Aqueous extract of Psidium guajava L. leaves has been shown to possess anti-prostate cancer activity in a cell line model” .The researchers reported that they were drawn to study guava leaves’ effect on prostate cancer cells after conducting a study which showed that guava leaves were “potent anti-glycative agents”; this action was ascribed to the unusual free radical scavenging and anti-oxidative capabilities of guava leaf polyphenols. The effects of glycation can result in the formation of irreversible advanced glycation end products (AGE’s), which are associated with many progressive diseases and can also trigger cancer formation. Since guava leaves showed strong anti-glycative properties, the scientists chose to study the leaves’ action against an abundant form of prostate cancer, LNCap: Lymph node-metastasis prostate cancer.