Fig. 7
In vivo and histopathological examination of the effects of Co3O4 NPs. a The average tumor volume variations after treatment with Co3O4 NPs (at 10 and 20 mg/kg concentrations), cisplatin (at 5 mg/kg concentration), and PBS on different days of treatment. The data are provided as mean ± SEM (*** p < 0.001). b Comparison between tumor volumes in different groups on the final day of the experiment. The values are provided as mean ± SD (**** p < 0.0001). c–s Histopathological analysis of mice tumor tissues along with different organs (liver, kidney, and spleen) after 19 days exposure to Co3O4 NPs (at 10 and 20 mg/kg concentrations), cisplatin (at 5 mg/kg concentration), and PBS, (n = 5). PBS was demonstrated to be non-toxic, in all investigated tissues. Treatment with cisplatin and Co3O4 NPs at the concentration of 20 mg/kg led to the reduction and almost elimination of the induced colorectal tumors in mice, and in general, Co3O4 NPs caused less side effects in all the examined organs compared to the cisplatin. N indicates necrosis, W.P indicates white pulp, and R.P indicates red pulp. Scale bars represent 200 µm