Effects of yeast hydrolysate on neuropeptide Y (NPY) and tryptophan hydroxylase (TPH) immunoreactivity in rats

To investigate the appetite regulation mechanism of low and high molecular weight yeast hydrolysate, neuropeptide Y (NPY) and tryptophan hydroxylase (TPH) expressions were analyzed in the brains on rats using immunohistochemical method; normal diet (control), 0.1 g/kg (BY‐1) or 1.0 g/kg (BY‐2) of yeast hydrolysate below 10 kDa, 0.1 g/kg (AY‐1) or 1.0 g/kg (AY‐2) of yeast hydrolysate of 10–30 kDa. Body weight gain was lower in the BY‐2 (133.0 g) than in the control (150.1 g) (p < 0.05). Triacylglyceride, total cholesterol, and LDL‐cholesterol levels were lower in the BY‐2 as compared to control, BY‐1 and AY‐2 (p < 0.05). NPY staining intensities at paraventricular nucleus (PVN) were lower in the BY groups (BY‐1: 96.1, BY‐2: 88.6) as compared to the control (105.6) and AY groups (AY‐1: 110.5, AY‐2: 114.1) (p < 0.05). NPY expression at lateral hypothalamic area (LHA) was lower in the BY‐2 (92.3) than in the control (98.9) (p < 0.05). The BY groups (BY‐1: 143.9, BY‐2: 154.6) had higher TPH staining intensities at dorsal raphe (DR) than the AY‐2 (115.9) (p < 0.05). In conclusion, the results indicate that administering yeast hydrolysate of below 10 kDa to normal diet‐fed rats reduced body weight gain and serum lipids by altering NPY and TPH expressions. Copyright © 2008 John Wiley & Sons, Ltd.     

Manassantin A and B from Saururus chinensis inhibiting cellular melanin production

Hyperpigmentation disorders such as freckles and senile lentigines in the skin are associated with abnormal accumulation of melanin pigments. In this study, two lignan constituents were isolated from Saururus chinensis Baill (Saururaceae) as inhibitors of cellular melanin production by bioassay‐guided fractionations. The active constituents were manassantin A and B that dose‐dependently inhibited melanin production in α‐melanocyte stimulating hormone (α‐MSH)‐activated melanoma B16 cells with IC₅₀ values of 13 nm and 8 nm , respectively. Arbutin as a positive control exhibited an IC₅₀ value of 96 µm on α‐MSH‐induced melanin production. Further, manassantin A inhibited forskolin‐ or 3‐isobutyl‐1‐methylxanthine (IBMX)‐induced melanin production with IC₅₀ values of 14 nm or 12 nm , respectively. Manassantin A decreased cellular amounts of IBMX‐inducible tyrosinase protein but could not affect the catalytic activity of cell‐free tyrosinase, a key enzyme in the biosynthetic pathway of melanin pigments. Finally, this study could provide a pharmacological potential of S. chinensis in hyperpigmentation disorders. Copyright © 2009 John Wiley & Sons, Ltd.     

Macular degeneration in an arc welder

A male welder who had been working in an industrial machine plant for more than 20 years experienced acute intense pain in his left eye with continuous lacrimation while performing arc welding in 1997. Later in 1997, at the age of 39 yr, macular edema was found in his left eye. He was diagnosed with macular degeneration (MD) of the left eye in 2002, and with right eye MD in 2004. Radiation in the visible and near infrared (IR) spectra penetrates the eye and is absorbed by the retina, possibly causing thermal or photochemical damage. Such retinal damage may be permanent and, therefore, sight-threatening. The young age and history of an acute painful eye injury are not consistent with age related macular degeneration (AMD) but rather is likely maculopathy caused by welding arc exposure.     

Chronic diseases and dietary changes in relation to Korean Americans' length of residence in the United States

BACKGROUND: National health in the United States is influenced by the dietary norms brought into the country by an increasing number of immigrants. OBJECTIVES: This cross-sectional study aimed to document dietary changes and disease prevalence in relation to the length of residence in the United States for Korean Americans in Michigan. DESIGN: Of 1,860 questionnaires mailed out, 637 (34.3%) were returned with respondent-reported information, including demographics, weight and height, chronic diseases, and dietary patterns. SUBJECTS/SETTING: Included in the final analyses were 497 first-generation Korean-American immigrants (263 men, 234 women, aged 30 to 87 years). STATISTICAL ANALYSES PERFORMED: Analysis of covariance with the Tukey test and logistic regression models provided sex-specific analysis of dietary changes and disease patterns. All statistical analyses were adjusted for age. RESULTS: Chronic diseases reported most frequently by men and women, respectively, were hypertension, digestive diseases, arthritis, and diabetes. Length of residence in the United States (or=26 years) was inversely associated with the prevalence of digestive diseases in men (P=0.017) and women (P=0.001), and positively with respiratory diseases in men and thyroid disease in women (P<0.05). Length of residence in the United States was inversely associated with intake of rice/rice dishes in both men (servings per week, P<0.001) and women (P=0.012). The prevalence of digestive diseases associated inversely with length of residence and positively with servings of rice/rice dishes consumed for Korean-American men. The age-adjusted odds ratio for digestive diseases was highest among men who had the shortest length of residence in the United States (2 servings per day) (odds ratio 12.10; P=0.03). CONCLUSIONS: Dietary changes of Korean-American immigrants in the United States over time were associated with changes in their chronic disease patterns. These findings may help food and nutrition professionals who work with minority immigrants because they identify factors that affect changes in dietary patterns and work toward preventing diet-related diseases. Prospective studies could address underlying mechanisms of the observed diet-disease relationship with subsequent generations of Korean Americans, as well as various ethnic minority immigrants in the United States.     

Ipomoea batatas attenuates amyloid β peptide-induced neurotoxicity in ICR mice

In this study, the protective effects of 17 Korean native plants against amyloid β peptide (Aβ)-induced oxidative stress were screened using the 2',7'-dichlorofluorescin diacetate assay and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Ipomoea batatas exerted the highest protective effects against oxidative stress and was selected for further investigation. To confirm the protective activity of this extract, the I. batatas extract was fed to ICR mice that had been injected with Aβ to induce neuronal deficits. In these experiments, the extract of I. batatas significantly reversed Aβ-induced neurotoxicity as assessed by the passive avoidance test, a behavioral experiment. Moreover, I. batatas administration reduced the level of lipid peroxidation and increased catalase activities in biochemical studies using the brain tissue of mice. These results indicate that I. batatas might be beneficial against Alzheimer's disease, especially by limiting oxidative stress in the brain.     

In vitro study of lysozyme in poly(lactide-co-glycolide) microspheres with sucrose acetate isobutyrate

This study investigated the suitability of microsphere formulations for extended protein delivery and complete protein release. These microspheres were prepared by a multi-emulsion method and prepared using a mixture of poly(lactide-co-glycolide) (PLGA), RG 502H (lactide:glycolide=50:50, M(W) 9300) and sucrose acetate isobutyrate (SAIB). SAIB embedded into the microspheres and mixed with PLGA, improved the efficiency of enzyme encapsulation. The in vitro release rate of lysozyme (Lys) from the microspheres was reduced due to the high viscosity of the added SAIB and less degradation of PLGA by SAIB. These properties enabled prolonged release of Lys for up to 2 months, characterized by a minimal initial burst of Lys and nearly zero-order protein release kinetics result from co-administration of sorbitan monooleate 80. When it is considered that degradation products of SAIB are inactive for labile proteins, SAIB may be regarded as a promising candidate for long-acting protein delivery.     

Electrophysiological characterization of benzofuroindole-induced potentiation of large-conductance Ca2+-activated K+ channels

Large-conductance Ca2+-activated K+ (BK(Ca)) channels are widely distributed and play key roles in various cell functions. We previously reported the chemical synthesis of several benzofuroindole compounds that act as potent openers of BK(Ca) channels. In this study, we investigated the mechanism of channel potentiation by one of the compounds, 7-trifluoromethyl-10H-benzo[4,5]furo[3,2-b]indole-1-carboxylic acid (TBIC), using electrophysiological means. This chemical highly activated cloned BK(Ca) channels from extracellular side independent of beta subunits and regardless of the presence of intracellular Ca2+. The EC50 and Hill coefficient for rat BK(Ca) channel alpha subunit, rSlo, were estimated as 8.9 +/- 1.5 microM and 0.9, respectively. TBIC shifted the conductance-voltage curve of rSlo channels to more hyperpolarized potentials without altering its voltage dependence. Single-channel recording revealed that TBIC increased the open probability of the channel in a dose-dependent manner without any changes in single-channel conductance. Strong potentiation by TBIC was also observed for native BK(Ca) channels from rat hippocampus pyramidal neurons. Thus, TBIC and the related benzofuroindole compounds can be useful tools to unravel the mechanism of this novel allosteric activation of BK(Ca) channels.     

Enantiomers of higenamine inhibit LPS-induced iNOS in a macrophage cell line and improve the survival of mice with experimental endotoxemia

The importance of development of single enantiomers (optically pure isomers) of chiral molecules has been recognized and manifested in countless pharmaceutical and biological advancement. (RS)-(+/-)-Higenamine (racemic mixture), an active ingredient of Aconite tuber, has been shown to have antioxidant activity along with inhibitory action of iNOS expression in various cells. In the present study, the effects of each enantiomer of higenamine [(S)-(-)-higenamine and (R)-(+)-higenamine] were investigated in comparison with the effects of racemic mixture [(RS)-(+/-)-higenamine] on iNOS expression and NO production in RAW 264.7 cells activated with LPS. In addition, the effects of higenamine enantiomers on the survival rates were also investigated using mice, in which each test compound was injected (i.p.) 90 min prior to LPS. All three forms of higenamine inhibited iNOS expression and reduced NO production with IC50 of 26.2, 86.3, and 53.4 microM, for (S)-, (R)-, and (RS)-higenamine, respectively. (S)-higenamine also significantly reduced serum NOx level and increased survival rates in LPS-treated mice. In contrast, (R)-isomer only showed tendency to increase the survival rates which was not statistically significant when compared to LPS-treated controls. Taken together, it was concluded that (S)-higenamine may be more beneficial than (R)-enantiomer in diseases associated with iNOS over-expression, such as septic shock.