[Pathophysiology, diagnosis and conservative therapy in calcium kidney calculi]

Antiurolithic Activity of Zaleya Pentandra (L.) C Jeffrey in Ethylene glycol-induced Calcium Oxalate Crystal Rat Model; A Scientific Validation of Traditional Use for Kidney Stone Prevention

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional herbal remedies have been used for treating nephrolithiasis, but the relevant scientific evidence is limited. Zaleya pentandra (L.) C. Jeffrey is traditionally used for the prevention of kidney stones in various cultures. However, its efficacy has not been scientifically studied.

AIM OF THE STUDY

This study aimed to investigate the antiurolithic activity of Zaleya pentandra, and validate its traditional used for preventing kidney stones.

MATERIALS AND METHODS

The crude ethanolic extract of Z. pentandra (Zp.Crd) was evaluated through in vitro and in vivo studies. In vitro experiments assessed its impact on crystal count and morphology in metastable calcium oxalate solutions. In vivo studies involved diuretic and ethylene glycol-induced calcium oxalate crystal formation in male Wistar rats.

RESULTS

Zp.Crd transforms calcium oxalate crystals from harmful calcium oxalate monohydrate (COM) to calcium oxalate dihydrate (COD). In vivo, Zp.Crd exhibited dose-dependent (30-300 mg/kg) diuretic activity in rats by significantly increasing urinary sodium (Na+) and potassium (K+) excretion, similar to the standard diuretic hydrochlorothiazide (HCT). In the urolithiasis model, Zp.Crd exhibited dose-dependent antiurolithic effects by reducing kidney crystals and significantly altering lithogenic factors induced by ethylene glycol, including crystalluria, oxaluria, calcium, creatinine, and urea, in the urine and serum of treated rats. Zp.Crd also exhibited antioxidant effects, effectively combating oxidative lithogenic stress in rats.

CONCLUSION

Zp.Crd has been shown to demonstrate antiurolithic activity against CaOx stones through CaOx crystal inhibition, diuretic activity, antioxidant properties, hypocalciuric effects, and hypercitrauric actions. The findings underscore Zp.Crd's potential as a viable alternative or supplemental therapy to current urolithiasis treatments, paving the door for further clinical trials and its inclusion into modern medical practices.

Blood Calcium, Genetic Risk, and Risk of Incident Kidney Stone: A Population-Based Cohort Study

OBJECTIVE

To investigate the association between blood calcium concentration and incident kidney stone as well as to assess the role played by genetic susceptibility.

METHODS

We performed a population-based cohort study based on participants from the UK Biobank. A multivariable Cox proportional hazards regression model was used to estimate hazard ratios (HRs) and 95% CIs of incident kidney stone for blood calcium level and polygenic risk score (PRS). In addition, the potential interaction was explored. The study was conducted from January 28, 2023, through June 4, 2023.

RESULTS

During the follow-up of 423,301 participants with a total of 5,490,332 person-years (median follow-up of 13.4 years), 4502 cases of kidney stone were recorded. Compared with the low blood calcium concentration group (first tertile), individuals in the high (third tertile) and moderate (second tertile) concentration groups had higher risks of kidney stone with HRs of 1.24 (95% CI, 1.15 to 1.33) and 1.11 (1.04 to 1.20), respectively. The PRS for kidney stone contained 40 independent single-nucleotide polymorphisms and was used to assign individuals to 3 groups according to the quintile. Participants with high (Q5) and moderate (Q2 to Q4) genetic risks had increased risks of kidney stone compared with low (Q1) genetic risk with HRs of 1.70 (1.53 to 1.89) and 1.31 (1.20 to 1.44), respectively. There was a joint cumulative risk of incident kidney stone between blood calcium concentration and genetic susceptibility.

CONCLUSIONS

Blood calcium concentration and PRS are significantly associated with incident kidney stone risk. Excessive blood calcium concentration might bring additional stone risk in populations at high genetic risk. A nonlinear correlation between blood calcium concentration and kidney stone risk was indicated.

Protective effect of apigenin on ethylene glycol-induced urolithiasis via attenuating oxidative stress and inflammatory parameters in adult male Wistar rats

AIMS

Apigenin (4',5,7-trihydroxyflavone) is one of the subclasses of flavonoids and has various pharmacological effects. The present work was carried out to study the effect of apigenin on ethylene glycol-induced kidney damage in male Wistar rats.

MAIN METHODS

We evaluated the effects of apigenin orally administrated in normal and urolithiatic rats. Animals were assigned to nine groups in random: normal control; apigenin alone (0.005, 0.01, and 0.02 g/kg bw); urolithiatic control (0.75% ethylene glycol and 1.0% ammonium chloride in drinking water); apigenin (0.005, 0.01, and 0.02 g/kg bw) plus ethylene glycol and ammonium chloride; and cystone (0.75 g/kg bw) plus ethylene glycol and ammonium chloride. At the end of 28th day of treatment, animals were sacrificed for biochemical and histopathological assays.

KEY FINDINGS

Our results indicated that the apigenin treatment decreased the formation of urinary stones in urolithiatic rats. Also, apigenin reduced the generation of malondialdehyde and enhanced antioxidant enzymes activities in the kidney homogenate of rats. It also caused a significant decrease in the calcium oxalate crystals numbers in urinary sample of rats with ethylene glycol-induced hyperoxaluria. These findings were supported by histopathological examinations.

SIGNIFICANCE

Based on the results obtained, apigenin attenuate ethylene glycol-related kidney damage in male Wistar rats. Although the underlying mechanism of apigenin effect has not been determined, reduction of urinary levels of stone-producing constituents, antioxidant activities, and inhibition of TGF-β signaling may be involved.

Association Between Serum Magnesium and the Prevalence of Kidney Stones: a Cross-sectional Study

Kidney stones, a painful and costly disease, have become a public health problem worldwide. The aim of this study was to evaluate the association between serum magnesium levels and the prevalence of kidney stones in a large population context. This study was conducted in Xiangya Hospital, Central South University in Changsha, Hunan, China, between October 2013 and December 2015. A total of 6228 subjects aged ≥ 18 years old were included. Kidney stones were diagnosed by (1) direct visualisation of stone(s) on the abdominal ultrasound examination, and (2) presence of stone(s) with a diameter ≥ 4 mm. The chemiluminescence method was used to measure the serum magnesium concentration. The association between serum magnesium and the prevalence of kidney stones was evaluated using logistic and spline regression in a cross-sectional study. The prevalence of kidney stones was 6.1% (7.5% in men and 4.2% in women). Compared with the lowest quartile, the crude odds ratio for kidney stones was 0.62 (95% CI 0.46-0.85) for the highest quartile of serum magnesium, and there was an inverse dose-response relationship (P for trend = 0.038). Similar results were observed for men and women separately. The findings were not materially altered by adjustment for potential confounders. In conclusion, subjects with relatively lower levels of serum magnesium, even though within the normal range, were subject to a higher prevalence of kidney stones in a dose-response relationship manner, indicating that magnesium may play a certain role in the prevention or treatment of kidney stones.

Inflammatory serum markers predicting spontaneous ureteral stone passage

INTRODUCTION

Ureteral stones pose a high economic and medical burden among Emergency Department (ED) admissions. Management strategies vary from expectant therapy to surgical interventions. However, predictors of spontaneous ureteral stone passage are still not well understood. We aim to explore the role of neutrophil-to-lymphocyte (NLR) and platelet-to-lymphocyte (PLR) ratios in the spontaneous ureteral stone passage (SSP).

METHODS

Chart review was done for 619 patients who presented to our institution's ED with non-febrile renal colic and received a radiological diagnosis of ureteral stone of less than 10 mm. Demographic, clinical, laboratory, and radiological data were collected. The Linear-by-Linear Association test was used to look at the trend among the NLR and PLR quartiles and other demographic variables. Univariate analysis was run for the collected variables. Then, a hierarchal backward multivariate logistic regression was run for each of NLR and PLR variables. To validate the results, bootstrapping was undertaken for each model.

RESULTS

NLR between 2.87 and 4.87 had odds ratio (OR) 2.96 (95% CI 1.80-5.49) and an NLR > 4.87 had 3.63 (2.04-6.69) the odds of retained ureteral stone. A PLR between 10.42 and 15.25 and a PLR > 15.25 had 3.28 (1.79-6.19) and 3.84 (2.28-7.12) the odds of failed SSP, respectively. Other significant variables in the two models are diabetes, urine leukocyte esterase > 10 white blood cell/μl, moderate-to-severe hydronephrosis, and stone size.

CONCLUSION

NLR and PLR are inversely associated with SSP of ureteral stones. In adjunct with other indicators, NLR and PLR are inflammatory markers that could be used in the clinical decision of ureteral stone management.

A clinical prediction rule for uncomplicated ureteral stone: The STONE score; a prospective observational validation cohort study

Introduction

Renal colic is one of the most common complaints in patients admitted to Emergency Department (ED). Computed Tomography (CT) is the reference standard for the diagnosis of any stones in the kidneys or ureters. However, CT has classical disadvantages, such as radiation exposure, cost and availability. Recently, STONE clinical prediction criteria were suggested to identify uncomplicated ureteral stone cases among patiens admitted to the ED with abdominal pain. Primary objective of this study was the external validation of the STONE criteria.

Methods

This was a diagnostic accuracy study conducted on a prospective, observational cohort. All consecutive patients who underwent a non-enhanced abdominopelvic CT scan in the ED with an initial diagnosis of ureteral stone disease were enrolled. Using a pre-prepared checklist, all data and the final diagnosis according to the CT scan were recorded. STONE score was calculated for all patients. The area under the curve (AUC) of the STONE Score and the CT, the reference standard, were compared using the ROC curve analysis.

Results

Totally, 237 patients (59.9% male) with an average age of 41.54 years (SD: 13.37) were evaluated, and 156 cases (65.8%) were proved to have renal stone. The mean (SD) STONE scores in the groups of patients with renal stone and in the group of patients without renal stone group were 9.1 (2.6) and 6.0 ( 2.8), respectively (p < 0.001). The area under the curve (AUC) for the STONE score was 0.789 (95% confidence interval (CI) 0.725 to 0.852). The optimum threshold value of the STONE score for the diagnosis of a renal stone was 8 or more, which had a sensitivity of 75.0% and a specificity of 70.4%.

Conclusion

Despite the acceptable diagnostic accuracy, further modifications and enhancements of the STONE score are needed to differentiate patients with low risk prior to imaging.

Epidemiological and imaging features that can affect the detection of ureterolithiasis on ultrasound

Objective

To identify, in patients with clinical suspicion of ureterolithiasis, epidemiological and imaging features that affect calculus detection on ultrasound, as well as to compare ultrasound with multidetector computed tomography (MDCT).

Materials and Methods

We searched our database for patients who underwent ultrasound, followed by MDCT (if the ultrasound was negative), for suspected ureterolithiasis in an emergency setting. Patients were divided into three groups: positive ultrasound (US+); negative ultrasound/positive MDCT (US−/MDCT+); and negative ultrasound/negative MDCT (US−/MDCT−). We evaluated age, gender, ureterolithiasis laterality, location of the calculus within the ureter, body mass index, calculus diameter, and calculus attenuation on MDCT.

Results

Of a total of 292 cases of suspected ureterolithiasis, 155 (53.1%) were in the US+ group, 46 (15.7%) were in the US−/MDCT+ group, and 91 (31.2%) were in the US−/MDCT− group. There were no significant differences among the groups in terms of age, gender, ureterolithiasis laterality, and mean MDCT attenuation values. Distal ureterolithiasis was most common in the US+ group, and calculi at other ureteral locations were more common in the US−/MDCT+ group. The mean body mass index was significantly higher in the US−/MDCT+ group than in the US+ group, and the mean calculus diameter was significantly greater in the US+ group than in the US−/MDCT+ group.

Conclusion

A high body mass index, large calculus diameter, and calculus location in the distal third of the ureter are the major factors favoring ureterolithiasis detection on ultrasound.

In vitro and in vivo models for the study of urolithiasis

Preclinical animal research has greatly contributed and will continue to contribute in our understanding of various disease states and provided methods for more understanding of disease states and designs to test novel pharmaco-therapeutic interventions against these diseases. For urolithiasis, scientists have developed numerous in vitro and in vivo models that attempt to replicate human urolithiasis. In this review, I have explained in vitro and in vivo models that are more common, affordable, and easy to replicate. In the in vitro models, I have focused on the CaOx crystallization models and in the in vivo models, hyperoxaluric rat model has been explained along with other available option such as Knockout (KO) mice and fly models. Each model has been explained stepwise along with its pros and cons.

Studies on the in vitro and in vivo antiurolithic activity of Holarrhena antidysenterica

Holarrhena antidysenterica has a traditional use in the treatment of urolithiasis, therefore, its crude extract has been investigated for possible antiurolithic effect. The crude aqueous-methanolic extract of Holarrhena antidysenterica (Ha.Cr) was studied using the in vitro and in vivo methods. In the in vitro experiments, Ha.Cr demonstrated a concentration-dependent (0.25-4 mg/ml) inhibitory effect on the slope of aggregation. It decreased the size of crystals and transformed the calcium oxalate monohydrate (COM) to calcium oxalate dehydrate (COD) crystals, in calcium oxalate metastable solutions. It also showed concentration-dependent antioxidant effect against 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals and lipid peroxidation induced in rat kidney tissue homogenate. Ha.Cr (0.3 mg/ml) reduced (p < 0.05) the cell toxicity and LDH release in renal epithelial cells (MDCK) exposed to oxalate (0.5 mM) and COM (66 μg/cm(2)) crystals. In male Wistar rats, receiving 0.75 % ethylene glycol (EG) for 21 days along with 1 % ammonium chloride (AC) in drinking water, Ha.Cr treatment (30-100 mg/kg) prevented the toxic changes caused by lithogenic agents; EG and AC, like loss of body weight, polyurea, oxaluria, raised serum urea and creatinine levels and crystal deposition in kidneys compared to their respective controls. These data indicate that Holarrhena antidysenterica possesses antiurolithic activity, possibly mediated through the inhibition of CaOx crystal aggregation, antioxidant and renal epithelial cell protective activities and may provide base for designing future studies to establish its efficacy and safety for clinical use.

Antiurolithic activity of Origanum vulgare is mediated through multiple pathways

Background

Origanum vulgare Linn has traditionally been used in the treatment of urolithiasis. Therefore, we investigated the crude extract of Origanum vulgare for possible antiurolithic effect, to rationalize its medicinal use.

Methods

The crude aqueous-methanolic extract of Origanum vulgare (Ov.Cr) was studied using the in vitro and in vivo methods. In the in vitro experiments, supersaturated solution of calcium and oxalate, kidney epithelial cell lines (MDCK) and urinary bladder of rabbits were used, whereas, in the in vivo studies, rat model of urolithiasis was used for the study of preventive and curative effect.

Results

In the in vitro experiments, Ov.Cr exhibited a concentration-dependent (0.25-4 mg/ml) inhibitory effect on the slope of nucleation and aggregation and also decreased the number of calcium oxalate monohydrate crystals (COM) produced in calcium oxalate metastable solutions. It also showed concentration-dependent antioxidant effect against DPPH free radical and lipid peroxidation induced in rat kidney tissue homogenate. Ov.Cr reduced the cell toxicity using MTT assay and LDH release in renal epithelial cells (MDCK) exposed to oxalate (0.5 mM) and COM (66 μg/cm²) crystals. Ov.Cr relaxed high K⁺ (80 mM) induced contraction in rabbit urinary bladder strips, and shifted the calcium concentration-response curves (CRCs) towards right with suppression of the maximum response similar to that of verapamil, a standard calcium channel blocker. In male Wistar rats receiving lithogenic treatment comprising of 0.75% ethylene glycol in drinking water given for 3 weeks along with ammonium chloride (NH₄Cl) for the first 5 days, Ov.Cr treatment (10-30 mg/kg) prevented as well as reversed toxic changes including loss of body weight, polyurea, crystalluria, oxaluria, raised serum urea and creatinine levels and crystal deposition in kidneys compared to their respective controls.

Conclusion

These data indicating the antiurolithic activity in Ov.Cr, possibly mediated through inhibition of CaOx crystallization, antioxidant, renal epithelial cell protective and antispasmodic activities, rationalizes its medicinal use in urolithiasis.

Berberis vulgaris root bark extract prevents hyperoxaluria induced urolithiasis in rats

Berberis vulgaris is a widely used plant for the treatment of urolithiasis. To evaluate its antiurolithic potential, the crude aqueous-methanol extract of Berberis vulgaris root bark (Bv.Cr) was tested in an animal model of urolithiasis, developed in male Wistar rats by adding 0.75% ethylene glycol in drinking water. Bv.Cr (50 mg/kg) inhibited CaOx crystal deposition in renal tubules and protected against associated changes including polyuria, weight loss, impaired renal function and the development of oxidative stress in kidneys. Activity-guided fractionation revealed the concentration of antiurolithic constituent(s) mainly in the aqueous fraction. These data, indicating the presence of antiurolithic activity in Berberis vulgaris root bark, rationalize its medicinal use for the treatment of urolithiasis.

Homocysteine enhances LDL fatty acid peroxidation, promoting microalbuminuria in type 2 diabetes

Background

We aimed to establish the relationship between glycated haemoglobin (HbA1c), hypertension and microalbuminuria onset in type 2 diabetes. We also intended to ascertain the metabolic action of homocysteine on LDL fatty acids and on renal function.

Methods

The study was carried out on 200 patients with type 2 diabetes and 200 healthy subjects. HbA1c, apolipoprotein B (apo B) and microalbuminuria were measured using immunoturbidimetric methods. Cholesterol, peroxide, urea and uric acid were assayed using colorimetric methods. Creatinine clearance was calculated using the Cockroft-Gault equation. Homocysteine was measured by immunological fluorescence polarization. LDL fatty acids were quantified by gas chromatography.

Results

Creatinine and microalbuminuria significantly increased in type 2 diabetes when compared with controls. Microalbuminuria was significantly correlated with HbA1c and with the presence of high blood pressure. Homocysteinaemia significantly correlated with creatinine clearance in diabetes. Linoleic acid (C18:2ω6) did not differ between groups. C18:2ω6/C18:3ω3 ratio was three times higher in diabetics than in controls. Total saturated fatty acids, homocysteine, H2O2 and LDL-thiobarbituric reactive substances significantly increased in microalbuminuric when compared with normoalbuminuric diabetes. Total polyunsaturated fatty acids, arachidonic acid (C20:4ω6), LDL-cholesterol, apo B and creatinine clearance significantly decreased in microalbuminuric when compared with normoalbuminuric diabetes.

Conclusion

Microalbuminuria onset is associated with renal protein oxidation that is preceded by LDL fatty acid oxidation. The latter is initiated by H2O2 produced from an auto-oxidation of homocysteine and increased metabolism of arachidonic acid towards its pro-inflammatory eicosanoids. An oxidative stress state is the common ground of diffused vasculopathy.

Clinical study on the effect of mineral waters containing bicarbonate on the risk of urinary stone formation in patients with multiple episodes of CaOx-urolithiasis

Investigations in healthy persons have shown that drinking mineral water containing HCO(3) has a positive effect on urine supersaturated with calcium oxalate (SS(CaOx)). The present study evaluates in a common setting whether these effects are also relevant in patients with multiepisodic urinary stone formation. A total of 34 patients with evident multiepisodic CaOx-urolithiasis were included in the study. Patients with hyperparathyroidism, renal tubular acidosis, Wilson's disease, Cushing disease, osteoporosis and malignant diseases were excluded. In a cross-over design and double-blinded the patients received 1.5 l of a mineral water with 2.673 mg HCO(3)/l (test water) or the same amount of water with a low mineral content (98 mg HCO(3)/l) (control water) daily for 3 days. During the study period the patients diet was recorded in a protocol, but not standardised. The main target parameter was SS(CaOx )in 24 h urine. In addition, urinary pH and the most important inhibiting and promoting factors were measured in 24 h urine (Ca, Ox, Mg, Cit). Both waters tested led to a highly significant increase in 24 h urine volume without a difference between each other. In the group, drinking the water containing HCO(3) the urinary pH increased significantly and was within a range relevant for metaphylaxis of calcium oxalate stone formation (x=6.73). This change was highly significant compared to the control group. In addition, significantly increased magnesium and citrate concentration were also observed. Supersaturation with calcium oxalate decreased significantly and to a relevant extent; however, there was no difference between the waters tested. As expected, the risk of uric acid precipitation also decreased significantly under bicarbonate water intake. However, an increase of the risk of calcium phosphate stone formation was observed. It is evident that both waters tested are able to lower significantly and to a relevant extent the risk of urinary stone formation in patients with multiepisodic CaOx-urolithiasis. In addition, the bicarbonate water increases the inhibitory factors citrate and magnesium due to its content of HCO(3) and Mg. Thus, it can be recommended for metaphylaxis of calcium oxalate and uric acid urinary stones.