Synergistic anti - Staphylococcus aureus activity of amoxicillin in combination with Emblica officinalis and Nymphae odorata extracts

Objective:To evaluate the antibacterial activity of Emblica officinalis Gaertn(E.officinalis: Family:Euphorbiaceae) seed and Nymphae odorala Aiton(N.odorala:Family:Nymphaeaceae) stamen extracts,alone and in combination,and in combination with amoxicillin(Ax) against Staphylococcus aureus(S.aureus).Methods:Antibacterial activity of ethanolic extracts of amla,E.officinalis,seed(AMS:500μg) and sapla,N.odorala,stamen(SAP:500 p g) for 12 methicillin-resistant S.aureus(MRSA) isolates was determined following agar diffusion:in order to assess the combined antibacterial activity,AMS(250μg) plus SAP(250μg) were considered.The Ax(10μg) activity alone and in combination with AMS(250μg),and SAP(250μg) was determined by disk diffusion.The zone diameters of inhibition(ZDIs) for the agents were recorded,and growth inhibitory indices(GIIs) were calculated.Results:The MRSA isolates (n=12) had AMS(500μg) and SAP(500μg) ZDIs of 12-19 mm and 21-24 mm,respectively.The ZDIs(range 24-27 mm) increased by 3-4 mm due to combined action of AMS(250μg) and SAP(250μg) indicating synergy between extracts for MRSA(GII 0.634-0.742).The MRSA isolates were resistant to Ax(ZDI:8-11 mm),which in combination with AMS and SAP had synergistic effect,both due to increased ZDI[mean±SD=(3.5±0.577) mm]and GII(0.631-0.894).Conclusions:The data suggest that the plants,E.officinalis and N.odorala alone or in combination,are promising in the development of phytomedicines,which may be used,alone or in combination with the antibiotic. Ax,against MRSA infection.