Caracterização, desenvolvimento tecnológico de extratos padronizados e avaliação da toxicidade de Dysphania Ambrosioides (L.) Mosyakin & Clemants (Amaranthaceae)

Abstract

Dysphania ambrosioides (L.) Mosyakin & Clemants (syn: Chenopodium ambrosoides L.), Amaranthaceae, is used in Brazilian folk medicine and is known as “erva-de-santa-maria” and “mastruz”. It has antiparasitic, antibacterial, anti-inflammatory, antifungal and antitumor properties. The present work aims at the characterization and technological development of the dry extract of D. ambrosioides aerial parts, standardized in flavonoids expressed as rutin, as well as the evaluation of its toxicity. The specimens were collected in the regions of Anápolis, Goiânia, Itapuranga and Pirenópolis, State of Goiás, identified and the vouchers were deposited at State University of Goiás herbarium, with number registers HUEG11387- 11392, 11873. The plant material was dried and characterized by pharmacopoeia methods. Part of the material was macerated, percolated in 70% (w/w) ethanol, in a drug/solvent ratio of 10% (w/w). The extract obtained was concentrated, characterized and added with colloidal silicon dioxide for spray-drying. The plant material was also submitted to ultrasound-assisted extraction (UAE), for which analytical methods for identification and quantification of rutin by high performance liquid chromatography (HPLC) and of total flavonoids, expressed as rutin, by spectrophotometric method were developed and validated. The processes of UAE and of dry extract standardization in flavonoids, as rutin equivalents, were optimized using a Box Behnken (33) design and the Response Surface Methodology (RSM). The standardized and characterized dry extract was subjected to in vitro and in vivo pre-clinical toxicological tests performed, respectively, in Artemia salina at concentrations of 62.5 to 1000 μg/mL, and in Wistar rats, approved by ethics commission, at dosages of 300 and 2000 mg/kg. The pharmacopoeia tests demonstrated relevant parameters in the vegetal identification of the species and quality control of the vegetal raw material. For the crude extract of aerial parts of D. ambrosioides, the high performance liquid chromatography analytical method for identification and assay of rutin was partially validated for the selectivity and linearity parameters. The spectrophotometric analytical method met the criteria of selectivity, linearity, precision, accuracy and robustness, being a fast, inexpensive and easy method to perform the dosage of flavonoids expressed as rutin. In the UAE the best conditions for the analyzed variables were: extraction time of 60 minutes, temperature of 57ºC and ethanol content of 57% (w/w). In order to obtain the standardized dry extract, the best conditions achieved in this study were: 50% (w/w) adjuvant concentration, inlet temperature of 148°C, feed flow of 0.5 L/h. For toxicological tests, the standardized dry extract was considered nontoxic in the test of Artemia salina and classified as low toxicity in the acute oral toxicity protocol in rodents, with LD50 between 2000 and 5000 mg/kg. The results obtained contribute to the development of high quality and low toxicity raw materials from D. ambrosioides aerial parts. However, chronic, sub chronic and maternal-fetal toxicity studies should be conducted.