Evaluation of In Vivo Toxicity of Dichloromethane: Methanolic Leaf Extracts of Prosopis Juliflora in Rat Models

Prosopis juliflora (Mathenge) is an exotic, evergreen leguminous plant found in the dry Coastal, Rift Valley and Northern parts of Kenya. It is tolerant to extreme environmental conditions, declared a deleterious weed in Kenya and is among top 100 most invasive species worldwide. The species leaves and pod extracts have promising pharmacological properties and have been used in treatment of various illnesses traditionally. However, information on toxicity of these extracts in animals or human is insufficient. The study assessed the phytochemical composition of leaf extracts of P. juliflora, effects on body weights, organ weights, hematological parameters, liver function markers and histopathology on major organs of Swiss albino female rats. The leaves were collected from Kenya Forestry Research Institute (KEFRI); Kitui, dried under shade, ground into fine powder and soaked in a mixture of Dichloromethane and Methanol to obtain the extracts. A total of 25 S. albino rats were used in the study. Acute toxicity test was carried out at 2000 mg/kgbw followed by a twenty eight days sub chronic toxicity study at 100, 350 and 1000 mg/kgbw extracts dosages. The control animals were administered with normal saline daily for the same duration. Animals were monitored for physical and behavioral changes including death. They were fasted overnight on 28 day and sacrificed on anesthesia on 29 day. Blood was collected by cardiac puncture in plain vials and vials with anticoagulant, while various organs were excised, weighed and refrigerated in a preservative. Hematological analysis was done using haematological analyzer while liver functions tests were done using chemical analyzer. Tissue samples from the organs were processed for histopathology. Data from control and treated animals groups were analyzed by ANOVA and Dunnett’s test. Phytochemical analysis showed presence of alkaloids, flavonoids, phenols, tannins, terpenoids and saponnins but not cardiac glycosides. Acute toxicity results showed that the extracts have LD50 above 2000 mg/kgbw. There were dose related transient symptoms of toxicity including wheezing, decreased activity, and pilo-erection. No significant toxicity effects of the extracts on erythrocytes, leucocytes and platelets parameters were noticed. An isolated important rise in mean platelet volume at 100 mg/kgbw was observed. But no significant adverse effects on liver function tests were noted at 100 and 350mg/kg body weight.The significant decrease in alanine aminotransferase and increase in aspartate aminotransferase were not correlated to toxicity. The significant decrease in alkaline phosphatase followed by a significant increase at 1000mg/kgbw implied potential liver toxicity at higher dosages of the extracts. Similarly, no significant adverse changes in plasma proteins and body weights were reported. There was significant decrease in absolute kidney weight at 100 and 350mg/kgbw and significant decrease in absolute spleen weight at 350mg/kgbw dosages. Histological examination of tissues prepared had no related pathological changes. In conclusion, the leaf extracts of P. juliflora was not toxic at doses below 2000 mg/kgbw and can be used safely in phytomedicine under recommended dosages. However caution should be taken on potential effects in kidney and spleen. Further research on toxicity of individual phytochemicals may be carried out.