The increasing popularity of Chinese herbal treatment has sparked interest in investigating how safe these alternative medicines are. This study scrutinized the Chinese herbs used most popularly in Thailand to identify the presence of heavy metals, microorganisms and aflatoxin contamination. Five commonly consumed Chinese herbs were investigated: Milkvetch root (Astragalus membranaceus), Chinese angelica (Angelica sinensis), Goji berry (Lycium barbarum), Chinese yam (Dioscorea opposita) and Jujube (Ziziphus jujuba). Any heavy metal (arsenic, lead, cadmium), microorganisms (total viable count; total aerobic microbial count, total combined yeast and mold count), pathogenic bacteria (Staphylococcus aureus, Salmonella spp., Clostridium spp.) or aflatoxin contamination were examined. Of the 25 samples, sixteen (64.0%) did not exceed acceptable limits. Nor did the total aerobic microbial count, total combined yeast and mold count, aflatoxin and heavy metals exceed permissible limits. Neither Salmonella spp., nor S. aureus were found in any of the samples. However, significant Clostridium spp. contamination (36.0%) was detected in 9 of the 25 samples. These health hazards should be addressed systematically and for the long term by the appropriate consumer protection agencies and related organizations.

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An epidemiologic study of methicillin-resistant Staphylococcus aureus (MRSA) was conducted by antibiotype, coagulase gene typing and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. A total of 129 MRSA strains were isolated from 17 hospitals in the regions of the central, northern, northeastern and eastern Thailand during November 2003 -March 2004. Antimicrobial susceptibility testing with a panel of 10 antimicrobial agents showed 9 different antibiotypes. The antibiotypes 1 and 2 were the most common phenotypes with 44.2% and 35.6% of the isolates, respectively. Coagulase gene typing of MRSA strains generated 4 different genotypes: I, II, III, IV, the PCR products of which were 492±20, 654±20, 735±20 and 816±20 bp with the percentages of 1.5 (2/129), 2.3 (3/129), 82.2 (106/129) and 14 (18/129), respectively. Coagulase gene PCR-RFLPs exhibited 4 patterns: A, B, C and D, with AluI digested PCR product fragments at 220±20 and 220±20 bp (pattern A); 400±20 and 220±20 bp (pattern B); 420±20 and 220±20 bp (pattern C); and 510±20 and 220±20 bp (pattern D). The percentage values for each pattern were compatible with those from the coagulase gene typing method. The results indicated that antibiotypes 1, 2, coagulase gene type III and PCR-RFLP pattern C were the epidemic strains while the rest were sporadic strains.

Objective: To investigate the prevalence of hepatitis B virus (HBV) infection and to diagnose an occult HBV infection in healthy Thai subjects after implementation of the expanded program on immunization (EPI) in newborns.Material and Method: The detection of HBsAg, anti-HBs and anti-HBc was done from serum samples of 5,886 healthy first year students from Huachiew Chalermprakiet University collected between 2009-2011 by immunochro-matography rapid assay (Alcon, USA). In case of only anti-HBc positive, the results were confirmed with chemiluminescence enzyme immunoassay (EIA) method and then they were investigated further for HBV occult infection by nested polymerase chain reaction technique.Results: A total of 78% (4,593/5,886) healthy first year students who had been vaccinated with HBV vaccine since birth were found to have no HBV markers, while 18.4% (1,083/5,886) had only anti-HBs. The prevalence of infection was 3.6% (210/5,886). Identification of patterns of HBV infection among the 210 infected subjects found that (1) Immuned due to past infection was 61.9% (130/210) (2) Infected with hepatitis B virus was 38.1% (80/120). The prevalence of both HBsAg and anti-HBc was 28.6% (60/210), while the prevalences of HBsAg and Anti-HBc alone were 3.8% (8/210) and 5.7% (12/210), respectively. Anti-HBc alone group was repeated with chemiluminescence EIA and HBV DNA was negative.Conclusion: The prevalence of HBV infection was 3.6% (210/5,886), however, seropositive rate of HBV infection was 1.4% (80/5,886). Most antibodies from vaccination had substantially declined to the point that it was undetectable. Therefore, the overall study showed an effective implementation of EPI in newborns.

Objective: To determine the antimalarial activity of ethanol crude extracts from 20 Thai herbs against Plasmodiumfalciparum (P. falciparum) chloroquine-resistant strain TM267. Molecular docking of the active compounds from the selected Thaiherbs were analyzed with Plasmodium falciparum dihydrofolate reductase (PfDHFR).Material and Method: An in vitro study of antimalarial activity against P. falciparum TM267 was done using a parasitelactate dehydrogenese assay, and the cytotoxic effects of extracts were tested against Vero cells using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The 50% inhibitory concentration (IC50) and 50%cytotoxicity concentration were calculated from the dose-response curves. Molecular docking and post-dockingwere analyzed with the x-ray crystal structure of PfDHFR-thymidylate synthase complexed with pyrimethamine,nicotinamide adenine dinucleotide phosphate and deoxyuridylate.Results: Of these, the Plumbago indica L. root extract showed high antimalarial activity, with an IC50 value of 3.7μg/ml and less cytotoxicity when tested against Vero cells, followed by the Citrus hystrix DC. fruit extract, Vitex trifoliaLinn. root extract, Ocimum sanctum L. leave extract, of Allium sativum L. bulb extract and Salacia chinensis L. stem extract,respectively. All 7 active compounds reported from these herbal extracts had high docking scores against PfDHFR.The Citrusoside C from Citrus hystrix DC. had the highest docking score.Conclusion: It could be purposed that there were active compounds in Plumbago indica L., Vitex trifolia Linn. and Citrus hystrix DC. which are potential inhibitors against malaria that could bind to the active site of PfDHFR. However, the active Citrusosides from Citrus hystrix DC. should be further investigated for their effectiveness against malaria.