Deepak Sharma

Publications (29) View all

• Article: Effect of L-deprenyl treatment on electrical activity, Na+, K+ ATPase, and protein kinase C activities in hippocampal subfields (CA1 and CA3) of aged rat brain.

  Rameshwar Singh, Monika Mishra, Sangeeta Singh, Deepak Sharma
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  ABSTRACT: L-deprenyl is considered to protect against age-related cognitive deficits by improving long-term learning/memory in the aged brain. The CA1 and CA3 hippocampal areas are the sites at which initial learning and memory processes occur. Chronic deprenyl treatment significantly augmented the basal electrical firing rate (multiple-unit action potentials), and Na+, K(+)-ATPase and protein kinase C activities of both CA1 and CA3 indicating that the drug increased the excitability of CA1 and CA3. The increase, however, was much greater in CA1 than in CA3 suggesting that deprenyl can improve longer-term learning in aged animals by its excitability-enhancing action in CA1. The drug also countered the ageing-related loss of hippocampal protein kinase C activity.
  Indian journal of experimental biology 02/2012; 50(2):101-9. · 1.29 Impact Factor
• Article: Amelioration of collagen-induced arthritis by Salix nigra bark extract via suppression of pro-inflammatory cytokines and oxidative stress.

  Shikha Sharma, Debasis Sahu, Hasi Rani Das, Deepak Sharma
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  ABSTRACT: Our study goals to investigate the anti-arthritic potential of Salix nigra bark methanol extract (SNME) against both inflammation and oxidative stress in the collagen-induced arthritis (CIA) rat model. Results showed that SNME exhibited maximum scavenging activity against superoxide, hypochlorous acid and hydrogen peroxide radicals along with the suppression of lipid peroxidation. Female wistar rats were immunized with porcine type II collagen and treated with SNME (100 mg/kg body weight) for 15 days starting on day 20. SNME significantly inhibited the paw swelling and arthritic score; exhibited maximum CIA inhibition of 93.7% by the end of the experimental period. Administration of SNME to arthritic rats significantly improved the histological findings in joints as evident by reduced infiltration of polymorphonuclear cells and smooth synovial lining. Roentgenograms of tibiotarsal joints of both SNME and indomethacin-treated rats showed protection against osteophyte formation, soft tissue swelling and bone resorption. Furthermore, levels of inflammatory mediators (nitric oxide, TNF-α, IL-1β, IL-6) measured in both plasma and joint exudates were significantly reduced by SNME treatment. Increased oxidative stress observed in the arthritic animals was also found to be significantly restored in SNME- treated rats. Taken together, our studies clearly indicate the potential of S. nigra as an anti-arthritic agent.
  Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association 12/2011; 49(12):3395-406. · 2.99 Impact Factor
• Source

  Available from: Jaya Tyagi

  Article: Comprehensive insights into Mycobacterium tuberculosis DevR (DosR) regulon activation switch.

  Santosh Chauhan, Deepak Sharma, Alka Singh, Avadhesha Surolia, Jaya Sivaswami Tyagi
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  ABSTRACT: DevR regulon function is believed to be crucial for the survival of Mycobacterium tuberculosis during dormancy. In this study, we undertook a comprehensive analysis of the DevR regulon. All the regulon promoters were assigned to four classes based on the number of DevR binding sites (Dev boxes). A minimum of two boxes are essential for complete interaction and their tandem arrangement is an architectural hallmark at all promoters. Initial interaction of DevR with the conserved box is essential for its cooperative binding to adjacent sites bearing low to very poor sequence conservation and is the universal mechanism underlying DevR-mediated transcriptional induction. The functional importance of tandem arrangement was established by analyzing promoter variants harboring Dev boxes with altered spacing. Conserved sequence logos were generated from 47 binding sequences which included 24 newly discovered Dev boxes. In each half site of an 18-bp binding motif, G(5) and C(7) are essential for DevR binding. Finally, we show that DevR regulon induction occurs in a temporal manner and genes that are induced early are also usually powerfully induced. The information theory-based approach along with binding and temporal expression studies provide us with comprehensive insights into the complex pattern of DevR regulon activation.
  Nucleic Acids Research 06/2011; 39(17):7400-14. · 8.03 Impact Factor
• Source

  Available from: Deepak Sharma

  Article: Computational tools to study and understand the intricate biology of mycobacteria.

  Deepak Sharma, Avadhesha Surolia
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  ABSTRACT: The field of mycobacteriology is currently an area of intense research. To deal with the copious amount of data being generated, numerous web servers and databases have been developed. However, these are available at disparate sites and there exists no single source/platform which provides information about their utility and access. Therefore, a comprehensive compilation of various bioinformatics tools/resources dedicated to mycobacteria is presented in this article.
  Tuberculosis (Edinburgh, Scotland) 03/2011; 91(3):273-6. · 2.54 Impact Factor
• Article: Antiepileptic action of exogenous dehydroepiandrosterone in iron-induced epilepsy in rat brain.

  Monika Mishra, Rameshwar Singh, Deepak Sharma
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  ABSTRACT: In the study described here, the antiepileptic effect of dehydroepiandrosterone (DHEA) treatment on iron-induced focal epileptiform activity in the rat brain was investigated. DHEA is a neuroactive corticosteroid hormone synthesized both in the adrenal cortex and in the brain. Its antioxidant properties are well known. As oxidative stress seems to play a major role in epileptogenesis in the iron-induced model of posttraumatic epilepsy, it was of interest to examine whether DHEA would exert antiepileptic activity. DHEA at a dose of 30 mg/kg/day administered intraperitoneally for 7, 14, and 21 days to iron-induced epileptic rats prevented epileptiform electrophysiological activity. Morris water maze and open-field tests on iron-induced epileptic rats revealed that DHEA also prevented behavioral alterations related to epileptiform activity. Thus, DHEA attenuated the cognitive defects produced by epileptic activity. Moreover, alterations in epileptogenesis-related biochemical parameters-lipid peroxidation, protein oxidation and Na(+), K(+)-ATPase (sodium pump) activity--were also countered by DHEA.
  Epilepsy & Behavior 11/2010; 19(3):264-71. · 2.34 Impact Factor