Cardiac and Metabolic Impact of Functional Foods with Antioxidant Properties Based on Whey Derived Proteins Enriched with Hemp Seed Oil

Abstract

The impaired ability to feed properly, evident in oncologic, elderly, and dysphagic patients, may result in malnutrition and sarcopenia. Increasing the consumption of dietary proteins by functional foods and enriching their composition by adding beneficial nutrients may represent an adjuvant therapy. We aimed to evaluate the safety and the positive effects of a standard diet (SD) supplemented with whey-derived protein puddings (WDPP), with appropriate rheological properties, and hemp seed oil (HSO), rich in polyphenols. Rats were assigned to SD, WDPP, WDPP plus hemp seed oil (HSOP), and HSO supplemented diets for eight weeks. "Anthropometric", metabolic, and biochemical variables, oxidative stress, tissue injury, liver histology, and cardiac susceptibility to ischemia/reperfusion were analyzed. All the supplementations did not induce significant changes in biochemical and metabolic variables, also in relation to glucose tolerance, and livers did not undergo morphological alteration and injury. An improvement of cardiac post-ischemic function in the Langendorff perfused heart model and a reduction of infarct size were observed in WDPP and HSOP groups, thanks to their antioxidant effects and the activation of Akt- and AMPK-dependent protective pathways. Data suggest that (i) functional foods enriched with WDPP and HSOP may be used to approach malnutrition and sarcopenia successfully under disabling conditions, also conferring cardioprotection, and that (ii) adequate rheological properties could positively impact dysphagia-related problems.

Keywords: cardioprotection; functional foods; hemp seed oil; nutrition; rheological approach; whey-derived proteins.

Figure 1

Frequency sweep test at 20 °C of samples HSOP (filled symbols) and WDPP (empty symbols).

Figure 2

Metabolic plasma variables in rats fed with SD, or WDPP, or HSOP, or HSO for 8 weeks: (A) total cholesterol; (B) LDL cholesterol; (C) HDL cholesterol; (D) glycemia; (E) triglycerides. n = 6 for each group; data are expressed as means ± SEM; statistical significance: * p < 0.05, ** p < 0.01 (One-way ANOVA and the non-parametric Newman-Keuls Multiple Comparison Test).

Figure 3

Injury (LDH) and oxidative stress (MDA) markers in plasma of rats fed with SD, or WDPP, or HSOP, or HSO for 8 weeks: (A) LDH; (B) MDA. n = 6 for each group; data are expressed as means ± SEM. statistical significance: One-way ANOVA and the non-parametric Newman-Keuls Multiple Comparison Test.

Figure 4

Hematoxylin and eosin (HE) stained liver sections in rats fed for 8 weeks with (A) SD; (B) WDPP; (C) HSOP; (D) HSO. V: central vein.

Figure 5

Sirius red-stained liver sections in rats fed for 8 weeks with (A) SD; (B) WDPP; (C) HSOP; (D) HSO. V: central vein; black arrows: vessel wall; blue arrows: pericellular spaces. (E) LDH activity in the liver of rats fed with SD, or WDP, or WDP + HSO, or HSO for 8 weeks. n = 6 for each group; data are expressed as means ± SEM; statistical significance: One-way ANOVA and the non-parametric Newman-Keuls Multiple Comparison Test).

Figure 6

Systolic (A) and diastolic (C) function under I/R protocols in rats fed with SD, or WDPP, or HSOP, or HSO for 8 weeks. Gray boxes indicate ischemic administration (Bonferroni multiple comparison test). dLVP = 25.3% of total variation between groups (p < 0.001); LVEDP = 23.7% of total variation between groups (p < 0.001). (B,D) show dLVP and LVEDP at the end of reperfusion. Data are expressed as changes of dLVP and LVEDP values (millimeters of mercury) from stabilization period to the end of the 120 min of reperfusion with respect to the baseline values for Control, WDPP, HSOP and HSO groups (n = 6). * p < 0.05, ** p < 0.01, *** p < 0.001 (1-way ANOVA and Newman-Keuls multiple comparison test).

Figure 7

Infarct size (A), cardiac MDA (B) and cardiac protein carbonyl groups (C) in I/R hearts from rats fed with SD, or WDPP, or HSOP, or HSO for 8 weeks. n = 6 for each group; data are expressed as means ± SEM; statistical significance: * p < 0.05, ** p < 0.01 (1-way ANOVA and Newman-Keuls multiple comparison test).

Figure 8

pAkt (A) and pAMPK (B) levels in I/R hearts from rats fed with SD, or WDPP, or HSOP, or HSO for 8 weeks. n = 3 for each group; data are expressed as means ± SEM; statistical significance: * p < 0.05. (1-way ANOVA and Newman-Keuls multiple comparison test).