Evaluation of genotoxicity of dry powders of pomelo (Citrus maxima) flowers by micronucleus assay

Plants have been used as traditional medicine or health products for several thousands of years. The present study was aimed to evaluate the genotoxicity of pomelo flower powders by micronucleus assay In vivo. During the In vivo genotoxicity-evaluated experiment, the experimental animal’s clinical behavior, body weight (BW), food consumption, and the percentage of RET/RBCs (reticulocytes/red blood cells) and MN-RET/RETs (micronucleated reticulocytes/reticulocytes) after the treatments of pomelo (Citrus maxima) flower powders were evaluated. Both sexes ICR mice were treated three daily treatments by intraperitoneal injection of 2 mg/kg of mitomycin C (genotoxicity induction) or by oral route of 200 μL of PBS (the normal control group). Until 30th hours after the last treatment, K2-EDTA-anticoagulated peripheral blood specimens were collected. These blood samples were processed for the microscopy-based analysis using Giemsa stain and the percentage of reticulocytes and micronucleated reticulocytes was determined. The results were shown that the experimental animal’s clinical behaviors were normal in all groups. The BW and food consumption were no significant difference between all groups. RET/RBCs (%) in male or female ICR mice in the negative control group, the normal control group, the low dose of pomelo (C. maxima) flower powder group, the middle dose of pomelo (C. maxima) flower powder group, and the high dose of pomelo (C. maxima) flower powder group were respectively 8.8 ± 2.3 / 9.6 ± 2.6, 23.0 ± 2.5 / 22.4 ± 2.3, 23.4 ± 2.1 / 23.2 ± 3.8, 24.2 ± 3.6 / 23.0 ± 1.9, and 21.6 ± 3.2 / 21.6 ± 2.4; MN-RET/RETs (‰) in male or female ICR mice in the negative control group, the normal control group, the low dose of pomelo (C. maxima) flower powders group, the middle dose of pomelo (C. maxima) flower powder group, and the high dose of pomelo (C. maxima) flower powder group were 43.0 ± 12.5 / 39.4 ± 9.8, 2.6 ± 1.5 / 2.6 ± 1.5, 2.4 ± 1.1 / 2.2 ± 1.3, 2.2 ± 1.3 / 2.0 ± 1.2, and 1.8 ± 0.8 / 1.8 ± 0.8, respectively. Both RET/RBCs (%) and MN-RET/RETs (%) in male or female ICR mice in the negative control group were significantly difference than the other groups (p < 0.001). Taken all results together, pomelo (C. maxima) flower powders were without genotoxicity. Therefore, pomelo (C. maxima) flower powders were safety.