Effect of Gymnema inodorum on postprandial peak plasma glucose levels in healthy human

Gymnema inodorum (GI), a vegetable widely used in a Northern Thai food, is known for not only its health nourishing effect, but also its hypoglycemic effect. But no scientific evidence on the hypoglycemic effect of GI has ever been reported in human. In this study, the effect of GI consumptionon peak plasma glucose concentrations in healthy subjects was investigated. Either oral glucose load (75 g) or standard meal was given to the subjects with respect to the presence or absence of GI consumption and postprandial peak glucose levels were compared. When GI was consumed, 15 min after oral glucose load, the glucose concentration with GI was significantly lower (130 ± 32 vs. 145 ± 27 mg/dl, p < 0.05; N = 73). Doubling dose of GI showed much greater decrease in peak blood glucoseconcentration than that of the single dose (108 ± 15 vs. 130 ± 32 mg/dl, p < 0.05). When standard meal was used instead of oral glucose load, similar hypoglycemic effect was observed in GI group; 16 out of 20 subjects had a lowered peak glucose concentration (129 ± 27 vs. 147 ± 39 mg/dl, p < 0.05). In order to evaluate the impact of long term GI consumption on plasma glucose concentration and liver function, fasting plasma glucose and liver function test (AST, ALT, GGT and ALP) were monitored at days 0, 2, 4, 7, 14, 21 and 28. The results showed no change in both fasting plasma glucose and liver enzymes. To envisage the mechanism of this hypoglycemic effect, GI leaves were extracted with various solvents and tested for insulinotropic property in INS-1 cells as well as the determination of its inhibition on aglucosidase activity. Neither increase in insulin level nor inhibition of a-glucosidase enzyme wasobserved, suggesting that the hypoglycemic effect of GI is involved with other mechanisms than the activation of beta cell or enzymatic inhibition of carbohydrate absorption

Subtype distribution of Blastocystis in communities along the Chao Phraya river, Thailand

© 2016, Korean Society for Parasitology and Tropical Medicine. Blastocystis is a common zoonotic enteric protozoan that has been classified into 17 distinct subtypes (STs). A cross-sectional study was conducted to determine the prevalence and subtype distributions of Blastocystis in villagers living along the Chao Phraya River, Ayutthaya Province, Thailand, and to assess the risk of zoonotic infection. In total, 220 stool samples were collected, and DNA was extracted. PCR and sequencing were performed with primers targeting the small-subunit ribosomal RNA (SSU rRNA) genes. Blastocystis was present in 5.9% (13/220) of samples, and ST3 (5.0%; 11/220) was the predominant subtype, followed by ST2 (0.45%; 1/220) and ST6 (0.45%; 1/220). Phylogenetic trees were constructed with the maximum-likelihood method based on the Hasegawa–Kishino–Yano + G + I model, neighbor-joining, and maximum parsimony methods. The percentage of bootstrapped trees in which the associated taxa clustered together was relatively high. All the sequences of the Blastocystis-positive samples (KU051524–KU051536) were closely related to those from animals (pig, cattle, and chicken), indicating a zoonotic risk. Therefore, the villagers require proper health education, especially regarding the prevention of parasitic infection, to improve their personal hygiene and community health. Further studies are required to investigate the Blastocystis STs in the animals living in these villages

Thai plants with high antioxidant levels, free radical scavenging activity, anti-tyrosinase and anti-collagenase activity

Abstract Background Ultraviolet radiation from sunlight induces overproduction of reactive oxygen species (ROS) resulting in skin photoaging and hyperpigmentation disorders. Novel whitening and anti-wrinkle compounds from natural products have recently become of increasing interest. The purpose of this study was to find products that reduce ROS in 14 Thai plant extracts. Methods To determine total phenolic and flavonoid content, antioxidant activity, anti-tyrosinase activity and anti-collagenase activity, we compared extracts of 14 Thai plants prepared using different solvents (petroleum ether, dichloromethane and ethanol). Antioxidant activities were determined by DPPH and ABTS assays. Results Total phenolic content of the 14 Thai plants extracts was found at the highest levels in ethanol followed by dichloromethane and petroleum ether extracts, respectively, while flavonoid content was normally found in the dichloromethane fraction. Scavenging activity ranged from 7 to 99% scavenging as assessed by DPPH and ABTS assays. The ethanol leaf extract of Ardisia elliptica Thunb. had the highest phenolic content, antioxidant activity and collagenase inhibition, while Cassia alata (L.) Roxb. extract had the richest flavonoid content. Interestingly, three plants extracts, which were the ethanolic fractions of Annona squamosa L., Ardisia elliptica Thunb. and Senna alata (L.) Roxb., had high antioxidant content and activity, and significantly inhibited both tyrosinase and collagenase. Conclusion Our finding show that the ethanol fractions of Annona squamosa L., Ardisia elliptica Thunb. and Senna alata (L.) Roxb. show promise as potential ingredients for cosmetic products such as anti-wrinkle agents and skin whitening products

08-3273

Abstract. Humans are thought to acquire Toxoplasma infection by three major routes: ingesting food and water contaminated with oocysts from cat excreta, consumption of under-cooked infected meat, and transplacental transfer. Congenital clinical toxoplasmosis in the newborn indicating definite transplacental transmission had been reported in Thailand, whilst studies concerning infection due to the other two routes were inconclusive. Since the way domestic cats live and eat and also the eating behavior of Thai people differ from those in the West, we conducted a sero-epidemiological study of T. gondii in cats and their owners in Bangkok metropolitan area. Among 327 humans, the prevalence of Toxoplasma antibody was 6.4% and in 315 cats it was 7.3%. These relatively low prevalence rates may result from the predominantly well-cooked fish and rice diet of stray cats, which congregate in temples where they are fed. Toxoplasma antibody seropositive was associated with living in close proximity to seropositivity cats [OR (95% CI) = 5.43 (1.28-23.04); p=0.01]. Risks were increased in and around temples, particularly if courtyards were of earth or grass, suggesting ground temperature was an important determinant of oocyst survival

Phyllanthus acidus (L.) Skeels and Rhinacanthus nasutus (L.) Kurz leaf extracts suppress melanogenesis in normal human epidermal melanocytes and reconstitutive skin culture

Objective: To determine the effect of extracts from Phyllanthus acidus (P. acidus) (L.) Skeels and Rhinacanthus nasutus (R. nasutus) (L.) Kurz leaves on melanogenesis and the underlying mechanism in normal human epidermal melanocytes (NHEM) and a reconstitutive skin model. Methods: NHEM and a reconstitutive skin model were stimulated with ethanol extracts of P. acidus (L.) Skeels and R. nasutus (L.) Kurz leaves. mRNA expression of microphthalmia-associated transcription factor (MITF), tyrosinase (TYR), tyrosinase-related protein 1 (TYRP1) and dopachrome tautomerase (DCT) were examined by real-time PCR. The melanin content in NHEM was also measured. Moreover, protein levels of tyrosinase were determined using western blot analysis. Results: In NHEM and the reconstitutive skin model, ethanol extracts from P. acidus (at 12.5 and 25.0 μg/mL) and R. nasutus (at 6.25 and 12.50 μg/mL) significantly diminished mRNA expression of MITF, TYR, TYRP1 and DCT in a concentration-dependent manner. P. acidus and R. nasutus extracts also reduced the amount of melanin in α-MSH-stimulated NHEM. Moreover, P. acidus and R. nasutus extracts markedly suppressed tyrosinase at the translational level in the reconstitutive skin model. Conclusions: P. acidus and R. nasutus extracts significantly reduced melanogenesis in NHEM and the reconstitutive skin model, suggesting that P. acidus and R. nasutus extracts can inhibit melanin synthesis through downregulation of MITF, TYR, TYRP1 and DCT. Therefore, the ethanol extracts of P. acidus and R. nasutus contain compounds that have the potential for development as a skin lightening agent for the treatment of hyperpigmentation disorder or melasma

Anti melanogenic effect of Croton roxburghii and Croton sublyratus leaves in α-MSH stimulated B16F10 cells

Croton roxburghii and Croton sublyratus have been used as skin treatments in traditional medicine. The objective of the present study was to investigate the antimelanogenic effect of ethanol extracts of Croton roxburghii (CRE) and Croton sublyratus (CSE) leaves on cellular melanin content and cellular tyrosinase activity as mediated by the action of microthalmia transcription factor (MITF) and melanogenic enzymes. Croton roxburghii and Croton sublyratus leaves were extracted by petroleum ether, dichloromethane and absolute ethanol, sequentially. The ethanolic crude extracts were examined for antimelanogenic activity by their ability to decrease melanin content and cellular tyrosinase activity in alpha-melanocyte-stimulating hormone-stimulated B16F10 melanoma cells. In addition, the extracts were evaluated to determine a plausible mechanism of melanogenesis suppression through determining the activation of MITF transcription factor and melanogenic proteins (tyrosinase, tyrosinase-related protein 1 or TRP-1 and tyrosinase-related protein 2 or TRP-2) at the transcriptional and translation levels in α-MSH-induced B16F10 cells. Upon treatment with CRE and CSE, the cells showed significant decreases in melanin content and cellular tyrosinase activity. CRE and CSE also suppressed MITF, tyrosinase, TRP-1 and TRP-2 at the transcription and translation levels in α-MSH-stimulated melanin biosynthesis in B16F10 cells. Our finding shows that CRE and CSE inhibit melanin content and cellular tyrosinase activity through suppressing MITF and melanogenic enzymes. CRE and CSE may be useful to combine with skin whitening agents for cosmetic uses. Keywords: Croton roxburghii, Croton sublyratus, Melanin, Tyrosinase, B16F10 mouse melanoma cell

Prevalence and Subtype Distribution of Blastocystis Isolated from School-Aged Children in the Thai-Myanmar Border, Ratchaburi Province, Thailand

Blastocystis is one of the most common enteric protozoa that inhabits the intestinal tract of humans and different animals. Moreover, it has a worldwide geographic distribution. Its main mode of transmission is via the fecal-oral route. At present, 26 subtypes are widely distributed across both humans and animals. The current study aimed to determine the prevalence and subtype distribution of Blastocystis among school-aged children living on the Thai-Myanmar border, Ratchaburi province, Thailand. In total, 508 samples were collected from children at six schools. The prevalence of Blastocystis infection was amplified and sequenced in the 600 bp barcode region of the small-subunit ribosomal RNA (SSU rRNA). The overall prevalence of Blastocystis infection was 3.35% (17/508). ST3 (11/17) was the most predominant subtype, followed by ST1 (5/17) and ST2 (1/17). A phylogenetic tree was constructed based on the Tamura92+G+I model using the maximum-likelihood algorithm. Surprisingly, all sequences of the ST3-positive samples were closely correlated with the cattle-derived sequence. Meanwhile, all sequences of the Blastocystis ST1-positive samples were closely correlated with the human-derived sequence. Nevertheless, further studies should be conducted to validate the zoonotic transmission of Blastocystis. Based on our findings, personal hygiene and sanitation should be improved to promote better health in children in this area