Safety evaluation of Rhodomyrtus tomentosa leaf extract: Sub-acute toxicity assessment in a murine modelAuemphon Mordmuang, Lavanya Goodla, Supayang Piyawan Voravuthikunchai.
Rhodomyrtus tomentosa (Aiton) Hassk. has been widely exploited in traditional medicine for the treatment of many diseases and disorders. There have been no scientific reports on safety information of R. tomentosa leaf extract. The present study attempted to assess in vivo toxicity profile of R. tomentosa extract in order to provide information on the safety margin of the extract to support its pharmacological and medical applications. The extract at a dosage of 0.5 to 3.0 g/kg body weight of mice was orally administered daily up to 14 days. Behavioural and functional integrity were assessed by functional observational battery (FOB) analysis. Histopathological and ultrastructural changes were visualized under light microscopy and transmission electron microscopy, respectively. The extract at the concentration up to 3.0 g/kg body weight per day for 14 days caused no mortality. The extract at 0.5 to 2.0 g/kg body weight showed no adverse effects or signs of toxicity. It is evident that R. tomentosa extract is safe up to the dosage of 2.0 g/kg body weight of mice per day which is equivalent to 20.0 g/day for 70 kg person. According to Economic Cooperation Development (OECD) Guidelines, the lethal dose of R. tomentosa extract falls under class four values with no signs of toxicity at 2.0 g/kg body weight. The results demonstrated that R. tomentosa extract is considered safe as there was no adverse effect related to its use. This study assures R. tomentosa extract as of high value for potential applications as alternative remedies or natural supplements.
Key words: Rhodomyrtus tomentosa, Toxicological study, Safety profile, Functional observational battery, Histopathology, Behaviour