# Litholytic Activities of Natural Bioactive Compounds and Their Mechanism Insights
## 5 Litholytic Activity of Other Compounds
### In Vivo Investigations
The prophylactic and curative effect of crocin, the main water-soluble carotenoid of _Crocus sativus_, was evaluated by [59] at different concentrations (10, 20, and 40 mg/kg/day) in violtitiasis rats. In the prophylactic effect, at 20 mg/kg/day, crocin significantly reduced the level of urinary oxalate (2.05 vs. 5.2 mg/day, respectively), urinary protein (0.98 vs. 2.35 mg/day, respectively), CaOOx crystal deposition number (306 vs. 727), and MDA (33 vs. 62 nmol/g tissue) compared to lithiasis rats. At the same time, crocin significantly enhanced the level of urinary citrate and magnesium in urolithiasis rats treated at 20 mg/kg/day compared to lithiasis rats (3.61 vs. 2.7 mg/day and 2.11 vs. 0.42 mg/day, respectively), while neither the urinary ionic parameters nor the number of crystals were significantly altered in the curative treatment. Figure 5: Chemical structures of other compounds with in vivo litholytic effects. Furthermore, two authors evaluated, in vivo, the effect of two alkaloids (berberberine and piperine) on CaOx urolithiasis in rats [48; 56]. [PERSON] et al. [56] evaluated the preventive and curative effects of berberine. At 10 mg/kg, this isoquinoline alkaloid significantly reduced crystal count and water intake compared to EG-induced nephrolithiasis in rats (6.17 vs. 53.6 crystal count/field and 12.3 vs. 21.5 mL, respectively). In parallel, berberine significantly increased the levels of urinary pH and urinary volume (6.59 vs. 5.35 and 13.7 vs. 6.67 mL, respectively), and decreased Ca\({}^{2+}\) excretion compared to normal rats (2.05 vs. 3.33 mg) [56]. The markers of glomerular and tubular damages (BUN, serum creatinine, and creatinine clearance) were significantly reduced (24.8 vs. 63.7, 0.95 vs. 1.43 mg/dL, and 0.81 vs. 0.53 mL/min, respectively). At the same concentration, this compound protects significantly against changes associated with oxidative stress. The contents of MDA and carbonyl protein were reduced very significantly while GSH was enhanced significantly compared to lithiasis rats (1.63 vs. 13.3 nmol/mg protein, 6.39 vs. 11.20 nmol/mg protein, and 17.2 vs. 11.6 nmol/mg protein, respectively) [56]. In curative treatment, a non-significant decrease in urine volume and water intake, as well as an increase in urine pH, were recorded. Whereas the crystal counts, urinary oxalate, and BUN have been significantly reduced (14.5 vs. 32 crystal count/field, 0.43 vs. 0.69 mg, and 23.01 vs. 39.13, respectively). These findings suggest that khellin nephrolithiasis activity is mediated by a combination of antioxidant, diuretic, hypocalciuric, and urine-alkalinizing activities. Recently, [PERSON] et al. [48] have evaluated, in vivo, the urolithiasis effect of piperine against hyperoxaluria induced in Wistar rats. The results showed that this alkaloid ameliorated the serum parameters (calcium, urea, uric acid, and creatinine) and urine parameters (calcium and oxalate) [48]. The anti-urolithiatic activity of fatty acid was reported by [PERSON] et al. [58]. Wistar male rats treated orally with oleanolic acid, from roots of _Lantana camana_, at different concentrations (60, 80, and 100 mg/kg/day) demonstrated an increase in urinary volume and a significant reduction in calcium urinary excretion compared to zinc disc implantation (1.9 vs. 1.6 mL, and 12 vs. 23 mg/dL, respectively at 60 mg/kg/day). In addition, oleanolic acid significantly reduced the weight of zinc discs as well as the deposited crystals (11 vs. 111 mg). From this research, the authors suggested that the increased urine output is mediated by activation of the muscarinic receptor in the bladder muscles. Tocopherol, a fat-soluble nutrient, exhibited several pharmacological effects, including antiproliferative, antioxidant, and neuroprotective activities [64; 65]. The anti-lithiasis activity of tocopherols (vitamin E) was tested in vivo on EG-induced kidney stones in a rat model by intraperitoneal administration with 15 mg/100 g b.w [54]. This dose did not inhibit CaOx stone formation in rats.