Assessment of the phytochemical constituents and antioxidant activity of a bloom forming microalgae Euglena tuba

Table 2 Comparison of the antioxidant and free radical scavenging capacities of 70% methanol extract of E. tuba and standard reference compounds

Name of assay	ETME	Standard	Values of standard compounds
TEAC Values	0.202 ± 0.001	-	-
*IC₅₀ values of the extracts for free radical scavenging capacity for
DPPH	146.07 ± 1.80	Ascorbic acid	5.29 ± 0.28^***
Hydroxyl radical (OH^•) scavenging	41.89 ± 0.41	Mannitol	571.45 ± 20.12^***
Lipid peroxidation	202.49 ± 33.32	Trolox	6.76 ± 0.17^***
Superoxide anion (O₂^•-) scavenging	5.83 ± 0.07	Quercetin	42.06 ± 1.35^***
Hydrogen peroxide (H₂O₂) scavenging	47.34 ± 5.05	Sodium pyruvate	3.24 ± 0.30^***
Nitric oxide radical (NO) scavenging	278.46 ± 15.02	Curcumin	90.82 ± 4.75^***
Peroxynitrite (ONOO^-) scavenging	2.821 ± 1.69	Gallic acid	0.876 ± 0.57^***
Singlet oxygen (¹O₂) scavenging	0.879 ± 0.29	Lipoic acid	0.046 ± 0.01^***
Hypochlorous acid (HOCl) scavenging	223.25 ± 4.19	Ascorbic acid	235.96 ± 5.75^**

*IC₅₀ Values are in μg/ml (except for Hydrogen peroxide, Peroxynitrite and Singlet oxygen scavenging assay where values are expressed in mg/ml). Each value represents mean ± S.D. (n = 6). ***p < 0.001, **p < 0.01 vs ETME.

ISSN: 0717-6287