Toxicity and antioxidant assessment of ethanol leaf extract of Hibiscus surattensis in Wistar rats: hepatotoxicity evaluation

Abstract

Hibiscus surattensis is a medicinal plant with a vast beneficial use in the management and
cure of a variety of diseases, ranging from urethritis to inflammation and vertigo among others.
Notwithstanding the population's increasing use of it, particularly in rural regions, there is still
lack of adequate investigation into its toxicity profile. The aim of this study was to investigate
the ethanolic extract of Hibiscus surattensis leaf's potential for hepatotoxicity in Wistar rats.
The acute toxicity test was carried out in two phases (phases 1 and 2). Phase 1, used nine
mice which were randomized into three groups (n=3), receiving graded doses of the extract as
follows: 10, 100, and 1000 mg/kg, ip respectively. Phase 2 used three mice which were
randomized into three groups of one mouse each and administered the extract in graded doses
of 2000, 3500, and 5000 mg/kg, ip, respectively. They were monitored for behavioral
abnormalities, toxicity signs, and mortality for 24 hours following treatment. A subacute toxicity
experiment was then carried out, in which Wistar rats were given oral doses of H. surattensis
extract (141, 282, and 424 mg/kg) every day for eight (8) days. Behavioural changes,
haematological and liver function parameters, in-vivo oxidative stress markers and histological
changes were then evaluated. The LD50 of H. surattensis leaf extract was estimated to be
1414 mg/kg. Results revealed significant rise (p<0.01-0.001) in the levels of alanine
aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP),
conjugated bilirubin (C.B) and total bilirubin (T.B), as well as in white blood cell (WBC) and
platelet at high doses of the extract-treated rats compared to control. A significant reduction
was recorded in catalase among other antioxidant parameters while the histopathological
evaluations showed mild alterations. While caution is urged during long-term administration,
administration of H. surattensis ethanolic extract may be safe at the dosages studied in this
investigation.