Department of Pharmacology, Lady Hardinge Medical College and Associated Hospitals, New Delhi, India.
Indian J Pharmacol. 2012 Jan;44(1):46-50. doi: 10.4103/0253-7613.91866.
To study the analgesic activity of ash of silver used in Indian system of medicine and to explore its safety.
Albino mice of either sex (20-30 gm) were used to investigate the role of ash of silver against noxious stimuli: thermal (Eddy's hot plate and analgesiometer), mechanical (tail clip), and chemical (0.6% acetic acid induced writhing). An effort was made to find nature and site of action of ash of silver following naloxone pre-treatment. Maximum tolerated dose (MTD) and lethal dosage 50 (LD50) were also studied along with toxicological aspects of ash of silver.
Test drug (ash of silver) at a dose of 50 mg/kg p.o exhibited analgesic activity against thermal, mechanical, and chemical stimuli. Analgesic effects were compared with the standard drug, morphine, in thermal and mechanical noxious stimuli and to aspirin in chemical stimulus. Analgesic activity of the test drug was reduced following naloxone pre-treatment. MTD was found out to be greater than 1.5 g/kg p.o. LD50 was 2 g/kg p.o. Fraction of mice showed symptoms of argyria as explained by autopsy reports.
Test drug exhibited moderate analgesic activity at 50 mg/kg p.o against all type of noxious stimuli, also suggesting a role of opioidergic system. The ash of silver was been found to be safe upto a dose of 1.5 g/kg p.o. in mice without any untoward toxicity. Further studies are required to explore the effect of ash of silver on pain mediators and excitatory neurotransmitters like glutamate, aspartate, or N-methyl-D-aspartic acid (NMDA).
研究印度医学体系中使用的银灰的镇痛活性，并探索其安全性。
使用雄性和雌性白化小鼠（20-30 克），研究银灰对有害刺激的作用：热（Eddy 热板和镇痛计）、机械（尾巴夹）和化学（0.6%乙酸引起的扭动）。努力发现银灰在纳洛酮预处理后的作用性质和作用部位。还研究了最大耐受剂量（MTD）和致死剂量 50（LD50）以及银灰的毒理学方面。
测试药物（银灰）以 50mg/kg po 的剂量显示出对热、机械和化学刺激的镇痛活性。将镇痛效果与标准药物吗啡在热和机械有害刺激以及阿司匹林在化学刺激中的效果进行了比较。在纳洛酮预处理后，测试药物的镇痛作用降低。发现 MTD 大于 1.5g/kg po。LD50 为 2g/kg po。根据尸检报告，部分小鼠出现银中毒症状。
测试药物以 50mg/kg po 的剂量对所有类型的有害刺激表现出中等镇痛活性，这也表明阿片能系统的作用。银灰已被发现对小鼠在 1.5g/kg po 剂量下是安全的，没有任何不良毒性。需要进一步研究以探索银灰对疼痛介质和兴奋性神经递质（如谷氨酸、天冬氨酸或 N-甲基-D-天冬氨酸（NMDA））的影响。
