Análise fitoquímica e toxicidade de espécies vegetais do Cerrado

Abstract

Phytotherapics have different natural compounds derived from the primary and secondarymetabolism of the plant, which are responsible for the therapeutic properties, such as tannins,saponins, flavonoids, coumarins, triterpenes, steroids, alkaloids, among others. Many specieswith toxic potential have received attention from the scientific community to verifypharmacological and/or therapeutic properties and to investigate possible toxicologicalactivities. Phytochemical screening of the aqueous extracts of Stryphnodendron adstringens,Dimorphandra mollis, Enterolobium contortisiliquum, Luffa operculata and Annona crassiflora toverify the presence of active principles with toxic and abortive action and to carry out atoxicological test to investigate the toxicity of the hydroalcoholic extract of the bark of the stalk ofStryphnodendron adstringens by determining the 50% lethal dose (LD50) and 90% (LD90). Theaqueous extracts were submitted to phytochemical characterization to identify phenols, tannins,flavonoids, saponins, steroids, triterpenes, coumarins and alkaloids. To investigate the toxicityof the plant, toxicological analyzes of the methanolic extract of the stem bark ofStryphnodendron adstringens administered by intraperitoneal route were carried out. Theregression model was used considering death as a binary variable with response as a functionof the extract concentration and the sex of the animals. The analysis was performed using theproc probit procedure of SAS 9.4 software. For the investigation of DL50 and DL90, the extractswere resuspended in water for injections and subjected to serial decimal dilutions, using the1:10 dilution factor, obtaining extracts with concentrations of 1000; 100; 10; 1; 0.1; 0.01; 0.001and 0.0001 mg/mL. Subsequently, they were inoculated intraperitoneally. Eight groups of Swissmice of both sexes were used, five animals per group, for each plant extract, totaling 90 animalsper sex. After inoculation, the animals were observed for seven days to verify behavioralchanges, number of dead animals, patients and survivors. The results of the phytochemicalanalysis were considered positive by formation of precipitates and appearance of staining andfoam, and negatives due to absence of these reactions. It was possible to identify secondarymetabolites such as tannins, flavonoids, coumarins, triterpenes, steroids, saponins andalkaloids in the analyzed species. For the toxicological study of the hydroalcoholic extract of thestem bark of Stryphnodendron adstringens in mice of both sexes, intraperitoneal, LD50 wasequal to 95.1mg mL-1 and DL90 564,76 mg mL-1, which characterized the plant as toxic to theseanimals.