Anti-inflammatory, anti-oxidant and anti-ulcer activities of aqueous lyophilizate of Markhamia lutea (Bignoniaceae).

Abstract

Objectives: This work was carried out with a view to determining the antioxidant, anti-inflammatory and anti-ulcer properties of the aqueous lyophilized extract of Markhamia lutea.

Methods: In vitro proteinases inhibition, albumin denaturation, hemolysis of red blood cells by heat, inhibition of the proton pump H⁺/K⁺ATPase, FRAP (Ferric reducing antioxidant power) and DPPH (1,1-diphenyl-2-picrylhydrazyl) assays were performed. In vivo, cold water immersion-induced ulceration and methylene blue-induced ulceration was used to determine the anti-ulcer properties of the lyophilizate (100, 200 and 300 mg/kg).

Results: In vitro, the lyophilizate (400 μg/mL) significantly inhibited protein denaturation (66.65 %), hemolysis of red blood cells (56.54 %), proteinase activity (69.22 %); then the IC₅₀ was 26.31 μg/mL on proton pump activity. It has also developed a strong ferric reducing antioxidant power (EC₅₀=52.96 mmol FeSO₄/g) as well as free radicals scavenging activity (EC₅₀=22.38 μg/mL). In vivo, the aqueous lyophilizate (200 and 300 mg/kg) protected the gastric mucosa (70.68 and 79.00 % protection respectively) and reduced (p<0.05) acetylcholine, calcium and corticosterone concentrations. A decrease in malondialdehyde level, an increased glutathione level and an increased in catalase and SOD activities were recorded. In the methylene blue test, it significantly increased gastric fluid pH, while reducing gastric volume and improving hematological parameters in ulcer animals. In addition, the histological sections show that the aqueous lyophilizate of M. lutea protected the gastric mucosa from the deleterious effects of stress.

Conclusions: The aqueous lyophilizate of M. lutea has anti-ulcer properties thanks to its anti-inflammatory, antioxidant and anti-secretory properties.