The mixture of different parts of Nelumbo nucifera and two bioactive components inhibited tyrosinase activity and melanogenesis.

Melanin is the pigment responsible for the color of the eyes, hair, and skin in humans. Tyrosinase is well known to be the key enzyme in melanin biosynthesis. JKTM-12 is composed of the flowers, roots, seeds, and receptacles of Nelumbo nucifera (lotus). In this study, JKTM-12 was investigated for its inhibitory effects on tyrosinase activity and melanin biosynthesis in B16F10 melanoma cells. Moreover, two main bioactive compounds (hyperoside and astragalin) were found from the receptacles of N. nucifera, which are used as the main material of JKTM-12. JKTM-12 was shown to inhibit tyrosinase activity and melanin biosynthesis in alpha-melanocyte-stimulating hormone-stimulated B16F10 melanoma cells. Hyperoside and astragalin, which are the main bioactive compounds of JKTM-12, not only inhibited tyrosinase activity and melanogenesis but also tyrosinase-related protein 1 and tyrosinase-related protein 2 mRNA expression without cytotoxicity at various experiment doses (0.1, 1, and 10 µg/ml). These results suggest that JKTM-12 has the potential for skin whitening with hyperoside and astragalin as the main bioactive compounds.

Neuroprotective effect of Citrus unshiu immature peel and nobiletin inhibiting hydrogen peroxide-induced oxidative stress in HT22 murine hippocampal neuronal cells.

BACKGROUND: Oxidative stress-induced cell damage is common in the etiology of several neurobiological disorders, including Alzheimer's disease and Parkinson's disease. In a case study, nobiletin-rich Citrus reticulata peels could prevent the progression of cognitive impairment in donepezil-preadministered Alzheimer's disease patients. OBJECTIVE: In this study, we investigated the effects and underlying mechanism of nobiletin and Citrus unshiu immature peel (CUIP) water extract, which contains nobiletin as a major compound, on hydrogen peroxide-induced oxidative stress in HT22 cells, a murine hippocampal neuronal model. MATERIALS AND METHODS: HT22 cells were treated with hydrogen peroxide in the presence or absence of various concentrations of CUIP and nobiletin. Cytotoxicity and apoptotic protein levels were measured by 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and Western blotting. RESULTS: Pretreatment with CUIP and nobiletin inhibited cell death due to hydrogen peroxide. Hydrogen peroxide-induced the expression of phospho-Jun N-terminal kinases (p-JNK) and p-p38 proteins in HT22 cells; however CUIP and nobiletin suppressed p-JNK and p-p38 without changing JNK or p38. Regarding apoptosis, caspase 3, B-cell lymphoma 2 (Bcl-2), and Bax protein expression was determined. CUIP and nobiletin suppressed caspase 3 and Bax expression, but they induced Bcl-2 expression in HT22 cells. CONCLUSION: These results show that CUIP and nobiletin can protect against hydrogen peroxide-induced cell death in HT22 neurons via mitogen-activated protein kinases and apoptotic pathways.

Heat-Processed Scutellariae Radix Enhances Anti-Inflammatory Effect against Lipopolysaccharide-Induced Acute Lung Injury in Mice via NF- κ B Signaling.

The present study was conducted to examine whether heat-processed Scutellariae Radix has an ameliorative effect on lipopolysaccharide- (LPS-) induced acute lung injury in mice. The effects of Scutellariae Radix heat-processed at 160°C (HSR) were compared with those of nonheat-processed Scutellariae Radix (NSR). The LPS-treated group displayed a markedly decreased body weight and significantly increased lung weight; however, the administration of NSR or HSR improved both the body and lung weights. The increased oxidative stress and inflammatory biomarker levels in the serum and lung were reduced significantly with HSR. The reduced superoxide dismutase and catalase increased significantly by both NSR and HSR. Also, the dysregulated oxidative stress and inflammation were significantly ameliorated by NSR and HSR. The expression of inflammatory mediators and cytokines by nuclear factor-kappa B activation was modulated through inhibition of a nuclear factor kappa Bα degradation. Also, lung histological change was markedly suppressed by HSR rather than NSR. Overall, the ameliorative effects of HSR were superior to those when being nonheat-processed. The representative flavonoid contents of Scutellariae Radix that include baicalin, baicalein, and wogonin were greater by heat process. These data reveal heat-processed Scutellariae Radix may be a critical factor involved in the improvement of lung disorders caused by LPS.