Prospecting native and analogous peptides with anti-SARS-CoV-2 potential derived from the trypsin inhibitor purified from tamarind seeds.

The study aimed to prospect in silico native and analogous peptides with anti-SARS-CoV-2 potential derived from the trypsin inhibitor purified from tamarind seeds (TTIp). From the most stable theoretical model of TTIp (TTIp 56/287), in silico cleavage was performed for the theoretical identification of native peptides and generation of analogous peptides. The anti-SARS-CoV-2 potential was investigated through molecular dynamics (MD) simulation between the peptides and binding sites of transmembrane serine protease 2 (TMPRSS2), responsible for the entry of SARS-CoV-2 into the host cell. Five native and analogous peptides were obtained and validated through chemical and physical parameters. The best interaction potential energy (IPE) occurred between TMPRSS2 and one of the native peptides obtained by cleavage with trypsin and its analogous peptide. Thus, both peptides showed many hydrophobic residues, a common physical-chemical property among the peptides that inhibit the entry of enveloped viruses, such as SARS-CoV-2, present in specific drugs to treat COVID-19.

Nanoparticles Containing Tamarind Isolate Protein Potentiate the Satiety without Promoting the Anti-Inflammatory Effect in a Preclinical Model of Diet-Induced Obesity.

The study aimed to evaluate the nanoparticles (ECW) containing tamarind trypsin inhibitor (TTI) concerning the storage effect under different conditions on antitrypsin activity and the bioactive potential in a preclinical model. ECW was exposed to different pH and temperatures to evaluate the interaction between TTI and its encapsulating agents, monitored by antitrypsin activity. Wistar rats (n = 25) with obesity induced by diet were divided into groups: untreated; treatment with nutritionally adequate diet; treatment with nutritionally adequate diet and ECW/12.5 mg/kg; treatment with ECW/12.5 mg/kg; and treatment with TTI/25 mg/kg. The groups were evaluated over ten days with regards to satiety, zoometric, biochemical, and inflammatory parameters, using ten times less TTI (2.5 mg/kg) contained in ECW. TTI was protected and encapsulated in ECW without showing residual inhibitory activity. Only at gastric pH did ECW show antitrypsin activity. At different temperatures, it showed high antitrypsin activity, similar to TTI. The animals treated with ECW had significantly reduced body weight variation (p < 0.05), and only TTI treatment reduced the inflammatory parameters significantly (p < 0.05). The study showed that by using lower concentrations of TTI in ECW it was possible to perceive promising effects with perspectives of use in functional products for managing obesity and its complications.