Browsing by Author "Shikha Chouhan"

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Comparison of the neuroprotective potential of Mucuna pruriens seed extract with estrogen in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mice model
(2014) Satyndra Kumar Yadav; Jay Prakash; Shikha Chouhan; Susan Westfall; Mradul Verma; Tryambak Deo Singh; Surya Pratap Singh
Parkinson's disease (PD) is one of the most common neurodegenerative disease found in the aging population. Currently, many studies are being conducted to find a suitable and effective cure for PD, with an emphasis on the use of herbal plants. In Ayurveda, Mucuna pruriens (Mp), a leguminous plant, is used as an anti-inflammatory drug. In this study, the neuroprotective effect of an ethanolic extract of Mp seed is evaluated in the 1-methyl-4-phenyl-1,2,3,6- tetrahydropyridine (MPTP) model of PD and compared to estrogen, a well reported neuroprotective agent used for treating PD. Twenty-four Swiss albino mice were randomly divided into four groups: Control, MPTP, MPTP + Mp and MPTP + estrogen. The behavioural recovery in both Mp and estrogen treated mice was investigated using the rotarod, foot printing and hanging tests. The recovery of dopamine neurons in the substantia nigra (SN) region was estimated by tyrosine hydroxylase (TH), immunostaining. Additionally inducible nitric oxide synthase (iNOS) and glial fibrillary acidic protein (GFAP) immunoreactivity was evaluated to assess the level of oxidative damage and glial activation respectively. The levels of dopamine and its metabolite in the nigrostriatal region were measured by HPLC. Mp treatment restored all the deficits induced by MPTP more effectively than estrogen. Mp treatment recovered the number of TH-positive cells in both the SN region and the striatum while reducing the expression of iNOS and GFAP in the SN. Treatment with Mp significantly increased the levels of dopamine, DOPAC and homovanillic acid compared to MPTP intoxicated mice. Notably, the effect of Mp was greater than that elicited by estrogen. Mp down regulates NO production, neuroinflammation and microglial activation and all of these actions contribute to Mp's neuroprotective activity. These results suggest that Mp can be an effective treatment for neurodegenerative diseases, especially PD by decreasing oxidative stress and possibly by implementing neuronal and glial cell crosstalk. © 2013 Elsevier B.V. All rights reserved.
Effect of Bisphenol A on human health and its degradation by microorganisms: A review
(2014) Shikha Chouhan; Satyndra K. Yadav; Jay Prakash; Swati; Surya P. Singh
Bisphenol A (BPA), is an industrially important compound and is widely used for the production of polycarbonates and other plastics. Over the past few years, there have been many issues raised all over the world on the use of BPA. BPA is known to possess estrogenic activities; hence, it mimics the role of estrogen once it enters living systems. Thus, it has been placed in the category of compounds called endocrine disruptors. It can cause damage to reproductive organs, thyroid gland, and brain tissues at developmental stages, and most recently it has also been linked to cancer development in humans. Here, in this review, we aim to summarize the various effects of BPA on humans and animals, and at the same time we wish to throw some light on the emerging field of biodegradation of BPA in the natural environment. A few studies conducted recently have tried to isolate BPA-degrading microorganisms from various sites, like water bodies receiving wastes from industries, landfills, etc. In the present scenario, with huge controversies on the use of BPA, we emphasize on bridging the gap between studies, aiming at finding the damage caused by BPA, and the studies which aim at the safe removal of BPA from the environment, with the help of naturally occurring microbes. Once this gap is filled, we will be able to find a way which will allow the use of BPA in manufacturing plastics, without its accumulation in the environment. © 2013 Springer-Verlag Berlin Heidelberg and the University of Milan.
Increase in the expression of inducible nitric oxide synthase on exposure to bisphenol A: A possible cause for decline in steroidogenesis in male mice
(Elsevier, 2015) Shikha Chouhan; Satyndra Kumar Yadav; Jay Prakash; Susan Westfall; Amrita Ghosh; Neeraj Kumar Agarwal; Surya Pratap Singh
Bisphenol A (BPA) is a well-known plasticizer and xenoestrogen that is responsible for many acquired reproductive difficulties, especially in men. Despite the prevalence of BPA in society, the mechanism behind reproductive deficits remains elusive. The present study investigates the mode of BPA's action by evaluating its effect on the expression of inducible nitric oxide synthase (iNOS) and steriodogenic acute regulatoryprotein (StAR) in male mice testis. Swiss albino mice were treated with a range BPA concentrations of 0.5, 50 and 100. μg/kg body weight/day intraperitoneally for 60 days. Several markers of oxidative stress and male fertility were investigated. Nitrite levels, malondialdehyde levels and testicular injury scores were elevated whereas the sperm count, serum testosterone levels and catalase activity were reduced in the BPA groups. Mechanistically, an increase in iNOS expression was observed in the testis whereas the expression of the StAR was down regulated in the BPA treated mouse. These results suggest that BPA induces oxidative stress by altering the expression of iNOS, which consequently leads to the down regulation of StAR expression in the testis of male mouse. © 2014 Elsevier B.V.
Mucuna pruriens seed extract reduces oxidative stress in nigrostriatal tissue and improves neurobehavioral activity in paraquat-induced Parkinsonian mouse model
(2013) Satyndra Kumar Yadav; Jay Prakash; Shikha Chouhan; Surya Pratap Singh
Parkinson's disease (PD) is a neurodegenerative disease which causes rigidity, resting tremor and postural instability. Treatment for this disease is still under investigation. Mucuna pruriens (L.), is a traditional herbal medicine, used in India since 1500 B.C.; as a neuroprotective agent. In this present study, we evaluated the therapeutic effects of aqueous extract of M. pruriens (Mp) seed in Parkinsonian mouse model developed by chronic exposure to paraquat (PQ). Results of our study revealed that the nigrostriatal portion of Parkinsonian mouse brain showed significantly increased levels of nitrite, malondialdehyde (MDA) and reduced levels of catalase compared to the control. In the Parkinsonian mice hanging time was decreased, whereas narrow beam walk time and foot printing errors were increased. Treatment with aqueous seed extract of Mp significantly increased the catalase activity and decreased the MDA and nitrite level, compared to untreated Parkinsonian mouse brain. Mp treatment also improved the behavioral abnormalities. It increased hanging time, whereas it decreased narrow beam walk time and foot printing error compared to untreated Parkinsonian mouse brain. Furthermore, we observed a significant reduction in tyrosine hydroxylase (TH) immunoreactivity in the substantia nigra (SN) and striatum region of the brain, after treatment with PQ which was considerably restored by the use of Mp seed extract. Our result suggested that Mp seed extract treatment significantly reduced the PQ induced neurotoxicity as evident by decrease in oxidative damage, physiological abnormalities and immunohistochemical changes in the Parkinsonian mouse. © 2013 Elsevier Ltd. All rights reserved.
Neuroprotective role of withania somnifera root extract in maneb-paraquat induced mouse model of parkinsonism
(2013) Jay Prakash; Satyndra Kumar Yadav; Shikha Chouhan; Surya Pratap Singh
Parkinson's disease (PD) is a neurodegenerative disorder and these days a lot of emphasis is given on the treatment of this disease using herbal medicines. The present study evaluates the neuroprotective effect of Withania somnifera (Ws) root extract on Parkinsonian mice. The mice were divided into three groups; the first group served as control, the second group was given maneb (MB) and paraquat (PQ) and the last group was administered MB-PQ along with Ws root extract for 3, 6 and 9 weeks. The behavioral studies showed a significant improvement in the motor movement patterns and gripping ability of Ws root extract exposed Parkinsonian mice. Tyrosine hydroxylase (TH) immunostaining was reduced in the substantia nigra of MB-PQ exposed mice, while Ws co-exposure restored TH immunostaining significantly. Additionally, our results also demonstrate generation of oxidative stress in the nigrostriatal region of MB-PQ exposed mice. There was a marked decline in the level of catalase and a simultaneous increase in the level of nitrite and lipid peroxidation in Parkinsonian mice. Thus, the Ws root extract have shown to counteract the pro-oxidants and their associated oxidative stress in the PD model studied here. Our results clearly indicate the usefulness of Ws root extract in providing protection against MB-PQ induced nigrostriatal dopaminergic neurodegeneration and marked improvement in the behavioral, anatomical and the biochemical deformities. © 2013 Springer Science+Business Media New York.
Toxic chemical from plastics attenuates phenylbiguanide-induced cardio-respiratory reflexes in anaesthetized rats
(Association of Physiologists and Pharmacologists of India, 2015) Jayanti Pant; Mahendra K. Pant; Shikha Chouhan; Surya P. Singh; Shripad B. Deshpande
Bisphenol A (BPA) attenuated phenylbiguanide (PBG)-induced cardio-respiratory reflexes involving decreased vagal afferent activity. BPA leaches out from plastics thus it is expected that chronic exposure to plastic boiled (PBW) water will also produce similar changes. Therefore, the present study was undertaken to evaluate the effects of chronic ingestion of PBW on PBG evoked reflexes and were compared with BPA. Adult female rats were ingested BPA containing pellets (2 μg/kg body weight)/PBW/tap water (ad libitum) for 30 days. On day 30, the animals were anaesthetized and BP, ECG and respiratory excursions were recorded. Further, PBG was injected intravenously to evoke cardio-respiratory reflexes and at the end lungs were excised for histopathological examination. BPA concentration in PBW was 6.6 μg/ml estimated by HPLC. In rats receiving tap water, PBG produced bradycardia, hypotension and tachypnoea. In PBW/ BPA treated groups, PBG-induced reflexes were attenuated significantly along with emphysematous and consolidative changes in lungs. The present results indicate that PBW attenuates the protective cardio- respiratory reflexes and also produces histopathological changes in lungs. © 2015, Association of Physiologists and Pharmacologists of India. All Rights Reserved.
Withania somnifera Alleviates Parkinsonian Phenotypes by Inhibiting Apoptotic Pathways in Dopaminergic Neurons
(Springer Science and Business Media, LLC, 2014) Jay Prakash; Shikha Chouhan; Satyndra Kumar Yadav; Susan Westfall; Sachchida Nand Rai; Surya Pratap Singh
Maneb (MB) and paraquat (PQ) are environmental toxins that have been experimentally used to induce selective damage of dopaminergic neurons leading to the development of Parkinson’s disease (PD). Although the mechanism of this selective neuronal toxicity in not fully understood, oxidative stress has been linked to the pathogenesis of PD. The present study investigates the mechanisms of neuroprotection elicited by Withania somnifera (Ws), a herb traditionally recognized by the Indian system of medicine, Ayurveda. An ethanolic root extract of Ws was co-treated with the MB–PQ induced mouse model of PD and was shown to significantly rescue canonical indicators of PD including compromised locomotor activity, reduced dopamine in the substantia nigra and various aspects of oxidative damage. In particular, Ws reduced the expression of iNOS, a measure of oxidative stress. Ws also significantly improved the MB + PQ mediated induction of a pro-apoptotic state by reducing Bax and inducing Bcl-2 protein expression, respectively. Finally, Ws reduced expression of the pro-inflammatory marker of astrocyte activation, GFAP. Altogether, the present study suggests that Ws treatment provides nigrostriatal dopaminergic neuroprotection against MB–PQ induced Parkinsonism by the modulation of oxidative stress and apoptotic machinery possibly accounting for the behavioural effects. © 2014, Springer Science+Business Media New York.