Amino acid HPLC-FLD analysis of spirulina and its protective mechanism against the combination of obesity and colitis in wistar rats

Abstract

Objective: The cafeteria diet (CD), designed as an experimental diet mimicking the obesogenic diet, may contribute to the pathogenesis of inflammatory bowel diseases (IBD). This study delves into the influence of spirulina (SP) on obesity associated with colitis in Wistar rats.

Methods: The amino acids composition of SP was analyzed using HPLC-FLD. Animals were equally separated into eight groups, each containing seven animals and treated daily for eight weeks as follows: Control diet (SD), cafeteria diet (CD) group, CD + SP (500 mg/kg) and SD + SP. Ulcerative colitis was provoked by rectal injection of acetic acid (AA) (3 % v/v, 5 ml/kg b.w.) on the last day of treatment in the following groups: SD + AA, SD + AA + SP, CD + AA, and CD + AA + SP.

Results: Findings revealed that UC and/or CD increased the abdominal fat, weights gain, and colons. Moreover, severe colonic alteration, perturbations in the serum metabolic parameters associated with an oxidative stress state in the colonic mucosa, defined by overproduction of reactive oxygen species (ROS) and increased levels of plasma scavenging activity (PSA). Additionally, obesity exacerbated the severity of AA-induced UC promoting inflammation marked by the overexpression of pro-inflammatory cytokines. Significantly, treatment with SP provided notable protection against inflammation severity, reduced histopathological alterations, attenuated lipid peroxidation (MDA), and enhanced antioxidant enzyme activities (CAT, SOD, and GPX) along with non-enzymatic antioxidants (GSH and SH-G).

Conclusions: Thus, the antioxidant effects and anti-inflammatory proprieties of SP could be attributed to its richness in amino acids, which could potentially mitigate inflammation severity in obese subjects suffering from ulcerative colitis. These results imply that SP hold promise as a therapeutic agent for managing of UC, particularly in individuals with concomitant obesity. Understanding SP's mechanisms of action may lead novel treatment strategies for inflammatory bowel diseases and hyperlipidemia in medical research.

Keywords: Cafeteria diet; Obesity; Oxidative stress; Spirulina; Ulcerative colitis.

Fig. 1

Effect of spirulina (SP 500 mg/kg) on AA-induced alteration in colon morphology of SD-fed and CD-fed rat. Animals was pre-treated with SP (500 mg/kg, b.w., p. o) or distilled water, and challenged with a single anal treatment of AA (3 % v/v, 5 mL/kg b.w.) or NaCl (0.9 %, 5 ml/kg 1, b.w.) for 24 h. (A) SD, (B) SD + SP, (C) CD, (D) CD + SP, (E) SD + AA, (F) SD + AA + SP, (G) CD + AA, (H) CD + AA + SP.

Fig. 2

Effect of spirulina (SP 500 mg/kg) on histological alteration in colonic mucosa associated with CD and AA treatments (A)and histological score (B). Animals was pre-treated with SP (500 mg/kg, b.w., p.o) or distilled water, and challenged with a single anal treatment of AA (3 % v/v, 5 mL/kg b.w.) or NaCl (0.9 %, 5 ml/kg 1, b.w.) for 24 h. (a) SD, (b) CD, (c) CD + SP, (d) SD + SP, (e) SD + AA, (f) SD + AA + SP, (g) CD + AA, (h) CD + AA + SP, (Magnification ×10).For the histological score, multi-groups comparison by One-way ANOVA. P ≤ 0.05, P ≤ 0.01, and P ≤ 0.001 were denoted as *, **, *** vs SD, ¥, ¥¥, ¥¥¥vs CD, #, ##, ###vs SD + AA, and £, ££, £££ vs CD + AA respectively.

Fig. 3

Effect of SP (500 mg/kg,b.w., p.o) on colonic oxidative stress of SD-fed and CD-fed rat treated, or not, with AA (3 % v/v, 5 mL/kg b.w.) such as MDA (A), SOD (B), CAT (C) and GPx (D), thiol groups (E) and GSH (F). Animals was pre-treated with SP (500 mg/kg, b.w., p.o) or distilled water, and challenged with a single anal treatment of AA (3 % v/v, 5 mL/kg b.w.) or NaCl (0.9 %, 5 ml/kg, b.w.) for 24 h. The data are expressed as mean S.E.M. (n = 7),different groups comparison by One-way ANOVA. P ≤ 0.05, P ≤ 0.01, and P ≤ 0.001 were denoted as *, **, *** vs SD, ¥, ¥¥, ¥¥¥vs CD, #, ##, ###vs SD + AA, and £, ££, £££ vs CD + AA respectively.

Fig. 4

Effect of SP (500 mg/kg, b.w., p.o) on colonic mucosa Hydrogen peroxide (A), hydroxyl radical (B) and superoxide anion (C) levels of SD-fed and CD-fed rat treated, or not, with AA (3 % v/v, 5 mL/kg b.w.). Animals was pre-treated with SP (500 mg/kg,b.w., p.o) or distilled water, and challenged with a single The data are expressed as mean S.E.M. (n = 7).All groups comparison by One-way ANOVA. P ≤ 0.05, P ≤ 0.01, and P ≤ 0.001 were denoted as *, **, *** vs SD, ¥, ¥¥, ¥¥¥vs CD, #, ##, ###vs SD + AA, and £, ££, £££ vs CD + AA respectively.

Fig. 5

Effect of SP (500 mg/kg,b.w., p.o) on plasma scavenging activity changes of SD-fed and CD-fed rat treated, or not, with AA (3 % v/v, 5 mL/kg b.w.). Animals was pre-treated with SP (500 mg/kg,b.w., p. o) or distilled water, and challenged with a single anal treatment of AA (3 % v/v, 5 mL/kg b.w.) or NaCl (0.9 %, 5 ml/kg 1, b.w.) for 24 h. The data are expressed as mean S.E.M. (n = 7),multi-group comparison by One-way ANOVA. P ≤ 0.05, P ≤ 0.01, and P ≤ 0.001 were denoted as *, **, *** vs SD, ¥, ¥¥, ¥¥¥ vs CD, #, ##, ### vs SD + AA, and £, ££, £££ vs CD + AA respectively.

Fig. 6

Effect of SP (500 mg/kg, b.w., p.o) on colitis inflammation during obesity and/or colitis of SD-fed and CD-fed rat treated, or not, with AA (3 % v/v, 5 mL/kg b.w.) such as CRP (A), ALP (B) IL-1β (C), IL-4 (D), IL-6 (E) and TNFα (F). Animals was pre-treated with SP (500 mg/kg, b.w., p. o) or distilled water, and challenged with a single anal treatment of AA (3 % v/v, 5 mL/kg b.w.) or NaCl (0.9 %, 5 ml/kg 1, b.w.) for 24 h. The data are expressed as mean S.E.M. (n = 7), multi-group comparison by One-way ANOVA. P ≤ 0.05, P ≤ 0.01, and P ≤ 0.001 were denoted as *, **, *** vs SD, ¥, ¥¥, ¥¥¥vs CD, #, ##, ###vs SD + AA, and £, ££, £££ vs CD + AA respectively.