Apoptotic activity in patient serum while on an acai juice product in the setting of a slowly rising PSA.

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e16055 Background: For patients with a slowly rising PSA, the timing of androgen deprivation therapy (ADT) initiation is highly debated given the long term side effects. In this setting, numerous nutraceuticals, or plant derivatives, such as grape seed, milk thistle, or pomegranate have been shown to slow the growth of prostate cancer (PCa). The acai berry has been shown to be rich in flavinoids with high antioxidant properties and was evaluated in this phase II single-institution study in asymptomatic PCa patients with a rising PSA. The primary endpoint was decline in PSA of 50% from baseline. While flavinoids have been shown to induce cell cycle arrest, understanding the actions of the mix of phytochemicals has not been rigorously undertaken for the acai berry. It has shown proapoptotic effects in vitro on leukemic cell lines, and decreased cytokine production correlated with subsequent anti-esophageal tumorogenesis effects in vivo. In order to better understand the mechanism of action of acai, patient serum samples were analyzed in vitro. Methods: While on trial, patients consumed 2oz of acai juice product daily for 30 weeks. Two serum samples were drawn at weeks 0, 2, 6, and 18 for correlative analysis with the M30 Apoptosense ELISA. This measures caspase cleaved Keratin18 (ccK18) as a marker of early apoptotic activity. Results: An increase from baseline in ccK18 was seen at 2 weeks in a majority of patients (13/19; p= 0.12). Additionally, the one clinical responder on trial had a significantly higher level of ccK18 throughout the trial with a peak at week 6. Baseline ccK18 values did not correlate with clinical outcome (Spearman coefficient r=-0.13, p=0.6). Conclusions: Nutraceuticals may offer a well-tolerated treatment option for slowing the growth of prostate cancer as evidenced by the prolongation in doubling time in 86% of patients in this trial. The rise of ccK18 at week 2 and elevated levels in the responder’s serum suggest there is a pro-apoptotic treatment effect with acai. Additional cytokine analysis, and ratio of necrotic death to apoptotic death is underway in order to compare additional mechanisms. This initial evaluation offers early insight of the mechanism of action of acai in PCa.