Study of the embryofeto-toxicity of Crown-of-Thorns (Euphorbia milii) latex, a natural molluscicide

The crude latex of Crown-of-Thorns (Euphorbia milii var. Hislopii) is a potent plant molluscicide and a promising alternative to the synthetic molluscicides used in schistosomiasis control. The present study was undertaken to investigate the embryofeto-toxic potential of E. Milii latex. The study is part of a comprehensive safety evaluation of this plant molluscicide. Lyophilized latex (0, 125, 250 and 500 mg/kg body weight) in corn oil was given by gavage to Wistar rats (N = 100) from days 6 to 15 of pregnancy and cesarean sections were performed on day 21 of pegnancy. The numbers of implantation sites, living and dead fetuses, resorptions and corpora lutea were recorded. Fetuses were weighed, examined for external malformations, and fixed for visceral examination, or cleared and stained with Alizarin red S for skeleton evaluation. A reduction of body weight minus uterine weight al term indicated that E. Milii latex was maternally toxic over the dose range tested. No latex-induced embryolethality was noted at the lowest dose (125 mg/kg) but the resorption rate was markedly increased at 250 mg/kg (62.5 percent) and 500 mg/kg (93.4 percent). A higher frequency of fetuses showing signs of delayed ossification (control: 17.4 percent; 125 mg/kg: 27.4 percent and 250 mg/kg: 62.8 percent; P<0.05 vs control) indicated that fetal growth was retarded at doses ³125 mg latex/kg body weight. No increase in the proportion of fetuses with skeletal anomalies was observed at the lowest dose but the incidence of minor skeletal malformations was higher at 250 mg/kg body weight (control: 13.7 percent; 125 mg/kg: 14.8 percent; 250 mg/kg: 45.7 percent; P<0.05 vs control). Since a higher frequency of minor malformations was noted only at very high doses of latex which are embryolethal and maternally toxic, it is reasonable to conclude that this plant molluscicide poses no teratogenic hazard or, at least, that this possibility is of a considerably low order of magnitude.

Single dose toxicity study of beta-myrcene, a natural analgesic substance

The present study was undertaken to provide date on acute toxicity of ß-myrcene, a peripheral analgesic substance found in the essential oils of several plants. Although myrcene has long been used in perfumes and as a food additive, there is almost no information on its toxicological hazards. The acute oral toxicity of myrcene was low in rodents, with with approximate lethal doses (ALD) of 5.06g/Kg body weight for mice and greater than 11.39 g/Kg body weight for rats. Necropsy data did not reveal any relevant alteration in rats but histophatology findings in mice suggested that the liver and stomach may be target organs for myrcene toxicity after oral administration. Myrcene is highly irritant to the peritoneum, and deaths after intraperitoneal injection of this monoterpene in rats (ALD 5.06 g/Kg body weight) and in mice (ALD 2.25 g/Kg body weight) were probably due to drug-induced chemical peritonitis