Qing Jin

Southwest University in Chongqing, Pehpei, Chongqing Shi, China

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Publications (4)7.24 Total impact

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    ABSTRACT: Objective: To screen the active constituents in hypoglycemic fractions in the roots of Aucklandiae lappa. Methods: The ethyl acetate fraction and butyl fraction were prepared by isolating the ethanol extracts in the roots of A. lappa using ethyl acetate and butyl alcohol, and the remaining water phase was named as water extract. The hypoglycemic effects of these fractions were first screened in glucose consume test by HepG2 cells, and then confirmed by alloxan-induced diabetic mice. The ethyl acetate fraction with high hypoglycemic activity was further purified using column chromatography, from which two compounds were obtained. They were costunolide and dehydrocostus lactone. Their structures were evaluated by NMR and their hypoglycemic activities were studied. Results: The ethyl acetate fraction was more hypoglycemic than butyl alcohol fraction and water extract. Costunolide and dehydrocostus lactone purified from ethyl acetate fraction revealed the significant hypoglycemic effect on alloxan-induced diabetic mice and also had anti-oxidative activities. Conclusion: Costunolide and dehydrocostus lactone isolated from the roots of A. lappa exert hypoglycemic activity through the inhibition of oxidative stress, thereby reducing insulin resistance.
    No preview · Article · Jul 2012 · Chinese Traditional and Herbal Drugs
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    ABSTRACT: The root of Polygonatum odoratum (YuZhu), also a medicinal food has long been used for the treatment of diabetes. The objective of the study was to characterize the anti-diabetic active fractions or compounds in this herb. Fractions with a different polarity were prepared by solvent extraction and macroporous absorptive resin (D101) column and their anti-diabetic potentials were evaluated by glucose uptake in HepG2 cells and STZ-induced diabetic rats. In addition, α-glycosidase inhibitory activities of active fractions were measured in vitro and chemical compositions including saponin, total flavonoids and total sugar in the fractions were determined. The n-buthanol fraction, a saponin-rich fraction obtained by partitioning the ethanol extract with n-buthanol after petroleum ether and acetic ether showed the highest anti-diabetic potential in glucose uptake in HepG2 cells followed by acetic ether fraction which was rich in flavonoids. Further fractionation the saponin-rich fraction using macroporous resin column (D101), polysaccharide, flavonoid and saponin rich fractions were obtained by elution with water, 40% and 60% ethanol, respectively and their anti-diabetic potentials proved by glucose uptake test in HepG2 cells and STZ-induced diabetic rats were in the order of saponin rich fraction>flavonoid rich fraction>polysaccharide rich fraction. Long-term therapy test (60d) in severe diabetic rats indicated that saponin-rich fraction significantly ameliorated clinical symptoms of diabetes including the elevated blood glucose, body weight loss as well as the increased food and water intake while flavonoid-rich fraction was more potential than saponin-rich fraction to increase superoxide dismutase (SOD) activity and decrease malondialdehyde (MDA) level in rat plasma. Additionally, saponin-rich fraction and flavonoid-rich fraction showed α-glycosidase inhibitory activity with IC(50) value of 2.05±0.32 and 3.92±0.65mg/ml, respectively. The results suggested that saponin in this herb was more important than flavonoid in exhibiting anti-diabetic activity and flavonoid contributed more to anti-oxidant activity in vivo.
    No preview · Article · Feb 2012 · Journal of ethnopharmacology
  • YF Deng · R E Aluko · Q Jin · Y Zhang · L J Yuan
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    ABSTRACT: Baicalin has been characterized as the active compound and quality control marker in Scutellaria baicalensis Georgi, traditionally used as a hypotensive herb. To investigate the inhibitory activities of baicalin against renin and angiotensin-I converting enzyme (ACE) and their molecule mechanism of interactions. The fluorescence method using renin substrate 1(R-2932) and the spectroscopy method by Cushman were used to determine renin and ACE activities, respectively. The fluorescence quench techniques were used to characterize their interactions. The results showed that baicalin inhibited renin activity with an IC(50) value of 120.36 µM and inhibited ACE activity with an IC(50) value of 2.24 mM in vitro. The fluorescence emission of both renin and ACE were efficiently quenched by baicalin and a complete quenching was achieved at a high concentration of baicalin. Furthermore, baicalin was more effective in quenching the fluorescence of renin (K(SV) = 60 × 10(3) M(-1)) than ACE (K(SV) = 17.1 × 10(3) M(-1)). The quenching of fluorescence of renin and ACE involved static interactions, which was characterized by the formation of quencher-enzyme complex. The baicalin-renin complex formed through three-sites binding including the active site with a binding constant of 796.15 × 10(13) M(-1), but there was only one binding site for the baicalin-ACE complex with a much smaller binding constant of 6.8 × 10(5) M(-1). The inhibition activity of baicalin against renin was a result of the formation of stable complex through multisites binding including the active site, which could explain the higher inhibitory efficiency.
    No preview · Article · Dec 2011 · Pharmaceutical Biology
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    ABSTRACT: Traditional Chinese medicine (TCM) has been used for treating complex chronic diseases owing to their fewer side-effects, better patient tolerance and relatively less cost. The present work was carried out to study the anti-diabetic efficacy and mechanisms of 34 TCMs. Streptozotocin (STZ)-diabetic mice were orally administrated with corresponding herbal solution once a day for 4 weeks. At the end of experiment, the level of plasma glucose, malondialdehyde (MDA), the activity of superoxide dismutase (SOD) and the serum aldose reductase (AR) were determined, the effects of TCM extract on α-glucosidase and angiotensin-converting enzyme (ACE) in vitro were also evaluated. 13 out of the 34 herbs showed a statistically significant plasma glucose lowering action compared with the diabetic control group. Biochemical analysis revealed that Atractylodes macrocephala, Codonopsis pilosula, Dioscorea opposite, Flos lonicerae and Pueraria lobata may retard the progression of diabetes via reduce the blood glucose level and prevent the increase of AR activity. Other tested herbs, such as Ramulus cinnamomi, Cinnamomum cassia, and Eucommia ulmoides, showed the antidiabetic ability by either prevent the decrease in SOD activity or suppress the increase of MDA. Zymologic assay reveals that Pueraria lobata and Anemarrhena asphodeloides showed the highest inhibition against α-glucosidase and ACE respectively. Interestingly, the post-treatment glucose levels and AR activity were positively correlated with kidney/body weight of 34 herbs treated diabetic mice (p = 0.02, 0.04 respectively). Several potential antidiabetic herbs derived from Chinese traditional pharmacopeia such as Dioscorea opposite, Pueraria lobata, Codonopsis pilosula and Ramulus cinnamomi, have been found to exert a beneficial action on diabetes and diabetic complications via multi-mechanisms.
    No preview · Article · Jul 2011 · Journal of ethnopharmacology