The antiproliferative extract from the leaves of Acacia sieberiana var. woodii (Fabaceae) is harmless as evidenced by acute and subacute toxicity studies in rats.

• Oral acute and sub-acute toxicities of Acacia sieberiana were evaluated in rats. • No major signs of toxicity were observed in the liver and kidneys. • Slight signs of toxicity were observed at a dose of 1000 mg/kg body weight/day. • Acacia sieberiana bark is harmless at lower dose. Acacia sieberiana DC. var. woodii or Vachellia sieberiana var. woodii (Burtt Davy) Kyal. & Boatwr. is a plant used in Cameroon to treat several diseases such as bilharzia, tapeworm, hemorrhage, rheumatism, gonorrhea, syphilis, ophthalmia, stomachache, urethral diseases, oedema, and diarrhea. The methanol extract of Acacia sieberiana leaves (ASL) has been reported previously for its antiproliferative activity towards several human cancer cell lines. This research aims to evaluate the acute toxicity and subacute toxicities of ASL. The acute toxicity was carried out according to established protocol. The crude extract (ASL) was administered orally to female rats at a single dose of 5000 mg/kg body weight (b.w.) and the animals were observed for any behavioral changes or mortality. In the subacute toxicity study, ASL was orally administered daily to male and female rats at different doses (250, 500, and 1000 mg/kg b.w.) for 28 days. During these treatment days, the animals were observed for any appearance of toxicity symptoms. Following the treatment period, animals were sacrificed for hematological, biochemical, and histopathology analysis. The acute toxicity study revealed neither behavioral disturbances nor death in rats. The lethal dose (LD 50) body weight was greater than 5000 mg/kg b.w. Subacute administration of ASL showed significant variations (P > 0.05) of body weight, the relative weight of organs, some hematological and biochemical parameters. Histopathological examinations showed no remarkable pathological changes on the kidney and slight cell lysis in the liver. This study shows that ASL is non-toxic, but that caution should be taken in case of the prolonged consumption of the botanical at a high dose (1000 mg/kg b.w.). [ABSTRACT FROM AUTHOR]