The in vivo anti-tumor activities of decursinol angelate (1) and decursin (2) isolated from the roots of Angelica gigas were investigated. These two compounds, when administered consecutively for 9 days at 50 and 100 mg/kg i.p. in mice, caused a significant increase in the life span and a significant decrease in the tumor weight and volume of mice inoculated with Sarcoma-180 tumor cells. These results suggest that decursinol angelate (1) and decursin (2) from A. gigas have anti-tumor activities.

Aldose reductase, the principal enzyme of the polyol pathway, has been shown to play an important role in the complications associated with diabetes. A methanol extract of the stamens of Nelumbo nucifera Gaertn. was shown to exert an inhibitory effect on rat lens aldose reductase (RLAR), and thus was fractionated using several organic solvents, including dichloromethane, ethyl acetate and n-butanol. The ethyl acetate-soluble fraction, which manifested potent RLAR-inhibitory properties, was then purified further via repeated measures of silica gel and Sephadex LH-20 column chromatography. Thirteen flavonoids: kaempferol (1) and seven of its glycosides (2-9), myricetin 3',5'-dimethylether 3-O-beta-d-glucopyranoside (10), quercetin 3-O-beta-d-glucopyranoside (11) and two isorhamnetin glycosides (12, 13) were isolated from N. nucifera, as well as four non-flavonoid compounds: adenine (14), myo-inositol (15), arbutin (16) and beta-sitosterol glucopyranoside (17). These compounds were all assessed with regard to their RLAR-inhibitory properties. Among the isolated flavonoids, those harboring 3-O-alpha-l-rhamnopyranosyl-(1-->6)-beta-d-glucopyranoside groups in their C rings, including kaempferol 3-O-alpha-l-rhamnopyranosyl-(1-->6)-beta-d-glucopyranoside (5) and isorhamnetin 3-O-alpha-l-rhamnopyranosyl-(1-->6)-beta-d-glucopyranoside (13), were determined to exhibit the highest degree of rat lens aldose reductase inhibitory activity in vitro, evidencing IC(50) values (concentration required for a 50% inhibition of enzyme activity) of 5.6 and 9.0 microm, respectively.

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The inhibitory effects of compounds from Salicornia herbacea (Chenopodiaceae) on rat lens aldose reductase (RLAR) and sorbitol accumulation in streptozotocin-induced diabetic rat tissues were investigated. The various fractions from the MeOH extract of S. herbacea were tested for their effects on RLAR in vitro. Among them, the EtOAc fraction was found to exhibit a potent RLAR inhibition (IC 50 ‫57.0؍‬ m mg/ml), from which an active principle as a potent AR inhibitor was isolated and its chemical structure was

The antioxidant activities of Acanthopanax senticosus stems were evaluated in CCl4-intoxicated rats. The n-butanol fraction from the water extract of the stems, when pretreated orally at 200 mg/kg/day for 7 consecutive days in rats, was demonstrated to exhibit significant increases in antioxidant enzyme activities such as hepatic cytosolic superoxide dismutase, catalase and glutathione peroxidase by 30.31, 19.82 and 155%, respectively. The n-butanol fraction whereas showed a significant inhibition of serum GPT activity (65.79% inhibition) elevated with hepatic damage induced by CCl4-intoxication. Eleutheroside B, a lignan component, isolated from the n-butanol fraction was found to cause a moderate free radical scavenging effect on DPPH, its scavenging potency as indicated in IC50 value, being 58.5 microM. These results suggested that the stems of A. senticosus possess not only antioxidant but also hepatoprotective activities.

We evaluated the inhibitory effects of components from the root of Glycyrrhiza uralensis (G. uralensis) on aldose reductase (AR) and sorbitol formation in rat lenses with high levels of glucose as part of our ongoing search of natural sources for therapeutic and preventive agents for diabetic complications. In order to identify the bioactive components of G. uralensis, 5 prenylated flavonoids (semilicoisoflavone B, 7-O-methylluteone, dehydroglyasperin C, dehydroglyasperin D, and isoangustone A), three flavonoids (liquiritigenin, isoliquiritigenin, and licochalcone A), and two triterpenoids (glycyrrhizin and glycyrrhetinic acid) were isolated; their chemical structures were then elucidated on the basis of spectroscopic evidence and comparison with published data. The anti-diabetic complication activities of 10 G. uralensis-derived components were investigated via inhibitory assays using rat lens AR (rAR) and human recombinant AR (rhAR). From the 10 isolated compounds, semilicoisoflavone B showed the most potent inhibition, with the IC 50 values of rAR and rhAR at 1.8 and 10.6 m mM, respectively. In the kinetic analyses using Lineweaver-Burk plots of 1/velocity and 1/concentration of substrate, semilicoisoflavone B showed noncompetitive inhibition against rhAR. The results clearly indicated that the presence of a g g,g g-dimethylchromene ring is partly responsible for the AR inhibitory activity of isoprenoid-type flavonoids. Further, semilicoisoflavone B inhibited sorbitol formation of rat lens incubated with a high concentration of glucose, indicating that this compound may be effective for preventing osmotic stress in hyperglycemia.

Four compounds were isolated from Salicornia herbacea by repeated column chromatography. Their structures were identified as beta-sitosterol (1), stigmasterol (2), uracil (3), and isorhamnetin-3-O-beta-D-glucopyranoside (4) by spectral analysis and comparison with the published data.

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