Effects of ginkgo biloba extract on the cognitive function and expression profile of inflammatory factors in a rat model of hemorrhagic stroke

Whole Plant Extracts for Neurocognitive Disorders: A Narrative Review of Neuropsychological and Preclinical Studies

The incidence of neurodegenerative disorders like Alzheimer's or Parkinson's Disease, characterized by a progressive cognitive decline, is rising worldwide. Despite the considerable efforts to unveil the neuropsychological bases of these diseases, there is still an unmet medical need for effective therapies against cognitive deficits. In recent years, increasing laboratory evidence indicates the potential of phytotherapy as an integrative aid to improve cognitive functions. In this review, we describe the data of plant whole extracts or single compounds' efficacy on validated preclinical models and neuropsychological tests, aiming to correlate brain mechanisms underlying rodent behavioral responses to human findings. After a search of the literature, the overview was limited to the following plants: Dioscorea batatas, Ginkgo biloba, Melissa officinalis, Nigella sativa, Olea europaea, Panax ginseng, Punica granatum, and Vitis vinifera. Results showed significant improvements in different cognitive functions, such as learning and memory or visuospatial abilities, in both humans and rodents. However, despite promising laboratory evidence, clinical translation has been dampened by a limited pharmacological characterization of the single bioactive components of the herbal products. Depicting the contribution of the single phytochemicals to the phytocomplex's pharmacological efficacy could enable the comprehension of their potential synergistic activity, leading to phytotherapy inclusion in the existing therapeutic package against cognitive decline.

Study on Synergistic Anti-Inflammatory Effect of Typical Functional Components of Extracts of Ginkgo Biloba Leaves

There are some differences in the anti-inflammatory activities of four typical components in EGB (extracts of ginkgo biloba leaves), and there is also a synergistic relationship. The order of inhibiting the NO-release ability of single functional components is OA > GF > OPC > G. Ginkgolide (G), proanthocyanidins (OPC), and organic acids (OA) all have synergistic effects on ginkgo flavonoids (GF). GF:OA (1:9) is the lowest interaction index among all complexes, showing the strongest synergy. The anti-inflammatory mechanism of the compound affects the expression of p-JNK, p-P38, and p-ERK1/2 proteins by inhibiting the expression of iNOS and COX2 genes on NFKB and MAPK pathways. This also provides a research basis for the development of anti-inflammatory deep-processing products of EGB.

Inflammatory mechanisms of Ginkgo Biloba extract in improving memory functions through lncRNA-COX2/NF-κB pathway in mice with status epilepticus

PURPOSE

This study was to explore whether Ginkgo biloba extract (GBE) improve memory impairment by alleviating neuroinflammation signaling in mice with status epilepticus.

METHODS

The status epilepticus (SE) mice model was established by pilocarpine and treated with 100 mg / kg of GBE for 14 days. Spontaneous alternation of Y-maze and new object recognition were used to explore memory impairment. To examine glial cell activation, we performed immunohistochemistry and immunofluorescence staining. The activation of NF-κB signaling and the expression level of lncRNA-COX2 were detected by Western blot and qRT-PCR, respectively. Adeno-associated virus lncRNA-COX2 was injected into mice for overexpression of lncRNA-COX2.

RESULTS

After GBE treatment, the spontaneous alternation rate and the recognition coefficient in SE mice were both increased. Moreover, activation of glial cells, NF-κB signaling and lncRNA-COX2 were significantly decreased in SE mice. In the GBE-treated SE mice with lncRNA-COX2 overexpression, NF-κB signaling was up-regulated again; the reduced level of inflammation factors was reversed; the GBE-rescued spontaneous alternation rate of Y-maze was eliminated.

CONCLUSION

Our results suggested that GBE reduces the hippocampal inflammation by down-regulating lncRNA-COX2 / NF-κB signaling in the SE mice, leading to the decrease of neuronal damage and the improvement of memory functions.

Changes in microglia during drug treatment of stroke

Microglia are the main immune cells in the brain and the first defense barrier of the nervous system. Microglia play a complex role in the process of stroke. A growing number of studies focus on the mechanism of action of drugs functions and how to regulate microglia. Therefore, we talk about the pathophysiological mechanisms of stroke and elaborate on the microglia signaling pathways of drug action in stroke models and how these drugs play a role in stroke treatment in this review. Understanding how drugs modulate proinflammatory and anti-inflammatory responses of microglia may be critical to implementing therapeutic strategies using immune interventions in stroke.

Xiao-Xu-Ming decoction prevented hemorrhagic transformation induced by acute hyperglycemia through inhibiting AGE-RAGE-mediated neuroinflammation

Stroke is one of the leading causes of death worldwide. Hemorrhagic transformation (HT) is a common serious complication of ischemic stroke (IS) and is related to poor prognosis. Hyperglycemia after stroke is associated with the occurrence of HT and seriously affects the clinical treatment of stroke. Our previous experiments demonstrated that the Xiao-Xu-Ming decoction effective components group (XXMD), which is a Chinese medicine formula reconstituted by active ingredients, has multiple pharmacological effects in the treatment of IS. However, the effects of XXMD on HT after IS remain unclear. Thus, we investigated the preventive effects of XXMD on hyperglycemia-induced HT and further explored the underlying mechanism. Acute hyperglycemia combined with the electrocoagulation cerebral ischemia model was used to establish the HT model. XXMD (37.5, 75, 150 mg/kg/d) was given by gavage for 5 days. Network pharmacology was used to predict potential targets and pathways of XXMD in HT occurrence, and further studies confirmed the related targets. The results showed that hyperglycemia aggravated neurological deficits and blood-brain barrier (BBB) disruption, leading to intracerebral hemorrhage. Pretreatment with XXMD improved neurological function and BBB integrity and inhibited HT occurrence. Network pharmacology revealed that AGE-RAGE-mediated neuroinflammation may be associated with hyperglycemia-induced HT. Further studies confirmed that hyperglycemia activated the AGE-RAGE signaling pathway, increased the expression of HMGB1, TLR4 and p-p65, and induced the release of inflammatory factors and neutrophil infiltration, leading to HT. XXMD could inhibit AGE-RAGE-mediated neuroinflammation. These findings indicated that pretreatment with XXMD alleviated hyperglycemia-induced HT, which may be associated with the inhibition of AGE-RAGE-mediated neuroinflammation. Therefore, XXMD may be a potential therapeutic drug for HT.

Cytotoxic effect of Ginkgo biloba kernel extract on HCT116 and A2058 cancer cell lines

While the pharmacology of Ginkgo biloba leaf extract has been studied extensively, little is known about the pharmacological potential of Ginkgo biloba seeds, although they contain similar active ingredients that are responsible for the therapeutic effects of the leaf extract. In this study we used 70%-methanol Ginkgo biloba kernel extract, quantified its bioactive constituents and tested their cytotoxic effect on two cancer cell lines, A2058 and HCT116, and the non-tumor cell line McCoy-Plovdiv. We studied the biological effect of the extract by real-time analysis in the xCELLigence system, WST-1 assay and LIVE/DEAD viability assay. We show that the extract significantly perturbed the viability of cancer cells in a concentration- and time-dependent manner. In contrast, non-cancerous McCoy-Plovdiv cells sustained their proliferation potential even at high concentrations of the extract. Therefore, we propose that the active constituents of the Ginkgo biloba endosperm extract may interact additively or synergistically to protect against cancer.

Gelatin-Coated Polycaprolactone Nanoparticle-Mediated Naringenin Delivery Rescue Human Mesenchymal Stem Cells from Oxygen Glucose Deprivation-Induced Inflammatory Stress

Ischemic stroke involves pro-inflammatory species, which implicates inflammation in the disease mechanism. Recent studies indicate that the prevalence of therapeutic choice such as stem cell transplantation has seen an upsurge in ischemic stroke. However, after transplantation the fate of transplanted cells is largely unknown. Human mesenchymal stem cells (MSCs), due to their robust survival rate upon transplantation in brain tissue, are being widely employed to treat ischemic stroke. In the present study, we have evaluated naringenin-loaded gelatin-coated polycaprolactone nanoparticles (nar-gel-c-PCL NPs) to rescue MSCs against oxygen glucose deprived insult. Naringenin, due to its strong anti-inflammatory effects, remains a therapeutic choice in neurological disorders. Though, the low solubility and inefficient delivery remain challenges in using naringenin as a therapeutic drug. The present study showed that inflammation occurred in MSCs during their treatment with oxygen glucose deprivation (OGD) and was well overturned by treatment with nar-gel-c-PCL NPs. In brief, the results indicated that nar-gel-c-PCL NPs were able to protect the loss of cell membrane integrity and restored neuronal morphology. Then nar-gel-c-PCL NPs successfully protected the human MSCs against OGD-induced inflammation as evident by reduced level of pro-inflammatory cytokine (TNF-α, IFN-γ, and IL-1β) and other inflammatory biomarkers (COX2, iNOS, and MPO activity). Therefore, the modulation of inflammation by treatment with nar-gel-c-PCL NPs in MSCs could provide a novel strategy to improve MSC-based therapy, and thus, our nanoformulation may find a wide therapeutic application in ischemic stroke and other neuro-inflammatory diseases.