A Lupin (Lupinus angustifolius) Protein Hydrolysate Decreases the Severity of Experimental Autoimmune Encephalomyelitis: A Preliminary Study

Abstract

Multiple sclerosis (MS) is a neurodegenerative disease, with inflammation and oxidative stress in the central nervous system being the main triggers. There are many drugs that reduce the clinical signs of MS, but none of them cure the disease. Food proteins have been shown to contain encrypted peptides that can be released after hydrolysis and exert numerous biological activities. Recently, we have demonstrated the anti-inflammatory and antioxidant activities of a lupin protein hydrolysate (LPH) both in vitro and in vivo. Therefore, the aim of this study was to evaluate whether LPH is capable of reducing the clinical signs of experimental autoimmune encephalomyelitis (EAE), a mouse model of MS. EAE was induced in female C57BL/6N mice and they were treated intragastrically with LPH (100 mg/kg) or vehicle (control group) from day 0 (prophylactic approach) or from the onset of the disease (day 12 post-induction; therapeutic approach) and the clinical score of each mouse was recorded daily. Prophylactic treatment with LPH reduced the clinical score of the mice compared to the control group, as well as the maximum and cumulative scores, without changing the day of onset of the symptoms while the therapeutic intervention did not significantly improve the severity of the disease. For the first time, we demonstrated that prophylactic administration of LPH reduces the severity of MS, suggesting a potential nutraceutical or new functional foods in neuroinflammation. However, further studies are needed to confirm this nutritional effect in a clinical context.

Keywords: EAE; MS; functional foods; hydrolysates; neurodegeneration; vegetable.

Figure 1

Weight of mice and clinical EAE score in the prophylactic approach. (A) Weight of animals during the experiments. (B) Clinical EAE score. (C) Linear regression of the clinical EAE score. (D) AUC of the clinical EAE score. (E) Day of onset of the clinical signs manifestation. * p ≤ 0.05; ** p ≤ 0.01; *** p ≤ 0.005; n = 20. AUC, area under the curve; Ctrl, control group; EAE, experimental autoimmune encephalomyelitis; LPH, lupin protein hydrolysate. The orange shade shows the duration of the treatment.

Figure 2

Severity of the EAE in the prophylactic approach. (A) Maximum score and (B) accumulated score reached by the two experimental groups. ** p ≤ 0.01; **** p ≤ 0.0001; n = 20. Ctrl, control group; LPH, lupin protein hydrolysate.

Figure 3

Weight of mice and clinical EAE score in the therapeutic approach. (A) Weight of animals during the experiments. (B) Clinical EAE score. (C) Linear regression of the clinical EAE score. (D) AUC of the clinical EAE score. (E) Day of onset of the clinical signs manifestation. n = 8. AUC, area under the curve; Ctrl, control group; EAE, experimental autoimmune encephalomyelitis; LPH, lupin protein hydrolysate; n.s., not significant. The purple shade shows the duration of treatment.

Figure 4

Severity of the EAE in the therapeutic approach. (A) Maximum score and (B) accumulated score reached by the two experimental groups. n = 8. Ctrl, control group; LPH, lupin protein hydrolysate.

Figure 5

Pleiotropic effects exerted by the LPH sequences. Number and percentage of the lupin protein hydrolysate sequences that contain a described motif with the biological effect.

Figure 6

Experimental design and timeline. Schematic diagram of the experimental design of the study. CFA, complete Freud adjuvant; EAE, experimental autoimmune encephalomyelitis; i.p., intraperitoneal injection; LPH, lupin protein hydrolysate; MOG, myelin oligodendrocyte glycoprotein; PTx, pertussis toxin; s.c., subcutaneous injection.