Phytochemical and genotoxicity studies of Citrus reticulata aerial part in mice

Abstract

Background and objectives The genus Citrus (family Rutaceae) is known to contain many bioactive compounds like flavonoids that protect mice against genotoxicity because of their antioxidant and free radical scavenging properties. The aim of this study was to investigate the phytochemical constituents and the protective effect of the ethanolic extract of the aerial part of Citrus reticulata cultivated in Saudi Arabia against genotoxicity induced by benzo(a)pyrene (BaP) in mice. Materials and methods The major constituents from of the aerial part of C. reticulata were isolated using different chromatographic techniques. Identification of compounds was realized through Rf values, shift reagents, and spectroscopic tools such as ultraviolet and nuclear magnetic resonance. The constituents of both unsaponifiable and methylated fatty acids were identified using Gas Liquid Chromatography (GLC) analysis. Essential oil constituents of peels and aerial part of C. reticulata were obtained by hydrodistillation and analyzed by gas chromatography–mass spectrometry. PBS, 1% LMPA, and ethidium bromide were used for the comet assay and quantitative analysis of DNA fragmentation in liver tissue in male rats was determined. About 50 male mice were used in this study, which were allocated in five groups (10 animals each) and treated with BaP and C. reticulata [total ethanolic extract (TE) and petroleum ether fraction]. Results and conclusion Phytochemical investigation of the ethanolic extract from the aerial part of C. reticulata revealed five flavonoids (1–5). GLC analysis of the unsaponifiable fraction showed the presence of α-tocotrienol and α-tocopherol, which belong to the group of vitamin E. A total of 22 compounds were identified in the essential oils of C. reticulata blanco, 12 compounds were found in the aerial part, and 12 compounds were found in the fruit peels. The ethanolic extract was tested for the first time against genotoxicity induced by BaP in mice using the comet assay. TE significantly reduced the damage of DNA caused by BaP in mice. There was a statistically significant increase (P≤0.05) in the DNA fragmentation in the liver tissues of male mice and an increased rate of DNA damage in mice blood cells in the BaP group. Treatment with TE has a significant liver and blood cell protection by inhibiting the rate of DNA damage. These findings led us to conclude that the aerial part of C. reticulata is useful to reduce the genotoxicity induced by hazardous chemical agents.