Anti-aggregatory effect of boswellic acid in high-fat fed rats: involvement of redox and inflammatory cascades

Abstract

Introduction: A high-fat diet is one of the main dietary factors promoting platelet aggregation. The present study was conducted to elucidate the involvement of boswellic acid (BA) on the platelet hyperaggregability in HFD-fed rats. As platelet hyperaggregability in HFD rats is closely linked to inflammation and enhanced free radical production, the present study was extended to evaluate the anti-inflammatory and anti-oxidative effect of BA on HFD-promoted platelet aggregation.

Material and methods: Rats were assigned to normal, HFD-fed, aspirin-treated (30 mg/kg), and BA-treated (250 and 500 mg/kg) groups.

Results: Boswellic acid administration in a high dose was effective in attenuating the severity of hyperlipidemia and platelet aggregation, indicated by lower collagen/epinephrine-induced platelet aggregation, as evidenced by the significant increase (p < 0.05) in the circulating platelet count and reduction in the number of thrombi in the lungs. Moreover, it attenuated the oxidative stress and the intensity of inflammatory mediators associated with platelet hyperaggregability, as evidenced by the inhibitory effects on interlukin-1β, COX-2 and tumor necrosis factor-α, indicating that the antiplatelet activity of BA is likely a consequence of controlling oxidative stress and inflammation.

Conclusions: The present data suggest that BA shows a promising anti-aggregatory effect by attenuating the enhanced hyperlipidemia, oxidative stress and inflammation associated with HFD.

Keywords: boswellic acid; high-fat diet; inflammation; oxidative stress; platelet aggregation; rat.

Figure 1

Platelet aggregation assay in the experimental groups. HFD: high-fat diet. Data are presented as mean ± SEM and analyzed using oneway ANOVA followed by Tukey’s post-hoc test at p < 0.05 (n = 8) *Compared to normal group. ^#Compared to HFD group.

Figure 2

Effect of boswellic acid or aspirin on circulating platelets. A – Platelet count before i.v. injection of collagen (1000 μg/kg) plus epinephrine (200 μg/kg). B – Platelet count 3 min after i.v. injection of collagen-epinephrine mixture. C – Number of thrombi in the lungs of rats 3 min after injection of collagen epinephrine mixture HFD – high-fat diet. Data are presented as mean ± SEM and analyzed using one-way ANOVA followed by Tukey’s post-hoc test at p < 0.05 (n = 8). *Compared to normal group. ^#Compared to HFD group.

Figure 3

Serum level of MDA (A), GSH (B), SOD (C), CATA (D) in the experimental groups HFD – high-fat diet. Data are presented as mean ± SEM and analyzed using one-way ANOVA followed by Tukey’s post-hoc test at p < 0.05 (n = 8). *Compared to normal group. ^#Compared to HFD group. ^$Compared to aspirin.

Figure 4

Serum level of interlukin-1β (A), COX-2 (B) and TNF-α (C) in the experimental groups HFD – high-fat diet. Data are presented as mean ± SEM and analyzed using one-way ANOVA followed by Tukey’s post-hoc test at p < 0.05 (n = 8). *Compared to normal group. ^#Compared to HFD group.