Inhibitory Effects of Active Compounds from Punica granatum Pericarp on Verocytotoxin Production by Enterohemorrhagic Escherichia coli O157 : H7

Abstract

Punica granatum (P. granatum) Linn. pericarp has been commonly employed as a crude drug in Thai traditional medicines for the treatment of diarrhea. The antibacterial activity of extracts from P. granatum pericarp against different strains of enterohemorrhagic Escherichia coli (E. coli) O157 : H7 and other strains of enterohemorrhagic E. coli were investigated. Successive chloroform, 95% ethanol, and water extracts of the plant were examined. The ethanolic extract was found to be the most effective against all the strains examined. Both the ethyl acetate and n-butanol fractions of P. granatum pericarp were demonstrated to have high activity with the highest minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values of 0.05 and 0.05 and 0.39 and 0.19 mg/ml, respectively. The inhibitory effects of both fractions on the production of verocytotoxin (VT)1 and VT2 by enterohemorrhagic E. coli O157 : H7 was observed at very low concentrations of 1/10 of the MIC value (0.05-0.09 mg/ml, respectively). Phytochemical screening of the ethanolic extracts demonstrated that they contain flavonoids, sterols, triterpenes, phenols, and tannins. Our findings suggest that an appropriate bioactive compound may be developed from P. granatum pericarp as alternative treatment for this E. coli O157 : H7 infection. The crude plant may also be administered to prevent VT production in the human intestine to solve the problem of subinhibitory effects from the use of antibiotics.

Antibacterial activity of aqueous extract of pomegranate peel against Pseudomonas stutzeri isolated from poultry meat

“…Hydrophilic extracts are reported to be better solvents for polyphenols and hydrophilic phytochemcials found in pomegranate peel (Negi and Jayaprakasha 2003;Alzoreky and Nakahara 2003). In pomegranate peels, tannins and other phenolics are the major bioactive compounds having antioxidant and antimicrobial activity (Voravuthikunchai et al 2005;Reddy et al 2007). These antimicrobial constituents like phenols and flavanoids might be responsible for inhibitory action of PPE against bacteria.…”

Antibacterial activity of vegetal extracts against serovars of Salmonella

“…Substances such as flavonoids, sesquiterpenes, tannins, antocianic pigments, and saponins were identified in its composition (LORENZI & MATOS, 2002). Tannins and saponins presented antimicrobial properties (LOGUERCIO et al, 2005;RAVEN et al, 2007;SANTOS & MELLO, 2003;VORAVUTHIKUNCHAI, 2005). Achyrocline satureioides presents bacteriostatic activity against 61.1% of the serovars (Table 2).…”

Effect of Gamma Irradiation on Total Phenolic Content and <i>in Vitro</i> Antioxidant Activity of Pomegranate (<i>Punica granatum</i> L.) Peels

“…The fruit can be divided into three parts: the seeds (3% w/w), the juice (30% w/w) and peels including the interior network of membranes (67% w/w) [2]. P. granatum is rich in tannins that have remarkable antimicrobial activity [3,4]. Interestingly, the peel fraction of pomegranate has higher total phenol-lic content and antioxidant activity than the pulp fraction.…”