Yuanyuan Gao

Development of a novel method combining HPLC fingerprint and multi-ingredients quantitative analysis for quality evaluation of traditional chinese medicine preparation

A novel method combining high performance liquid chromatography (HPLC) fingerprint and simultaneous quantitative analysis of multiple active components was developed and validated for quality evaluation of one type of traditional Chinese medicine preparations: Shuang-huang-lian (SHL) oral liquid formulation. For fingerprint analysis, 45 peaks were selected as the common peaks to evaluate the similarities among several different SHL oral liquid preparations collected from manufacturers. Additionally, simultaneous quantification of eleven markers, including chlorogenic acid, caffeic acid, rutin, forsythiaside, scutellarin, baicalin, forsythin, luteoloside, apigenin, baicalein and wogonin, was performed. Statistical analysis of the obtained data demonstrated that our method has achieved desired linearity, precision and accuracy. Finally, concentrations of these eleven markers in SHL oral liquid prepared by different manufacturers in China were determined. These results demonstrated that the combination of HPLC chromatographic fingerprint and simultaneous quantification of multi-ingredients offers an efficient and reliable approach for quality evaluation of SHL oral liquid preparations.

Effects of Ginkgo biloba on prevention of development of experimental diabetic nephropathy in rats

AbstractAim:To observe the preventive and therapeutic effects of Ginkgo biloba extract (GbE) on early experimental diabetic nephropathy (DN) in rats.Methods:After an early DN model was induced by streptozotocin, rats were administered GbE at 3 doses for 12 weeks. Fasting blood glucose, creatinine (Cr), blood urea nitrogen (BUN), urine protein, kidney index, anti-oxidase, advanced glycosylation end products (AGE), collagen IV and laminin, matrix metalloproteinases-2 (MMP-2) and the tissue inhibitor of metalloproteinase-2 (TIMP-2), connective tissue growth factor (CTGF), and transforming growth factor-β1 (TGF-β1) mRNA were measured by different methods. The ultrastructural morphology and the thickness of glomerular base membrane (GBM) were observed by a transmission electron microscope.Results:For the GbE-treated DN rats, when compared with the vehicle-treated DN rats, the fasting blood glucose level, Cr, BUN, urine protein level, and the intensity of oxidative stress were significantly decreased. The expression of MMP-2 greatly increased, and TIMP-2 decreased. Also, AGE, either in serum or in renal, the collagen IV, laminin, CTGF levels, and TGF-β1 mRNA were reduced. Furthermore, both relative grades of mesangium hyperplasia by microscopical observation and the thickness of GBM by electron microscope measurement decreased significantly.Conclusion:GbE has protective effects on several pharmacological targets in the progress of DN and is a potential drug for the prevention of early DN.

Ginkgo biloba extract prevents glucose‐induced accumulation of ECM in rat mesangial cells

Pathological remodeling characterized by extracellular matrix (ECM) accumulation contributes to diabetic nephropathy (DN). This study evaluated the effects of Ginkgo biloba extract (GbE) on the metabolism of the ECM in rat mesangial cells cultured in hyperglycemic conditions. The cultured mesangial cells in high glucose conditions were allotted into six groups: normal control group, high glucose group, low concentration of GbE group, moderate concentration of GbE group, high concentration of GbE group, and captopril group. In the presence of high glucose, the levels of matrix metalloproteinase‐2 (MMP‐2), matrix metalloproteinase‐9 (MMP‐9) and extracellular matrix metalloproteinase inducer (EMMPRIN) were decreased significantly, and the levels of tissue inhibitor of metalloproteinase‐2 (TIMP‐2), tissue inhibitor of metalloproteinase‐1 (TIMP‐1) and plasminogen activator inhibitor‐1 (PAI‐1) were increased significantly. These changes were reversed by GbE. GbE lowered the levels of transforming growth factor‐β1 (TGF‐β1), insulin‐like growth factor‐1 (IGF‐1) and connective tissue growth factor (CTGF) of the high glucose group. Furthermore, GbE also decreased the expressions of collagen IV and laminin of the high glucose group. In summary, the results suggest that GbE postpones the extracellular matrix accumulation by inhibiting the synthesis of ECM and promoting the degradation of ECM, and therefore, is a potential drug for the prevention and treatment of DN. Copyright

Ginkgo biloba extract suppresses hypertrophy and extracellular matrix accumulation in rat mesangial cells

AbstractAim:To observe the effects of Ginkgo biloba extract (EGb) on the hypertrophy of mesangial cells and the accumulation of extracellular matrix (ECM) in mesangial cells.Methods:Cultured mesangial cells were allotted into 7 groups: normal group, solvent control group, high glucose group, low dose of EGb group, moderate dose of EGb group, high dose of EGb group, and captopril group. Activities of cell antioxidases, S phase percentage and G0/G1 phase percentage, collagen IV and laminin, Smad2/3 and Smad7, TGF-β1 mRNA were measured by different methods.Results:For EGb-treated groups, when compared with high glucose group, the cell percentage of S phase was raised and the percentage of G0/G1 was lowered. The intensity of oxidative stress was weakened. The expression of Smad2/3 was greatly decreased and Smad7 was increased. Collagen IV, laminin and TGF-β1 mRNA were also reduced.Conclusion:EGb can suppress cell hypertrophy and the accumulation of ECM in rat mesangial cells, which means it could play a vital role in the delay of glomerulosclerosis in diabetic nephropathy.

Retracted: Protective Effects of Rutin on Rat Glomerular Mesangial Cells Cultured in High Glucose Conditions

The protective effect of rutin on the glomerulosclerosis of diabetic nephropathy (DN) in rat mesangial cells was investigated. The cultured mesangial cells were divided into eight groups: normal, solvent control, high glucose, low dose of rutin, moderate dose of rutin, high dose of rutin, captopril and Ginkgo biloba extract. The cell cycles, type IV collagen and laminin in cytoplasm, TGF‐β1 mRNA of mesangial cells, Smad 2/3 and Smad 7, and the activities of four antioxidant indexes including T‐SOD, MDA, CAT and GSH‐Px were measured by flow cytometry, radioimmunoassay, RT‐PCR, western blotting and visible spectrophotometry, respectively. Compared with the high glucose group, rutin decreased the cell percentages of the G0/G1 phase and inhibited the expression of Smad 2/3, laminin and type IV collagen, and TGF‐β1 mRNA level, significantly. The antioxidant capacity, the cell percentages of S phase and Smad 7 expression were significantly increased by rutin. These results suggest that rutin is a potent protective agent against glomerulosclerosis in DN. Copyright

Ginkgo biloba extract prevents against apoptosis induced by high glucose in human lens epithelial cells

AbstractAim:To investigate the protective effects of Ginkgo biloba extract (GBE) on high glucose-induced apoptosis of human lens epithelial cells (HLEC) and the possible molecular mechanisms.Methods:The cultured HLEC were allotted into 6 groups: normal group, high glucose group, low-, moderate-, and highdose GBE group, and the bendazac lysine group. Cell viability, cell apoptosis, the activities of cell antioxidases, aldose reductase, caspase-3, the levels of cell antioxidants, and the expressions of Bcl-2 and Bax were assessed by different methods.Results:After being incubated with high glucose for 24 h, HLEC underwent apoptosis and exhibited significant oxidative stress. In the presence of GBE at different doses, the rate of HLEC apoptosis was lower and the oxidative stress state was significantly ameliorated. The increased ratio of Bax to Bcl-2 was significantly reduced and the activation of caspase-3 was suppressed by GBE in a dose-dependent manner.Conclusion:GBE prevents HLEC from high glucose-induced apoptosis through inhibiting oxidative stress, reducing the ratio of Bax to Bcl-2, and decreasing the activity of caspase-3. Therefore, GBE has a potential protective effect against diabetic cataract formation.

Protective effects of serum containing Ginkgo biloba extract on glomerulosclerosis in rat mesangial cells.

ETHNOPHARMACOLOGICAL RELEVANCE Ginkgo biloba extract (GBE) is an ancient Chinese phytomedicine which was used to treat various ailments including circulatory and demential disorders. AIM OF THE STUDY To study GBEs protective effects on the glomerulosclerosis of diabetic nephropathy (DN) in rat mesangial cells by serum pharmacological methods. MATERIALS AND METHODS The cultured mesangial cells were divided into seven groups: normal, solvent control, high glucose, low dose of GBE serum, moderate dose of GBE serum, high dose of GBE serum, and GBE. The activities of cell antioxidases, type IV collagen and laminin, Smad2/3 and Smad7, and TGF-beta(1) mRNA were measured by methods of spectrophotometry, radioimmunoassay, immunocytochemistry, and RT-PCR, respectively. RESULTS The intensity of oxidative stress decreased in the GBE serum-treated groups in comparison with the high glucose group. In addition, the expression of Smad2/3 was greatly reduced, whereas Smad7 expression increased; type IV collagen, laminin and TGF-beta(1) mRNA levels were also diminished. CONCLUSION These results suggest that GBE is protective agent against glomerulosclerosis in diabetic nephropathy of mesangial cells.

Gradient HPLC-DAD for the Simultaneous Determination of Five Flavonoids in Plasma After Intravenously Administrated Ginkgo biloba Extract and its Application in the Study of Pharmacokinetics in Rats

Abstract A HPLC-DAD method was used and validated for the simultaneous determination of five flavonoids (rutin, quercitrin, quercetin, kaempferol, and isorahamnetin) in rat plasma. Chromatographic separation was performed using a Kromasil C18 column (250 × 4.6 mm, 5 µm) maintained at 35°C. The mobile phase was a mixture of methanol and 0.1% formic acid with a step linear gradient. At 1.0 mL/min flow rate, the eluent of five flavonoids were detected simultaneously at 350 nm with good separation. Under optimum conditions, good linear relationship between the peak area and the concentrations were obtained in the ranges of 0.2525 ∼ 20.2, 0.1208 ∼ 9.66, 0.1008 ∼ 20.16, 0.031 ∼ 2.46, and 0.098 ∼ 7.84 µg/mL for rutin, quercitrin, quercetin, kaempferol, and isorhamnetin, respectively. The correlation coefficient for each analyte was above 0.999. The intra-day and inter-day precisions were better than 7% and 10%. The detection limit (S/N = 3) for rutin, quercitrin, quercetin, kaempferol, and isorhamnetin were 0.01, 0.02, 0.006, 0.02 and 0.02 µg/mL, respectively. The method was validated for accuracy and precision, and it has been successfully applied to determine drug concentrations in rat plasma samples from rat that had been intravenously administrated Ginkgo biloba extract.