Protein Digests and Pure Peptides from Chia Seed (Salvia hispanica L) Prevented Adipogenesis and Its Associated Inflammation by Inhibition of PPAR-γ and NF-κB Pathways

Abstract

Abstract Objectives To evaluate the mechanism of action of the effect of digested total proteins (DTP), albumin, and glutelin from chia seed to prevent and inhibit inflammation in 3T3-L1 adipocytes. Methods Preadipocytes (3T3-L1) were differentiated into mature adipocytes and received DTP, digested albumin, or glutelin (1 mg/ml) from chia seed together with conditioned medium (CM) from inflamed macrophages during 48 h (prevention), or the digested samples were added after 48 h of CM-stimulated inflammation (inhibition). ROS and cytokines secretion (IL-10, IL-12, IL-6, MCP-1, PGE2, and TNF-α) were analyzed by ELISA and lipid accumulation by oil red-O staining, triglyceride content, lipase activity and expression of proteins (PPAR-γ, SREBP1, FAS, LPL, COX-2, iNOS, and NF-κB) by western-blot. The interactions of peptides with FAS, MAGL, and PPAR-γ were evaluated in silico. Data analyses were performed in triplicate from two independent experiments by ANOVA and post-hoc of Tukey (P < 0.05). Results DTP and digested albumin and glutelin in both, prevention and inhibition of induced inflammation, decreased the expression of PPAR-γ more than 50% (P < 0.05). Digested samples reduced TNF-α secretion, ROS production, lipid accumulation, iNOS and COX-2 expression, especially glutelin (−71, −53, −15, −75, and -85%, respectively) on prevention of inflammation. Albumin digest inhibited NO and PGE2 (−42 and 64%, respectively). DTP reduced the lipase activity (−13%), triglyceride content (−27%), and NF-κB expression (−48%) (P < 0.05). On inhibition of inflammation, only SREBP-1 expression was reduced more than 33% (P < 0.05) by every digested protein. DTP was effective to reduce LPL (-32%), FAS (−29%), iNOS (−52%), and COX-2 (−66%) expression, as well as NO secretion (−15%), and triglyceride content (−18%) (P < 0.05). Peptides TGPSPTAGPPAPGGGTH and YLGAHPGTAN, from digested albumin, showed the highest interaction with PPAR-γ (−9.1 kcal/mol) and MAGL (−7.8 kcal/mol), respectively. Peptide APSPPVLGPP from DTP, showed the highest interaction with FAS (−9.8 kcal/mol). Conclusions Digested samples from chia seed were effective in preventing and even inhibiting inflammation in adipocytes by inhibition of PPAR-γ and NF-κB pathways which highlight the effectiveness these digested proteins against obesity complications. Funding Sources CNPq and CAPES (Brazil), and NIFA HATCH (USA).