Ginkgo biloba Extracts EGb 761 and Bilobalide Increase NADH Dehydrogenase mRNA Level and Mitochondrial Respiratory Control Ratio in PC12 Cells

In the present study, we investigated the effect of Ginkgo biloba extract, EGb 761, and one of its components, bilobalide, on gene expression of subunit 1 of mitochondrial NADH dehydrogenase (ND1) in PC12 cells. By Northern blot analysis we found a 2-fold significant increase in ND1 mRNA level, after 48 and 72 h exposure to 100 g/ml EGb 761 and to 10 g/ml bilobalide. We also evaluated, by oxygraphy measurements, mitochondrial respiration during state 3 and state 4. In cells treated with EGb 761 and bilobalide for 48 and 72 h, state 4 respiration was significantly decreased, and the respiratory control ratio was increased. These results provide evidence that EGb 761 and bilobalide exert their protective effects by up-regulating mitochondrial ND1 gene expression and by decreasing state 4 respiration, whose increase is thought to be responsible for oxidative damage.     

Production of ginkgolides and bilobalide from optimized the<Emphasis Type="Italic">Ginkgo biloba</Emphasis> cell culture

The influence of various culture conditions on growth and ginkgolides (GKA and GKB), and bilobalide formation in callus and suspension cultures ofGinkgo biloba were investigated. Callus induced from the leaf petioles exhibited distinct morphological and physiological responses. The cell biomass and ginkgolides content varied among the cell lines brownish callus lines produced high levels of ginkgolides and bilobalide in spite of poor cell growth. Among the culture media used, MS medium showed significant effect on cell growth and ginkgolides production. Low concentration of sucrose (3%) improved cell growth, while higher sucrose levels (5 and 7%) improved ginkgolides production. Cultivation of callus cultures above 28°C dramatically reduced their growth rate; however the cell lines grown at 36°C showed increased levels of bilobalide content. A 2.5-L balloon type bubble bioreactor (BTBB) was successfully developed for the cell growth and ginkgolides production.     

Effects of methyl jasmonate and salicylic acid on the production of bilobalide and ginkgolides in cell cultures of Ginkgo biloba

Summary In an attempt to increase productivity, the effects of the elicitors methyl jasmonate (MJ) and salicylic acid (SA) on the production of bilobalide (B), ginkgolide A (GA), and ginkgolide B (GB) were studied in cell suspension cultures of Ginkgo biloba. MJ treatments increased the amounts of B, GA, and GB, concomitant with a slight decrease in cell growth. After treatment of 0.01 mM MJ, levels of GA and GB increased 4.3-and 8.2-fold over controls by 12 h and declined after 24h. The 1.0mM MJ treatment produced a maximal release of B after 12h of exposure and increased the concentration of B in the culture medium up to 6.25-fold compared with the controls. Treatment with 1.0mM SA transiently enhanced GA and GB production up to 3.1-and 6.1-fold, respectively, compared with the control. However, treatment 1.0 mM SA did not have a significant effect on B production. When treated with 0.01 mM SA, the level of B in the cells was increased 5.4-fold over controls by 12h and declined after 24h. The concentrations and exposure times of both MJ and SA were factors that strongly affected the production of B, GA, and GB. The results from this study suggest that MJ and SA directly or indirectly increased the production of B, GA, and GB in cells, and stimulated the release of these metabolites into the culture medium.