Assessment of Dermal Irritation and Acute Toxicity Potential of Extracts from Synadenium glaucescens on Healthy Rabbits, Wistar Albino Rats and Albino Mice

Aim: This study was conceived for the purpose of evaluating dermal toxicity potentials of extracts from S. glaucescens which is known for many traditional application in human and animals including healing wounds, boils, HIV, worms and application on the swollen lymph nodes of cattle suffering from east coast fever (ECF). This followed the scanty availability of information regarding dermal toxicity of this and many other plants in Tanzania despite the growing practice of utilizing plant products and extracts respectively to control and treat ectoparasites, and skin disorders.

Materials and Methods: The dried plant materials were subjected to sequential solvent extraction using organic and aqueous solvents. All test animals were obtained from Sokoine University of Agriculture (SUA), Tanzania. Thus, irritation, and acute dermal toxicity tests were respectively conducted in healthy rabbits and albino rats using the Organization for Economic Cooperation and Development (OECD) guidelines. Albino mice were used to test skin sensitization using method developed by Sailstad.

Results and Discussion: Irritation indices ranged from 3.2 and 0.05, thus according to Draize these are considered as mild and moderate irritants since none of them could reach PII of 5. On the other hand, findings from acute dermal toxicity tests showed no any overt signs of toxicity after two weeks of treatment. Similarly the extracts did not produce any sensitization reaction based on the mouse ear diameter taken by vernier calipers.

Conclusion: Findings from this study have shown that, extracts from dried plant of S. glaucescens exhibit neither sensitization nor acute dermal toxicity effects except for mild to moderate irritancy. The findings therefore suggests that extracts from dried plant parts of S. glaucescens under the short term use of different extracts from dried leaves and root barks applied on skin of animals do not cause any adverse effects both externally and internally.