Abstract:
Lime powder regmimen (LPR) produced by adding citrate and potassium into lime juice was proved to be able to increase urinary citrate and potassium excretion, which reduces risk of kidney stone formation. It also alleviated urinary protein loss. However, excretion of which urinary protein is not yet elucidated. This study aimed to identify a profile of urinary protein in kidney stone patients with LPR supplement. We recruited 10 immediate post-stone removed urolithiasis patients, and randomly allocated into LPR (n=5) and Placebo (n=5) supplement group. 24-hour urine samples were collected at the initiation and after 6-month of supplement. Total urinary protein was measured. Then, urinary proteins were identified by mass spectrometry. In addition, 3 interesting proteins were selected to validate the levels. Urinary albumin was measured by immunoturbidimetric assay, while serotransferrin (TF) and Tamm-Horsfall protein (THP) were measured by ELISA. We found that urinary protein excretion was significantly decreased after supplement in only LPR group. Proteomic profiles revealed 17 proteins exclusively altered after LPR supplement. Albumin and TF, which are glomerular markers, and THP-a stone inhibitory protein, were selected to be validated. According to the validation results, markedly decreased of albumin (91.63%) and slightly decreased of TF (58.44%) were observed, while, there was no significant change of these proteins found in Placebo group. Moreover, we found positive correlation between urinary albumin and TF excretion (r = 0.589, p = 0.006). And, urinary THP was significantly increased after LPR supplement (1,470%), but not that of placebo group. We can conclude that LPR supplement attenuated urinary albumin loss and increased THP excretion. We believed that these effects were mainly due to citrate and antioxidants which were highly rich in LPR.