Extract of Ginkgo biloba promotes neuronal regeneration in the hippocampus after exposure to acrylamide

Role of Cytoskeletal Elements in Regulation of Synaptic Functions: Implications Toward Alzheimer's Disease and Phytochemicals-Based Interventions

Alzheimer's disease (AD), a multifactorial disease, is characterized by the accumulation of neurofibrillary tangles (NFTs) and amyloid beta (Aβ) plaques. AD is triggered via several factors like alteration in cytoskeletal proteins, a mutation in presenilin 1 (PSEN1), presenilin 2 (PSEN2), amyloid precursor protein (APP), and post-translational modifications (PTMs) in the cytoskeletal elements. Owing to the major structural and functional role of cytoskeletal elements, like the organization of axon initial segmentation, dendritic spines, synaptic regulation, and delivery of cargo at the synapse; modulation of these elements plays an important role in AD pathogenesis; like Tau is a microtubule-associated protein that stabilizes the microtubules, and it also causes inhibition of nucleo-cytoplasmic transportation by disrupting the integrity of nuclear pore complex. One of the major cytoskeletal elements, actin and its dynamics, regulate the dendritic spine structure and functions; impairments have been documented towards learning and memory defects. The second major constituent of these cytoskeletal elements, microtubules, are necessary for the delivery of the cargo, like ion channels and receptors at the synaptic membranes, whereas actin-binding protein, i.e., Cofilin's activation form rod-like structures, is involved in the formation of paired helical filaments (PHFs) observed in AD. Also, the glial cells rely on their cytoskeleton to maintain synaptic functionality. Thus, making cytoskeletal elements and their regulation in synaptic structure and function as an important aspect to be focused for better management and targeting AD pathology. This review advocates exploring phytochemicals and Ayurvedic plant extracts against AD by elucidating their neuroprotective mechanisms involving cytoskeletal modulation and enhancing synaptic plasticity. However, challenges include their limited bioavailability due to the poor solubility and the limited potential to cross the blood-brain barrier (BBB), emphasizing the need for targeted strategies to improve therapeutic efficacy.

Polysucrose hydrogel loaded with natural molecules/extracts for multiphase-directed sustainable wound healing

Natural molecules/extracts have numerous beneficial effects on wound healing processes which are challenged by appropriate use and non-toxic dosage. Polysucrose-based (PSucMA) hydrogels have been synthesized with in situ loading of one or more natural molecules/extracts namely Manuka honey (MH), Eucalyptus honey (EH1, EH2), Ginkgo biloba (GK), thymol (THY) and metformin (MET). EH1 presented low amounts of hydroxymethylfurfural and methylglyoxal compared to MH indicating that EH1 was not temperature-abused. It also showed high diastase activity and conductivity. GK was added to PSucMA solution along with other additives including MH, EH1 and MET and crosslinked to form dual loaded hydrogels. The in vitro release profiles of EH1, MH, GK and THY from the hydrogels followed the exponential Korsmeyer-Peppas equation, with a release exponent value of less than 0.5 indicating a quasi-Fickian diffusion mechanism. The IC50 values of these natural products using L929 fibroblasts and RAW 264.7 macrophages indicated that EH1, MH and GK were cytocompatible at relatively high concentrations compared to MET, THY and curcumin used as a control. MH and EH1 induced high IL6 concentration compared to GK. In vitro studies were modelled to mimic the overlapping wound healing phases using human dermal fibroblasts (HDFs), macrophages and human umbilical endothelial cells (HUVECs) in dual culture. HDFs showed a highly interconnected cellular network on GK loaded scaffolds. EH1 loaded scaffolds were seen to induce formation of spheroids which increased in number and size in co-culture studies. The SEM images of HDF/HUVEC seeded GK, GKMH and GKEH1 loaded hydrogels indicated formation of vacuoles and lumen structures. These results indicated that a combination of GK and EH1 in the hydrogel scaffold would accelerate tissue regeneration by acting on the four overlapping phases of wound healing.

Biochemical, molecular and cytological impacts of alpha-lipoic acid and Ginkgo biloba in ameliorating testicular dysfunctions induced by silver nanoparticles in rats

Silver nanoparticles (AgNPs) are commonly utilized in medicine. However, they have negative effects on the majority of organs, including the reproductive system. AgNPs were reported to be able to reach the testicular tissues due to their nano size, which allows them to pass through blood-testicular barriers. The goal of this study was to see if alpha-lipoic acid (LA) or Ginkgo biloba (GB) might protect adult rat testes after intraperitoneal injection of AgNPs. Forty male healthy adult Wister albino rats were randomly assigned to four groups: control, AgNPs-intoxicated group intraperitoneally injected AgNPs 50 mg/kg b.w, 3 times a week; LA + AgNPs group intoxicated with AgNPs and orally gavaged with 100 mg LA/kg b.w; and GB + AgNPs group injected with AgNPs and orally given GB extract 120 mg/kg b.w for 30 consecutive days. Biochemical changes (testosterone, ACP, and prostatic acid phosphatase), oxidative indices, mRNA expression of proapoptotic (BAX) and anti-apoptotic (BCL-2) biomarkers, histological, and immunohistochemical changes in testicular tissues were investigated. Significant decrease in serum testosterone level and elevation in ACP and PACP enzyme activity in AgNPs-treated rats. As well, there were lowering in tGSH, GSH GR, GPx, and elevation in MDA and GSSG values. AgNPs-exposed rats expressed downregulation of testicular thirodexin-1 (Txn-1), transforming growth factor-1β (TGF-1β), anti-apoptotic (BCL-2), and upregulaion of proapoptotic biomarkers (BAX) mRNA expressions. Strong positive action to BAX and lowering the action of Ki-67 antibody were observed. Because of their antioxidant, anti-inflammatory, and anti-apoptotic properties, cotreatment with LA or GB could be beneficial in reducing the harmful effects of AgNPs on the testicles.

Ginkgo biloba Alleviates Cisplatin-Mediated Neurotoxicity in Rats via Modulating APP/Aβ/P2X7R/P2Y12R and XIAP/BDNF-Dependent Caspase-3 Apoptotic Pathway

Neurotoxicity is an obvious adverse effect in Patients encountering a complete course of chemotherapy. The present work is conducted to evaluate the neuroprotective effect of Ginkgo biloba (Ginkgo) against the neurotoxicity induced by Cisplatin (Cis) in rats. Forty male Wistar albino rats were arranged into four groups: (1) Control group, rats were given saline; (2) Cis group, rats were injected by Cis 2 mg/kg body weight i.p., twice a week starting on the fifth day for thirty days; (3) Ginkgo group, rats were administered Ginkgo (50 mg/kg orally) daily for thirty days; and (4) Ginkgo+Cis group, rats received Ginkgo (50 mg/kg orally) daily and on the fifth day, rats were injected with Cis (2 mg/Kg body weight i.p.) twice a week for thirty days. Cis significantly increased Gamma glutamyltransferase (GGT) and Acetyl Cholinesterase (CHE) as compared to the control group and also disturbed cerebral oxidative/antioxidant redox. Co-administration of Ginkgo and Cis reversed the adverse effect of Cis on the brain tissue. Moreover, co-administration of Ginkgo and Cis ameliorated Cis induced brain damage by reducing Amyloid precursor protein (APP), amyloid β (Aβ), P2Y12R and P2X7R mRNA expressions and proteins. Furthermore, Ginkgo regulated XIAP/BDNF expressions with a consequent decrease of caspase-3 and DNA fragmentation%. The current results concluded that concurrent treatment with Ginkgo can mitigate neurotoxicity mediated by Cis in experimental animals through exhibiting antioxidant effect by restoring cerebral oxidative/antioxidant redox and anti-apoptotic effect via regulating cerebral APP/Aβ/P2Y12R/P2X7R and XIAP/BDNF signaling pathways.

Minocycline protects against acrylamide-induced neurotoxicity and testicular damage in Sprague-Dawley rats

This study investigated the protective effects of minocycline against acrylamide (ACR)-induced neurotoxicity and testicular damage in Sprague-Dawley rats. Forty rats were divided into five groups (eight rats each). Group I received saline (0.5 mL/rat) daily for 10 days and served as the untreated control group. Group II received ACR (30 mg/kg body weight (b.w.)) daily for 10 days. Group III received ACR (30 mg/kg b.w.) daily for 10 days and subsequently minocycline (60 mg/kg b.w.) for five days. Group IV received ACR (30 mg/kg b.w.) daily for 10 days followed by saline for five days and served as the control group for the ACR-minocycline-treated group. Group V received minocycline (60 mg/kg b.w.) for five days. All treatments were administered orally. Rats in group I and V showed normal locomotor behavior and normal histology of the brain and testes. Administration of ACR (Group II and IV) resulted in weight loss and gait abnormalities. Furthermore, neuronal degeneration in the hippocampus and cerebellum and degeneration of the seminiferous tubular epithelium with formation of spermatid giant cells were observed. Ultrastructurally, ACR specifically damaged spermatogonia and spermatocytes. Acrylamide was also seen to cause a significant increase of malondialdehyde levels in the brain and testes. Treatment of ACR-administered rats with minocycline (Group III) significantly alleviated the loss of body weight and improved locomotor function. Minocycline also ameliorated neuronal degeneration and seminiferous tubular damage and decreased malondialdehyde concentrations. In conclusion, minocycline protects against neurotoxic effects of acrylamide and seminiferous tubular damage. Decreasing lipid peroxidation by minocycline might play a role in such protection.

Ginkgo Biloba Extract Alleviates Methotrexate-Induced Renal Injury: New Impact on PI3K/Akt/mTOR Signaling and MALAT1 Expression

Renal injury induced by the chemotherapeutic agent methotrexate (MTX) is a serious adverse effect that has limited its use in the treatment of various clinical conditions. The antioxidant activity of Ginkgo biloba extract (GB) was reported to mitigate renal injury induced by MTX. Our research was conducted to examine the nephroprotective role of GB versus MTX-induced renal injury for the first time through its impact on the regulation of phosphatidylinositol 3-kinase/protein kinase B/ mammalian target of rapamycin (PI3K/Akt/mTOR) signaling together with the renal level of TGF-β mRNA and long non-coding RNA-metastasis-associated lung adenocarcinoma transcript-1 (MALAT1) expression. A group of adult rats was intraperitoneally (ip) injected with MTX 20 mg/kg as a single dose to induce kidney injury (MTX group). The other group of rats was orally administered with GB 60 mg/kg every day for 10 days (GB+ MTX group). The MTX increased the serum creatinine and urea levels, renal TGF-β mRNA and MALAT1 expression, in addition to dysregulation of the PI3K/Akt/mTOR signaling when compared with normal control rats that received saline only (NC group). Moreover, renal damage was reported histopathologically in the MTX group. The GB ameliorated the renal injury induced by MTX and reversed the changes of these biochemical analyses. The involvement of PI3K/Akt/mTOR signaling and downregulation of TGF-β mRNA and MALAT1 renal expressions were firstly reported in the nephroprotective molecular mechanism of GB versus MTX-induced renal injury.

Potential role of α-lipoic acid and Ginkgo biloba against silver nanoparticles-induced neuronal apoptosis and blood-brain barrier impairments in rats

AIMS

This study explored whether silver nanoparticles (AgNPs) can disrupt tight-junctions integrity resulted in blood-brain barrier dysfunction along with oxidative stress, pro-inflammation, and apoptosis induction. Additionally, neuroprotective activities of α-lipoic acid (LA) and Ginkgo biloba (GB) were investigated.

MAIN METHODS

Forty adults rats were enrolled into; Control, AgNPs (50 mg/kg), LA (100 mg/kg) + AgNPs, and GB (120 mg/kg) + AgNPs. After 30 days, neuronal changes were assessed biochemically and histopathologically. Brain tissues oxidative indices, mRNA expression of proinflammatory cytokines and tight-junction proteins and pro-apoptotic biomarker, caspase-3 were investigated.

KEY FINDINGS

AgNPs exposure enhanced lipid peroxidation (+195%) along with declines in glutathione (-43%), glutathione peroxidase (-34%), glutathione S-transferase (-31%), catalase (-43%), and superoxide dismutase (-38%) activities in brain tissues. The apparent brain oxidative damage was associated with obvious neuronal dysfunction that was ascertained by neuropathological lesions. AgNPs lowered serum acetylcholine esterase, iron and copper levels, and increased creatine phosphokinase and creatine phosphokinase-brain type activities. Following AgNPs exposure, brain silver and iron contents were increased, but the copper level was decreased. AgNPs up-regulated TNF-α (6.5-fold) and IL-1β (8.9-fold) transcript levels, and simultaneously over-expressed the caspase-3 protein in cerebrum and cerebellum inducing cell apoptosis. Moreover, AgNPs down-regulated the transcript levels of tight-junction proteins; JP-1 (0.65-fold) and JAM-3(0.81-fold).

SIGNIFICANCE

LA and relatively GB improved the serious effects of AgNPs on the blood-brain barrier function and tight-junction proteins through their antioxidants, anti-inflammatory, and anti-apoptotic efficacies. Co-treatment with LA or GB may be favorable in ameliorating the neurotoxic side effects of AgNPs.