2% & 3% w/v were 0.4824, 0.698 & 0.543mM, while the Vmax value were 0.0269, 0.0283 & 0.0255 μmol/min, respectively. Lineweaver-Burk’s plots in presence of P. guajava fruit extract showed that the extract inhibited tyrosinase competitively. From the plots, the IC50 of the fruit extract was determined as 0.26mM; the control in 0.26mM concentration inhibited 56.523%. Finally, P. guajava fruit extract showed higher effect than ascorbic acid on Tyrosinase activity.