Effects of Isoflavone-Rich NADES Extract of Pueraria lobata Roots and Astaxanthin-Rich Phaffia rhodozyma Extract on Prostate Carcinogenesis in Rats.

Prostate cancer (PCa) is one of the most common male malignancies worldwide. In the current study, we evaluated the effects of a natural deep eutectic solvent (NADES) extract of Pueraria lobata roots rich in isoflavones (ISF) and Phaffia rhodozyma extract rich in astaxanthin (ASX) on an N-methyl-N-nitrosourea plus testosterone PCa model in rats. ISF consisted of puerarin, daidzein, genistein, formononetin and other polyphenols, while ASX contained lipids and unsaturated species in addition to astaxanthin. Extracts were administered through a whole promotion period in daily doses shown by our group to successfully inhibit benign prostate hyperplasia (BPH) development - 200 mg/kg for ISF and 25 mg/kg for ASX. Though a similar effect was found for BPH processes accompanying PCa induction, the incidence of PCa in animals treated with placebo, ISF and ASX was 37%, 37% and 41%, respectively, showing no chemopreventive activity of ISF and ASX. PCa development was associated with a decrease in the Ca/Mg ratio in serum and an increase in prostate tissue. Treatment with both extracts produced a normalization effect on Ca balance in serum, which, combined with a decrease in the prostatic index, suggests some positive health effects of ISF and ASX.

Astaxantin and Isoflavones Inhibit Benign Prostatic Hyperplasia in Rats by Reducing Oxidative Stress and Normalizing Ca/Mg Balance.

Benign prostatic hyperplasia (BPH) is a common pathology among aging men. Despite the broad pharmacological interventions, the available remedies to treat BPH are yet not devoid of side effects. Herbal compounds are suggested to be an alternative option for the BPH treatment. In our study, we evaluated the effect of kudzu isoflavones and astaxanthin on the BPH animal model. The animals were randomly divided into five groups: control; testosterone-induced BPH group; and three BPH-induced groups, which received intragastrically for 28 days finasteride (5 mg/kg) as a positive control, isoflavones (200 mg/kg), and astaxanthin (25 mg/kg). BPH was induced by castration of animals and subsequent subcutaneous injections of prolonged testosterone (25 mg/kg). Prostate index and histology, biochemical parameters, and antioxidant activity were evaluated. A significant decrease in prostate weight, immunohistochemical markers, and normalization of prostate Ca/Mg ratio was found in all treatment groups. Astaxanthin treatment also resulted in decreased epithelial proliferation and normalized superoxide dismutase activity. In conclusion, both isoflavones and astaxanthin inhibited BPH development at a level comparable to finasteride in terms of prostate weight, prostatic epithelium proliferation, and prostate tissue cumulative histology score. These results suggest that isoflavones and especially astaxanthin could serve as a potential alternative therapy to treat BHP.