Effects of water extract of 1:1 mixture of Phellodendron cortex and Aralia cortex on polyol pathway and oxidative damage in lenses of diabetic rats.

Enhanced activity of the polyol pathway and oxidative damage have been implicated in the pathogenesis of diabetic cataract. We decided to investigate whether these changes in diabetic lenses could be prevented by the water extract of Phellodendron cortex and Aralia cortex (P55A). Aldose reductase activity was inhibited significantly by the treatment with P55A. Consequently, it caused a dramatic reduction in the high sorbitol contents observed in the lenses of diabetic rats. In addition, the greatly elevated content of thiobarbituric acid reactive substances (TBARS) and carbonylated protein in diabetic rats were reduced by P55A treatment. These results suggest that P55A extract exerts an antioxidant effect by reducing lipid peroxidation and protein carbonylation as well as having an inhibitory action against aldose reductase in the lenses of diabetic rats.

Biostatic activity of Coix lacryma seed extract on Toxoplasma gondii in macrophages.

Water extract of Coix lacryma seeds (Co-Ex) was separated into several components; dissolved with Tris-Cl buffer and the supernatant (WC1), ammonium sulfate treatment supernatant (WC2) and the pellet (WC3), QAE column chromatography of WC1 and the peak portions; WC4, WC5 and WC6. Murine peritoneal macrophages in DMEM containing 10% heat-inactivated FCS were infected with tachyzoites of Toxoplasma gondii, RH strain, in vitro. By adding modulators such as Co-Ex, WC1,2,3,4,5,6 and LPS or IFN-gamma for 24 hrs, toxoplasmastatic activity of macrophages was examined in relation to nitrite production. Nitrite production of macrophages was enhanced especially in the series of WC2, WC1 and the combination sample (WC1+WC2+WC3) by order, than other components or fractions (WC4, WC5, WC6) tested. Toxoplasmastatic actions such as percentage of the macrophages infected by T. gondii and fold increase of T. gondii in macrophages showed retroverse relations with the amount of nitrite production; i.e., as nitric oxide (NO) increased the phagocytic index of macrophages and the fold increase of tachyzoites in macrophages decreased. Nitrite (NO2) production was increased by adding IFN-gamma in all cases together with enhancement of biostatic effects. Through the results obtained, it is speculated that some components other than the non-proteinous and defatted components in Coix lacryma seeds may contribute to activate macrophages through induction of NO for the biostatic activity.

Isolation of isoguanosine from Croton tiglium and its antitumor activity.

This paper describes the isolation of isoguanosine from Croton tiglium L. and its cytotoxic effect against several tumor cell lines in culture and newly reports that isoguanosine has an antitumor activity against implanted S-180 ascitic tumor mice. Isoguanosine is effective at the dose of 24 mg/kg/day x 5, with T/C value of 168%. Isoguanosine inhibits the growth of S-180 and Ehrlich solid tumor in mice at the optimal doses of 96 mg/kg/day x 12 and 48 mg/kg/day x 12, with 1-T/C values of 65% and 60%, respectively.

Sapogenins from Melandrium firmum.

Two sapogenins isolated from MELANDRIUM FIRMUM are shown to have the structures of 3beta,21beta-dihydroxy-16,23,dioxo-28-nor-17alpha,18beta-olean-12-ene and 3beta-16alpha-dihydroxy-23-oxo-olean-13(18)-en-28-oic acid, respectively by spectral data and X-ray crystallographic analysis.