Avaliação da toxicidade, citotoxicidade e de características fenológicas e físico-químicas da planta Pereskia aculeata

Abstract

The Pereskia aculeata plant has valuable nutritional properties and could be a supplementary food source, because it contains high amounts of minerals, amino acids, vitamins, fibers and antioxidants. However, we have limited information about toxicity, cytotoxicity, phenological and physicochemical characteristics of this plant, particularly when cultivated in subtropical areas with temperate climate. Thus, we analyzed Pereskia aculeata plants cultivated in Pelotas, RS, Brazil, under temperate climate, for: (a) acute toxicity, (b) cytotoxicity, (c) phenological characteristics and (d) physicochemical properties. The acute toxicity experiment was performed with 24 female Wistar rats. The animals were divided into four groups, according to the single dose of ethanolic plant extract they received: 0 mg/kg, 1250 mg/kg, 2500 mg/kg e 5000 mg/kg of body weight. After a 15 days period of observation the euthanasia was performed and 8 different animal tissues were sampled for histopathological analysis. The cytotoxicity was evaluated using lettuce (L. sativa) as an experimental model. The lettuce seeds were treated with different doses of P. aculeata extract (0.13 mg/ml; 1.30 mg/ml; 3.25 mg/ml; 6.50 mg/ml; 13.00 mg/ml) and analyzed for germination and mitotic indexes, and also for roots and shoots length. During 12 months cultivation period the plant was analyzed for physicochemical properties (humidity, color, leaf area, protein content, antioxidant activity, total phenolic content) and phenological aspects (leaf changes, flowering and fructification). Our results for acute toxicity of Pereskia aculeata show that it has non-toxic effect to rats at concentrations of 5000 mg/kg of body weight. We also found this plant to have minimal deleterious cytotoxicity effects on lettuce, consisting of abnormal growth of roots and shoots, but without affecting germination or causing genotoxic effect on lettuce seeds. Furthermore, Pereskia aculeata showed a good adaptation under temperate climate, with normal growth and development. Though, a quiescent state happened in the winter and the plant did not produce leaves. We conclude that cultivation of Pereskia aculeata under temperate climate is feasible and also, the leaves of these plants are safe for consumption as food.