3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitory activity of Indonesian Cajanus cajan leaves and Zingiber officinale extracts

Abstract

One indicator of antihypercholesterolemic candidates is their inhibitory activity on 3hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase enzyme. This study aimed to analyze the HMG-CoA reductase inhibitory activities of Cajanus cajan leaves, Zingiber officinale var Amarum and Zingiber officinale var Rubrum. C. cajan leaves and two types of Z. officinale were extracted using the maceration method with three solvents: distilled water, 70% ethanol and 96% ethanol. All nine types of resulted extracts were then analyzed for bioactive compounds and tested for the HMG-CoA reductase inhibitory activity using the HMG-CoA reductase analysis kit (BioVision’s K588-100). It was carried out in vitro using a colorimetric microplate reader with a wavelength of 340 nm at 37°C. The results showed that the extracts contained flavonoids, tannins, saponins and steroids. The nine extracts showed inhibitory activities on the HMG-CoA reductase enzyme. The three extracts showed the highest inhibitory activity; 70% ethanolic Z. officinale var Amarum extract (47.87%), aqueous Z. officinale var Rubrum extract (40.62%) and 70% ethanolic C. cajan leaves extract (39.38%). These results indicate that the three extracts have a medium inhibitory level of HMG-CoA reductase. The study suggested that the three types of extracts could be used as antihypercholesterolemic candidates such as antihypercholesterolemic functional food.