TUMBO SEED OIL ATTENUATES CARDIOMETABOLIC ALTERATIONS AND MODULATES ENDOTHELIAL, INFLAMMATORY, AND ANTIOXIDANT GENE EXPRESSION IN HYPERLIPIDEMIC GUINEA PIGS

Introduction: Diet-induced hyperlipidemia involves dyslipidemia, impaired glucose homeostasis, hepatic alterations, oxidative stress, inflammation, and endothelial dysfunction. Tumbo (Passiflora tripartita var. mollissima) seeds, an underutilized Andean by-product, are a potential bioactive lipid source, yet their cardiometabolic and gene-expression effects remain poorly understood.

Objective: To evaluate the effects of tumbo seed oil on cardiometabolic parameters and endothelial, inflammatory, and antioxidant gene expression in guinea pigs with diet-induced hyperlipidemia.

Methodology: Twenty-four male guinea pigs were allocated to four groups (n=6/group): standard diet (SD), high-fat diet (HFD), HFD+olive oil (HFD-OO), and HFD+tumbo seed oil (HFD-TSO). Hyperlipidemia was induced for 52 days, followed by 45 days of oral treatment with olive or tumbo seed oil (2 mL/kg body weight/day). Diets were not isocaloric or macronutrient-matched (322 vs. 412 kcal/100 g; 2.70% vs. 17.29% ether extract, SD vs. HFD). Tumbo seed oil contained 75.96% linoleic acid, 342.11 mg GAE/100 g total phenolics, 307.58 mg QE/100 g total flavonoids, and antioxidant capacity (ABTS 57.38, DPPH 33.20, FRAP 59.13 mg TE/100 g). Serum lipids, glucose, ALT, and AST were measured. Aortic and hepatic expression of endothelial, inflammatory, and antioxidant genes was assessed by qPCR (β-actin and SDHA as reference genes in aorta and liver, respectively). Data were analyzed by Kruskal-Wallis and Dunn's tests.

Results: HFD induced dyslipidemia, hyperglycemia, and increased ALT and AST vs. SD (p<0.05). Compared with HFD, HFD-TSO reduced total cholesterol (69.17 vs. 166.70 mg/dL), triglycerides (59.17 vs. 194.80 mg/dL), VLDL-c (11.83 vs. 38.97 mg/dL), glucose (120.70 vs. 227.20 mg/dL), and ALT/AST, while increasing HDL-c (18.00 vs. 6.83 mg/dL) (all p<0.05). At the molecular level, HFD-TSO increased aortic eNOS and GPX1 and hepatic GPX1 expression, while reducing hepatic TNF-α (p<0.05); other aortic markers showed favorable, non-significant changes.

Discussion: The concurrent improvement in lipid and glucose metabolism, hepatic function, and the upregulation of eNOS and GPX1 alongside TNF-α downregulation suggest that tumbo seed oil's phenolic and flavonoid content underlies combined antioxidant, anti-inflammatory, and endothelial-protective effects.

Conclusion: These findings support tumbo seed oil as a promising bioactive lipid source for functional-food strategies targeting cardiometabolic and vascular health.

Funding: This study was funded by the National Program for Scientific Research and Advanced Studies – PROCIENCIA, within the framework of the Project "Interinstitutional Alliances for Doctoral Programs – Stage II, Nutrition", Contract No. PE501084302-2023-PROCIENCIA-BM.