The Effectiveness of Pineapple Juice (Ananas comosus (L.) Merr) in Preventing the Formation of Calcium Oxalate Crystals In Vitro

Background: Kidney stones (urolithiasis), particularly those composed of calcium oxalate (CaOx), remain a global health issue with a high recurrence rate. Non-pharmacological approaches using natural compounds are considered valuable alternatives to invasive treatments. Pineapple (Ananas comosus) contains citric acid and bromelain, which have potential inhibitory effects on CaOx crystallization, although scientific evidence is still limited.

Methods: A true experimental study with a post-test only control group design was conducted using four crystallization parameters (Tmax, SN, SA, and percentage of inhibition) across five groups: negative control, positive control (0.5% potassium citrate), and pineapple juice at concentrations of 25%, 50%, and 100%. Absorbance measurements were performed using a UV-Vis spectrophotometer at two-minute intervals for 60 minutes. Data were analyzed using Shapiro–Wilk, Levene’s Test, Kruskal–Wallis, and Dunn’s Post Hoc tests with a 95% confidence level.

Results: Pineapple juice exhibited strong inhibitory activity against CaOx crystal formation. All treatment concentrations reduced SN by more than 90% and achieved complete aggregation inhibition, along with increased Tmax compared to the negative control. The 25% concentration produced the most optimal inhibition effect, showing substantial SN reduction and a significant rise in Tmax. The Kruskal–Wallis test showed significant differences between groups for SN and Tmax, though pairwise comparison with Dunn’s Post Hoc indicated no significant differences after correction.

Conclusion: Pineapple juice effectively inhibited CaOx crystallization in vitro by delaying nucleation and preventing crystal aggregation, suggesting its potential role as a natural non-pharmacological preventive agent for kidney stone formation.