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Ischemic stroke (IS) is a rapidly increasing global burden and is associated with severe neurological decline and mortality. There is urgent requirement of the efforts, aimed to identify therapeutic strategies that are effective in clinic to promote significant recovery from IS. Studies have shown that mitochondria mediated neuroprotection can be a competent target against ischemic damage. Therefore, we examined whether mitochondrial impairment is regulated by Piperine (PIP), an alkaloid of Piper Longum, which has neuroprotective activity against ischemic brain injury. In this study, transient middle cerebral artery occlusion (tMCAO) surgery was performed on male Wistar rats for 90 min followed by 22.5 h of reperfusion for mimicking the IS condition. This study consisted of three groups: sham, tMCAO and tMCAO + PIP (10 mg/kg b.wt., p.o/day for 15 days), and studied for behavioral tests, infarct volume, brain pathological changes, mitochondrial dysfunction, inflammation alongwith cell survival status. PIP pre-treatment showed reduction in neurological alterations and infarct volume. In addition, PIP pre-treatment suppressed the mitochondrial dysfunction and might have anti-apoptotic potential by preventing Cytochrome c (Cyt c) release from mitochondria to cytoplasm and caspase 3 activation. It also regulates pro-apoptotic, Bax and anti-apoptotic, Bcl-2 proteins accompanied by glial fibrillary acidic protein (GFAP) positive cells in cortex region. Quantitative Reverse transcription-polymerase chain reaction (qRT-PCR) results also showed that PIP reduced the expression of pro-inflammatory protein, interleukin-1 β (IL-1β) and enhanced cell survival by restoring the activity of brain derived neurotrophic factor (BDNF) and its transcription protein, cAMP response element binding protein (CREB). Taken together, PIP reduced the mitochondrial dysfunction, neurological impairment, and enhanced neuronal survival. In conclusion, our findings reinforce PIP as an effective neuroprotective agent and provide important evidence about its role as a potential target to serve as a promising therapy for treatment of IS., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Excessive mitochondrial fission has been implicated in the etiology of neuronal cell death in traumatic brain injury (TBI). In the present study, we examined the efficacy of melatonin (Mel) as a neuroprotective agent against TBI-induced oxidative damage and mitochondrial dysfunction. We assessed the impact of Mel post-treatment (10 mg/kg b.wt., i.p.) at different time intervals in TBI-subjected Wistar rats. We found that the Mel treatment significantly attenuated brain edema, oxidative damage, mitochondrial fission, and promoted mitochondrial fusion. Additionally, Mel-treated rats showed restoration of mitochondrial membrane potential and oxidative phosphorylation with a concomitant reduction in cytochrome-c release. Further, Mel treatment significantly inhibited the translocation of Bax and Drp1 proteins to mitochondria in TBI-subjected rats. The restorative role of Mel treatment in TBI rats was supported by the mitochondrial ultra-structural analysis, which showed activation of mitochondrial fusion mechanism. Mel enhanced mitochondrial biogenesis by upregulation of PGC-1α protein. Our results demonstrated the remedial role of Mel in ameliorating mitochondrial dysfunctions that are modulated in TBI-subjected rats and provided support for mitochondrial-mediated neuroprotection as a putative therapeutic agent in the brain trauma.

Organelle damage and increases in mitochondrial permeabilization are key events in the development of cerebral ischemic tissue injury because they cause both modifications in ATP turnover and cellular apoptosis/necrosis. Early restoration of blood flow and improvement of mitochondrial function might reverse the situation and help in recovery following an onset of stroke. Mitochondria and related bioenergetic processes can be effectively used as pharmacological targets. Progesterone (P4), one of the promising neurosteroids, has been found to be neuroprotective in various models of neurological diseases, through a number of mechanisms. This influenced us to investigate the possible role of P4 in the mitochondria-mediated neuroprotective mechanism in an ischemic stroke model of rat. In this study, we have shown the positive effect of P4 administration on behavioral deficits and mitochondrial health in an ischemic stroke injury model of transient middle cerebral artery occlusion (tMCAO). After induction of tMCAO, the rats received an initial intraperitoneal injection of P4 (8 mg/kg body weight) or vehicle at 1 h post-occlusion followed by subcutaneous injections at 6, 12 and 18 h. Behavioral assessment for functional deficits included grip strength, motor coordination and gait analysis. Findings revealed a significant improvement with P4 treatment in tMCAO animals. Staining of isolated brain slices from P4-treated rats with 2,3,5-triphenyltetrazolium chloride (TTC) showed a reduction in the infarct area in comparison to the vehicle group, indicating the presence of an increased number of viable mitochondria. P4 treatment was also able to attenuate mitochondrial reactive oxygen species (ROS) production, as well as block the mitochondrial permeability transition pore (mPTP), in the tMCAO injury model. In addition, it was also able to ameliorate the altered mitochondrial membrane potential and respiration ratio in the ischemic animals, thereby suggesting that P4 has a positive effect on mitochondrial bioenergetics. In conclusion, these results demonstrate that P4 treatment is beneficial in preserving the mitochondrial functions that are altered in cerebral ischemic injury and thus can help in defining better therapies., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2017. Published by The Company of Biologists Ltd.)

Naringenin is a powerful antioxidant and anti-inflammatory flavonoid which has been widely used as a therapeutic agent in various toxic models. However, few studies have clearly discussed the neuromodulatory effects of naringenin against different neurodegenerative disorders. We investigated the neuroprotective efficacy of naringenin against 3-nitropropionic acid (3-NP)-induced neurobehavioral, biochemical and histopathological alterations in rats. Albino Wistar rats were randomly divided into three experimental groups. Group 1, the vehicle administered group, received saline. Group 2 received 3-NP (20 mg/kg body weight, i.p.) for 4 consecutive days. Group 3 received naringenin (50 mg/kg body weight, p.o.) twice daily for a period of 4 days, 30 min before and 6 h after the 3-NP administration. On the 5th day, neurobehavioral experiments were performed to access the behavioral outcomes and the striatum tissue was used for analysis of the monoamine oxidase (MAO) activity and serotonin (5-HT) levels. In addition, astrocytes activation was observed by glial fibrillary acidic protein (GFAP) immunostaining. Our results showed that naringenin co-treatment provides neuroprotection against 3-NP-induced neurological disorders. Naringenin also increased the MAO activity and 5-HT levels in the striatum. Moreover, co-treatment with naringenin reduced the expression of GFAP protein in the striatal part and significantly attenuated the neuronal cell death. The findings of the present study suggest that naringenin provides neuroprotection and mitigates neurobehavioral alterations in experimental rats. The results show that co-treatment with naringenin ameliorates 3-NP-induced HD-like symptoms in rats. [ABSTRACT FROM AUTHOR]

Huntington disease (HD) is an autosomal dominant inheritance neurodegenerative disorder. 3-Nitropropanoic acid (3-NP) is a mitochondrial toxin that induces HD-like symptoms and thus serves as a good experimental model of HD. Chrysin (5, 7-dihydroxyflavone) is a natural flavonoid that have multiple biological activities. The present work was aimed to evaluate the neuroprotective efficacy of Chrysin in rat brain, under the influence of 3-NP treatment, by studying neurobehavioral and biochemical alterations alongwith histo-architectural changes. Male Wistar rats (220–250 g) were used in the study and were divided into three groups following randomization. Each group comprised of nine animals. Group I animals served as control group and administered with normal saline (orally) as vehicle. Animals of Group II were treated with 3-NP for four successive days, at the dose of 20 mg/kg, intraperitoneally (i.p.). Animals that received Chrysin for the period of four consecutive days with the dose of 50 mg/kg, orally twice daily (30 min pre-treatment and 6 h post-treatment) following 3-NP administration served as Group III. After the treatment regime, animals were evaluated for neurobehavioral alterations and brain homogenates were used for estimation of neurotoxicity marker activity and neurotransmitter level along with histological assessment. The significant alteration in neurobehavioral, biochemical and neuronal structure in striatal part of brain was observed in the 3-NP administered (Group II) animals. It was observed that co-treatment of Chrysin with 3-NP treated rats the rotarod performance, grip strength, stride length as well as monoamine oxidase activity and serotonin levels were elevated. The results of this study reveal that Chrysin treatment alleviated the neurobehavioral, biochemical and histological alterations against HD symptoms in rats. [ABSTRACT FROM AUTHOR]

Background: Piperine (PIP) is a powerful anti-oxidant and anti-inflammatory alkaloid which has been widely used in the treatment of various pathological conditions. However, few studies have clearly discussed the protective effects and potential mechanism of PIP in different neurological diseases. The aim of this study was to investigate the neuroprotective effect of PIP against 3-nitropropioninc acid (3-NP) induced neurobehavioral, biochemical and histopathological alterations in animals. Methods: Adult male Wistar rats were randomly divided into three groups. Group 1, the vehicle administered control group, received normal saline (p.o.). Group 2 received 3-NP (20 mg/kg.b.wt., i.p.) for 4 consecutive days. Group 3 received PIP (10 mg/kg.b.wt., p.o.) twice daily for a period of 4 days, 30 min before and 6 h after the 3-NP injection. Upon termination of treatment schedule, behavioral experiments were performed to access the behavioral outcomes. The brain striatal tissue was used for the estimation of monoamine oxidase activity and serotonin level. In addition, astrocytes activation was observed by GFAP immunostaining. Results: Our results showed that 3-NP induced behavioral impairments are attenuated by PIP co-treatment. Next, the extent of neuronal loss and astrocytes activation was reduced in the striatal brain region in PIP treated rats. Finally, it was observed that PIP alleviated the behavioral, biochemical, immunohistochemical and histological alterations. Conclusion: The results of the current study reveal the neuroprotective competency of PIP against Huntington disease like symptoms in rats. [ABSTRACT FROM AUTHOR]

Cerebral ischemic stroke leads to mitochondrial alterations which are key factors for initiation of various cascades resulting in neuronal damage. Dopamine D2 receptor (D2R) agonist, Sumanirole (SUM) has been reported to possess anti-inflammatory, anti-oxidant, and anti-apoptotic properties. However, the role of SUM in ischemic stroke (IS) has not been studied yet. The aim of the present study was to investigate the neuroprotective efficiency of SUM against ischemic injury and its possible effect on mitochondrial restorative mechanisms. Transient middle cerebral artery occlusion (tMCAO) was performed in Wistar rats for 90 min occlusion and 22.5 h reperfusion to mimic ischemic stroke. Post- treatment with Sumanirole (0.1 mg/kg and 1 mg/kg; s.c.) was done at 1 h, 6 h, 12 hand 18 h after surgery. In addition, neurobehavioral analysis, mitochondrial reactive oxygen species and mitochondrial membrane potential by flow cytometric analysis, mitochondrial complexes analysis, infarct size evaluation and histological analysis were performed. Sumanirole restored behavioural alterations as measured by rotarod performance, grip strength, adhesive tape removal analysis and neurological deficits. In addition, it also refurbished mitochondrial dysfunction by decreasing mitochondrial reactive oxygen species production, elevating mitochondrial membrane potential and by protecting the activity of mitochondrial complexes along with histological alterations. As a result, infarct sizes were markedly reduced in tMCAO surgery animals. Findings from the study provide evidence that SUM promotes neuronal survival in in vivo model of IS through mitochondria mediated neuroprotective features. • We investigated the neuroprotective efficiency of highly selective dopamine D2 agonist Sumanirole against ischemic injury. • Sumanirole restored behavioural alterations and neurological deficits in a stroke rodent mode. • Mitochondrial dysfunction was attemnuated by decreasing mitochondrial ROS production. • Infarct sizes were markedly reduced in tMCAO surgery animals. • Our study provides evidence for mitochondrial mediated neuroprotective features of Sumanirole against ischemic stroke. [ABSTRACT FROM AUTHOR]