Ameliorative effect of Vernonia cinerea in vincristine-induced painful neuropathy in rats

• Published in: Toxicology and industrial health 2014-10, Vol.30 (9), p.794-805
• Main Authors: Thiagarajan, Venkata Rathina Kumar, Shanmugam, Palanichamy, Krishnan, Uma Maheswari, Muthuraman, Arunachalam
• Format: Article
• Language: English
• Subjects: Analgesics; Animals; Attenuation; Behavior, Animal; Calcium; Calcium - blood; Cancer; Channels; Female; gamma-Aminobutyric Acid - analogs & derivatives; gamma-Aminobutyric Acid - pharmacology; Glutathione; Glutathione - metabolism; Hyperalgesia - drug therapy; Lipid Peroxidation; Male; Nerves; Oxidative stress; Oxidative Stress - drug effects; Pain; Pain - chemically induced; Pain - drug therapy; Peripheral Nervous System Diseases - chemically induced; Peripheral Nervous System Diseases - drug therapy; Pharmaceutical sciences; Pharmacy; Phytotherapy - methods; Plant Leaves - chemistry; Plant Preparations - pharmacology; Pregabalin; Rats; Rats, Wistar; Reduction; Sciatic Nerve - drug effects; Sterols; Thiobarbituric Acid Reactive Substances - metabolism; Vernonia - chemistry; Vernonia cinerea; Vincristine - adverse effects
• ISSN: 0748-2337; 1477-0393
• DOI: 10.1177/0748233712463779

The present study was designed to investigate the antinociceptive potential of Vernonia cinerea (VC) on vincristine-induced painful neuropathy in rats. A chemotherapeutic agent, vincristine (50 μg/kg intraperitoneally for 10 consecutive days), was administered for the induction of neuropathic pain in rats. The painful behavioral changes were assessed using hot plate, acetone drop, paw pressure, Von Frey hair and tail immersion tests to assess the degree of hyperalgesic and allodynic pain sensation in paw and tail. Tissue biomarker changes including  thiobarbituric acid reactive substances (TBARSs), reduced glutathione (GSH) and total calcium levels were estimated in sciatic nerve tissue samples to assess the degree of oxidative stress. Histopathological changes were also observed in transverse sections of rat sciatic nerve tissue. Ethanolic extract of VC leaves and pregabalin were administered for 14 consecutive days from day 0 (day of surgery). Pregabalin served as a positive control in the present study. Vincristine administration resulted in a significant reduction in painful behavioral changes along with a rise in the levels of TBARS, total calcium and decrease in GSH levels when compared with the normal control group. Furthermore, significant histopathological changes were also observed. Pretreatment with VC significantly attenuated vincristine-induced development of painful behavioral, biochemical and histological changes in a dose-dependent manner, which is similar to that of pregabalin-pretreated group. The attenuating effect of VC in vincristine-induced nociceptive painful sensation may be due to its potential of antioxidative, neuroprotective and calcium channel inhibitory action.