Anti-obesity activity of Yamabushitake (Hericium erinaceus) powder in ovariectomized mice, and its potentially active compounds.

Hericium erinaceus (H. erinaceus) improves the symptoms of menopause. In this study, using ovariectomized mice as a model of menopause, we investigated the anti-obesity effect of this mushroom in menopause. Mice fed diets containing H. erinaceus powder showed significant decreases in the amounts of fat tissue, plasma levels of total cholesterol, and leptin. To determine the mechanism, groups of mice were respectively fed a diet containing H. erinaceus powder, a diet containing ethanol extract of H. erinaceus, and a diet containing a residue of the extract. As a result, H. erinaceus powder was found to increase fecal lipid levels in excreted matter. Further in vitro investigation showed that ethanol extract inhibited the activity of lipase, and four lipase-inhibitory compounds were isolated from the extract: hericenone C, hericenone D, hericenone F, and hericenone G. In short, we suggest that H. erinaceus has an anti-obesity effect during menopause because it decreases the ability to absorb lipids.

Hericium erinaceus extracts alter behavioral rhythm in mice.

Hericium erinaceus (HE), an edible mushroom, has been used as a herbal medicine in several Asian countries since ancient times. HE has potential as a medicine for the treatment and prevention of dementia, a disorder closely linked with circadian rhythm. This study investigated the effects of the intake of HE extracts on behavioral rhythm, photosensitivity of the circadian clock, and clock gene mRNA expression in the suprachiasmatic nucleus (SCN), a central clock, in mice. Although the HE ethanol extract only affected the offset time of activity, the HE water extract advanced the sleep-wake cycle without affecting the free-running period, photosensitivity, or the clock gene mRNA expression in SCN. In addition, both extracts decreased wakefulness around end of active phase. The findings of the present study suggest that HE may serve as a functional food in the prevention and treatment of Alzheimer's disease and delayed sleep phase syndrome.

The inhibitory effects of representative chalcones contained in Angelica keiskei on melanin biosynthesis in B16 melanoma cells.

In our effort to find new whitening agents, we evaluated the effects of representative chalcones [4-hydroxyderricin (1), xanthoangelol (2), xanthoangelol H (3), deoxyxanthoangelol H (4), and deoxydihydroxanthoangelol H (5)] contained in the stem of Angelica keiskei on tyrosinase and melanin formation in B16 melanoma cells. In addition, the antioxidant effects of these chalcones in ORAC and DPPH assays were also determined. Interestingly, all chalcones (1-5) inhibit melanin formation in B16 melanoma cells, with low cytotoxicity.

Melanin biosynthesis inhibitory and antioxidant activities of quercetin-3'-O-beta-D-glucoside isolated from Allium cepa.

In the course of searching for new whitening agents, we have found that the methanol extract of dried skin of Allium cepa shows potent melanin biosynthesis inhibitory activity in B16 melanoma cells. Bioassay-guided fractionation led to the isolation of quercetin-3'-O-beta-D-glucoside (1) from the methanol extract of dried skin of A. cepa, which inhibited melanin formation in B16 melanoma cells with an IC50 value of 38.8 microM and mushroom tyrosinase with an IC50 value of 6.5 microM using L-tyrosine and 48.5 microM using L-dihydroxyphenylalanine as substrates, respectively. In addition, the antioxidant activity of 1 was evaluated in the oxygen radical absorbance capacity assay; it showed 3.04 micromol Trolox equivalents/mmol. 1 was shown to be a promising ingredient that could be useful for treating hyperpigmentation and for protecting against oxidative stress.