Anti-inflammatory and Antioxidant Activities of the Extracts from Leaves and Stems of Polygonum odoratum Lour.

BACKGROUND: Polygonum odoratum is an indigenous vegetable that has been used as a favoring agent and also used as a Thai traditional medicine to treat flatulence. OBJECTIVE: To analyze active ingredients, total phenolic and total flavonoid contents, antiinflammatory and antioxidant activities from leaf and stem extracts of P. odoratum. METHODS: Leaves and stems were dried and extracted by using methanol, dichloromethane and water for obtaining Methanolic Leaf Extract (MLE), Methanolic Stem Extract (MTE), Dichloromethane Leaf Extract (DLE), Dichloromethane Stem Extract (DTE), Water Leaf Extract (WLE) and Water Stem Extract (WTE). The extracts were quantified for total phenolic and total flavonoid contents by spectrophotometry and active compounds were analyzed by using GC-MS. Antioxidant activity was determined by ABTS and DPPH radicals scavenging assays. Anti-inflammatory activity was tested by the inhibition of nitric oxide production in RAW 264.7 macrophage cells induced by lipopolysaccharide. RESULTS: The DLE exhibited the most potent anti-inflammatory effect by inhibiting nitric oxide production in a concentration-dependent manner (IC50 = 53.75±0.72 µg/mL). MLE exhibited strong antioxidant activity and contained the highest concentration of phenolic compounds (52.59±0.58 mg gallic acid equivalent/g extract) and flavonoid (19.97+0.11 mg quercetin equivalent/g extract). E-15-Heptadecenal and 3, 7, 11, 15-tetramethyl-2- hexadecen-1-ol were found predominantly in the methanol extracts. CONCLUSION: The leaf extract of P. odoratum showed potent anti-inflammatory and antioxidant activities, mediated by DLE and MLE, respectively.

Antimicrobial resistance of Enterococcus spp. isolated from Thai fermented pork in Chiang Rai Province, Thailand.

OBJECTIVES: The aim of this study was to evaluate the prevalence of antimicrobial-resistant phenotypes and genes of Enterococcus spp. in order to explore the range of resistance profiles from Thai traditional fermented pork. METHODS: A total of 120 Thai fermented pork specimens were collected in Chiang Rai, Thailand. Antimicrobial resistance among isolated enterococci to 11 antimicrobial agents was determined by the agar disk diffusion method. Antibiotic resistance genes from resistant phenotypes and virulence genes were observed. RESULTS: A total of 119 enterococci were found contaminating the collected samples. The most prevalent species was Enterococcus faecalis (68.9%), followed by Enterococcus hirae (16.0%), Enterococcus faecium (13.4%) and Enterococcus gallinarum (1.7%). The highest percentage of resistance was to ciprofloxacin (97.5%), followed by erythromycin (78.2%) and tetracycline (67.2%), whilst high-level gentamicin- and streptomycin-resistant isolates were of lower frequency (7.6% and 22.7%, respectively). All isolates were susceptible to the clinically important agents vancomycin and teicoplanin. Overall, a relatively high frequency of multidrug-resistant (MDR) enterococci was observed (76.2%). Antimicrobial-resistant phenotypes were found to carry aacA-aphD, addE, erm(B), mefA/E, cat, tet(L) and tet(M) resistance genes. Virulence genes were also evaluated and the gelE gene was found to be the most common (37.8%). CONCLUSIONS: These data highlight the importance of MDR enterococci in fermented pork in Thailand. This is the first report to detect the unusual species E. hirae carrying the mefA/E macrolide resistance gene. These clinically important and unusual enterococci isolates from Thai fermented pork could be a source of transferable resistance genes to other bacteria.