Identification of an antiamyloidogenic substance from mulberry leaves.

Fibrillar aggregates of amyloid beta-peptides are major constituents of the plaques found in the brains of patients with Alzheimer's disease, and have been implicated in the neurotoxicity of Alzheimer's. We previously reported that the methanol extract of mulberry leaves inhibits the formation of amyloid beta-peptide (1-42)-fibrils in vitro, and protects hippocampal neurons from amyloid beta-peptide (1-42)-induced cell death. In this study, we identified antiamyloidogenic substances, pheophorbide a, kaempferol -3-O-glucoside, and kaempferol -3-O-(6-malonyl) glucoside, from the methanol extract of mulberry leaves.

The relationship between 1-deoxynojirimycin content and alpha-glucosidase inhibitory activity in leaves of 276 mulberry cultivars (Morus spp.) in Kyoto, Japan.

The relationship between 1-deoxynojirimycin (DNJ) content and alpha-glucosidase inhibitory activity in mulberry (Morus) leaves is discussed. Mulberry leaves were collected from the Center for Bioresource Field Science, Kyoto Institute of Technology, Kyoto, Japan on 19 May, 9 July, and 9 August, 2003. Mulberry leaves were extracted with 75% ethanol.

Mulberry leaf extract prevents amyloid beta-peptide fibril formation and neurotoxicity.

Mulberry leaf has been reported to possess medicinal properties, including hypoglycemic, hypotensive and diuretic effects. Little is known, however, about its medicinal properties for central nervous system disorders, including Alzheimer's disease. Accumulating evidence suggests that amyloid beta-peptide (1-42) plays an important role in the etiology of Alzheimer's disease.

Somatic mutation in larvae of the silkworm, Bombyx mori, induced by heavy ion irradiation to diapause eggs.

In order to investigate whether eggs of the black-striped strain (P(S)) of the silkworm, Bombyx mori, represent an appropriate model for estimating the biological effect of cosmic radiation, radiosensitivity of the eggs against X-rays and heavy ion particles was examined as ground-based experiments. The exposure of diapause eggs to X-rays or heavy ion particles resulted in somatic mutations appearing as a white spot on the black integument during larval stage. Irradiation of non-diapause eggs with X-rays demonstrated a significant difference in frequency of the mutation between fractionated and single administration doses, but no difference was observed in diapause eggs.