Evaluation of the in vitro and in vivo antioxidant potentials of food grade Phycocyanin

Abstract

Excessive generation of oxygen free radicals plays a pivotal role in destruction of biological molecules like DNA, proteins, lipids, carbohydrates and results in various pathologies including neuronal disorders. Antioxidant molecules from natural products are reported to have ability to mitigate their production or at least halt their progression and metastasis in the system. Different studies have been performed to spot antioxidants from natural sources and attempts have been made to integrate them in conventional therapy. In our present study, food grade Phycocyanin, a nutraceutical isolated from Spirulina platensis, has been evaluated for its in vitro and in vivo antioxidant potential using a battery of antioxidant assays viz. DPPH, TAC, FRAP, hydroxyl radical, hydrogen peroxide scavenging, SOD, GSH, and LPO assays. Reducing properties of Phycocyanin were also assessed by FRAC assay. For in vivo evaluation of antioxidant profile, animal model of intracerebroventricular administration of streptozotocin was employed. Levels of oxidative stress biomarkers were measured in cortex and hippocampal parts of brain. Results obtained depicted that Phycocyanin demonstrated a dose-dependent pattern in its efficacy, which indicates the presence of free radical scavenger moieties and possible role as a neuroprotective agent.

Keywords: Antioxidant; Food grade; In vitro; In vivo; Phycocyanin.

Fig. 1

a Percent free radical inhibition of Pc as per DPPH assay; b Ferric reducing antioxidant power of Pc expressed as absorbance at 593 nm; c Percent free radical inhibition of Pc as per Hydroxyl radical antioxidant assay; d Percent free radical inhibition of Pc as per Hydrogen per oxide antioxidant assay; e Total antioxidant capacity (TAC) of Pc; f Reducing power assay of Pc expressed as absorbance at 700 nm. Values are given as mean ± S. D. (n = 3)

Fig. 2

Effect of treatment with Pc (50, 100 mg/kg) on lipid peroxides levels in (a) cerebral cortex; ^###p <0.001—sham versus ICV-STZ, ^***p <0.001–ICV-STZ versus RIV, ^**p <0.01—ICV-STZ versus Pc 50, ^***p <0.001—ICV-STZ versus Pc 100, (b) hippocampus; ^###p <0.001—sham versus ICV-STZ, ^***p <0.001—ICV-STZ versus RIV, ^***p <0.001—ICV-STZ versus Pc 100 and (c) nitrite levels in plasma of ICV-STZ administered rats; ^###p <0.001—sham versus ICV-STZ, ^***p <0.001—ICV-STZ versus RIV, ^*p <0.05—ICV-STZ versus Pc 100. Values were expressed as mean ± SEM. The intergroup variation was measured by one way ANOVA followed by Tukey’s test using Graphpad prism 5.0 (Graphpad Software Inc, CA, USA)

Fig. 3

Effect of treatment with Pc (50, 100 mg/kg) on superoxide dismutase (SOD) levels in (a) cerebral cortex; ^#p <0.05—sham versus ICV-STZ, ^**p <0.01—ICV-STZ versus RIV, ^*p <0.05—ICV-STZ versus Pc 100 and (b) hippocampus of ICV-STZ administered rats; ^###p <0.001—sham versus ICV-STZ, ^**p <0.01—ICV-STZ versus RIV, ^*p <0.05—ICV-STZ versus Pc 100. Values were expressed as mean ± SEM. The intergroup variation was measured by one way ANOVA followed by Tukey’s test using Graphpad prism 5.0 (Graphpad Software Inc, CA, USA)

Fig. 4

Effect of treatment with Pc (50, 100 mg/kg) on glutathione levels in (a) cerebral cortex; ^#p <0.05—sham versus ICV-STZ, ^***p <0.001—ICV-STZ versus RIV, ^**p <0.01—ICV-STZ versus Pc 100 and (b) hippocampus of ICV-STZ administered rats; ^#p <0.05—sham versus ICV-STZ, ^***p <0.001—ICV-STZ versus RIV,^***p <0.001—ICV-STZ versus Pc 100. Values were expressed as mean ± SEM. The intergroup variation was measured by one way ANOVA followed by Tukey’s test using Graphpad prism 5.0 (Graphpad Software Inc, CA, USA)