Cyclocarya paliurus tea leaves enhances pancreatic ß cell preservation through inhibition of apoptosis.

Leaves of Cyclocarya paliurus are a sweet tea traditionally used to treat obesity and diabetes in China. However, its protective mechanisms against hyperglycemia remains unclear. Here, we demonstrate that the extract of C. paliurus leaves significantly decreased body loss, food intake and blood glucose level, and increased blood insulin level, ß-cell number and insulin-producing ß cells in high-fat diet-low dose STZ-induced diabetic mice. In vivo and in vitro studies also showed the extract of C. paliurus leaves significantly inhibited pancreatic ß cell apoptosis by suppressing the expression of caspase 8, caspase 9 and cleaved caspase-3, as well as Bax/Bcl-2 ratio, down-regulating p38, ERK and JNK phosphorylation, and up-regulating Akt phosphorylation. These effects were significantly enhanced by inhibitor p-38 or ERK or JNK, and counteracted by inhibitor of PI3K. In addition, the extract of C. paliurus leaves also significantly improved hepatic steatosis, nephropathy and cardiac hypertrophy of diabetic mice. Taken together, these results provide the insight into the effects of C. paliurus leaves on pancreatic ß cell preservation in standing glucolipotoxicity. Therefore, C. paliurus tea leaves may be used as a new remedy for diabetes through enhancing pancreatic ß cell preservation by inhibiting ß cell apoptosis.

Dibenzocyclooctadiene lignans and norlignans from fruits of Schisandra wilsoniana.

Seven new dibenzocyclooctadiene lignans, marlignans M-S (1-7), four new norlignans, marphenols C-F (8-11), and 21 known compounds (12-32) were isolated from the fruits of Schisandra wilsoniana. The structures of 1-11 were elucidated by spectroscopic methods including 1D- and 2D-NMR techniques and CD experiments. Compounds 1-11 were evaluated for their anti-HIV activities and showed EC(50) values in the range 2.97-6.18 µg/mL and therapeutic index values of 5.33-29.13.

Secolignans, neolignans and phenylpropanoids from Daphne feddei and their biological activities.

Two new secolignans and one new neolignan, named feddeiphenols A-C (1-3), together with eight known compounds (4-11), were isolated from the leaves and stems of Daphne feddei. Their structures were established on the base of spectroscopic methods, mainly extensive NMR, UV spectroscopy, and MS spectrometry. Compounds 1-11 were tested for their anti-human immunodeficiency virus (HIV)-1 activity and cytotoxicity. The results revealed that compounds 1, 2, 3, 7, and 9 showed therapeutic index (TI) values above 30, respectively, and the other compounds also showed weak anti-HIV-1 activity. Compound 1 showed modest cytotoxic activity. The other compounds also showed weak cytotoxic activity.

Dibenzocyclooctadiene lignans from the fruits of Schisandra rubriflora and their anti-HIV-1 activities.

Two new dibenzocyclooctadiene lignans, rubrilignans A and B (1, 2), together with 17 known ones, were isolated from the fruits of Schisandra rubriflora. The structures of 1 and 2 were elucidated by spectroscopic methods including extensive 1D and 2D NMR techniques. Compounds 1 and 2 were also evaluated for their anti-HIV-1 activities and showed weak anti-HIV-1 activity with EC(50) values of 2.26 and 1.82 µg/ml, and therapeutic index values of 35.5 and 18.6, respectively.