Reevaluation of Single Nucleotide Polymorphism of OCA2 in Koreans / 체질인류학회지

Oculocutaneous albinism type 2 (OCA2) is an autosomal recessive disorder that results from mutations in the P gene, and has approximately 70% function of melanin biosynthesis in the melanocytes. While the overwhelming majority of pigmentation studies have focused on European populations, very little is known about the gene and mechanisms affecting skin lightening in Asian population. The main goal of the study was to test the distribution of three polymorphisms located in a pigmentation candidate gene, OCA2, in a sample of individuals of Koreans (N=250). The genetic markers were selected for polymorphisms that had an allele frequency difference of at least 30% between East Asian populations and European populations. We investigated Minor Allele Frequencies (MAFs) for each of three polymorphisms within OCA2 and reevaluated the difference of the allele frequency along with populations. MAFs of polymorphisms of OCA2 were presented the different frequency in Korean samples (SNP rs1800414 (His615Arg), A allele=38.8%, rs74653330 (Ala481Thr), A allele=0.8% and rs7497270 (intronic polymorphism), C allele=33.4%). While our results had different distributions to European and Caucasians, they showed similar frequencies with East Asian. This study was to reevaluate the distribution of pigmentation candidate gene in Korean samples, further domestic study will aid in developments of the genetic information on worldwide study.

Effect of Green Tea Extract/Poly-gamma-Glutamic Acid Complex in Obese Type 2 Diabetic Mice

BACKGROUND: The increasing prevalence of type 2 diabetes mellitus (T2DM) is associated with the rapid spread of obesity. Obesity induces insulin resistance, resulting in beta-cell dysfunction and thus T2DM. Green tea extract (GTE) has been known to prevent obesity and T2DM, but this effect is still being debated. Our previous results suggested that circulating green tea gallated catechins (GCs) hinders postprandial blood glucose lowering, regardless of reducing glucose and cholesterol absorption when GCs are present in the intestinal lumen. This study aimed to compare the effect of GTE with that of GTE coadministered with poly-gamma-glutamic acid (gamma-PGA), which is likely to inhibit the intestinal absorption of GCs. METHODS: The db/db mice and age-matched nondiabetic mice were provided with normal chow diet containing GTE (1%), gamma-PGA (0.1%), or GTE+gamma-PGA (1%:0.1%) for 4 weeks. RESULTS: In nondiabetic mice, none of the drugs showed any effects after 4 weeks. In db/db mice, however, weight gain and body fat gain were significantly reduced in the GTE+gamma-PGA group compared to nondrug-treated db/db control mice without the corresponding changes in food intake and appetite. Glucose intolerance was also ameliorated in the GTE+gamma-PGA group. Histopathological analyses showed that GTE+gamma-PGA-treated db/db mice had a significantly reduced incidence of fatty liver and decreased pancreatic islet size. Neither GTE nor gamma-PGA treatment showed any significant results. CONCLUSION: These results suggest that GTE+gamma-PGA treatment than GTE or gamma-PGA alone may be a useful tool for preventing both obesity and obesity-induced T2DM.