BackgroundHancornia speciosa Gomes (Apocynaceae), popularly known as “mangabeira,” has been used in folk medicine to treat inflammatory disorders, hypertension, dermatitis, diabetes, liver diseases and gastric disorders. Although the ethnobotany indicates that its fruits can be used for the treatment of ulcers and inflammatory disorders, only few studies have been conducted to prove such biological activities. This study investigated the anti-inflammatory properties of the aqueous extract of the fruits of H. speciosa Gomes as well as its bioactive compounds using in vivo experimental models.MethodsThe bioactive compounds were identified by High Performance Liquid Chromatography coupled with diode array detector (HPLC-DAD) and Liquid Chromatography coupled with Mass Spectrometry (LC-MS). The anti-inflammatory properties were investigated through in vivo tests, which comprised xylene-induced ear edema, carrageenan-induced peritonitis and zymosan-induced air pouch. The levels of IL-1β, IL-6, IL-12 and TNF-α were determined using ELISA.ResultsRutin and chlorogenic acid were identified in the extract as the main secondary metabolites. In addition, the extract as well as rutin and chlorogenic acid significantly inhibited the xilol-induced ear edema and also reduced the cell migration in both carrageenan-induced peritonitis and zymosan-induced air pouch models. Reduced levels of cytokines were also observed.ConclusionThis is the first study that demonstrated the anti-inflammatory activity of the extract of H. speciosa fruits against different inflammatory agents in animal models, suggesting that its bioactive molecules, especially rutin and chlorogenic acid are, at least in part, responsible for such activity. These findings support the widespread use of Hancornia speciosa in popular medicine and demonstrate that its aqueous extract has therapeutical potential for the development of herbal drugs with anti-inflammatory properties.

Scorpion venom is a rich source of biologically active components and various peptides with high-potential therapeutic use that have been characterized for their antimicrobial and antiproliferative activities. Stigmurin is a peptide identified from the Tityus stigmurus venom gland with high antibacterial and antiproliferative activities and low toxicity. Amino acid substitutions in peptides without a disulfide bridge sequence have been made with the aim of reducing their toxicity and increasing their biological activities. The purpose of this study was to evaluate the structural conformation and structural stability, as well as antimicrobial, antiproliferative, and hemolytic activities of two peptide analogs to Stigmurin, denominated StigA6 and StigA16. In silico analysis revealed the α-helix structure for both analog peptides, which was confirmed by circular dichroism. Data showed that the net charge and hydrophobic moment of the analog peptides were higher than those for Stigmurin, which can explain the increase in antimicrobial activity presented by them. Both analog peptides exhibited activity on cancerous cells similar to the native peptide; however, they were less toxic when tested on the normal cell line. These results reveal a potential biotechnological application of the analog peptides StigA6 and StigA16 as prototypes to new therapeutic agents.

Scorpion venom constitutes a rich source of biologically active compounds with high potential for therapeutic and biotechnological applications that can be used as prototypes for the design of new drugs. The aim of this study was to characterize the structural conformation, evaluate the antimicrobial activity, and gain insight into the possible action mechanism underlying it, for two new analog peptides of the scorpion peptide Stigmurin, named StigA25 and StigA31. The amino acid substitutions in the native sequence for lysine residues resulted in peptides with higher positive net charge and hydrophobicity, with an increase in the theoretical helical content. StigA25 and StigA31 showed the capacity to modify their structural conformation according to the environment, and were stable to pH and temperature variation—results similar to the native peptide. Both analog peptides demonstrated broad-spectrum antimicrobial activity in vitro, showing an effect superior to that of the native peptide, being non-hemolytic at the biologically active concentrations. Therefore, this study demonstrates the therapeutic potential of the analog peptides from Stigmurin and the promising approach of rational drug design based on scorpion venom peptide to obtain new anti-infective agents.

This is the first study to identify and confirm these phenolic compounds in I. asarifolia leaves extract and to suggest that these compounds contribute to the anti-inflammatory activity in vivo, as reported by ethnomedicinal use of this plant. Through the different experimental models performed, we can conclude that the results obtained with the aqueous extract from I. asarifolia leaves support its popular use for the treatment of inflammatory disorders.

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