Total phenolic contents, quercetin determination and anti elastase activity of Melastoma malabathricum L. Leaves extract from different method of extractions

Objective: Leaves of M. malabathricum has been detected to contain quercetin and other phenolic contents. Quercetin has been proven to have elastase inhibitory activity. The aim of this study was to evaluate the effects of extraction method on total phenolic and quercetin contents as well as elastase inhibitory activity of M. malabathricum leaves extracts. Methods: Leaves powder was extracted by two conventional methods, maceration and reflux. Two different concentrations of ethanol were used as a solvent, 70 and 96% ethanol. Leaves were also defatted with chloroform before further extraction. The total phenolic content was determined by the Folin-Ciocalteu method and quercetin content was determined by using the high-performance liquid chromatography method. Elastase inhibitor activity of leaves extract was determined on human neutrophil elastase in vitro. Results: Generally, 96% ethanol obtained higher total phenolic and quercetin content than 70% ethanol. However, defatted extract of 70% ethanol contained higher total phenolic content than defatted 96% ethanol. The highest elastase inhibitory activity of the sample was obtained from 70% ethanol extract with the value of 89.50% at 200 ppm, which is no significant difference compared to quercetin with the value of 93.86%. Conclusion: Extraction methods and different concentration of solvents affect the total phenolic and quercetin contents of the extracts. M. malabathricum leaves have potential effect as anti-elastase as well as quercetin, where the anti-elastase activity of M. malabathricum leaves is not only due to quercetin.