UA has been intensively studied in the past; mainly as an anti-cancer compound and for its cardiovascular protective properties. The controversy of reports suggests anti-angiogenic and cytotoxic effects of UA on one side and cardiovascular and endothelial protective effects on the other side. Currently, there is insufficient evidence to recommend an ideal human dose. Animal studies suggest benefit use between 0.05–0.2% of the rat diet as UA. Assuming a range of 10–40 mg/kg bodyweight, the benefits in rat studies associated with UA are about equal to a human dose of 1.6–6.4 mg/kg bodyweight (110–440 mg for a 150 lb person).
The side effects of UA from mainly include two aspects: male fertility and DNA damage. Previous study has revealed that UA has the potential of sperm motility inhibition and can serve as a topical vaginal contraceptive [24], [25]. Specifically, it causes breaking of bridges in between cells that are soon to be sperm, and the damaged cells then collect to form symplasts in the seminiferous tubules that are associated with male infertility. UA as an anti-angiogenesis, anti-cancer and locally applied cardiovascular drug may be helpful. However, the DNA damaging activity of UA may also constitute a serious problem. UA was able to induce cell death in endothelial cells when the concentration exceeded 12.5 µM [26].