Protective effects of succimer against lead induced neurotoxicity in developing brain of rats

Aim: The aim of this study was to evaluate the protective effects of succimer against lead induced neurotoxicity in developing brain of rats. Methodology: Healthy albino Wistar rats were segregated into four groups, Control (receives normal water), Lead (100 ppm through drinking water), Lead+Succimer (100 ppm + 50 mg kg-1 b.wt. day-1) and succimer alone (50 mg kg-1 b.wt. day-1). Doses were started from the first day of pregnancy confirmed and continued till day 30 post-natal pups. The 1st, 15th, 30th day post-natal pups were used for oxidative stress markers assessment, histological study, whereas 15th, 30th day pups were used for behavioral assessment. Results: Lead treated rats showed lowered motor coordination, thermal and mechanical pain sensitivity when compared to control group and these responses reversed on treatment with succimer (p< 0.01). Lead treated rats showed a significant (p< 0.01) decrease in CAT, SOD activity and GSH levels, while LPO and GSSG levels were increased as compared to control group, and succimer treatment reversed the altered oxidative metabolism. Lead treated rats showed a decrease in number of branches in neurons and branching of neuronal networks. The number of branches and branching of neuronal networks were reverted on treatment with succimer. Interpretation: This study concludes that succimer has considerable therapeutic value against lead induced neurotoxicity along with neurodegeneration with its chelation as well as anti-oxidant properties reverse neuro-behavioral alterations, oxidative stress and histological impairments caused with lead during pre- and post-natal exposure to rats.

Prolonged constriction of sciatic nerve affecting oxidative stressors & antioxidant enzymes in rat.

Background & objective: This study was carried out to determine the effects of reactive oxygen species in the balance between the pro-oxidant and antioxidant levels in experimental peripheral constriction injury induced by silver wire looping of sciatic nerve of rats. Methods: Rats were divided into experimental group 1 (silver wire ligated) and group 2 (control, sham operated). Functional and behavioural activities were assessed by a modifi ed Basso Beattie Bresnahan (BBB) locomotory rating scale. Mechanical pain intensity was measured with Randall and Selitto apparatus. Foot positioning, toe spread, paw withdrawal threshold and paw withdrawal latency were carried out on days 1, 3, 7, 14, 21 and 28 in rats with chronic pain. Oxidative stress markers such as malondialdehyde (MDA) and advanced oxidation protein products (AOPP) were measured along with antioxidants such as glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT) and reduced glutathione (GSH) on day 30 after constriction in sciatic nerve, spinal cord, dorsal root ganglion, dorsal root and ventral root. Results: Signifi cant : Signififi (P<0.05) increase in MDA, AOPP, SOD and GPx and decrease in the GSH and catalase activities in sciatic nerve, spinal cord, dorsal root ganglion, dorsal root and ventral root were observed in experimental group rats compared to control group. There was no recovery in foot positioning and toe spread. Reduced paw withdrawal threshold and paw withdrawal latency was observed in ligated rats compared to control rats. Interpretation & conclusion: Foot positioning, toe spread, paw withdrawal threshold and paw withdrawal latency with no recovery until day 30 confi rmed locomotory defi cits, hyperalgesia and neuronal impairment. Oxidative stress evidenced by increased MDA, AOPP and decreased GSH and catalase support the generation of reactive oxygen species in constriction model. The present experimental model for chronic pain induced by silver wire spirally coiled around sciatic nerve may be useful for future studies.

Reduced nociceptive responses in mice with alloxan induced hyperglycemia after garlic (Allium sativum Linn.) treatment.

Administration of ethanol (95%) extract (45 mg/kg body wt/day for 28 days) of garlic (A. sativum) to alloxan induced diabetic (ALX-D) mice significantly lowered the serum glucose levels, nociceptive response in tail-flick, hotplate, allodynia, formalin test and relative thickness, weight of hind paw in formalin induced Paw oedema test, over 28 days, thus, showing the reversal trend in hyperglycemia and hyperalgesia compared to ALX-D mice. The reversal of hyperglycemia and hyperalgesia was progressive and more effective as duration of extract administration increased. The results suggest therapeutic potential of ethanol extract of garlic for anti-hyperglycemic and anti-nociceptive effects in diabetes.

Transient elevations of AChE in soleus, plantaris and EDL muscles of palm squirrel (Funambulus palmaram) during prolonged reinnervation.

Recovery of acetylcholinesterase (AChE) activity after nerve crush was observed at second week in soleus (slow-extensor) and plantaris (fast-extensor) muscles whereas the same was observed in extensor digitorum longus (fast-flexor) only after third week. In contrast to earlier observations the AChE was found to exhibit specific transient elevations with intermittent reversal to control values in different type of skeletal muscles during later periods of reinnervation.