Gingko biloba extract improves the lipid profile, inflammatory markers, leptin level and the antioxidant status of T2DM patients poorly responding to metformin: A double- blind, randomized, placebo-controlled trial

Abstract The present study aims to evaluate the effects of Ginkgo biloba (GKB) extract as "add- on" therapy with metformin on the lipid profile, inflammatory markers, leptin and the total antioxidant capacity (TAOC) of patients with type 2 diabetes mellitus (T2DM). It is a multi- center, randomized, placebo-controlled double-blinded clinical study. Sixty patients were allocated into two groups: control and treatment groups; they received orally either 120 mg starch/capsule or 120mg GKB/capsule, respectively as an adjuvant with metformin for 90 days. Blood samples were obtained at zero time and after 90 days. The blood was utilized for analysis of the lipid profile, inflammatory markers, leptin, and TAOC. The GKB extract produced a significant decrease in the levels of TG, LDL-c, and CRP, with a significant increase in HDL-c compared to baseline values. There were no significant changes reported in the placebo-treated group. It also produced a significant decrease in the concentrations of IL-6, TNF-α, and leptin compared to baseline values and placebo-treated groups with a significant increase in TAOC compared to baseline values. In conclusion, GKB extract, as an adjuvant with metformin, decreases inflammatory mediators, leptin level and improves the antioxidant status and lipid profile of T2DM patients improperly managed with metformin

Electrocardiographic profile of guinea pig heart submitted to Ginkgo biloba extract and its terpenoids / Perfil eletrocardiográfico do coração de cobaia submetido ao extrato de Ginkgo biloba e seus terpenóides

Electrocardiographic effects produced by Ginkgo biloba extract (EGb) and by ginkgolides A (GA) and B (GB), and bilobalide (BB) were investigated in guinea pig heart mounted in Langendorff apparatus (Tyrode, 34 ± 0.1 ºC, 95% O2, 5% CO2). Electrocardiographic parameters were evaluated in the conditions: 1) control with Tyrode and DMSO, 2) EGb (n=4), GA (n=5), GB (n=5) or BB (n=6), and 3) washout. The results showed that 0.1 and 1.0 mg/ml of EGb do not change the electrocardiographic parameters. However, 10 mg/ml of EGb increased the PR interval (PRi) at 21% (p<0.001). This increase was also observed for 50 mM GA (20%, p<0.001) and 70 mM BB (13%, p<0.001), which indicates Ca2+ channel block. However, the 50 mM GB reduced the PRi at 11 % (p<0.001). The GA (23%, p<0.001), GB (16%, p<0.001), and BB (40%, p<0.001) reduced the QT interval (QTi), which suggests the activation of the potassium channel. However, EGb increased QTi (6%, p<0.001). The EGb (28%, p<0.05) and GB (13%, p<0.05) reduced the heart rate. Atrioventricular (AV) block was observed with EGb, GA, and BB. We can conclude that EGb and its terpenoids alter the ECG parameters inducing AV block, which indicates possible arrhythmogenic potential.

Os efeitos eletrocardiográficos produzidos pelo extrato de Ginkgo biloba (EGb) e gingkolídeos A (GA) e B (GB), e bilobalide (BB) foram investigados em coração de cobaia montado sistema de Langendorff (Tyrode, 34 ± 0.1 ºC, 95% O2, 5% CO2). Os parâmetros do ECG foram avaliados nas condições: 1) Tyrode e DMSO, 2) EGb (n=4), GA (n=5), GB (n=5) ou BB (n=6) diluídos em DMSO e 3) washout. Os resultados demonstram que 0,1 e 1,0 mg/mL de EGb não alteraram os parâmetros eletrocardiográficos. Entretanto, 10 mg/ml de EGb aumentaram o intervalo PR (PRi) em 21% (p<0.001). Esse aumento também foi observado com GA a 50µM (20%, p<0,001) e BB a 70 mM (13%, p<0,001) indicando bloqueio de canais de cálcio. Por outro lado, GB reduziu o PRi (11%, p<0,001). O intervalo QT (QTi) foi reduzido por GA (23%, p<0,001), GB (16%, p<0,001) e BB (40%, p < 0.001) sugerindo uma ativação de canais de potássio. Entretanto, EGb aumentou o QTi (6%, p<0.001). A frequência cardíaca foi reduzida por EGb (28%, p<0.05) e GB (13%, p<0.05). Bloqueios átrio-ventriculares (BAV) foram observados com EGb, GA e BB. Podemos concluir que EGb e os terpenos alteram parâmetros eletrocardiográficos induzindo BAV e demonstrando possível potencial arritmogênico.

Ginkgo modulates noise induced hippocampal damage in male albino rats: a light and electron microscopic study

Noise has been a major problem to mankind and induces many auditory and extra-auditory hazards. This study was carried out to determine the injurious effects of noise on the hippocampus and to show whether Ginkgo biloba has any modulatory effect on hippocampal injury. Twenty-five adult male albino rats were divided into five groups: a control group; a noise group exposed to 100 dB of sound pressure level white noise 4h/day for 4 weeks; a protected group exposed to the same noise level with the administration of a G. biloba extract [50mg/kg daily] for 4 weeks; a recovery group, which was allowed to recover for 4 weeks after noise cessation; and a treated group, administered the same dose of G. biloba for 4 weeks after noise cessation. In the noise-exposed group, the pyramidal cell layer of CA1 and CA3 and the granular cell layer of the dentate gyrus [DG] showed a decrease in thickness compared with the control group, which showed loss and degeneration of many cells, and evidence of increased apoptosis. The protected and treated groups showed improvement in many parameters compared with the recovery group, that is, an increase in the thickness of CA1, CA3, and DG; increase in the surface area of cells; increased vascularity; and a statistically significant decrease in apoptosis compared with the recovery group. Noise exerted detrimental effects on cells of CA1, CA3, and DG of the hippocampus. Although partial spontaneous recovery may occur after cessation of noise exposure, the administration of G. biloba led to a marked decrease in the injurious effect of noise on the hippocampus. This might suggest the probable usefulness of G. biloba in reducing the central hazardous effects in individuals exposed to noise

involvement of GABA-ergic transmission in the anticonvulsant effect of ginkgo biloba against kainic acid-induced seizures in mice

Ginkgo biloba[GbE] is an herbal product that has been proven to be effective in many neurological disorders. However, its anticonvulsant activity is not sufficiently studied. The aim of this work is to study the anticonvulsant activity of GbE and the role of GABA-ergic transmission in this effect.[1] Studying the anticonvulsant activity of GbE in different dose levels [20, 30 and 50 mg/kg/d, orally] for 15 days against kainic acid [KA]-induced seizures in mice. [2] Measurement of the brain giutamate and GAB A levels and glutamate decarboxylase [GAD] activity. GbE showed a protective effect for animals against KA-induced seizures in a dose-related manner. This appeared in form of a significant increase in time of seizure onset and decrease in percent of seizures and mortality in animals treated with GbE. Furthermore, there was a significant decrease in brain glutamate level and increase in GABA level and GAD activity in GbE-treated groups relative to KA-treated group. From the obtained results, we can conclude that GbE has effective anticonvulsant activity against KA-induced seizures. This effect may be mediated via various mechanisms but GABA-ergic transmission plays a vital role in this effect. Future research directions include further studies of the other possible mechanisms of GbE involved in its anticonvulsant and neuropotective activity

Ginkgo biloba effects on mice fetal liver / Efectos de la ginkgo biloba en el hígado fetal de ratón

Ginkgo biloba is considered to be an alternative drug for various indications; unfortunately very few studies are available on its side effects. This present study describes the harmful effects of Ginkgo biloba on developing fetal liver. Two experimental groups of six pregnant female mice each were given Ginkgo biloba at human therapeutic dose (A) and a higher dose (B) throughout the gestation period. A third group (C) was taken as a control and given distilled water only. Fetal livers were examined and the effects of the drug observed. There were signs of congestion and fatty change along with dilatation of sinusoids in a dose dependent manner concluding that Ginkgo biloba affects fetal liver.

La Ginkgo biloba es considerada, en varias indicaciones, como un medicamento alternativo; sin embargo, existen pocos reportes disponibles sobre sus efectos secundarios. Este estudio describe los efectos nocivos de Ginkgo biloba en el desarrollo del hígado fetal. Dos grupos experimentales de 6 ratones hembras preñadas recibieron Ginkgo biloba en la dosis terapéutica humana (A) y una dosis más alta (B) por el período de gestación. Un tercer grupo control (C) recibió agua destilada. Los hígados fetales fueron examinados y observados los efectos de la droga. Hubo signos de congestión y degeneración grasa, junto con la dilatación de sinusoides en función de la dosis. Como conclusión la Ginkgo biloba afecta el hígado fetal.