Inhibitory Effects of Hydroethanolic Leaf Extracts of Kalanchoe brasiliensis and Kalanchoe pinnata (Crassulaceae) against Local Effects Induced by Bothrops jararaca Snake Venom

The species Kalanchoe brasiliensis and Kalanchoe pinnata, both known popularly as "Saião," are used interchangeably in traditional medicine for their antiophidic properties. Studies evaluating the anti-venom activity of these species are scarce. This study aims to characterize the chemical constituents and evaluate the inhibitory effects of hydroethanolic leaf extracts of K. brasiliensis and K. pinnata against local effects induced by Bothrops jararaca snake venom. Thin Layer Chromatography (TLC) and High Performance Liquid Chromatography coupled with Diode Array Detection and Electrospray Mass Spectrometry (HPLC-DAD-MS/MS) were performed for characterization of chemical markers of the extracts from these species. For antiophidic activity evaluation, B. jararaca venom-induced paw edema and skin hemorrhage in mice were evaluated. In both models, hydroethanolic extracts (125-500 mg/kg) were administered intraperitoneally in different protocols. Inhibition of phospholipase enzymatic activity of B. jararaca was evaluated. The HPLC-DAD-MS/MS chromatographic profile of extracts showed some particularities in the chemical profile of the two species. K. brasileinsis exhibited major peaks that have UV spectra similar to flavonoid glycosides derived from patuletin and eupafolin, while K. pinnata showed UV spectra similar to flavonoids glycosides derived from quercetin and kaempferol. Both extracts significantly reduced the hemorrhagic activity of B. jararaca venom in pre-treatment protocol, reaching about 40% of inhibition, while only K. pinnata was active in post-treatment protocol (about 30% of inhibition). In the antiedematogenic activity, only K. pinnata was active, inhibiting about 66% and 30% in pre and post-treatment protocols, respectively. Both extracts inhibited phospholipase activity; however, K. pinnata was more active. In conclusion, the results indicate the potential antiophidic activity of Kalanchoe species against local effects induced by B. jararaca snake venom, suggesting their potential use as a new source of bioactive molecules against bothropic venom.