Thai red rice extract provides liver protection in paracetamol-treated mice by restoring the glutathione system.

CONTEXT: The incidence of drug-induced liver disease associated with oxidant-antioxidant imbalance is increasing. Colored rice can potentially improve these hepatic disorders through antioxidative and glutathione-restoring effects. OBJECTIVES: The objective of this study is to determine the in vitro antioxidant properties of extracts from red (Hom-Dang and Hom-Kularb-Dang) and black (Hom-Dum-Sukhothai and Kum-Doi-Saket) Thai rice cultivars [Oryza sativa L. (Poaceae)] and to examine the in vivo hepatoprotective potential of Hom-Dang extract in paracetamol-treated mice. MATERIALS AND METHODS: The in vitro antioxidant properties of the extracts were determined by ABTS, [Formula: see text], [Formula: see text], metal chelating capacity, and lipid peroxidation assays. To investigate hepatoprotective effects in vivo, mice administered 60 mg/kg/d paracetamol were given Hom-Dang extract (128, 256, and 512 mg/kg/d) and/or control antioxidant N-acetyl-cysteine (NAC, 150 mg/kg/d) for 7 and 30 d. Liver health was ascertained by measuring levels of hepatic transaminases (GPT/GOT), determining the glutathione profile (GSH/GSSG ratio), and histomorphological examination of liver tissue. RESULTS: Hom-Dang extract showed the highest in vitro antioxidant potency (an IC50 value of 36.50 ± 0.46, 12.98 ± 0.23, 21.83 ± 2.58, 15.87 ± 0.30, and 86.21 ± 2.45 mg/mL for ABTS, OH(•), [Formula: see text], metal chelating, and lipid peroxidation, respectively). Mice administered paracetamol exhibited increases in GPT/GOT with decreases in GSH and GSH/GSSG ratio followed by histomorphological signs of liver injury. In the presence of the Hom-Dang extract, the GPT/GOT values were normalized, GSH production was induced, and the GSH/GSSG ratio was increased. CONCLUSION: Thai colored rice cultivars, especially the Hom-Dang variety, are promising candidates for health supplements due to their antioxidative and hepatoprotective properties.

Preparation and optimization of chlorophene-loaded nanospheres as controlled release antimicrobial delivery systems.

Chlorophene-loaded nanospheres with various formulation parameters were evaluated. The optimal formulation was found at 0.1% w/v of poloxamer 407, 15 mL of ethyl acetate and 20% initial chlorophene loading that provided the suitable size (179 nm), the highest loading content (19.2%), encapsulation efficiency (88.0%) and yield (91.6%). Moreover, encapsulation of chlorophene in nanospheres was able to prolong and sustain drug release over one month. Chlorophene-loaded nanospheres were effective against Staphylococcus aureus (S. aureus) and Candida albicans (C. albicans), the main cause of hospital-acquired infections. Chlorophene-loaded nanospheres were effective against S. aureus (>46 µg/mL) and C. albicans (>184 µg/mL). These nanospheres appeared to have profound effect on the time-dependent hemolytic activity due to gradual release of chlorophene. At the concentration of 46 µg/mL, nearly no HRBC hemolysis in 24 h compared to 80% of hemolysis from free drug. In conclusion, polymeric nanospheres were successfully fabricated to encapsulate chlorophene which can eliminate inherent toxicity of drugs and have potential uses in prolonged release of antimicrobial.

In vitro probiotic properties of Lactobacillus fermentum SK5 isolated from vagina of a healthy woman.

A lactobacillus strain isolated from a vaginal tract of a healthy woman was examined in vitro for its probiotic potential. This strain, identified as Lactobacillus fermentum SK5, was able to survive at pH 3-4 and 0.1-0.2% bile, and unaffected by pepsin (3 g l(-1)) and pancreatin (1 g l(-1)), but was susceptible to all tested antibiotics except metronidazole. L. fermentum SK5 had an antimicrobial potential against gastrointestinal pathogenic Escherichia coli and vaginal pathogenic Gardnerella vaginalis. The effective substance was suspected to be a bacteriocin-like compound with a molecular weight of more than 10 kDa, but hydrogen peroxide was also detected. Further studies revealed that L. fermentum SK5 had good autoaggregation characteristic and a high surface hydrophobicity that enhanced its adhesion ability to epithelial cells and for biofilm formation. This lactobacillus showed coaggregation with E. coli and G. vaginalis to affect their adhesion and colonization. The adhesion of L. fermentum SK5 to HeLa, HT-29 and Caco-2 cells and its inhibition of E. coli and G. vaginalis adherence to these cells were demonstrated. These incidences provided evidence of the possible colonization of L. fermentum SK5 that would prevent binding and growth of E. coli and G. vaginalis onto intestinal and vaginal epithelial cells. On the basis of the ability of L. fermentum SK5 to inhibit pathogenic microorganisms through coaggregation and antimicrobial substances, it is likely that this lactobacillus strain could be a potential probiotic candidate for beneficial use in protecting against gastrointestinal and vaginal microbial infections.

Mutagenic and antimutagenic effects of the traditional herb used for treating erectile dysfunction, Butea superba Roxb.

Butea superba is a traditional tuberous Thai plant enriched with flavonoids that is used for treating erectile dysfunction. We investigated the mutagenic and antimutagenic potentials of a B. superba extract by using the pre-incubation method of the Ames test. Salmonella typhimurium strains TA 98 and TA 100 were applied as the tester strains in the presence and absence of an S9 mixture. Prior to the mutagenic and antimutagenic tests, the survival of the tester strains was measured by treating with the B. superba extract. The results show that the B. superba extract exhibited dose-dependent cytotoxic effects. Data from the Ames test revealed that the B. superba extract to be non-mutagenic in the presence and absence of the S9 mixture. In contrast, the B. superba extract showed antimutagenic potential towards either or both of the tested mutagens: 2-(2-furyl)-3-(5-nitro-2-furyl)-acrylamide (AF-2) and benzo(a)pyrene (B(a)P) in the respective presence and absence of the S9 mixture, respectively. The plant antimutagenic activity was confirmed by a rec assay. A further study by micronucleus test demonstrated that the B. superba extract at the maximum loading volume could induce acute micronucleus formation in the tested animals. The in vitro mutagenic and antimutagenic assays confirmed the safe consumption of B. superba products at low dose (not more than 781.25 microg/ml of the plant extract), but the in vivo genotoxic assay demonstrated the unsafe consumption at a high dose (300 mg/kg of the BW plant extract or 16 g/kg of the BW plant powder).

Antimutagenic potential of the Thai herb, Mucuna collettii Lace.

Mucuna collettii Lace is a Thai herb with a long record of consumption among mature Thai males for the promotion of sexual potency. The mutagenic and antimutagenic potentials of Mucuna collettii extract were carried out by using the Ames test pre-incubation method in the presence and absence of S9 mixture. Salmonella typhimurium strains TA 98 and TA 100 were applied as the tester strains. Prior to mutagenic and antimutagenic tests, the survival of the tester strains was performed by treating with the plant extract. Results showed Mucuna collettii extract exhibited strong cytotoxic effects in a dose-dependent manner. Toxicity of the plant was confirmed in mice in which negative adverse effect was found in kidney, uterus, ovary, and testis. Mucuna collettii extract in the presence and absence of S9 mixture was negative for mutagenic Ames test. Mucuna collettii extract in the presence and absence of S9 mixture was positive for antimutagenic Ames test towards either one or both of the tested mutagens: 2-(2-furyl)-3-(5-nitro-2-furyl)-acrylamide (AF-2) and benzo(a)pyrene. The antimutagenic activity of the plant extract was confirmed in rec-assays. Micronucleus test demonstrated that Mucuna collettii extract at high dose and a long incubation time could induce micronucleus formation in tested animals, but less than the response of the positive control. The overall mutagenic and antimutagenic assays are further evidences for the antimutagenic potential of Mucuna collettii.

Time-kill curves as a tool for targeting ceftazidime serum concentration during continuous infusion for treatment of septicaemic melioidosis.

Melioidosis is a fatal community-acquired infection endemic in tropical areas. Ten isolates of the causative microorganism were subjected to time-kill study using a range of ceftazidime concentrations. This study demonstrated that a ceftazidime concentration of eight times the minimum inhibitory concentration yielded an optimal bactericidal effect and should be the target concentration administered by continuous infusion.

International conferences on environmental mutagens in human populations-opportunities, accomplishments and challenges.

A major mission for organizing the series of International Conferences on Environmental Mutagens in Human Populations is to bring science and scientists to the sites where the field of environmental health is in developmental stages and environmental health is a serious concern. The mission has been fulfilled in each of the previous conferences that were held in Egypt, Czech Republic, Thailand and Brazil. These conferences have led to significant enhancement of regional scientific expertise from the acquisition of scientific knowledge and from the generation of sustainable collaborative programs.