Acute and Sub-acute Toxicity Studies of a Siddha Medicine Ganthaga Mezhugu by Oral Administration in Sprague Dawley Rats

Abstract

Psoriasis, a chronic auto-immune skin disease, is troubling 1-3 % of the world population with a 0.44-2.8% prevalence rate in India affecting more males than females. It is considered a dermatologist’s menace as it is challenging to treat the condition. Siddha, one of the traditional systems of medicine practised more in South India, includes a wide range of medicines that are used to treat or manage various ailments, including psoriasis. One such medicine is Ganthaga Mezhugu (GM) used in treating skin diseases like psoriasis. This present study deals with the evaluation of the safety of GM as per the Organization for Economic Co-operation and Development (OECD) Guidelines 423 and 407 in Sprague Dawley (SD) rats. In the Acute Toxicity study, SD female rats were grouped into five, in which Groups I and II received elemental Sulphur in two different doses, Groups III and IV received Sulphur ‘purified’ with two different Siddha processes and Group V received GM (2000mg/kg b.wt.). In the subacute toxicity study, SD rats of both sexes were grouped into six in which Group 1 served as vehicle control, Groups 2, 3, and 4 as low, mid, and high dose groups and the last two (Groups 5 and 6) as satellite control and satellite high-dose groups. In the acute study, no mortality, toxic signs or any gross pathological changes were noted. Hence, the LD₅₀ value of GM was found to be greater than 2000mg/kg b.wt. In the sub-acute toxicity study, no mortality or morbidity occurred. There was a gradual increase in body weight with normal food and water intake indicating normalcy in its metabolism. There were no significant changes in hematological and biochemical parameters, serum electrolytes and gross pathology. Also, no pathological changes were found in the histopathology of organs in treated animals when compared with control group animals. Based on the results, regarding the Globally Harmonized System of Classification and Labelling of chemicals, GM can be classified as Category−5, which implies its safety for human consumption. Moreover, the results of the sub-acute study also confirm the safety of GM up to the dose of 400mg/kg b.wt.