DAYA HAMBAT EKSTRAK DAUN DEWANDARU (Eugenia uniflora L.) TERHADAP AKTIVITAS GST KELAS PI GINJAL TIKUS SECARA IN VITRO

Abstract

Extracts of dewandaru (Eugenia uniflora L.) have been reported to be inhibitor of general classes (α, µ, and π) of glutathione S-transferase (GST), but it had not been known yet the kind of GST (α, µ, or π) which was inhibited by the extracts. The objective of this research was to know the inhibitory potency of extracts of dewandaru on π (pi) class rat’s renal GST activity. The extracts were obtained by maceration method with chloroform, ethyl acetic, and ethanol as a solvent. To represent the pi class of GST activity, ethacrinic acid was used as a specific substrate on the conjugation reaction with glutation (GSH) was measured spectrometrically. Preparation of sitosol fraction which contains GST by centrifugation. Protein was determined according to the method of Lowry with bovine serum albumin (BSA) as the standard. In the determining IC50 (the concentration of extract which resulting in 50% of inhibitory potency on GST activity), the activity test of GST was added with extract of dewandaru in vary concentrations. IC50 was obtained from linier regression curve which stated the correlation between the log concentration of extract of dewandaru which was added and % inhibition resulted. The result shown that chloroform, ethyl acetic, and ethanolic extract of dewandaru inhibit the pi class of rat’s renal GST activity (EA substrate) with IC50 438,62; 257,35 and 112,86 µg/ml respectively.