Paul Jazon I Sarne
1. University of the Philippines Manila, Philippines 2. United Laboratories Inc., Philippines
Title: Anti-MRSA extracts and alkaloidal fractions from Nephelium lappaceum L.
Biography
Biography: Paul Jazon I Sarne
Abstract
Alkaloidal extracts from Nephelium lappaceum L. (Rambutan) were investigated for selective anti-Staphylococcal and anti-MRSA activities. Ethanolic extracts of the pericarp, seeds and leaves were extracted for alkaloids (through a modified Stas-Otto Method I) and had undergone bioassay-guided fractionation via C18 SPE. Resazurin assays were done to determine MIC on clinically isolated Staphylococcus aureus and an MRSA variant. It was also used to determine safety on MDCK cell line (a non-cancerous mammalian cell line). Selectivity Index (SI), a ratio of the MDCK IC50 to MIC, was used as the measure of safety. The Ethanolic Pericarp Extract (EPE) was potently inhibitory to both S. aureus and MRSA, but was not selective (Sa & MRSA MIC=500 µg/mL, SI= 0.86). The alkaloid extract had similar MIC against MRSA but was more selective (Palk-B, SI> 2.00), while the third fraction of the alkaloidal extract had greatly improved antibacterial effect and selectivity (PB-f3, Sa & MRSA MIC=125 µg/mL, SI= 5.22). Results suggest the presence of a potent and selective anti-staphylococcal agent in PB-f3, which is also effective against MRSA.
