The Molecular Aspect of Nephrolithiasis Development

Carboxymethylated Rhizoma alismatis polysaccharides reduces the risk of calcium oxalate stone formation by reducing cellular inflammation and oxidative stress

This study aims to elucidate the mechanism and potential of Rhizoma alismatis polysaccharides (RAPs) in preventing oxidative damage to human renal proximal tubule epithelial cells. The experimental approach involved incubating HK-2 cells with 100 nm calcium oxalate monohydrate for 24 h to establish a cellular injury model. Protection was provided by RAPs with varying carboxyl group contents: 3.57%, 7.79%, 10.84%, and 15.33%. The safeguarding effect of RAPs was evaluated by analyzing relevant cellular biochemical indicators. Findings demonstrate that RAPs exhibit notable antioxidative properties. They effectively diminish the release of reactive oxygen species, lactate dehydrogenase, and malondialdehyde, a lipid oxidation byproduct. Moreover, RAPs enhance superoxide dismutase activity and mitochondrial membrane potential while attenuating the permeability of the mitochondrial permeability transition pore. Additionally, RAPs significantly reduce levels of inflammatory factors, including NLRP3, TNF-α, IL-6, and NO. This reduction corresponds to the inhibition of overproduced pro-inflammatory mediator nitric oxide and the caspase 3 enzyme, leading to a reduction in cellular apoptosis. RAPs also display the ability to suppress the expression of the HK-2 cell surface adhesion molecule CD44. The observed results collectively underscore the substantial anti-inflammatory and anti-apoptotic potential of all four RAPs. Moreover, their capacity to modulate the expression of cell surface adhesion molecules highlights their potential in inhibiting the formation of kidney stones. Notably, RAP3, boasting the highest carboxyl group content, emerges as the most potent agent in this regard.

Cymbopogon proximus and Petroselinum crispum seed ethanolic extract/Gum Arabic nanogel emulsion: Preventing ethylene glycol and ammonium chloride-induced urolithiasis in rats

Urolithiasis is a prevalent urological disorder that contributes significantly to global morbidity. This study aimed to assess the anti-urolithic effects of Cymbopogon proximus (Halfa Bar) and Petroselinum crispum (parsley) seed ethanolic extract /Gum Arabic (GA) emulsion, and its nanogel form against ethylene glycol (EG) and ammonium chloride (AC)-induced experimental urolithiasis in rats. Rats were divided into four groups: group 1 served as the normal control, group 2 received EG with AC in drinking water for 14 days to induce urolithiasis, groups 3 and 4 were orally administered emulsion (600 mg/kg/day) and nanogel emulsion (600 mg/kg/day) for 7 days, followed by co-administration with EG and AC in drinking water for 14 days. Urolithiatic rats exhibited a significant decrease in urinary excreted magnesium, and non-enzymic antioxidant glutathione and catalase activity. Moreover, they showed an increase in oxalate crystal numbers and various urolithiasis promoters, including excreted calcium, oxalate, phosphate, and uric acid. Renal function parameters and lipid peroxidation were intensified. Treatment with either emulsion or nanogel emulsion significantly elevated urolithiasis inhibitors, excreted magnesium, glutathione levels, and catalase activities. Reduced oxalate crystal numbers, urolithiasis promoters' excretion, renal function parameters, and lipid peroxidation while improving histopathological changes. Moreover, it decreased renal crystal deposition score and the expression of Tumer necrosis factor-α (TNF-α) and cleaved caspase-3. Notably, nanogel emulsion showed superior effects compared to the emulsion. Cymbopogon proximus (C. proximus) and Petroselinum crispum (P. crispum) seed ethanolic extracts/GA nanogel emulsion demonstrated protective effects against ethylene glycol induced renal stones by mitigating kidney dysfunction, oxalate crystal formation, and histological alterations.

Multivitamins co-intake can reduce the prevalence of kidney stones: a large-scale cross-sectional study

BACKGROUND

This research aimed to explore the association between changes in the intake of common individual vitamins and combinations of vitamins and the prevalence of kidney calculi.

METHODS

We used data from NHANES to investigate the association between nine common vitamins and kidney stone prevalence. Participants were clustered into several vitamin exposure patterns using an unsupervised K-means clustering method. We used logistic regression models and restrictive cubic spline curves to explore the influence of vitamins.

RESULTS

The regression model exposed that compared to lower intake, high intake of vitamin B6 [Q4: OR (95% CI) = 0.76 (0.62, 0.93)], vitamin C [Q4: OR (95% CI) = 0.73 (0.59, 0.90)] and vitamin D [Q4: OR (95% CI) = 0.77 (0.64, 0.94)] individually exerted protective effects against the prevalence of kidney stones. Furthermore, the restrictive cubic spline analysis showed that the protective effect against the prevalence of kidney stones is enhanced as the take of vitamin B6 and vitamin D increased. Moreover, with the increase in vitamin C intake, its protective effect may turn into a risk factor. Regarding mixed exposure, Cluster 4 exhibited a significant protective effect against kidney stones compared with Cluster 1 [Model 3: OR (95% CI) = 0.79 (0.64, 0.98)].

CONCLUSIONS

Our research revealed that high levels of vitamin B6 and vitamin D intake were linked to a lower prevalence of kidney stone. With the gradual increase intake of vitamin C, the prevalence of kidney calculi decreased first and then increased. In addition, the co-exposure of nine vitamins is a protective factor for kidney stone disease.

Understanding formation processes of calcareous nephrolithiasis in renal interstitium and tubule lumen

Kidney stone, one of the oldest known diseases, has plagued humans for centuries, consistently imposing a heavy burden on patients and healthcare systems worldwide due to their high incidence and recurrence rates. Advancements in endoscopy, imaging, genetics, molecular biology and bioinformatics have led to a deeper and more comprehensive understanding of the mechanism behind nephrolithiasis. Kidney stone formation is a complex, multi-step and long-term process involving the transformation of stone-forming salts from free ions into asymptomatic or symptomatic stones influenced by physical, chemical and biological factors. Among the various types of kidney stones observed in clinical practice, calcareous nephrolithiasis is currently the most common and exhibits the most intricate formation mechanism. Extensive research suggests that calcareous nephrolithiasis primarily originates from interstitial subepithelial calcified plaques and/or calcified blockages in the openings of collecting ducts. These calcified plaques and blockages eventually come into contact with urine in the renal pelvis, serving as a nidus for crystal formation and subsequent stone growth. Both pathways of stone formation share similar mechanisms, such as the drive of abnormal urine composition, involvement of oxidative stress and inflammation, and an imbalance of stone inhibitors and promoters. However, they also possess unique characteristics. Hence, this review aims to provide detailed description and present recent discoveries regarding the formation processes of calcareous nephrolithiasis from two distinct birthplaces: renal interstitium and tubule lumen.

Occupational hazard in urolithiasis patients in Qatar: A single-center cross-sectional study

BACKGROUND

Urolithiasis is one of the most prevalent urological diseases and is associated with a substantial economic burden. Its prevalence varies according to geographical location. Qatar is a Middle Eastern country located in the Afro-Asian Stone Belt. It has a dry and hot climate, which may predispose individuals working in these environments to form kidney stones (KSs).

METHODS

A population sample of 4204 patients was categorized into five occupational classes. The frequencies and correlations of these occupations with KS formation were calculated.

RESULTS

Among the total cases, 2000 presented with KSs, with the majority being of Asian descent (49%), followed by individuals of Middle Eastern descent (35.1%). Technicians accounted for 35.15% of KS cases followed by clerks (29.2%) and executives (14.6%). Among KS cases, 44% had a single stone, 30% had multiple stones, and 26% had two stones. In comparing both KS and non-KS groups, age, gender, occupation, and race were significantly associated with KS formation (p<0.05), while BMI did not show any significant correlation (p>0.05). Asian males aged 31-40, working as technicians, were significantly more prone to urolithiasis. In comparing age, BMI, and gender with stone characteristics, only age was found significantly associated with stone size (p<0.05). Occupation showed an impact on all studied stone characteristics. Clerks and technicians presented more frequently with stones within the 11-15 mm range, while executives more frequently presented with smaller stones (p<0.001). Stone density was more frequently <500 HU in workers, technicians and housewives and >500 HU in executives and clerks (p<0.001).

CONCLUSIONS

Our findings revealed an elevated risk of urolithiasis among certain occupational groups, particularly technicians, who frequently work outdoors in high-temperature environments. Alternatively, the sedentary nature of clerical and executive positions can also contribute to the risk of urolithiasis.

Pathophysiology and Main Molecular Mechanisms of Urinary Stone Formation and Recurrence

Kidney stone disease (KSD) is one of the most common urological diseases. The incidence of kidney stones has increased dramatically in the last few decades. Kidney stones are mineral deposits in the calyces or the pelvis, free or attached to the renal papillae. They contain crystals and organic components, and they are made when urine is supersaturated with minerals. Calcium-containing stones are the most common, with calcium oxalate as the main component of most stones. However, many of these form on a calcium phosphate matrix called Randall's plaque, which is found on the surface of the kidney papilla. The etiology is multifactorial, and the recurrence rate is as high as 50% within 5 years after the first stone onset. There is a great need for recurrence prevention that requires a better understanding of the mechanisms involved in stone formation to facilitate the development of more effective drugs. This review aims to understand the pathophysiology and the main molecular mechanisms known to date to prevent recurrences, which requires behavioral and nutritional interventions, as well as pharmacological treatments that are specific to the type of stone.

Potential role of glutathione S‑transferase M1 gene polymorphism in kidney calcium oxalate stone formation

BACKGROUND

The purpose of this study was to look into the effects of glutathione S-transferase M1 (GSTM1) gene polymorphism on the formation of kidney calcium oxalate stones.

METHODS

A total of 159 patients with kidney calcium oxalate stones were included in this study as a case group. One hundred and three healthy individuals were included in the control group. The age, gender, and levels of calcium (Ca), uric acid (UA), creatinine (Cr), and urinary creatinine (Ucr) are tracked. Peripheral blood samples are used to perform a polymerase chain reaction to identify the glutathione S-transferase (GST) gene polymorphism (PCR). A commercial kit was used in this study to measure the levels of malondialdehyde (MDA), nitric oxide (NO), total antioxidant capacity (T-AOC), and 8-hydroxydeoxyguanosine (8-OHdG) in peripheral blood.

RESULTS

There was no difference in age or gender distribution between the case and control groups (P > 0.05). The Cr, Ucr, Ca, UA, 8-OHdG, MDA, NO, and T-AOC in the case group were significantly higher than those in the control group (P < 0.001). The Hardy-Weinberg genetic equilibrium test showed no difference between the case group (P = 0.23) and the control group (P = 0.09). In the case group, the 8-OHdG and NO in GSTM1 null genotype were significantly higher than those in GSTM1 genotype (P < 0.05), but there was no significant difference in MDA and T-AOC (P > 0.05). Multivariate regression analysis showed that the GSTM1 null genotype was positively correlated with 8-OHdG (P < 0.001) and NO (P < 0.001).

CONCLUSIONS

GSTM1 gene polymorphism might be a detecting risk factor for kidney calcium oxalate stone formation.

TRIAL REGISTRATION

ChiCTR2100051300.

Ferroptosis and its emerging role in kidney stone formation

Kidney stone is a common and highly recurrent disease in urology, and its pathogenesis is associated with various factors. However, its precise pathogenesis is still unknown. Ferroptosis describes a form of regulated cell death that is driven by unrestricted lipid peroxidation, which does not require the activation of caspase and can be suppressed by iron chelators, lipophilic antioxidants, inhibitors of lipid peroxidation, and depletion of polyunsaturated fatty acids. Recent studies have shown that ferroptosis plays a crucial role in kidney stone formation. An increasing number of studies have shown that calcium oxalate, urate, phosphate, and selenium deficiency induce ferroptosis and promote kidney stone formation through mechanisms such as oxidative stress, endoplasmic reticulum stress, and autophagy. We also offered a new direction for the downstream mechanism of ferroptosis in kidney stone formation based on the "death wave" phenomenon. We reviewed the emerging role of ferroptosis in kidney stone formation and provided new ideas for the future treatment and prevention of kidney stones.

Dysregulated palmitic acid metabolism promotes the formation of renal calcium-oxalate stones through ferroptosis induced by polyunsaturated fatty acids/phosphatidic acid

The pathogenesis of renal calcium-oxalate (CaOx) stones is complex and influenced by various metabolic factors. In parallel, palmitic acid (PA) has been identified as an upregulated lipid metabolite in the urine and serum of patients with renal CaOx stones via untargeted metabolomics. Thus, this study aimed to mechanistically assess whether PA is involved in stone formation. Lipidomics analysis of PA-treated renal tubular epithelial cells compared with the control samples revealed that α-linoleic acid and α-linolenic acid were desaturated and elongated, resulting in the formation of downstream polyunsaturated fatty acids (PUFAs). In correlation, the levels of fatty acid desaturase 1 and 2 (FADS1 and FADS2) and peroxisome proliferator-activated receptor α (PPARα) in these cells treated with PA were increased relative to the control levels, suggesting that PA-induced upregulation of PPARα, which in turn upregulated these two enzymes, forming the observed PUFAs. Lipid peroxidation occurred in these downstream PUFAs under oxidative stress and Fenton Reaction. Furthermore, transcriptomics analysis revealed significant changes in the expression levels of ferroptosis-related genes in PA-treated renal tubular epithelial cells, induced by PUFA peroxides. In addition, phosphatidyl ethanolamine binding protein 1 (PEBP1) formed a complex with 15-lipoxygenase (15-LO) to exacerbate PUFA peroxidation under protein kinase C ζ (PKC ζ) phosphorylation, and PKC ζ was activated by phosphatidic acid derived from PA. In conclusion, this study found that the formation of renal CaOx stones is promoted by ferroptosis of renal tubular epithelial cells resulting from PA-induced dysregulation of PUFA and phosphatidic acid metabolism, and PA can promote the renal adhesion and deposition of CaOx crystals by injuring renal tubular epithelial cells, consequently upregulating adhesion molecules. Accordingly, this study provides a new theoretical basis for understanding the correlation between fatty acid metabolism and the formation of renal CaOx stones, offering potential targets for clinical applications.

Habitual fish oil supplementation, genetic susceptibility of kidney stones and the risk of new-onset kidney stones

OBJECTIVE

We aimed to assess the association between habitual fish oil use and new-onset kidney stones in participants with different levels of genetic risks of kidney stones.

METHODS

477,311 participants free of kidney stones at baseline from the UK Biobank cohort were included. Fish oil use was collected by both food frequency questionnaires and 24-h dietary recalls. A genetic risk score (GRS) for kidney stones was calculated based on 20 single-nucleotide polymorphisms associated with kidney stones. The primary outcome was new-onset kidney stones.

RESULTS

During a median follow-up of 12.0 years, 5,637 cases of kidney stones were documented. Participants with high genetic risks of kidney stones had a higher risk of new-onset kidney stones (vs. low or intermediate risks; adjusted HR, 1.52; 95 %CI:1.44-1.60). Compared with non-users, habitual use of fish oil was associated with a lower risk of new-onset kidney stones (adjusted HR, 0.84, 95 %CI, 0.78-0.92) in participants with low or intermediate genetic risks, but not in those with high genetic risks of kidney stones (adjusted HR, 1.02, 95 %CI, 0.93-1.12; P-interaction =0.001). Among those with low or intermediate genetic risks of kidney stones, compared with fish oil constant nonusers, the adjusted HRs (95 %CI) for kidney stones were 0.89 (0.75-1.06), 0.72 (0.58-0.90), and 0.79 (0.64-0.97), for fish oil occasional users, modestly constant users, and moderately and highly constant users (P for trend = 0.001), respectively.

CONCLUSIONS

Habitual fish oil use was associated with a lower risk of new-onset kidney stones in participants with low or intermediate genetic risk of kidney stones.

Gamma-glutamyl transferase and calculus of kidney incidence: a Mendelian randomization study

Elevated Gamma-glutamyl transferase (GGT) levels are often suggestive of cholelithiasis, and previous studies have indicated that GGT is highly expressed in the urinary system. Therefore, we hypothesized that there may be an association between GGT levels and calculus of kidney (CK) incidence. To investigate this potential causal relationship, we employed Mendelian randomization (MR) analysis. Additionally, we analyzed the levels of other liver enzymes, including alanine transaminase (ALT) and alkaline phosphatase (ALP). The relationship between GGT levels and CK incidence was analyzed using two-sample Mendelian randomization. Summary Genome-Wide Association Studies data were utilized for this analysis. 33 single nucleotide polymorphisms known to be associated with GGT levels were employed as instrumental variables. We employed several MR methods including IVW (inverse variance weighting), MR-Egger, weighted median, weighted mode, and MR-PRESSO (Mendelian Randomization Pleiotropy RESidual Sum and Outlier). Furthermore, we conducted tests for horizontal multivariate validity, heterogeneity, and performed leave-one-out analysis to ensure the stability of the results. Overall, several MR methods yielded statistically significant results with a p-value < 0.05. The results from the IVW analysis yielded an odds ratio (OR) of 1.0062 with a 95% confidence interval (CI) of 1.0016-1.0109 (p = 0.0077). Additional MR methods provided supplementary results: MR-Egger (OR 1.0167, 95% CI 1.0070-1.0266, p = 0.0040); weighted median (OR 1.0058, 95% CI 1.0002-1.0115, p = 0.0423); and weighted mode (OR 1.0083, 95% CI 1.0020-1.0146, p- = 0.0188). Sensitivity analyses did not reveal heterogeneity or outliers. Although potential horizontal pleiotropy emerged, we speculate that this could be attributed to inadequate test efficacy. However, subsequent use of MR-PRESSO did not provide evidence of pleiotropy. Our analysis suggests a positive association between elevated GGT levels and CK incidence, indicating an increased risk of CK development. However, no causal relationship was observed between levels of ALP or ALT and CK incidence.

Positive association between ambient air pollutants and incident kidney stones

We aimed to assess the association between exposure to various air pollutants, individually or jointly, and incident kidney stones, and examine whether genetic susceptibility for kidney stones may modify this association. 453,977 participants without prior kidney stones from the UK Biobank were included. Annual mean concentrations of PM2.5, PM2.5-10, PM10, NO2, and NOx were estimated with a land use regression model. A weighted air pollution score was constructed that incorporates the five pollutants mentioned above. A genetic risk score (GRS) was calculated based on 20 single-nucleotide polymorphisms associated with kidney stones. The primary outcome was incident kidney stones. During a median follow-up of 11.9 years, 5,375 kidney stones were recorded. The adjusted HRs (95%CI) of incident kidney stones were 1.04 (1.01-1.07), 1.02 (1.00-1.05), 1.03 (1.01-1.06), 1.05 (1.02-1.08), and 1.04 (1.01-1.07), for per standard deviation (SD) increment in PM2.5 (SD:1.06 μg/m3), PM2.5-10 (SD:0.90 μg/m3), PM10 (SD:1.90 μg/m3), NO2 (SD:7.63 μg/m3), and NOx (SD: 15.63 μg/m3), respectively. Moreover, there was a significantly linear association between the air pollution score and incident kidney stones (per SD increment: HR, 1.05, 95%CI: 1.02-1.08), especially in those without diabetes (vs. participants with diabetes; P-interaction = 0.037). In addition, the association between air pollution and kidney stones was statistically significant only in participants within intermediate-high kidney stone GRS, but not in those with low GRS kidney stone, though the interaction was not significant (P-interaction = 0.385). In conclusion, exposure to air pollution was associated with a higher risk of incident kidney stones, calling for the need to improve air quality.

Inverse association of glucosamine use and risk of new-onset kidney stones in UK adults with less sedentary time

OBJECTIVE

To assess the association of different sedentary behaviors and glucosamine use with the risk of kidney stones and examine the modification of genetic risk of kidney stones on this association.

METHODS

473,225 participants free of kidney stones at baseline from the UK Biobank were included. Total sedentary time was calculated as the sum of the duration of TV-watching, driving, and non-occupational computer using. The primary outcome was new-onset kidney stones.

RESULTS

During a median follow-up of 12.0 years, 5528 cases of kidney stones were documented. All major sedentary behaviors and total sedentary time were significantly positively related to the risk of kidney stones (All P for trend<0.05). Participants with total sedentary time ≥ 3.5 h/day had a significantly higher risk of new-onset kidney stones (vs. <3.5 h/day [tertile 1]; HR, 1.18; 95%CI,1.10-1.27). Compared with non-users, participants who regularly used glucosamine had a significantly lower risk of new-onset kidney stones in those with total sedentary time < 3.5 h/day (HR, 0.72; 95%CI,0.59-0.86), but not in those with total sedentary time ≥ 3.5 h/day (HR, 0.99; 95%CI,0.91-1.08; P-interaction = 0.001). Among participants with total sedentary time < 3.5 h/day, there was a dose-response relationship of glucosamine use with new-onset kidney stones (P for trend<0.001). Genetic risks of kidney stones did not significantly modify the association.

CONCLUSIONS

TV-watching, driving and non-occupational computer using were all positively associated with the risk of new-onset kidney stones. Glucosamine use was associated with a lower risk of new-onset kidney stones in participants with total sedentary time < 3.5 h/day, following a dose-response relationship.

The causal association between smoking, alcohol consumption and risk of upper urinary calculi: insights from a Mendelian randomization study

Background: The causal link between smoking, alcohol consumption, and upper urinary calculi remains uncertain in observational studies due to confounding factors. To uncover potential causal associations, we utilized two-sample univariable and multivariable Mendelian randomization (MR) methods. Methods: Five risk factors related to lifestyles (cigarettes per day, lifetime smoking index, smoking initiation, drinks per week and alcohol intake frequency) were chosen from the Genome-Wide Association Study (GWAS). Upper urinary calculi were obtained from the FinnGen and United Kingdom Biobank consortium. Inverse-variance-weighted (IVW) was mainly used to compute odds ratios (OR) and 95% confidence intervals (Cl). While diligently scrutinizing potential sources of heterogeneity and horizontal pleiotropy via the rigorous utilization of Cochran's Q test, the MR-PRESSO method, and MR-Egger. Results: The summary OR for upper urinary calculi was 0.6 (IVW 95% CI: 0.49-0.74; p = 1.31 × 10-06) per standard deviation decrease in drinks per week. Interestingly, the genetically predicted alcohol intake frequency was associated with a significantly increased risk upper urinary calculi (OR = 1.27; 95% CI: 1.11-1.45; p = 0.0005). Our study found no association between smoking initiation, the number of cigarettes per day, and the lifetime smoking index and the risk of upper urinary calculi. By adjusting for body mass index and education, estimates of drinks per week remained consistent in multivariate MR analyses, while alcohol intake frequency became non-significant. Conclusion: MR analysis showed that drinks per week was negatively associated with upper urinary calculi, whereas the effect of tobacco on upper urinary calculi was not significant and the detrimental effect of alcohol intake frequency on upper urinary calculi became non-significant after adjusting for BMI and education.

Roots of Zea mays L.: As a Potential Source to Treat Sodium Oxalate-Induced Renal Cell Injury

Zea mays L. is an annual grass of the Gramineae family and is known as one of the cereal crops. Its by-products exhibited significant medicinal properties. In some regions of China, water extracts of Z. mays roots (RM) are utilized to treat kidney stones, but no research has been reported. In our present study, a bioassay-guided isolation method was used to yield five new lignans (1-5) as well as 15 known components, among which 8-15 and 17-20 were first identified from the genus. The fractions and all components were evaluated for their abilities to inhibit sodium oxalate-induced injury to human proximal tubular HK-2 cells. Fraction 50W and compounds 3, 4, and 11 exhibited the most potent activities. Further investigation indicated that these potential agents inhibited the LDH release, decreased the MDA and H2O2 concentrations, and increased the level of SOD2 in HK-2 cells. These results indicated that RM is a promising and valuable crop waste for further development and utilization in nephrolithiasis pharmaceutical research.

Effective deep learning classification for kidney stone using axial computed tomography (CT) images

INTRODUCTION

Stone formation in the kidneys is a common disease, and the high rate of recurrence and morbidity of the disease worries all patients with kidney stones. There are many imaging options for diagnosing and managing kidney stone disease, and CT imaging is the preferred method.

OBJECTIVES

Radiologists need to manually analyse large numbers of CT slices to diagnose kidney stones, and this process is laborious and time-consuming. This study used deep automated learning (DL) algorithms to analyse kidney stones. The primary purpose of this study is to classify kidney stones accurately from CT scans using deep learning algorithms.

METHODS

The Inception-V3 model was selected as a reference in this study. Pre-trained with other CNN architectures were applied to a recorded dataset of abdominal CT scans of patients with kidney stones labelled by a radiologist. The minibatch size has been modified to 7, and the initial learning rate was 0.0085.

RESULTS

The performance of the eight models has been analysed with 8209 CT images recorded at the hospital for the first time. The training and test phases were processed with limited authentic recorded CT images. The outcome result of the test shows that the Inception-V3 model has a test accuracy of 98.52 % using CT images in detecting kidney stones.

CONCLUSIONS

The observation is that the Inception-V3 model is successful in detecting kidney stones of small size. The performance of the Inception-V3 Model is at a high level and can be used for clinical applications. The research helps the radiologist identify kidney stones with less computational cost and disregards the need for many experts for such applications.

Sanjin Paishi Decoction improves the imbalance of gut microbiota and regulates MAPK signaling pathway to inhibit calcium oxalate stones in rats

INTRODUCTION

Sanjin Paishi Decoction (SJPSD) has positive effects on stone prevention; however, there is a lack of convincing evidence in the prevention of calcium oxalate stones. This study aimed investigates the effect of SJPSD on calcium oxalate stones and to explore its mechanism.

METHODS

The rat model of calcium oxalate stones was established and rats were treated with different doses of SJPSD. The pathological damage of kidney tissues was observed by HE staining, the deposition of calcium oxalate crystals in kidney tissues was examined by Von Kossa staining, and the levels of creatinine (CREA), urea (UREA), calcium (Ca), phosphorus (P), and magnesium (Mg) in serum were analyzed biochemically, the levels of IL-1β, IL-6, and TNF-α in serum were measured by ELISA, and the protein expression of Raf1, MEK1, p-MEK1, ERK1/2, p-ERK1/2, and Cleaved caspase-3 in kidney tissues was analyzed by Western blot. Moreover, the changes in gut microbiota were analyzed by 16S rRNA sequencing.

RESULTS

SJPSD attenuated the pathological damage of renal tissues, reduced the levels of CREA, UREA, Ca, P, and Mg, and inhibited the expression of Raf1, p-MEK1, p-ERK1/2, and Cleaved caspase-3 in renal tissues (P < 0.05). SJPSD treatment affected the composition of intestinal microbiota in rats with calcium oxalate stones.

CONCLUSION

The mechanism of SJPSD inhibition of calcium oxalate stone injury in rats may be related to the inhibition of the MAPK signaling pathway and regulation of gut microbiota imbalance.

Association of short-term nitrogen dioxide exposure with hospitalization for urolithiasis in Xinxiang, China: a time series study

Urolithiasis accounts for the highest incidence of all urologic-associated hospitalizations. However, few studies have explored the effect of nitrogen dioxide (NO2) on hospitalizations for urolithiasis. We included 5956 patients with urolithiasis, collected daily meteorological and air pollution data between 2016 and 2021, and analyzed the associations between air pollutants and hospitalization, length of the hospital stay, and hospitalization costs attributable to urolithiasis. NO2 exposure was associated with an increased risk of hospitalization for urinary tract stones. For each 10-μg/m3 increase and 1-day lag of NO2, the maximum daily effect on the risk of hospitalization for urolithiasis was 1.020 (95% confidence interval [CI]: 1.001-1.039), and the cumulative effect peaked on lag day 4 (relative risk [RR]: 1.061; 95% CI: 1.003-1.122). Attribution scores and quantitative analysis revealed that the mean number of hospital days and mean hospital costs were 16 days and 21,164.39 RMB, respectively. Up to 5.75% of all urolithiasis hospitalizations were estimated to be attributable to NO2, and the cost of NO2-related urolithiasis hospitalizations reached approximately 3,430,000 RMB. Stratified analysis showed that NO2 had a more sensitive impact on urolithiasis hospitalizations in women and in those aged ≥65 years. Notably, men and those younger than 65 years of age (exclude people aged 65) incurred more costs for urolithiasis hospitalizations. In the population level, the association between NO2 and risk of urolithiasis hospitalization was more pronounced during the warm season. NO2 can increase hospitalizations for urolithiasis for Xinxiang City residents, and there is a cumulative lag effect. Focusing on air pollution may have practical significance in terms of the prevention and control of urolithiasis.

Asymptomatic hyperuricemia associated with increased risk of nephrolithiasis: a cross-sectional study

BACKGROUND

Existing evidence shows that there is an independent correlation between nephrolithiasis and gout, and hyperuricemia is the most important risk factor for gout. However, hyperuricemia was often used as an accompanying symptom of gout to explore its association with nephrolithiasis, there were few studies to explore whether hyperuricemia itself or serum uric acid (SUA) is related to the risk of nephrolithiasis. Evidence on the relationship between hyperuricemia and nephrolithiasis is still insufficient.

METHODS

A total of 22,303 participants aged 30 to 79 years who participated in the China Multi-Ethnic Cohort (CMEC) study in Yunnan Province from May 2018 to September 2019 were included in the study. All participants received standardized face-to-face interviews, medical examinations, and biochemical examinations. Logistic regression was used to estimate the association between hyperuricemia and nephrolithiasis, and a restricted cubic spline (RCS) model was used to explore the dose-response relationship between SUA and the risk of nephrolithiasis.

RESULTS

14.5% of all participants were diagnosed with hyperuricemia, and 12.1% were diagnosed with nephrolithiasis. After adjusting for all potential confounders, the OR (95%CI) for nephrolithiasis in participants with hyperuricemia compared with participants without hyperuricemia was 1.464 (1.312,1.633), p < 0.001. Restricted cubic spline regression analysis showed that the risk of nephrolithiasis increased with the increase of SUA, and when the level of SUA is higher than 356 μmol/L in males and higher than 265 μmol/L in females, there is a dose-response relationship between the increase of SUA and the risk of nephrolithiasis in both males and females (p for nonlinearity = 0.1668, p for nonlinearity = 0.0667).

CONCLUSION

Asymptomatic hyperuricemia is associated with an increased risk of developing nephrolithiasis. Before reaching the diagnostic criteria for hyperuricemia, the risk of nephrolithiasis rises with the increase in SUA. This suggests that controlling SUA levels may be significant for the prevention of nephrolithiasis.

Association between Serum Klotho and Kidney Stones in US Middle-Aged and Older Individuals with Diabetes Mellitus: Results from 2007 to 2016 National Health and Nutrition Survey

INTRODUCTION

Kidney stones (KSs) are associated with hematuria and renal failure and pose a significant clinical and public health concern. Diabetes is associated with a higher risk of KSs. In addition, α-Klotho (Klotho), as a novel antiaging protein, is associated with kidney disease, diabetes, and complications and may participate in the pathological mechanism of KSs. However, studies that used large population-based database research are limited. Therefore, this study aimed to investigate whether or not KS prevalence is associated with serum Klotho levels in diabetic adults in the USA.

METHODS

This nationally representative cross-sectional study used data on diabetic adults in the USA aged 40-79 years from the National Health and Nutrition Examination Survey 2007-2016 cycles. Multivariate logistic regression models were used to calculate the association between Klotho and KS. Restricted cubic splines were used to further test for linearity and explore the shape of the dose-response association. Moreover, we performed stratified and interaction analyses to see if the relationship was stable in different subgroups.

RESULTS

Among the 3,537 diabetic patients included in this study (mean age of 61.4 years, consisting of 51.3% males), 543 participants (15.4%) suffered from KS. In the fully adjusted model, Klotho was negatively associated with KS (OR = 0.72; 95% CI: 0.54-0.96; p = 0.027). A negative relationship was observed between the occurrence of KS and Klotho (nonlinear: p = 0.560). Some differences in the association between Klotho and KS were found in stratified analyses; however, these differences lacked statistical significance.

CONCLUSIONS

Serum Klotho was negatively associated with the incidence of KS; when ln-transformed Klotho concentration increased by 1 unit, the risk of KS was 28% lower.

Semisynthesis, Biological Evaluation and Molecular Docking Studies of Barbatic Acid Derivatives as Novel Diuretic Candidates

Barbatic acid, a compound isolated from lichen, has demonstrated a variety of biological activities. In this study, a series of esters based on barbatic acid (6a-q') were designed, synthesized, and evaluated for their diuretic and litholytic activity at a concentration of 100 μmol/L in vitro. All target compounds were characterized using ¹H NMR, ¹³C NMR, and HRMS, and the spatial structure of compound 6w was confirmed using X-ray crystallography. The biological results showed that some derivatives, including 6c, 6b', and 6f', exhibited potent diuretic activity, and 6j and 6m displayed promising litholytic activity. Molecular docking studies further suggested that 6b' had an optimal binding affinity to WNK1 kinases related to diuresis, while 6j could bind to the bicarbonate transporter CaSR through a variety of forces. These findings indicate that some barbatic acid derivatives could be further developed into novel diuretic agents.

Vitamin D and Calcium Supplementation and Urolithiasis: A Controversial and Multifaceted Relationship

Patients with urolithiasis, and particularly those with hypercalciuria, frequently have a marked reduction of bone mineral content up to the levels of osteoporosis, with a significant increase in bone fracture risk. For these reasons, the indication to prescribe vitamin D and/or calcium supplementations is very frequent in such patients. On the other hand, both calcium supplementation, and even more vitamin D therapy, can worsen the risk of developing urolithiasis by increasing calcium, phosphate, and oxalate urinary excretion. Despite the clinical and practical relevance of this issue, the evidence on this topic is scarce and contradictory. Therefore, some concerns exist about how and whether to prescribe such supplements to a patient with a history of kidney stones. In this narrative review, we resume some pivotal pathophysiological concepts strictly related to the dealt topic, and we draw some considerations and personal opinions on the pros and cons of such prescriptions. Finally, we share with the reader our pragmatic algorithm for handling the urolithiasis risk in patients who have strong indications to be prescribed vitamin D and calcium supplementations.

Network pharmacology and molecular modelling study of Enhydra fluctuans for the prediction of the molecular mechanisms involved in the amelioration of nephrolithiasis

In view of the ethno medicinal use of Enhydra fluctuans for the treatment of kidney stones; the present study aimed to elucidate the molecular mechanisms involved in the amelioration of nephrolithiasis through a network pharmacology approach. The phytoconstituents were queried in DIGEP-Pred to identify the regulated proteins. The modulated proteins were then enriched in the STRING to predict the protein-protein interactions and the probably regulated pathways were traced in the Kyoto Encyclopedia of Genes and Genomes. Further, the network was constructed using Cytoscape ver 3.5.1. Results showed that β-carotene was found to be regulating maximum targets i.e. 26. In addition, 63 proteins were triggered by the components in which the vitamin D receptor was targeted by the maximum phytoconstituents i.e. 16. The enrichment analysis identified the regulation of 67 pathways in which fluid shear stress and atherosclerosis-associated pathways (KEGG entry hsa05418) regulated ten genes. Further, protein kinase C-α was traced in 23 different pathways. In addition, the majority of the regulated genes were identified from the extracellular space via the modulation of 43 genes. Also, nuclear receptor activity had the maximum molecular function via the regulation of 7 genes. Likewise, the response to organic substance was predicted to trigger the top genes i.e. 43. In contrast, Stigmasterol, Baicalein-7-o-glucoside, and Kauran-16-ol were found to have a high affinity to bind with the VDR receptor confirmed by the molecular modelling and the dynamics. Hence, the study elucidated the probable molecular mechanisms of E. fluctuans in managing nephrolithiasis and identified the lead molecules, their targets, and possible pathways.Communicated by Ramaswamy H. Sarma.

Role of microbiome in kidney stone disease

PURPOSE OF REVIEW

The process of renal stone formation is complex, multifactorial, and variable depending on the type of stone. The microbiome, whether by direct or indirect action, is a factor that both promotes the formation and protects from developing of renal stones. It is a highly variable factor due to the great interindividual and intraindividual variability that it presents. In recent years, with the incorporation of nonculture-based techniques such as the high-throughput sequencing of 16S rRNA bacterian gene, both intestinal and urinary microbiota have been deeply studied in various diseases such as the kidney stone disease.

RECENT FINDINGS

This review has examined the new insights on the influence of the intestinal and urinary microbiome in nephrolithiasis disease and its usefulness as a diagnostic and prognostic tool, highlighting its contribution to the pathogenesis, its ability to modulate it and to influence disease development.

SUMMARY

The incidence of urolithiasis has been increasing considerably. These patients represent a significant expense for national health systems. With the knowledge of the influence of the urobiome and intestinal microbiota on the urolithiasis, it could be possible to modulate it to interrupt its development.

Metabolic Syndrome and Nephrolithiasis; A Cross Sectional Population-based Study on the Baseline Data of the PERSIAN Kavar Cohort Study

OBJECTIVE

To explore the relationship between metabolic syndrome and its components with nephrolithiasis.

METHODS

In current study, 4,901 individuals from the PERSIAN (Prospective Epidemiological Research Studies in IrAN) Kavar cohort study were included. Metabolic syndrome was defined according to the ATP III criteria (2005 revision). The nephrolithiasis was assessed using a structured questionnaire, and ultrasound findings were reviewed in subjects who reported positive history of nephrolithiasis. We applied logistic regression to estimate the odds ratio (OR) and 95% confidence interval (CI).

RESULTS

The prevalence of nephrolithiasis and metabolic syndrome was 28.5% and 40.91%, respectively. Almost 31% of the patients with metabolic syndrome had a history of nephrolithiasis. Multivariable logistic regression analysis revealed a positive association between metabolic syndrome and nephrolithiasis (OR= 1.30, 95% CI: 1.14-1.49, P<.001) after adjustment age, sex, ethnicity, physical activity, smoking status, and alcohol intake. Furthermore, the relation was higher for elders aged 50 years or more (P for interaction= .016) and Turk Nomad participants (P for interaction= 0.044) than the others. There was also a positive independent association between hypertension (OR=1.29, 95% CI: 1.12-1.48, P<.001) and hypertriglyceridemia (OR= 1.15, 95% CI: 1.01-1.31, P=.033) with nephrolithiasis.

CONCLUSION

In this large sample study, we demonstrate a weak positive association between metabolic syndrome, hypertension, and hypertriglyceridemia with nephrolithiasis.

Anti-Struvite, Antimicrobial, and Anti-Inflammatory Activities of Aqueous and Ethanolic Extracts of Saussurea costus (Falc) Lipsch Asteraceae

Saussurea costus (Falc) Lipsch is a traditional herb used to treat kidney stone problems because it contains several molecules used to treat this health problem, such as quercitrin. Infectious stones are the most painful of all urinary tract disorders, with ammonium phosphate (struvite) and carbapatite stones being the most common, caused by a bacterial infection with urease activity. These stones are treated with antibiotics, but antibiotic resistance is on the rise. The current study investigated the anti-urolithic activities of S. costus aqueous and ethanolic extracts of against struvite crystals synthesized using microscopic crystallization and turbidimetric methods, respectively. The utilized methods indicated that the ethanolic extract of this plant has a significant inhibitory effect on struvite crystallization, with a percentage inhibition of (87.45 ± 1.107) (p < 0.001) for a concentration of 1 mg mL−1 and a decrease in the number of struvite crystals, reaching values less than 100/mm3. For the number of struvite crystals inhibited by cystone, we found a value of 400/mm3 and with the aqueous extract we found 700/mm3. The antibacterial activity of the plant extracts studied was examined against several urease-producing bacteria, and this activity was evaluated by qualitative and quantitative evaluation methods; the highest minimum inhibitory concentration was seen in the ethanolic extract, with an MIC of 50 mg mL−1 for Staphylococcus aureus followed by an MIC of 200 mg mL−1 for Klebsiella pneumoniae. It showed a minimal bactericidal concentration (MBC) against S. aureus and K. pneumoniae (>50 mg mL−1 and >200 mg mL−1, respectively). Furthermore, to determine the extract’s anti-inflammatory activity, in vivo anti-inflammatory activity was investigated in rats. The results show that at a dose of 400 mg kg−1, the ethanolic extract has a maximum edema inhibition of 66%.

Effect of Carnosine on the Activity of Matrix Metalloproteinase-2 and Oxidative Stress in the Kidneys in Experimental Urate Nephrolithiasis

The effect of carnosine on MMP-2 activity and oxidative stress in the kidneys in experimental urate nephrolithiasis was studied. Urate nephrolithiasis was modeled in Wistar rats by intragastric administration of a mixture of oxonic and uric acids. Carnosine was administered intragastrically through a tube in a dose of 15 mg/kg. In rats treated with carnosine, the concentration of MMP-2 in the urine decreased by 3.7 times, and the excretion of MMP-2 with urine decreased by 4.3 times. In the homogenate of the kidneys from rats treated with carnosine, the concentration of TBA-reactive substances decreased by 5 times and the concentration of MMP-2 decreased by 12.7%. After treatment with carnosine, the number of histologically confirmed cases of urate nephrolithiasis decreased by 2 times, while the mean size of urate deposits decreased by 2.7 times. Thus, carnosine inhibits MMP-2 and reduces the intensity of oxidative stress in the kidneys, which prevents the development of urate nephrolithiasis.

Expression Optimizing of Recombinant Oxalyl-CoA Decarboxylase in Escherichia coli

Background

One of the most common diseases of the urinary tract is stones of this system, including kidney stones. About 70%-80% of kidney stones are calcium oxalate. Oxalyl-CoA decarboxylase is a single polypeptide included of 568 amino acids which play a key role in oxalate degradation.

Materials and Methods

The aim of current study is high-level expression of oxalyl-CoA decarboxylase in Escherichia coli BL21 (DE3). To achieve this aim, oxalyl-CoA decarboxylase gene was cloned upon pET-30a (+) with T7 promoter. The vector containing the oxalyl-CoA decarboxylase gene was transformed into E. coli and the expression of the gene was examined on a laboratory scale and fermentor. Atfirst, the effect of temperature, culture medium, and induction time on oxalyl-CoA decarboxylase expression at three levels was examined.

Results

The obtained data showed that the highest expression was related to the terrific broth culture medium and temperature of 32°C with an inducer concentration of 1 mM. Under this situation the ultimate cells dry weight and the final oxalyl-CoA decarboxylase expression were 2.46 g/l and 36% of total protein, respectively. Then induction time was optimized in a bench bioreactor and productivity of oxalyl-CoA decarboxylase was calculated. Under optimized condition the cell density, biomass productivity and oxalyl-CoA decarboxylase concentration reached 4.02 g/l, 0.22 g/l/h, and 0.7 g/l which are one of the highest reported rates.

Conclusion

This study demonstrated that high levels of oxalyl-CoA decarboxylase can be achieved by optimizing the expression conditions.

Ureteral calculi lithotripsy for single ureteral calculi: can DNN-assisted model help preoperatively predict risk factors for sepsis?

OBJECTIVES

To explore the utility of radiomics and deep learning model in assessing the risk factors for sepsis after flexible ureteroscopy lithotripsy (FURL) or percutaneous nephrolithotomy (PCNL) in patients with ureteral calculi.

METHODS

This retrospective analysis included 847 patients with treatment-naive proximal ureteral calculi who received FURL or PCNL. All participants were preoperatively conducted non-contrast computed tomography scans, and relevant clinical information was meanwhile collected. After propensity score matching, the radiomics model was established to predict the onset of sepsis. A deep learning model was also adapted to further improve the prediction accuracy. Performance of these trained models was verified in another independent external validation set including 40 cases of ureteral calculi patients.

RESULTS

The overall incidence of sepsis after FURL or PCNL was 5.9%. The least absolute shrinkage and selection operator (LASSO) regression analysis revealed 26 predictive variables, with an overall AUC of 0.881 (95% CI, 0.813-0.931) and an AUC of 0.783 (95% CI, 0.766-0.801) in external validation cohort. Judicious adaption of a deep neural network (DNN) model to our dataset improved the AUC to 0.920 (95% CI, 0.906-0.933) in the internal validation. To eliminate the overfitting, external validation was carried out for DNN model (AUC = 0.874 (95% CI, 0.858-0.891)).

CONCLUSIONS

The DNN was more effective than the LASSO model in revealing risk factors for sepsis after FURL or PCNL in single ureteral calculi patients, and females are more susceptible to sepsis than males. Deep learning models have the potential to act as gatekeepers to facilitate patient stratification.

KEY POINTS

• Both the least absolute shrinkage and selection operator (LASSO) and deep neural network (DNN) models were shown to be effective in sepsis prediction. • The DNN model achieved superior prediction capability, with an AUC of 0.920 (95% CI, 0.906-0.933). • DNN-assisted model has potential to serve as a gatekeeper to facilitate patient stratification.

Plants Used in Mexican Traditional Medicine for the Management of Urolithiasis: A Review of Preclinical Evidence, Bioactive Compounds, and Molecular Mechanisms

Urolithiasis (UL) involves the formation of stones in different parts of the urinary tract. UL is a health problem, and its prevalence has increased considerably in developing countries. Several regions use plants in traditional medicine as an alternative in the treatment or prevention of UL. Mexico has known about the role of traditional medicine in the management of urinary stones. Mexican traditional medicine uses plants such as Argemone mexicana L., Berberis trifoliata Hartw. ex Lindl., Costus mexicanus Liebm, Chenopodium album L., Ammi visnaga (L.) Lam., Eysenhardtia polystachya (Ortega) Sarg., Selaginella lepidophylla (Hook. & Grev.) Spring, and Taraxacum officinale L. These plants contain different bioactive compounds, including polyphenols, flavonoids, phytosterols, saponins, furanochromones, alkaloids, and terpenoids, which could be effective in preventing the process of stone formation. Evidence suggests that their beneficial effects might be associated with litholytic, antispasmodic, and diuretic activities, as well as an inhibitory effect on crystallization, nucleation, and aggregation of crystals. The molecular mechanisms involving these effects could be related to antioxidant, anti-inflammatory, and antimicrobial properties. Thus, the review aims to summarize the preclinical evidence, bioactive compounds, and molecular mechanisms of the plants used in Mexican traditional medicine for the management of UL.

Identification of Resolvin D1 and Protectin D1 as Potential Therapeutic Agents for Treating Kidney Stones

Intrarenal calcium oxalate (CaOx) crystals induce renal tubular epithelial cell (TEC) inflammatory and oxidative injury. This study is aimed at exploring potential therapeutic lipid components in kidney stones because lipids are involved in the development of several diseases and indicate the risk of kidney stones. Serum specimens were collected from 35 kidney stone patients and 35 normal controls. The lipid components in serum were measured, and differences were analyzed. The documented biological importance was comprehensively reviewed to identify lipids that differed significantly between the two groups to find potential agents associated with kidney stones. CaOx nephrocalcinosis mouse model was established to examine the therapeutic effects of specific lipids on CaOx deposition and CaOx-induced oxidative renal injury. Several lipids with significantly different levels were present in the serum of patients with stones and normal controls. Resolvin D1 (RvD1) (4.93-fold change, P < 0.001) and protectin D1 (PD1) (5.06-fold change, P < 0.001) were significantly decreased in the serum of patients with kidney stones, and an integrative review suggested that these factors might be associated with inflammatory responses, which is a crucial mechanism associated with stone damage. The administration of RvD1 and PD1 significantly inhibited kidney CaOx deposition and suppressed CaOx-induced renal tubular cell inflammatory injury and necrosis in a CaOx nephrocalcinosis mouse model. Furthermore, RvD1 and PD1 facilitated the expression of the oxidative indicator superoxide dismutase 2 (SOD2), inhibited NADPH oxidase 2 (NOX2) expression, and diminished intracellular reactive oxygen species (ROS) levels. This study preliminarily elucidated the role of lipids in kidney stones. The inhibitory effects of RvD1 and PD1 on oxidative damage induced by CaOx deposition provide a promising perspective for kidney stone treatment strategies.

Association Between Gestational Diabetes Mellitus and Future Risk of Kidney Stones

Objective

The association between history of gestational diabetes mellitus (GDM) and risk of kidney stones has not been reported. GDM increases the risk of long-term complications including diabetes, hypertension and metabolic syndrome, which are risk factors of kidney stones. This study aimed to explore the association between previous GDM and odds of kidney stones.

Methods

Women (age ≥ 20 years) who had delivered at least one live birth were included from the 2007–2018 National Health and Nutrition Examination Survey cohort (N = 12,003). Patients with kidney stones and history of GDM were identified by in-home interview for all participants. Subgroup analyses were conducted by age, race/ethnicity, postpartum duration and status of hypertension, obesity, current diabetes and metabolic syndrome.

Results

Previous GDM was positively associated with odds of kidney stones [multivariate-adjusted odds ratio (95% confidence interval): 1.41 (1.13–1.77)], and the association was stronger with odds of passing 2 or more times of kidney stones [1.72 (1.31–2.26)]. In subgroup analyses, the association between previous GDM and odds of kidney stones was significant in women within 15 years of a pregnancy complicated by GDM [1.54 (1.12–2.11)], in obese participants [1.56 (1.18–2.06)], in women without hypertension [1.49 (1.07–2.08)], current diabetes [1.38 (1.02–1.87)] and metabolic syndrome [1.56 (1.10–2.19)], in women of Non-Hispanic White [1.59 (1.15–2.18)] and in women aged more than 50 year [1.45 (1.02–2.07)].

Conclusions

Previous GDM was positively associated with odds of kidney stones, and the association was independent of type 2 diabetes, hypertension and metabolic syndrome.

Comparison of Phenolic Metabolites in Purified Extracts of Three Wild-Growing Herniaria L. Species and Their Antioxidant and Anti-Inflammatory Activities In Vitro

The work is aimed at phytochemical characterization and In Vitro evaluation of antioxidant actions, anti-inflammatory effects, and cytotoxicity of purified extracts from three rupturewort (Herniaria L.) species, i.e., Herniaria glabra (HG), H. polygama (HP), and H. incana herb (HIh). The total phenolic content established in the purified extracts (PEs) of HIh, HP, and HG was 29.6, 24.0, and 13.0%, respectively. Thirty-eight non-saponin metabolites were identified using LC-HR-QTOF-ESI-MS; however, only 9 were common for the studied Herniaria species. The most abundant phenolic compound in HG-PE was narcissin (7.4%), HP-PE shared 3 major constituents, namely cis-2-hydroxy-4-methoxycinnamic acid 2-O-β-glucoside (cis-GMCA, 5.8%), narcissin (5.4%), and rutin (5.3%). Almost half of HIh phenolic content (14.7%) belonged to oxytroflavoside A (7-O-methylkaempferol-3-O-[3-hydroxy-3-methylglutaryl-(1→6)]-[α-rhamnopyranosyl-(1→2)]-β-galactopyranoside). Antioxidant properties of the Herniaria PEs were evaluated employing an experimental model of human blood plasma, exposed to the peroxynitrite-induced oxidative stress. The assays demonstrated significant reduction of oxidative damage to protein and lipid plasma components (estimated by measurements of 3-nitrotyrosine, protein thiol groups, thiobarbituric acid-reactive substances), and moderate protection of its non-enzymatic antioxidant capacity. Anti-inflammatory properties of the Herniaria PEs were evaluated In Vitro as inhibitory effects against cyclooxygenases (COX-1 and -2) and concanavalin A-induced inflammatory response of the peripheral blood mononuclear cells (PBMCs). None of the studied plants showed inhibitory effects on COXs but all purified extracts partly reduced the release of interleukin 2 (IL-2) and tumor necrosis factor-alpha (TNF-α) from PBMCs, which suggested their prospective ability to up-regulate inflammatory response of the cells. The purified extract from H. glabra turned out to be the most efficient suppressor of PBMCs’ inflammatory response. Additionally, cytotoxicity of purified Herniaria extracts on PBMCs was ruled out based on In Vitro studies.