Homoisoflavanones from Polygonatum odoratum rhizomes inhibit advanced glycation end product formation.

Protein glycation inhibitors from Polygonatum odoratum rhizomes were investigated using a bioassay-guided procedure to characterize active compounds for preventing and treating diabetic complications. The EtOH extract and soluble fractions were evaluated using an in vivo model of renal advanced glycation end-product (AGE) accumulation in streptozotocin-induced diabetic rats and an in vitro bovine serum albumin-glucose assay. Three homoisoflavanones 3-(4'-hydroxybenzyl)-5,7-dihydroxy-6-methyl-8-methoxychroman-4-one (1), 3-(4'-hydroxybenzyl)-5,7-dihydroxy-6,8-dimethylchroman-4-one (2), and 3-(4'-methoxybenzyl)-5,7-dihydroxy-6-methyl-8-methoxychroman-4-one (3), isolated from the active CHCl3-soluble fraction of the EtOH extract, were subjected to in vitro bioassays to evaluate their inhibitory activities against AGE formation. All the isolates inhibited AGE formation more effectively than the positive control, aminoguanidine. These results indicate that pending further study these compounds could be used as novel natural product drug for mitigating diabetic complications.

[Study on the theraputic effect of plants of Camellia genus on osteoporosis].

OBJECTIVE: To observe anti-osteoporotic effect of Plants of Camelia genus induced by retinoic acid in rats, in adqulis crude drug dosage, and to compare activities of them. METHODS: Extracts of Camellia japonica and Camellia oleifera were given to rats with osteoporosis induced by retinoic acid, some indexes of rats were measured and compared with those of modle group, control group and positive control group, including weight/length (G/L), bone density, earth and calcium content of bone, morphology change and serum calcium, tartrate-resistant acid phosphatase and alkaline phosphatase. We also compared effective intensity between different groups in adqulis crude drug dosage. RESULTS: Ethanol extracts of seed from Camellia japonica 0.51 g/kg could markedly enhance weight/length (G/L), bone density of femur, serum calcium and alkaline phosphatase level, with the decreasing of anti-tartaric acid tartrate-resistant acid phosphatase level. Meanwhile, they were accompanied by a significant increase of morphologic observed sclerotomal cell and by a significant decrease of osteoclast. Moreover, it was observed greatly that bone trabecula transformateed to normal morphous. The results of this study indicated that effects of ethanol extracts of seed from Camellia japonica on anti-osteoporosis with retinoic acid were the strongest. Ethanol extracts of seed from Camellia japonica , ethanol extracts of leaves from Camellia Oleifera, and aqueous extracts of leaves from Camellia Oleifera were stronger than positive control drug. The other extracts didnt show obvious anti-osteoporotic effects. Eventually the strength order of each group on anti-osteoporosis was as following: ethanol extracts of seed from Camellia japonica > ethanol extracts of leaves from Camellia Oleifera > aqueous extracts of leaves from Camellia Oleifera > aqueous extracts of seed from Camellia Oleifera > positive control drug > aqueous extracts of seed from Camellia Japonica. CONCLUSION: Plants of Camellia genus have different degree anti-osteoporosis effect, which can offer significant theory basis for progressive investigation and exploitation of them.