INHIBITORY EFFECT OF SOLVENT EXTRACTS AND THEIR FRACTIONS OF MEMECYLON SPECIES ON RNASE AND PROTEASE ACTIVITYAbstract
Genus Memecylon belonging to the family Melastomataceae is a large shrub or a small tree native to Western Ghats of India. Memecylon species are reported to show various biological activities and are also used as medication in herpes virus infection. RNases and proteases are involved in the replication of herpes simplex virus (HSV). The present study was taken up to screen RNase and protease (trypsin and thrombin) inhibitors in different solvent extracts of Memecylon species viz., M. umbellatum, M. malabaricum, M. wightii, M. edule and M. talbotianium. The methanol extract of the leaves of Memecylon species was observed to strongly inhibit RNase, trypsin, and thrombin functions in a dose-dependent manner. The percent inhibition of RNase activity ranged from 53-84% in 50 ug/mL of plant extracts. The highest inhibition was observed in M. malabaricum and M. wightii for RNase. Similarly, for trypsin the percent inhibition ranged from 55-68% in 1 mg/mL of plant extracts. Highest inhibition was observed in M. malabaricum, M. wightii, and M. talbotianium. For thrombin the percent inhibition was between 44-52% in 1 mg/mL of plant extracts. The extracts from M. umbellatum, M. edule showed moderate inhibition. M. malbaricum extracts that had shown promising results were further fractionated using silica gel column chromatography, where 20:80 ethyl acetate: methanol fraction showed good protease as well as ribonuclease inhibitory properties. This study provides an important clue for scaling up further work on managing the herpes virus infection using Memecylon extracts, and this is the first report on RNase and protease inhibition in Memecylon species.
T. R. Bharathi * and H. S. Prakash
Department of Studies in Biotechnology, University of Mysore, Manasagangotri, Mysore, Karnataka, India.
21 July 2020
27 September 2020
22 November 2020
31 December 2020