Background & Aim: The mechanism of action of Crinum glaucumbulb (Cgb) A. Chev (Amaryllidaceae) is enigmatic. Therefore, this study aimed at investigating the possible modulating properties of an aqueous extract of Cgb on endogenous antioxidant enzymes during lipopolysaccharide (LPS)-induced oxidative stress in a rat model.Experimental: 25 male and 25 female rats were divided into five groups (n=5) each: control group; treatment group, rats were given an aqueous extract of Cgb for 7 days; induced-oxidative stress group, rats were injected with LPS for 4 hours; post-Cgb group, rats were injected with LPS for 4 hours and treated with an aqueous extract of Cgb; and pre-Cgb group, rats were given an aqueous extract of Cgb for 7 days, injected with LPS for 4 hours, and treated with an aqueous extract of Cgb for 7 days. The blood, brain, heart, lungs, liver, and kidneys were harvested for the biochemical analysis. The endogenous antioxidant enzymes (catalase, superoxide dismutase, and glutathione-S-transferase) were analysed spectrophotometrically.Results: The hallmark of LPS is its ability to decrease the activity of oxidative stress marker enzymes, as observed in this study. The pre- and post-administration of an aqueous extract of Cgb significantly (P≤0.05) reversed the damaging effect of LPS by increasing the activities of catalase and superoxide dismutase in the blood and organs of male and female rats, respectively, while plasma glutathione-S-transferase activity was inhibited.Recommended applications/industries: The aqueous extract of Cgb has modulating properties to reduce the action of LPS-induced oxidative stress on endogenous antioxidant enzymes in male and female rats. Manuscript profile