Effect of certain bioactive plant extracts on clinical isolates of β‐lactamase producing methicillin resistant Staphylococcus aureus

Abstract

Ethanolic extracts and some fractions from 10 Indian medicinal plants, known for antibacterial activity, were investigated for their ability to inhibit clinical isolates of beta-lactamase producing methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive S. aureus (MSSA). Synergistic interaction of plant extracts with certain antibiotics was also evaluated. The MRSA test strains were found to be multi-drug resistant and also exhibited high level of resistance to common beta-lactam antibiotics. These strains produced beta-lactamases, which hydrolyze one or other beta-lactam antibiotics, tested. The extract of the plants from Camellia sinensis (leaves), Delonix regia (flowers), Holarrhena antidysenterica (bark), Lawsonia inermis (leaves), Punica granatum (rind), Terminalia chebula (fruits) and Terminalia belerica (fruits) showed a broad-spectrum of antibacterial activity with an inhibition zone size of 11 mm to 27 mm, against all the test bacteria. The extracts from the leaves of Ocimum sanctum showed better activity against the three MRSA strains. On the other hand, extracts from Allium sativum (bulb) and Citrus sinensis (rind) exhibited little or no activity, against MRSA strains. The antibacterial potency of crude extracts was determined in terms of minimum inhibitory concentration (MIC) by the tube dilution method. MIC values, of the plant extracts, ranged from 1.3 to 8.2 mg/ml, against the test bacteria. Further, the extracts from Punica granatum and Delonix regia were fractionated in benzene, acetone and methanol. Antibacterial activity was observed in acetone as well as in the methanol fractions. In vitro synergistic interaction of crude extracts from Camellia sinensis, Lawsonia inermis, Punica granatum, Terminalia chebula and Terminalia belerica was detected with tetracycline. Moreover, the extract from Camellia sinensis also showed synergism with ampicillin.TLC of the above extracts revealed the presence of major phytocompounds, like alkaloids, glycosides, flavonoids, phenols and saponins. TLC-bioautography indicated phenols and flavonoids as major active compounds.

Effect of ethanolic extract of Ecballium elaterium against Staphylococcus aureus and Candida albicans

“…In order to assess the effect of combinations of ethanolic extract and antibiotic, the MIC values for antibiotic were determined to be as a reference point for defining the interactions [26] . Synergistic effects resulting from the combination of antibiotics with various plant extracts have been studied earlier against MRSA or MSSA [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41] . From this study, ethanolic extract of E. elaterium fruits is very efficient in treating infectious diseases caused by MRSA and may also helpful for treating diseases caused by C. albicans.…”

“…Exposure to light was avoided to prevent the loss of effective ingredients. Approximately [30][31][32][33][34][35][36][37][38][39][40] g of dried material were mixed thoroughly with magnetic stirrer in 200 mL of 80% ethanol at room temperature and the mixture left for 24 h. The insoluble materials were removed by centrifugation at 10 000 rpm for 10 min at 4 曟. Then, the extract was evaporated to dryness at 37 曟.…”

Synergism between plant extract and antimicrobial drugs used on Staphylococcus aureus diseases

“…Research on synergism is very limited and few studies have been reported (Nascimento et al 2000, Aburjai et al 2001, Aqil et al 2005. Thus, in our research, we evaluated in vitro synergism between extracts of M. glomerata, P.…”

Antimicrobial activity of Citrox® bioflavonoid preparations against oral microorganisms

“…23 Other bioactive plant extracts, containing flavonoids and phenols as major components, have proven effective against MRSA and a range of Gram-negative bacteria. 27,28 From the oral perspective, naringin, a flavonoid extract from grapefruit, has shown promise in the growth inhibition of A. actinomycetemcomitans and P. gingivalis in planktonic phase. 29 Polyphenols extracted from hop extracts and cranberry have shown activity against streptococcal species associated with dental caries [30][31][32] and a citrus extract combined with lemon juice and lemon grass has been used successfully to treat oral candidosis.…”