*13.5.1. Animal toxicity*

In acute toxicity studies, mice treated with the dose of 20 g/kg body weight showed some behavioral changes 120 min after oral administration. These changes included slow response to external stimuli, reduction of mobility and aggression, slight excitability sketching and sluggishness all of which disappeared after 24 h. On the contrary, no adverse changes were noted in mice treated with less than 12 g/kg body weight. Weight gain recorded was increased in both sexes 8 days after oral administration of *S. alata*.

No animals showed immediate behavioral changes on administration of the extract. Yet, mice on both doses showed piloerection and were restless for 24 h following extract administration. They, however, did not vomit nor was there ptosis. Those animals placed on higher doses went into convulsions and died in hyperextension. Post-mortem examination revealed no gross abnormality of the brain, the organs of the chest and abdominal cavities. On the other hand, histopathological examination showed congestion and focal necrosis in the liver

Toxicity and Safety Implications of Herbal Medicines Used in Africa

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*V. amygdalina* is a shrub which is widely found in West Africa. The leaves are very popular vegetables used for soup. The roots and the leaves are used in ethnomedicine to treat fever, hiccups, kidney problems and stomach discomfort among other uses [79]. Both aqueous and alcoholic extracts of the stem, bark, roots and leaves are used extensively as purgative, antimalarial and in the treatment of eczema [80]. The use of the plant has been validated in humans to possess potent antimalarial and antihelminthic properties [81], antitumorigenic properties [82] and antiparasitic activity. It has been found to be used for self-medication by parasitized chimpanzees [83]. It has also been shown that the leaf extract has both hypoglyce-

Acute toxicity studies produced an LD50 of 500 mg/kg body weight in Wistar albino rats. Biochemical parameters such as total, conjugated and unconjugated bilirubin levels showed no significant increase. The levels of both alanine aminotransferase and alkaline phosphatase in the presence of *V. amygdalina* leaf extract increased slightly in a dose-dependent manner when compared with the control but none of the observed increases was statistically significant (*P* > 0.05) when compared to the control or when compared within doses. The processed extracts of the

In Africa and other parts of the world, herbal medications are prepared mostly from a combination of two or more plant parts which contain many active constituents with multiple physiological activities and could be used in the treatment of various health conditions [72] and possibly to reduce toxicity. The herbal formulation prepared with *A. congensis* bark and *X. aethiopica* fruits in equal proportion is a popular local herbal product taken over a long time

In the acute and sub-acute study of the mixture in Swiss albino mice and Wistar albino rats, respectively, no changes in the behavior and in the sensory nervous system responses were

plant were able to reverse carbon tetrachloride-induced hepatotoxicity in rats [85].

**13.8. Herbal mixtures containing** *Alstonia congensis* **Engler bark and** *Xylopia* 

mic and hypolipidemic properties in experimental animals [84].

and renal tubules [76].

*13.7.1. Animal toxicity*

*aethiopica* **fruits (Dunal) A. Rich**

for the treatment of diabetes.

*13.8.1. Animal toxicity*

**13.7.** *Vernonia amygdalina* **del**

In the sub-acute toxicity, the hydro-ethanolic extract of *S. alata* at doses of 500 and 1000 mg/kg given *per os* every 48 h for 26 days did not result in death of the animals. Also, there was no sign of toxicity *during* the experimental period. However, there was a progressive increase in body weight at the stated doses of 500 and 1000 mg/kg of the rats for 26 days of administration of the extract of *S. alata* which may indicate the improvement of the nutritional state of the animal. The relative weights of the control and treated animal groups showed variation from one organ to another: the hearts and livers from the control group had relative weights quite similar to those of the treated groups. Same observations were noted in the relative weights of the liver, lung and kidney [72].

The histopathological study of the liver of groups of rats showed a normal architecture but they showed slight abnormalities such as steatosis and ballooning of hepatocytes when treated orally with the extract of *S. alata* for 26 days at doses of 1000 mg/kg body weight. However, no necrosis, infiltration, edema and conjunction, which are the signs of hepatotoxicity, were found. The effect of *S. alata* seems to have a protective effect on hepatocytes and improves liver architecture, giving justification for the wide usage of the hydro-ethanolic extract of *S. alata* [72].
