Acute Toxicity and Reproductive Impact of Aqueous Extract of the Aerial Parts of Caralluma dalzielii N E Br on Reproductive Functions in Female Wistar Rats

Abstract

IntroductionCaralluma dalzielii N. E. Brown (family: Asclepiadaceae), is a popular cactus‐shaped plant native to East Africa. Its aerial parts are used traditionally for treating infertility, obesity and diabetes. The aim of the study was to evaluate the effects of aqueous extract of the aerial parts of Caralluma dalzielii (AECD) on reproductive functions of female Wistar rats.MethodsOral acute toxicity study was carried out using the up and down method of LD50 determination at a limit dose of 5 g/kg according to OECD guidelines. Effect of AECD (250, 500 and 750 mg/kg/day p.o) on oestrus cycling pattern and hormonal assay were studied. Oestrus cycle changes were determined by daily vaginal smear monitoring for 15 days. After the treatment, at diestrus phase, blood samples were collected for hormonal assay. For the effect on reproductive functions, adult female virgin rats were grouped into four namely, pre‐conception, post‐conception, implantation site and ovariectomized rats’ groups. Each group was subdivided into 4 groups and treated orally with 125, 250, 500 mg/kg of AECD or distilled water. In the pre‐conception and post‐conception groups, litter sizes, pups’ weights and reproductive indices were determined. In the implantation site and ovariectomised rats’ groups, number of implantation sites and uterine weights were determined respectively.ResultsOral dose of AECD at 5 g/kg caused no death and observable signs of toxicity in the rats. AECD produced a disruption in the oestrus cycle at all dose levels with increased oestrus (p<0.001) and decreased diestrus (p<0.05) phases frequency (Figure 1). AECD also caused a significant (p<0.05) increase in luteinising hormone (LH) but not follicle stimulating hormone (FSH) levels. It produced no difference in litter size and reproductive indices in pre‐conception group while in post‐conception group the litter size at 500 mg/kg was significantly (p<0.05) reduced compared to the control. Post‐implantation loss index was highly elevated at 500 mg/kg. Whereas at 125 mg/kg, post‐implantation loss index was reduced, and litter size increased when compared to the control group. At 500 mg/kg, number of implantation sites and weight of embryos decreased significantly (p<0.05) (Figure 2) while at 125 mg/kg the implantation sites increased. A significant (p<0.05) increase in the uterine weight in the ovariectomised rats’ group was observed at all dose levels.ConclusionThe LD50 of AECD was found to be greater than 5 g/kg and therefore considered safe. AECD may act to promote fertility/reproduction through increasing LH levels, reducing post‐implantation loss and possessing oestrogenic activity. At a lower dose, AECD may be used to promote fertility but at higher dose, it may be embryotoxic.Support or Funding InformationFinancial support from Usmanu Danfodiyo University SokotoEffect of aqueous extract on oestrus cycleData presented as Mean ± SD. **p<0.001, *p<0.05; n=5Figure 1Effect of aqueous extract on implantation sites of ratsA= implantation sites of rats treated with 125 mg/kg/day aqueous extract; B= implantation sites of rats treated with 250 mg/kg/day aqueous extract; C=implantation sites of rats treated with 125 mg/kg/day aqueous extract; D= implantation sites of Control ratsFigure 2