Bioactive components, antioxidant, and anti-inflammatory activities of the wood of Albizia myriophylla

Abstract The scientific basis corresponding with the folkloric use of Albizia myriophylla Benth., Fabaceae, for the treatment of inflammation-related diseases was established by measuring antioxidant potential using 2,2-diphenyl-1-picrylhydrazyl, 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) free radicals, and ferric reducing antioxidant power assays as well as anti-inflammatory effect using nitrite assay and ethyl phenylpropiolate (EPP)-induced rat ear edema model. Both ethanol extract (DPPH, IC50 46.23 µg/ml; ABTS, IC50 57.14 µg/ml; FRAP, 950.14 mM Fe (II)/g) and dichloromethane fraction (DPPH, IC50 29.54 µg/ml; ABTS, IC50 40.36 µg/ml; FRAP, 946.69 mM Fe (II)/g) from A. myriophylla demonstrated a promising antioxidant activity. Furthermore, it was found that the ethanol extract of A. myriophylla showed significant inhibitory activity against lipopolysaccharide (LPS)-induced nitric oxide production in murine macrophage cells (IC50 13.8 µg/ml). The ethanol extract (15% w/v) also exhibited the maximum percentage inhibition (81-95%) of inflammation in the ear edema model at all assessment times comparable to indomethacin (0.5 mg/ear). Among all isolates 1-5 from the active extract of A. myriophylla, indenoic acid (1) (DPPH, IC50 8.96 µg/ml; ABTS, IC50 10.12 µg/ml) and 8-methoxy-7,3′,4′-trihydroxyflavone (2) (DPPH, IC50 5.05 µg/ml; ABTS, IC50 7.89 µg/ml) had potent free radical scavenging effects comparable to those of ascorbic acid (DPPH, IC50 2.12 µg/ml; ABTS, IC50 3.26 µg/ml). Compound 2 also displayed remarkable reducing power in FRAP test (261.81 mg QE/g) and showed a marked inhibition of the cellular nitric oxide production (IC50 27.7 µg/ml). Our results suggest that the anti-inflammatory mechanism of A. myriophylla is most probably based on its capacity to suppress nitric oxide production as well as to be free radical scavenger.

Effect of Different Decontamination Methods on Microbiological Aspects, Bioactive Constituents and Antibacterial Activity of Turmeric (Curcuma longa Linn.) Powder.

Turmeric (Curcuma longa Linn.) has long been widely used for food, food additives, and traditional medicine. This study was aimed to assess effects of different decontamination procedures of turmeric rhizomes on microbiological quality and bioactive constituents of aseptically prepared turmeric powder. In addition, antibacterial activity of the powder on skin and wound pathogens was performed. The tested rhizomes were decontaminated by different methods including soaking in 70% (v/v) ethanol for 15 min, boiling in water for 15 min, boiling in 5% (v/v) acetic acid for 15 min, steaming at 100ºC for 15 min and autoclaving at 121ºC and 15 psi for 15 min. There were no foreign materials detected among the tested samples. The moisture content of each analyzed powder was similar (6.1±0.4%; v/w). The microbial contamination of the turmeric samples prepared from the ethanol soaked rhizome, water boiled rhizome, acetic acid boiled rhizome, and autoclaved rhizome were of satisfactory quality as required by the Thai Herbal Pharmacopoeia (THP) standard. Even though, the decontamination processes altered the contents of ethanoland water-soluble extractives, curcuminoids, and volatile oils of the turmeric products but all of them conform to the THP standard. Among these techniques, the autoclave method was found to be sufficient for complete microbial decontamination without significantly affecting on the active constitutes of the turmeric powder.

Antibodies among healthy population of developing countries against enterohaemorrhagic Escherichia coli O157:H7.

In Thailand, no reports are available on Escherichia coli serotype O157:H7, a causative agent of severe bloody diarrhoea, sometimes associated with haemolytic-uraemic syndrome and thrombotic thrombocytopenic purpura. The reason for the non-identification of infection due to E. coli O157 in this country and in other developing countries has not been rigorously discussed. The aim of this study was to determine the humoral response against the infectious organism. The IgM and IgG antibody responses against E. coli O157 lipopolysaccharide were studied using indirect enzyme-linked immunosorbent assay. Three hundred and thirty-two serum samples obtained from healthy blood donors and patients with diseases unrelated to diarrhoea were investigated. With a cut-off value of mean +2 SDs for each age-group, the frequency of the IgM and IgG responses to O157 lipopolysaccharide was 11.74% (39 of 332 samples) and 22.59% (75 of 332 samples) respectively. Furthermore, agglutination test of 173 subjects revealed titres ranging from 10 to 40 in all the samples. The results suggest possible exposure of the Thai population to cross-reacting antigens from other intestinal organisms in addition to infection due to E. coli O157:H7.