Phenolic Profiling and Bioactive Properties of Arthrospira platensis Extract in Alleviating Acute and Sub-Chronic Colitis

Abstract

Arthrospira platensis, a filamentous photosynthetic cyanobacterium, is widely recognized for its high nutritional value, broad spectrum of bioactive compounds, and excellent safety profile, making it a promising natural source for health-promoting applications. This study aimed to profile the phenolic constituents of an ethanolic extract of A. platensis (EAP) using HPLC-DAD-ESI-MS and to investigate its pharmacological effects in attenuating acute and sub-chronic experimental colitis, as well as its antioxidant and antifungal properties. Colitis was induced in BALB/c mice by intrarectal administration of 2,4-dinitrobenzenesulfonic acid (DNBS), followed by oral administration of EAP at doses of 50, 100, and 200 mg/kg. Phenolic profiling revealed eight major compounds, with a cumulative content of 6.777 mg/g of extract, with Pyrogallol, Ferulic acid, and Chlorogenic acid being the most abundant. In vivo, EAP treatment significantly reduced the Disease Activity Index (DAI), alleviated macroscopic colonic damage, and preserved colonic mucosal integrity in both inflammatory phases. Biochemical analyses revealed significant reductions in myeloperoxidase (MPO) activity, nitric oxide (NO), and malondialdehyde (MDA) levels, accompanied by increased reduced glutathione (GSH) content and catalase activity. In vitro, EAP demonstrated notable antioxidant effects, including 56% DPPH and 47% ABTS radical scavenging activities, and an 81% ferrous ion-chelating capacity. Furthermore, it exhibited antifungal activity, with inhibition zones of 20 mm against Candida albicans and 15 mm against Aspergillus flavus, respectively. These findings highlight the multitarget bioactivity of EAP and support its potential as a natural agent for managing intestinal inflammation and oxidative stress across both acute and sub-chronic phases.

Keywords: DNBS-induced colitis; HPLC-DAD-ESI-MS; phenolic compounds; spirulina.

Figure 1

DAD chromatogram of phenolic compounds in the ethanolic extract of A. platensis (EAP) obtained by HPLC-DAD-ESI-MS analysis.

Figure 2

Effect of the ethanolic extract of A. platensis (EAP) on clinical and morphological parameters in DNBS-induced acute colitis. (A) Disease Activity Index (DAI). (B) Representative macroscopic appearance of colons. (C) Colon weight-to-length ratio. Mice were treated orally with EAP at doses of 50, 100, and 200 mg/kg. Data are expressed as mean ± SD (n = 7 per group). Statistical analysis was performed using one-way ANOVA followed by Dunnett’s multiple comparisons test. * p < 0.05, ** p < 0.01, *** p < 0.001 vs. the DNBS group; ### p < 0.001 vs. the healthy control group.

Figure 3

Histological evaluation of colonic tissues following treatment with the ethanolic extract of A. platensis (EAP) in DNBS-induced acute colitis in mice. Representative photomicrographs of hematoxylin–eosin-stained transverse colon sections (G × 40 and G × 100), illustrating (A) normal histology in the control group, (B) severe histopathological damage in the DNBS group, and (C–E) histological improvements in groups treated with EAP at doses of 50, 100, and 200 mg/kg, respectively. Key: () submucosal edema; () infiltration of mononuclear cells in the submucosa; () disruption of crypt integrity; () necrotic areas. M: mucosa. SM: submucosa. ME: muscularis externa.

Figure 3

Histological evaluation of colonic tissues following treatment with the ethanolic extract of A. platensis (EAP) in DNBS-induced acute colitis in mice. Representative photomicrographs of hematoxylin–eosin-stained transverse colon sections (G × 40 and G × 100), illustrating (A) normal histology in the control group, (B) severe histopathological damage in the DNBS group, and (C–E) histological improvements in groups treated with EAP at doses of 50, 100, and 200 mg/kg, respectively. Key: () submucosal edema; () infiltration of mononuclear cells in the submucosa; () disruption of crypt integrity; () necrotic areas. M: mucosa. SM: submucosa. ME: muscularis externa.

Figure 4

Effects of the ethanolic extract of A. platensis (EAP) on biochemical markers in DNBS-induced acute colitis in BALB/c mice. (A) Malondialdehyde (MDA) levels, (B) nitrite concentrations (NO), and (C) reduced glutathione (GSH) levels in colonic tissues following treatment with EAP at doses of 50, 100, and 200 mg/kg. Data are presented as mean ± standard deviation (SD), (n = 7 mice per group). Statistical analysis was performed using one-way ANOVA followed by Dunnett’s multiple comparisons test. * p < 0.05, ** p < 0.01, *** p < 0.001 vs. the DNBS group; ### p < 0.001 vs. the control group.

Figure 5

Effect of the ethanolic extract of A. platensis (EAP) on clinical and morphological parameters in DNBS-induced sub-chronic colitis in BALB/c mice. (A) Disease Activity Index (DAI). (B) Representative macroscopic appearance of the colon. (C) Colon weight-to-length ratio. Mice were treated orally with EAP at doses of 50, 100, and 200 mg/kg. Data are expressed as mean ± standard deviation (SD) (n = 7 per group). Statistical analysis was performed using one-way ANOVA followed by Dunnett’s multiple comparisons test. * p < 0.05, ** p < 0.01, *** p < 0.001 vs. the DNBS group; ### p < 0.001 vs. the control group.

Figure 6

Histological evaluation of colonic tissue following treatment with the ethanolic extract of A. platensis (EAP) in DNBS-induced sub-chronic colitis in mice. Representative photomicrographs of hematoxylin–eosin-stained transverse colon sections, analyzed under light microscopy (G × 40 and G × 200), illustrate (A) normal histology in the control group, (B) severe histopathological damage in the DNBS group, and (C–E) histological improvements in groups treated with EAP at doses of 50, 100, and 200 mg/kg, respectively. Key: () submucosal edema; () infiltration of mononuclear cells in the submucosa; () disruption of crypt integrity; () granulomas. M: mucosa. SM: submucosa. ME: muscularis externa.

Figure 7

Effects of the ethanolic extract of A. platensis (EAP) on biochemical markers in DNBS-induced sub-chronic colitis in BALB/c mice. (A) Myeloperoxidase (MPO) activity; (B) nitrite (NO) levels; (C) malondialdehyde (MDA) content; (D) catalase activity; and (E) reduced glutathione (GSH) levels in colonic tissues following oral administration of EAP at doses of 50, 100, and 200 mg/kg. Data are expressed as mean ± standard deviation (SD). (n = 7 per group). Statistical analysis was performed using one-way ANOVA followed by Dunnett’s multiple comparisons test. ns, p > 0.05; * p < 0.05, ** p < 0.01, *** p < 0.001 vs. the DNBS group; ### p < 0.001 vs. the control group.

Figure 8

Antioxidant activity of the ethanolic extract of A. platensis (EAP) compared with Trolox and ascorbic acid. (A) DPPH• radical-scavenging activity; (B) ABTS•⁺ radical-scavenging activity; (C) ferrous ion-chelating (FIC) activity. Data are expressed as mean ± standard deviation (SD) (n = 3 independent replicates). Statistical analysis was conducted using one-way ANOVA followed by Tukey’s multiple comparisons test. *** p < 0.001 vs. Trolox/Ascorbic acid.

Figure 9

Schematic representation of the experimental protocols for DNBS-induced acute (A) and sub-chronic (B) colitis in BALB/c mice, including treatment timelines with the ethanolic extract of A. platensis (EAP).