HMG-COA REDUCTASE INHIBITORY ACTIVITY OF EXTRACT AND CATECHIN ISOLATE FROM UNCARIA GAMBIR AS A TREATMENT FOR HYPERCHOLESTEROLEMIA

The article describes a new idea of plant-based hypercholesterolemia treatment. Statins are commonly used for hypercholesterolemia treatment. Due to the side effects of statins, natural HMG-CoA reductase inhibitors plant-based are needed. Based on the affordability and less toxicity, the plant has increasing acceptability for treating ailments. The 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase is the key enzyme of the mevalonate pathway producing cholesterol. Inhibition of HMG-CoA reductase reduces cholesterol biosynthesis in a liver. As an Indonesian plant containing catechin, Uncaria gambir can reduce cholesterol in the blood through HMG-CoA reductase inhibitory activity. This study aims to investigate the potential antihypercholesterolemic of the extract and catechin isolate of Uncaria gambir. Gambier leaves were extracted in water. The catechin from gambier extract was isolated with ethyl acetate-hexane using column chromatography. Phytochemical analysis of extract and catechin isolate were conducted by high-performance liquid chromatography (HPLC). Antioxidant activity was tested using a 2.2-diphenyl-1-picrylhydrazyl (DPPH) assay with vitamin C as a positive control. The inhibitory activity of HMG-CoA enzymes was carried out enzymatically using an HMG-CoA reductase assay kit by spectrophotometric and simvastatin as a standard. The results showed that the catechin in the extract was 68.32% while in isolate - 96.74%. The extract's scavenging activity (IC50) was 6.2 μg/mL, catechin isolate was 2.4 μg/mL, and vitamin C was 4.1 μg/mL. The in-vitro assessment of HMG-CoA reductase activity indicated 73.12%; 97.46%; 85.74% inhibition by the extract, catechin isolate, and simvastatin, respectively. Catechin isolate from Uncaria gambir showed strong HMG-CoA reductase inhibitory activity offers a high potential for hypercholesterolemia treatment.