Gestational Fisetin Exerts Neuroprotection by Regulating Mitochondria-Directed Canonical Wnt Signaling, BBB Integrity, and Apoptosis in Prenatal VPA-Induced Rodent Model of Autism.

Embryonic valproic acid (VPA) has been considered a potential risk factor for autism. Majority of studies indicated that targeting autism-associated alterations in VPA-induced autistic model could be promising in defining and designing therapeutics for autism. Numerous investigations in this field investigated the role of canonical Wnt signaling cascade in regulating the pathophysiology of autism. The impaired blood-brain barrier (BBB) permeability and mitochondrial dysfunction are some key implied features of the autistic brain. So, the current study was conducted to target canonical Wnt signaling pathway with a natural polyphenolic modulator cum antioxidant namely fisetin. A single dose of intraperitoneal VPA sodium salt (400 mg/kg) at gestational day 12.5 induced developmental delays, social behaviour impairments (tube dominance test), and anxiety-like behaviour (sucrose preference test) similar to autism. VPA induced mitochondrial damage and over-activated the canonical Wnt signaling which further increased the blood-brain barrier (BBB) disruption, apoptosis, and neuronal damage. Our findings revealed that oral administration of 10 mg/kg gestational fisetin (GD 13-till parturition) improved social and anxiety-like behaviour by modulating the ROS-regulated mitochondrial-canonical Wnt signaling. Moreover, fisetin controls BBB permeability, apoptosis, and neuronal damage in autism model proving its neuroprotective efficacy. Collectively, our findings revealed that fisetin-evoked modulation of the Wnt signaling cascade successfully relieved the associated symptoms of autism along with developmental delays in the model and indicates its potential as a bioceutical against autism.

Neuroprotective Efficacy of Fisetin Against VPA-Induced Autistic Neurobehavioral Alterations by Targeting Dysregulated Redox Homeostasis.

Autism is a neurodevelopmental condition, and it's associated pathophysiology, viz., oxidative stress and altered cellular homeostasis, has been extensively intertwined with behavioral impairments. Therefore, targeting oxidative stress and redox cellular homeostasis could be beneficial in relieving autistic-like symptoms. For this purpose, we examined a library of nutraceutical compounds that led us to a bioflavonoid fisetin. Autism-like neurobehavior was induced by subjecting the pregnant rodents to valproic acid at the time of neural tube closure (GD12.5). In this novel study, fisetin was evaluated for its neuroprotective potential at gestational (GD13 until delivery) and post-weaning developmental windows (PND 23-32) in VPA-induced rodent model of autism. Developmental VPA exposure increased intracellular ROS production, oxidative stress, altered AChE and ATPases in brain regions, and induced autistic-like behavioral impairments (social, repetitive, stereotyped, and sensorimotor). The present findings suggested that gestational and post-weaning fisetin treatment significantly improved the behavioral impairments by attenuating elevated oxidative stress, ROS, lipid peroxidation, and re-establishing redox homeostasis. Also, it effectively reinstated the reduced levels of endogenous antioxidants, glutathione, AChE, and ATPases by its antioxidant potential. Therefore, fisetin with its properties could be used as a potential therapeutic agent in overcoming the symptoms associated with autism.

Berberine affords protection against oxidative stress and apoptotic damage in F1 generation of wistar rats following lactational exposure to chlorpyrifos.

Chlorpyrifos (0,0-diethyl 0-(3,5,6-trichloro-2-pyridinyl)-phosphorothioate; (CPF)) is a widely used lipophilic organophosphorus insecticide that primarily manifests into central and peripheral nervous system toxicity. However, it is poorly investigated as a developmental neurotoxicant and thus remains less explored for pharmacological interventions as well. Berberine (BBR) is a benzylisoquinoline alkaloid, primarily found in the plants of Berberidaceae family, and is used for the synthesis of several bioactive derivatives. The goal of this study was to evaluate the CPF-induced neuronal damage through lactational route and analyze the neuroprotective efficacy of berberine (BBR), a potent antioxidant compound in the F1 generation. The environmentally relevant dose of CPF (3 mg/kg b.wt.) was administered via gavage to pregnant dams from postnatal day 1 to day 20 (PND 1-20). BBR (10 mg/kg b.wt.) was administered concurrently with CPF for the same duration as a co-treatment. Levels of reactive oxygen species, lipid peroxidation, membrane bound ATPases (Na+K+ATPase, Ca2+ATPase, and Mg2+ATPase), DNA damage, histomorphological alterations, cellular apoptosis were increased, and activities of glutathione reductase, endogenous antioxidant enzymes (SOD, CAT, GST, and GR) were decreased in cerebellum and cerebrum regions of CPF exposed pups. CPF triggered neuronal apoptosis by upregulating Bax and caspase-3 and downregulating Bcl-2. Co-treatment of BBR significantly attenuated these effects of CPF signifying oxidative stress mediated chlorpyrifos induced neuronal apoptosis. Berberine treatment ameliorated the CPF-induced downregulation of Bcl-2, Bax translocation, and up-regulation of caspase-3 in F1 pups. Therefore, BBR owing to its multiple pharmacological properties can be further explored for its therapeutic potential as an alternative neuroprotective agent against lactational exposure of chlorpyrifos-induced developmental neurotoxicity.

Safranal inhibits NLRP3 inflammasome activation by preventing ASC oligomerization.

NLRP3 inflammasome is involved in several chronic inflammatory diseases. The inflammatory effect of the NLRP3 inflammasome is executed through IL-1ß and IL-18. Therefore, IL-1ß is one of the primary targets in chronic inflammatory conditions. However, current treatment regimens are dependent on anti- IL-1ß biologicals. The therapies targeting IL-1ß through inhibition of NLRP3 inflammasome are thus being actively explored. We identified safranal, a small molecule responsible for the essence of saffron as a potential inhibitor of the NLRP3 inflammasome. Safranal significantly suppressed the release of IL-1ß from ATP stimulated J774A.1 and bone marrow-derived macrophages (BMDMs) by regulating CASP1 and CASP8 dependent cleavage of pro-IL-1ß. Safranal markedly suppressed the expression of NLRP3 and its ATPase activity. Safranal treatment enhanced the expression of NRF2, whereas, si-RNA mediated silencing of Nrf2 abrogated the anti-NLRP3 effect of safranal. Furthermore, safranal inhibited ASC oligomerization and formation of ASC specks. Safranal also displayed anti-NLRP3 activity in multiple mice models. Treatment of animals with safranal reduced the production of IL-1ß in ATP elicited peritoneal inflammation, MSU induced air pouch inflammation, and MSU injected foot paw edema in mice. Thus, our data projects safranal as a potential preclinical drug candidate against NLRP3 inflammasome triggered chronic inflammation.

Naringenin Upregulates AMPK-Mediated Autophagy to Rescue Neuronal Cells From ß-Amyloid (1-42) Evoked Neurotoxicity.

Deposition of an amyloid-ß peptide is one of the first events in the pathophysiology of Alzheimer's disease (AD) and is clinically characterized by Aß plaques, tau tangles, and behavioral impairments that lead to neuronal death. A substantial number of studies encourage targeting the skewness in the production and degradation of amyloid-ß could be among the promising therapies in the disease. Neuronal autophagy has emerged for an essential role in the degradation of such toxic aggregate-prone proteins in various neurodegenerative diseases. We profiled a small library of common dietary compounds and identified those that can enhance autophagy in neuronal cells. Here we noted naringenin in silico exhibits a robust affinity with AMP-activated protein kinase (AMPK) and upregulated AMPK-mediated autophagy signaling in neurons. Naringenin can induce autophagy promoting proteins such as ULK1, Beclin1, ATG5, and ATG7 in Neuro2a cells and primary mouse neurons as well. The knockdown of AMPK by siRNA-AMPK was complemented by naringenin that restored transcript levels of AMPK. Further, naringenin can reduce the levels of Aß at a nontoxic concentration from neuronal cells. Moreover, it maintained the mitochondrial membrane potential and resisted reactive oxygen species production, which led to the protection against Aß1-42 evoked neurotoxicity. This highlights the neuroprotective potential of naringenin that can be developed as an anti-amyloidogenic nutraceutical.

Epigallocatechin gallate attenuates arsenic induced genotoxicity via regulation of oxidative stress in balb/C mice.

Arsenic is well known genotoxicant which causes the excessive generation of reactive oxygen species (ROS) and inhibition of antioxidant enzyme systems leading to cell damage through the activation of oxidative sensitive signaling pathways. Epigallocatechin gallate (EGCG), the main and active polyphenolic catechin present in green tea, has shown potent antioxidant, free radical scavenging and genoprotective activity in vivo. The present study attempted to investigate antioxidant and geno-protective efficacy of EGCG by regulating arsenic induced oxidative stress in mice. Animals received prophylactic and therapeutic treatments at two different doses (25 and 50 mg/kg b.wt.) of EGCG orally for 15 days and administered arsenic intraperitoneally at dose of 1.5 mg/kg b.wt (1/10th of LD50) for 10 days. Arsenic intoxication revealed enhanced ROS production (114%) in lymphocytes; elevated levels of LPO (2-4 fold); reduced levels of hepato-renal antioxidants (approx. 45%) and augmented genomic fragmentation in hepato-renal tissues; increased chromosomal anomalies (78%) and micronucleation (21.93%) in bone marrow cells and comet tailing (25%) in lymphocytes of mice. Both pre and post treatments of EGCG decreased ROS production, restored lipid peroxidation (LPO) and reduced hepato-renal antioxidants levels, reduced the DNA fragmentation, number of chromosomal aberrations (CA), micronucleation (MN), and comet tailing but prophylactic treatment of 50 mg/kg b.wt was the most effective treatment in regulating arsenic induced oxidative stress. The effectiveness of this dose was furthermore validated by calculating the inhibitory index. Thus, results of present work empirically demonstrate free radical scavenging, anti-oxidative and genoprotective efficacy of EGCG against arsenic toxicity.

Alborixin clears amyloid-ß by inducing autophagy through PTEN-mediated inhibition of the AKT pathway.

Imbalance in production and clearance of amyloid beta (Aß) is the primary reason for its deposition in Alzheimer disease. Macroautophagy/autophagy is one of the important mechanisms for clearance of both intracellular and extracellular Aß. Here, through screening, we identified alborixin, an ionophore, as a potent inducer of autophagy. We found that autophagy induced by alborixin substantially cleared Aß in microglia and primary neuronal cells. Induction of autophagy was accompanied by up regulation of autophagy proteins BECN1/Beclin 1, ATG5, ATG7 and increased lysosomal activities. Autophagy induced by alborixin was associated with inhibition of the phosphoinositide 3-kinase (PI3K)-AKT pathway. A knock down of PTEN and consistent, constitutive activation of AKT inhibited alborixin-induced autophagy and consequent clearance of Aß. Furthermore, clearance of Aß by alborixin led to significant reduction of Aß-mediated cytotoxicity in primary neurons and differentiated N2a cells. Thus, our findings put forward alborixin as a potential anti-Alzheimer therapeutic lead. Abbreviations: Aß: amyloid beta; ALB: alborixin; ATG: autophagy-related; BECN1: beclin 1; DAPI: 4, 6-diamidino-2-phenylindole; DCFH-DA: 2,7-dichlorodihydrofluorescein diacetate; fAß: fibrillary form of amyloid beta; GFAP: glial fibrillary acidic protein; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MAP2: microtubule-associated protein 2; MTOR: mechanistic target of rapamycin kinase; PTEN: phosphatase and tensin homolog; ROS: reactive oxygen species; SQSTM1: sequestosome 1; TMRE: tetramethylrhodamine, ethyl ester.

The amino analogue of ß-boswellic acid efficiently attenuates the release of pro-inflammatory mediators than its parent compound through the suppression of NF-κB/IκBα signalling axis.

Natural product derivatives have proven to be cutting edge window for drug discovery and development. BA-25 (3-α-o-acetoxy-4ß-amino-11-oxo-24-norurs-12-ene) an amino analogue of ß-boswellic acid exhibited inhibition of TNF-α and IL-6 in THP-1 cells as demonstrated previously, however, the effect on principal inflammatory mediators such as cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and the pathways that mediate this function remains unknown. This study was designed to examine the comparative anti-inflammatory activity of BA-25 with its parent compound, ß boswellic acid both in vitro and in vivo. The effect of BA and BA-25 on suppression of NO, PGE2, LTB4, COX-2 in LPS-stimulated RAW 264.7 cells was determined by ELISA, RT-PCR and ROS by flow cytometry. Phosphorylation of NF-kBp65, IKB degradation was determined by western blotting and also the nuclear localization of NF-kBp65 was assessed by immunofluorescence. Furthermore, this study was extended on Carrageenan induced paw oedema modelled BALB/c mice. A novel derivative BA-25, reported first time notably decreased the LPS (1 µg/mL) induced upregulation in the transcription of TNF-α, IL-6, iNOS and COX-2. Also the protein expression of iNOS and COX-2 as well as their downstream products NO and PGE2 respectively, were also decreased efficiently at a concentration of 10 µM than BA. Moreover, LPS upregulated NF-kB p65 expression and IκB degradation was significantly decreased after BA-25 treatment. In addition, the treatment of BA-25 also restored the paw oedema and decreased the magnitude of histopathological alterations. Our data together suggested that BA-25 might be regarded as prospective therapeutic anti-inflammatory alternative and demands further investigation in pharmacological studies.