Nephroprotective and Antioxidant Effects of Flavonoid-Rich Extract of <i>Thymelaea microphylla</i> Coss. et Dur Aerial Part

Abstract

Thymelaea microphylla Coss. et Dur (T. microphylla), a medicinal herb that grows in arid and desert pastures, has been traditionally utilized by Moroccans to treat many diseases, including kidney failure. This study aims to evaluate the nephroprotective effect against gentamicin-induced nephrotoxicity (GM), and thus the antioxidant activity of an aqueous extract rich in flavonoids from the aerial part of T. microphylla (APTM). The antioxidant activity of APTM was assessed using the 2-2-diphenyl-1-picrylhydrazyl (DPPH) scavenging test and the β-carotene bleaching assay. The nephroprotective effect of this extract was evaluated in two doses of 200 and 400 mg/kg in GM-exposed male rats. Acute toxicity of the APTM was tested out on Swiss albino mice using 2000 mg/kg as the dose limit. The findings showed that the aqueous extract of APTM is abundant in total polyphenols and flavonoids and has significant antioxidant properties against DPPH radicals and β-carotene oxidation. According to the acute toxicity research findings, the administered doses of the APTM extract do not cause toxicity and death. A significant increase in the serum concentrations of creatinine, urea, uric acid, sodium, chloride, calcium, gamma-glutamyl transpeptidase (gamma-GT), and alkaline phosphatase, as well as an increase in urinary volume, water consumption, and relative kidney weight, were all caused by the administration of GM to rats. In addition, a significant reduction in urinary concentrations of creatinine, uric acid, urea, and albumin, and thus the clearance of creatinine and weight gain were observed in rats injected with GM. Also, the administration of GM dramatically raised the malondialdehyde level in the kidneys. Likewise, rats that had been poisoned with GM had histological kidney abnormalities. However, the daily treatment of APTM aqueous extract to rats given GM injections dramatically improved the biochemical and histological parameters affected by GM administration in rats. Finally, APTM extract enhanced GM’s biochemical and histological indicators of nephrotoxicity, supporting its use as an ethnomedicinal.

Keywords

• polyphenols
• flavonoids
• antioxidant
• gentamicin
• nephrotoxicity
• protective effects