The Effect of Ginkgo Biloba Dropping Pills on Hemorheology and Blood Lipid: A Systematic Review of Randomized Trials

Pharmacokinetic and pharmacodynamic herb-drug interactions-part I. Herbal medicines of the central nervous system

Unlike conventional drug substances, herbal medicines are composed of a complex of biologically active compounds. Therefore, the potential occurrence of herb-drug interactions is even more probable than for drug-drug interactions. Interactions can occur on both the pharmacokinetic and pharmacodynamic level. Herbal medicines may affect the resulting efficacy of the concomitantly used (synthetic) drugs, mainly on the pharmacokinetic level, by changing their absorption, distribution, metabolism, and excretion. Studies on the pharmacodynamic interactions of herbal medicines and conventional drugs are still very limited. This interaction level is related to the mechanism of action of different plant constituents. Herb-drug interactions can cause changes in drug levels and activities and lead to therapeutic failure and/or side effects (sometimes toxicities, even fatal). This review aims to provide a summary of recent information on the potential drug interactions involving commonly used herbal medicines that affect the central nervous system (Camellia, Valeriana, Ginkgo, Hypericum, Humulus, Cannabis) and conventional drugs. The survey databases were used to identify primary scientific publications, case reports, and secondary databases on interactions were used later on as well. Search keywords were based on plant names (botanical genera), officinal herbal drugs, herbal drug preparations, herbal drug extracts.

Ginkgo biloba Extract Attenuates Light-Induced Photoreceptor Degeneration by Modulating CAV-1—Redoxosome Signaling

The clinical potential of Ginkgo biloba extract (GBE) in the prevention and/or treatment of retinal degenerative diseases has been widely explored; however, the underlying molecular mechanism is poorly understood. Photoreceptor degeneration is the hallmark of retinal degenerative diseases and leads to vision impairment or loss. In this study, the effect of GBE against white light (WL) illumination-induced photoreceptor degeneration was investigated, as well as its underlying mechanism. To evaluate the in vitro activity of GBE, analysis of cell viability, cell apoptosis, oxidative stress, NOX (NADH oxidase) activity and mitochondrial membrane potential (MMP), as well as Western blotting and transcriptome sequencing and analysis, were conducted. To evaluate the in vivo activity of GBE, HE staining, electroretinography (ERG), Terminal-deoxynucleoitidyl transferase (TdT)-mediated nick end labeling (TUNEL) assay and immunofluorescence analysis were conducted. Our study showed that GBE treatment significantly attenuated WL illumination-induced oxidative damage in photoreceptor 661W cells—a finding that was also verified in C57BL/6J mice. Further molecular study revealed that WL illumination downregulated caveolin-1 (CAV-1) expression, interrupted CAV-1-NOX2 interaction, re-located NOX2 from the cell membrane to the cytoplasm and induced the formation of redoxosomes, which led to cell death. However, these cytotoxic events were significantly alleviated by GBE treatment. Interestingly, CAV-1 overexpression showed a consistent protective effect with GBE, while CAV-1 silencing impacted the protective effect of GBE against WL illumination-induced oxidative damage in in vitro and in vivo models. Thus, GBE was identified to prevent photoreceptor cell death due to CAV-1-dependent redoxosome activation, oxidative stress and mitochondrial dysfunction resulting from WL illumination. Overall, our study reveals the protective effect of GBE on photoreceptors against WL illumination-induced oxidative damage in in vitro and in vivo models, which effect is mediated through the modulation of CAV-1-redoxosome signaling. Our findings contribute to better understanding the therapeutic effect of GBE in preventing photoreceptor degeneration in retinal degenerative diseases, and GBE may become a novel therapeutic agent that is effective in reducing the morbidity of these diseases.

EGb in the Treatment for Patients with VCI: A Systematic Review and Meta-Analysis

Background

Ginkgo biloba extract (EGb) is widely used to treat impairments in memory, cognition, activities of daily living, inflammation, edema, stroke, Alzheimer's dementia, and aging.

Aim

We aimed to evaluate the safety and efficacy of EGb in treating vascular cognitive impairment (VCI).

Methods

The systematic review was performed using the latest guidelines. We searched for EGb-related trials up to March 1, 2021, in four Chinese databases, three English databases, and clinical trial registry platforms. Randomized controlled trials (RCTs) were included if the study enrolled participants with VCI. Two reviewers independently extracted the data and critically appraised the study quality. Heterogeneity was quantified with I ². Both sensitivity and subgroup analyses were used to identify the sources of heterogeneity. Publication bias was assessed with funnel plots. We used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach to rate the evidence quality. Outcomes included assessments using the Activities of Daily Living (ADL), Montreal Cognitive Assessment (MoCA), Mini-Mental State Examination (MMSE), Hasegawa Dementia Scale (HDS), Barthel Index (BI), Functional Activity Questionnaire (FAQ), and adverse events.

Results

In this study, a total of 2019 patients in 23 RCTs were included. EGb appeared to be more effective than control conditions as assessed by the results of cognitive function evaluation, including MMSE (MD_{MMSE,EGb vs.blank} = 3.04, 95% CI: 0.10-5.98; MD_{MMSE,EGb vs.drugs for VCI} = 2.70, 95% CI: 1.39-4.01; MD_{MMSE,EGb+drugs for VCI vs.blank} = 5.90, 95% CI: 4.21-7.59; and MD_{MMSE,EGb+drugs for VCI vs.drugs for VCI} = 3.14, 95% CI: 2.14-4.15), MoCA (MD_{MoCA,EGb vs.blank} = 5.30, 95% CI: 2.15-8.46; MD_{MoCA,EGb+drugs for VCI vs.blank} = 2.66, 95% CI: 1.82-3.50; and MD_{MoCA,EGb+drugs for VCI vs.drugs for VCI} = 2.56, 95% CI: 1.85-3.27), HDS (MD_{HDS,EGb vs.blank} = 6.50; 95% CI: 4.86-8.14; MD_{HDS,EGb+drugs for VCI vs.drugs for VCI} = 3.60, 95% CI: 2.50-4.70), ADL (MD_{ADL,EGb vs.blank} = 7.20, 95% CI: 3.28-11.12; MD_{ADL,EGb+drugs for VCI vs.blank} = 10.00, 95% CI: 7.51-12.49; and MD_{ADL,EGb+drugs for VCI vs.drugs for VCI} = 9.20, 95% CI: 7.26-11.14), BI (MD_{BI,EGb+drugs for VCI vs.drugs for VCI} = 5.71, 95% CI: 2.99-8.43; MD_{FAQ,EGb vs.drugs for VCI} = -1.43, 95% CI: -2.78 to 0.08), and FAQ (MD_{FAQ,EGb+drugs for VCI vs.drugs for VCI} = -2.17, 95% CI: -4.13 to 0.21). Evidence of certainty ranged from medium certainty to very low certainty.

Conclusion

This meta-analysis showed that EGb may be an effective and safe treatment in improving MMSE, MOCA, ADL, and BI for VCI patients within three months of diagnosis. However, given the quality of the included RCTs, more preregistered trials are needed that explicitly examine the efficacy of EGb. This systematic review has been registered on PROSPERO, with the registration number CRD42021232967.