Bladder cancer has become the most common malignant urinary carcinoma. Studies have shown that significant antioxidant and bladder cancer-fighting properties of several plant-based diets like Psidium guajava, ginger and amomum, are associated with their high kaempferol content. In this paper, we evaluated the antioxidant and anticancer activities of kaempferol and its mechanism of induction to apoptosis on bladder cancer cells. Our findings demonstrated that kaempferol showed an obvious radical scavenging activity in erythrocytes damaged by oxygen. Kaempferol promoted antioxidant enzymes, inhibited ROS generation and lipid peroxidation and finally prevented the occurrence of hemolysis. Additionally, kaempferol exhibited a strong inhibitory effect on bladder cancer cells and high safety on normal bladder cells. At the molecular level, kaempferol suppressed EJ bladder cancer cell proliferation by inhibiting the function of phosphorylated AKT (p-AKT), CyclinD1, CDK4, Bid, Mcl-1 and Bcl-xL, and promoting p-BRCA1, p-ATM, p53, p21, p38, Bax and Bid expression, and finally triggering apoptosis and S phase arrest. We found that Kaempferol exhibited strong anti-oxidant activity on erythrocyte and inhibitory effects on the growth of cancerous bladder cells through inducing apoptosis and S phase arrest. These findings suggested that kaempferol might be regarded as a bioactive food ingredient to prevent oxidative damage and treat bladder cancer.

Here, the antioxidant and hypoglycemic activities of polysaccharides from Huidouba were preliminarily characterized. Two novel polysaccharides, HDBP-1 and HDBP-2 (127.33 kDa and 9.703 kDa, respectively), were purified by ultrafiltration using a Sephadex G-200 column and then characterized by high-performance gel permeation chromatography (HPGPC), high-performance liquid chromatography (HPLC), infrared spectroscopy (FT-IR), GC-MS, NMR and the Congo red test. HDBPs (crude Huidouba polysaccharide (CHDBP), HDBP-1 and HDBP-2) exhibited significant antioxidant and α-glucosidase inhibitory activities in vitro. In addition, in vivo hypoglycemia experiments in mice revealed that CHDBP, HDBP-1 and HDBP-2 demonstrated active roles in reversing diabetic symptoms. These polysaccharides decreased the serum triglyceride (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) levels and significantly improved oral glucose tolerance (OGT), indicating that HDBPs suppressed obesity and alleviated insulin resistance. Moreover, HDBP-2 with lower molecular weight performed better in antioxidant capacity, α-glucosidase-inhibiting activity and hypoglycemic activity. These results suggest that HDBPs have the potential to be functional foods with hypoglycemic properties.