Calcium Oxalate Formation Research Articles

Regulation of bone mineral density in the grey squirrel, Sciurus carolinensis: Bioavailability of calcium oxalate, and implications for bark stripping.

SummaryThe damage caused when grey squirrels strip the outer bark off trees and ingest the underlying phloem can result in reduced timber quality or tree death. This is extremely costly to the UK forestry industry and can alter woodland composition, hampering conservation efforts. The calcium hypothesis proposes that grey squirrels ingest phloem to ameliorate a seasonal calcium deficiency. Calcium in the phloem predominantly takes the form of calcium oxalate (CaOx), however not all mammals can utilise CaOx as a source of calcium. Here, we present the results of a small‐scale study to determine the extent to which grey squirrels can utilise CaOx. One of three custom‐made diets containing calcium in varying forms and quantities (CaOx diet, Low‐calcium carbonate (CaCO 3) diet and Control diet) were fed to three treatment groups of six squirrels for 8 weeks. Bone densitometric properties were measured at the end of this time using peripheral quantitative computed tomography and micro‐computed tomography. Pyridinoline—a serum marker of bone resorption—was measured regularly throughout the study. Bone mineral density and cortical mineralisation were lower in squirrels fed the CaOx diet compared to the Control group but similar to that of those on the Low‐calcium diet, suggesting that calcium from calcium oxalate was not effectively utilised to maintain bone mineralisation. Whilst no differences were observed in serum pyridinoline levels between individuals on different diets, females had on average higher levels than males throughout the study. Future work should seek to determine if this apparent lack of ability to utilise CaOx is common to a large sample of grey squirrels and if so, whether it is consistent across all areas and seasons.

Pathogenesis of calcium oxalate urinary stone disease: species comparison of humans, dogs, and cats

Idiopathic calcium oxalate nephrolithiasis is a highly recurrent disease that is increasing in prevalence. Decades of research have not identified effective methods to consistently prevent the formation of nephroliths or induce medical dissolution. Idiopathic calcium oxalate nephroliths form in association with renal papillary subepithelial calcium phosphate deposits called Randall's plaques (RPs). Rodent models are commonly used to experimentally induce calcium oxalate crystal and stone formation, but a rodent model that conclusively forms RPs has not been identified. Both dogs and cats form calcium oxalate uroliths that can be recurrent, but the etiopathologic mechanisms of stone formation, especially renal pathologic findings, are a relatively unexploited area of study. A large animal model that shares a similar environment to humans, along with a shorter lifespan and thus shorter time to recurrence, might provide an excellent means to study preventative and therapeutic measures, along with enhancing the concepts of the one health initiative. This review article summarizes and compares important known features of idiopathic calcium oxalate stone disease in humans, dogs, and cats, and emphasizes important knowledge gaps and areas for future study in the quest to discover a naturally occurring animal model of idiopathic calcium oxalate stone disease.

Inhibitory effect of an aqueous extract of Radix Paeoniae Alba on calcium oxalate nephrolithiasis in a rat model

Objective: To examine the effect of an aqueous extract of Radix Paeoniae Alba (RPA) on the formation of calcium oxalate (CaOx) stones and the potential mechanism underlying the effect.Materials and methods: An in vitro assay was used to determine whether the RPA extract prevents the formation of CaOx or promotes CaOx dissolution. We also investigated the efficacy of the extract in vivo as a preventive and therapeutic agent for experimentally induced CaOx nephrolithiasis in rats. Various biochemical, molecular, and histological parameters were assessed in kidney tissue and urine at the end of the in vivo experiment.Results: Significant dissolution of formed crystals (8.99 ± 1.43) and inhibition of crystal formation (2.55 ± 0.21) were observed in vitro after treatment with 64 mg/mL of the RPA extract compared with a control treatment (55.10 ± 4.98 and 54.57 ± 5.84, respectively) (p < .05). In preventive protocols, the RPA extract significantly reduced urinary and renal oxalate levels and increased urinary calcium and citrate levels compared to the control. In addition, the RPA preventive protocol significantly decreased osteopontin expression, renal crystallization, and pathological changes compared to the control. These changes were not observed in rats on the therapeutic protocol.Conclusions: RPA is a useful agent that prevents the formation of CaOx kidney stones.

Mechanism of Randall’s Plugs Development

Mechanism of formation and development of intraluminal concretion, also called Randall's plug, extracted from a female patient forming calcium oxalate dihydrate (COD) calculi was examined. Some of these calculi were connected to the papillary tip, and had connections with the interior of the papilla with finger-like extensions in the collecting duct (CD). The intraluminal concretion consisted of inter-grown COD crystals of irregular size (30–100 μm), approximately 5% of biological hydroxyapatite (BHAP) and an organic matter. Urine of the patient was moderately supersaturated with respect to COD and amorphous calcium phosphate (ACP). Model of kidney, recently refined by Robertson, was used in calculations. Calculated Reynolds number indicated that the flow of liquid through tubules was purely laminar with parabolic velocity profile. COD crystals formed at the beginning of ascending loop of Henle by heterogeneous nucleation. Concentration of COD crystals in urine was limited and considered equal to concentration of crystals during crystaluria. The free particle and the fixed particle mechanisms were considered. The free particle mechanism assumes formation of a single crystal or agglomerate of crystals blocking the CD by virtue of size. The growth of COD crystals at concrete urinary supersaturation was too slow for a single crystal to attain size with settling velocity faster than the translation flow rate of liquid. Hydrodynamic shear caused aggregation of COD solid particles dispersed in a liquid flowing in the nephron. Number of COD crystals present in urine was not sufficient for formation of fractal agglomerate blocking the Bellini duct. Similarly, a fractal agglomerate of urinary phosphate present in the form of Posner's clusters was not large enough to obstruct the Bellini duct. The opening of the CD could not be obstructed by a single crystal of COD or fractal agglomerate composed of either COD crystals or calcium phosphate clusters, formed in urine by virtue of size. Solid objects not immobilised inside the CD were always washed out by urine flow from the CD of any orientation (also upward-draining CD). The formation and development of plug of our patient was explained by the fixed particle mechanism assuming that Randall's plug developes from crystal(s) attached directly to the tubule wall. The plug was modelled as concretion composed of successive layers of COD crystals originating on the top of underlying layer. When growth of a layer stopped, its surface was covered by organic matter that served as a substrate for nucleation of a new layer. The time of plug development was estimated as the time a COD crystal needed to reach the opposite side of the duct plus duration of interruptions of crystalline growth when plug surface was covered by a layer of organic matter and phosphatic particles were incorporated into concretion. The flux of Posner's clusters arriving to the concretion surface was estimated from theory of Brownian motion. These calculations suggested that obstruction of the Bellini duct of our patient by the Randall's plug occurred over a period of approximately 4 months after nucleus of concretion became attached to the duct wall or on the papillary tip.

Alteration in Oxidative/nitrosative imbalance, histochemical expression of osteopontin and antiurolithiatic efficacy of Xanthium strumarium (L.) in ethylene glycol induced urolithiasis.

Xanthium strumarium has traditionally been used in the treatment of urolitiasis especially by the rural people in India, but its antiurolithiatic efficacy was not explored scientifically till now. Therefore, the present study was designed to validate the ethnic practice scientifically, and explore the possible antiurolithiatic effect to rationalize its medicinal use. Urolitiasis was induced in hyperoxaluric rat model by giving 0.75% ethylene glycol (EG) for 28days along with 1% ammonium chloride (AC) for first 14days. Antiurolithiatic effect of aqueous-ethanol extract of Xanthium strumarium bur (xanthium) was evaluated based on urine and serum biochemistry, oxidative/nitrosative stress indices, histopathology, kidney calcium and calcium oxalate content and immunohistochemical expression of matrix glycoprotein, osteopontin (OPN). Administration of EG and AC resulted in hyperoxaluria, crystalluria, hypocalciuria, polyurea, raised serum urea, creatinine, erythrocytic lipid peroxidise and nitric oxide, kidney calcium content as well as crystal deposition in kidney section in lithiatic group rats. However, xanthium treatment significantly restored the impairment in above kidney function test as that of standard treatment, cystone. The up-regulation of OPN was also significantly decreased after xanthium treatment. The present findings demonstrate the curative efficacy of xanthium in ethylene glycol induced urolithiasis, possibly mediated through inhibition of various pathways involved in renal calcium oxalate formation, antioxidant property and down regulation of matrix glycoprotein, OPN. Therefore, future studies may be established to evaluate its efficacy and safety for clinical use.

A follow-up on the analytical study of discolouration of the marble statues of Orsanmichele in Florence.

The research complements the complex study carried out to understand the source of brown discolourations of ten marble statues in the Church of Orsanmichele in Florence, Italy. Originally located in exterior niches, the statues were restored to reverse the extensive alterations they had undergone throughout the centuries. One of the major alterations was the application of a dark brown patina that dated just after 1789. After the statues were placed indoors, brownish discolourations started to appear on their surfaces. Cross sections were examined using FTIR mapping and immunological methods. In parallel, the pyrolysis-gas chromatography/mass spectrometry (py-GC/MS) data already obtained from the statues' scrapings were compared with data from aged casein films applied to microscope glass slides and aged milk-treated marble. All the statues had been treated with milk-based substances before the time the bronze patina was applied. The values of temperature and illumination of the room were important factors in the ageing of organic substances and in the formation of calcium oxalates. It is likely that products of thermo-oxidation and photo-oxidation of the oils together with the oxalates caused the darkening. The marble samples corresponded to a Lunense provenance.

Assessment of Urine Proteomics in Type 1 Primary Hyperoxaluria

Background: Primary hyperoxaluria type 1 (PH1) and idiopathic hypercalciuria (IHC) are stone-forming diseases that may result in the formation of calcium (Ca) oxalate (Ox) stones, nephrocalcinosis, and progressive chronic kidney disease (CKD). Poorer clinical outcome in PH1 is segregated by the highest urine (Ur)-Ox (UrOx), while IHC outcomes are not predictable by UrCa. We hypothesized that differences would be found in selected Ur-protein (PRO) patterns in PH1 and IHC, compared to healthy intra-familial sibling controls (C) of PH1 patients. We also hypothesized that the PRO patterns associated with higher UrOx levels would reflect injury, inflammation, biomineralization, and abnormal tissue repair processes in PH1. Methods: Twenty four-hour Ur samples were obtained from 3 cohorts: PH1 (n = 47); IHC (n = 35) and C (n = 13) and were analyzed using targeted platform-based multi-analyte profile immunoassays and for UrOx and UrCa by biochemical measurements. Results: Known stone matrix constituents, osteopontin, calbindin, and vitronectin were lowest in PH1 (C > IHC > PH1; p < 0.05). Ur-interleukin-10; chromogranin A; epidermal growth factor (EGF); insulin-like growth factor-1 (IGF-1), and macrophage inflammatory PRO-1α (MIP-1α) were higher in PH1 > C (p = 0.03 to p < 0.05). Fetuin A; IGF-1, MIP-1α, and vascular cell adhesion molecule-1 were highest in PH1 > IHC (p < 0.001 to p = 0.005). Conclusion: PH1 Ur-PROs reflected overt inflammation, chemotaxis, oxidative stress, growth factors (including EGF), and pro-angiogenic and calcification regulation/inhibition compared to the C and IHC cohorts. Many of the up- and downregulated PH1-PROs found in this study are also found in CKD, acute kidney injury, stone formers, and/or stone matrices. Further data analyses may provide evidence for PH1 unique PROs or demonstrate a poorer clinical outcome.

In Vitro Inhibition Capacity in Ca Oxalate Formation by Lemon (Citrus Lemon) Juice

This research aims to determine the inhibition capacity of lemon juice (Citrus lemon) in the formation of calcium oxalate in a variety of concentrations of 5%, 7.5%, 10% which is then compared to pure citric acid. Lemon juice contains citric acid that can inhibit calcium oxalate’s formation. Inhibitory activity found in lemon juice is examined by observing its inhibition capacity towards the formation of calcium oxalate crystal. At the end of the treatment process the turbidity level is compared to citric acid acting as an inhibitor in the formation of calcium oxalate and then the percentage of the inhibition capacity is calculated. Result of the study shows that the optimum concentration of the lemon juice (Citrus lemon) and citric acid is 10%. The inhibition capacities in calcium oxalate formation by lemon juice with concentration variations of 5%, 7.5%, 10% are 47.06%, 73.68%, 94.19% and by citric acid with concentration variations of 5%, 7.5 %, 10% are 29.90%, 30.85%, 42.30%. It can be concluded that the higher the concentration of lemon juice and citric acid used the higher the inhibition capacity of calcium oxalate. Based on the inhibition capacity percentage, lemon juice is more effective in inhibiting the formation of calcium oxalate compared to citric acid and it can function as an alternative to prevent the formation of kidney stone. © 2015 JNSMR UIN Walisongo. All rights reserved

DISTRIBUTION OF CALCIUM IN FRUIT TISSUES OF LOQUAT

Fruits are a good source of various minerals for humans. Calcium in fruits is important for normal development and quality maintenance. The present study examined calcium distribution in different fruit tissues of ‘Zhaozhong No. 6’ loquat (Eriobtorya japonica Lindl.). Calcium concentration in young fruit was high but declined throughout fruit development, while in the pedicel calcium concentration was relatively constant and became far higher than in fruit flesh and seed as fruit matured. Calcium mapping in the flesh using X-ray microanalyzer revealed that a larger amount of Ca was distributed in the outer portion or exocarp, where a large number of calcium-rich particles were found in young fruit. These calcium-rich particles disappeared as fruit grew and matured. Within the pedicel, calcium was more abundant in the phloem and pith than in the cortex and xylem. There were a lot of calcium oxalate crystals, either in styloids or druses, in the phloem and pith cells neighboring the xylem and fiber clusters, where Ca level was the lowest. There was a good positive correlation between Ca content in the pedicel and that in the flesh. It was concluded that Ca is likely transported to fruit through the phloem tissues and that the formation of calcium oxalate in the pedicel may not interfere with calcium transport to fruit.

Precipitation of Amorphous Calcium Oxalate in Aqueous Solution

Inspired by the observation that crystalline calcium carbonate and calcium phosphate biominerals frequently form via amorphous precursors, a wide range of studies have been performed which demonstrate that many inorganic crystals can precipitate from solution via amorphous phases. This article considers the crystallization mechanism of calcium oxalate, which is a significant biomineral in many plants and the primary constituent of kidney stones in vertebrates, and shows that this can also precipitate via an amorphous precursor phase from aqueous solution. A range of approaches were employed to study calcium oxalate formation, including precipitation in bulk solution in the presence and absence of additives and in the spatially confined volumes offered by track etched membranes and a crossed cylinders apparatus. A freeze concentration method was also used to generate sufficient quantities of amorphous calcium oxalate (ACO) for analysis. The results show that amorphous calcium oxalate crystallizes rapidly in bulk solution but can be significantly stabilized through the concerted activity of additives and confinement. We also demonstrate that ACO has a composition of ≈CaC2O4:H2O. These data suggest that calcium oxalate biominerals, in common with their carbonate and phosphate counterparts, may also precipitate via amorphous phases.

Oxalobacter formigenes Colonization and Oxalate Dynamics in a Mouse Model.

Animal and human studies have provided compelling evidence that colonization of the intestine with Oxalobacter formigenes reduces urinary oxalate excretion and lowers the risk of forming calcium oxalate kidney stones. The mechanism providing protection appears to be related to the unique ability of O. formigenes to rely on oxalate as a major source of carbon and energy for growth. However, much is not known about the factors that influence colonization and host-bacterium interactions. We have colonized mice with O. formigenes OxCC13 and systematically investigated the impacts of diets with different levels of calcium and oxalate on O. formigenes intestinal densities and urinary and intestinal oxalate levels. Measurement of intestinal oxalate levels in mice colonized or not colonized with O. formigenes demonstrated the highly efficient degradation of soluble oxalate by O. formigenes relative to other microbiota. The ratio of calcium to oxalate in diets was important in determining colonization densities and conditions where urinary oxalate and fecal oxalate excretion were modified, and the results were consistent with those from studies we have performed with colonized and noncolonized humans. The use of low-oxalate purified diets showed that 80% of animals retained O. formigenes colonization after a 1-week dietary oxalate deprivation. Animals not colonized with O. formigenes excreted two times more oxalate in feces than they had ingested. This nondietary source of oxalate may play an important role in the survival of O. formigenes during periods of dietary oxalate deprivation. These studies suggest that the mouse will be a useful model to further characterize interactions between O. formigenes and the host and factors that impact colonization.

Raphides in Food ? An Unsafe Menu

Calcium oxalate in plant bodies lead to stones in kidney, upon consumption. Calcium oxalate is frequently found in plants in the form of tiny needle like raphides. Out of the 5 types of calcium oxalate crystals, raphides are the predominant ones. Calcium oxalate gets incorporated in our body through plant derived food that contains them; a little amount of them is also synthesized in humans endogenously. Both the sources contribute to kidney problems. Occurrence of calcium oxalate is not limited to higher plants only but also extends to algae, fungi and lichens. Out of all the 3 forms of calcium oxalate, monohydrate form is the one widely reported to cause kidney problems. In this study, we review raphides and explore their possible remediation in order to utilize plants of food and medicinal importance the better way. We also review traditional knowledge of raphide neutralization and point to the methods of removal of calcium oxalate and raphides.

Direct Evidence of Calcium Oxalate Formation in Spinach

Abstract An X-ray absorption fine structure (XAFS) study has been performed to examine the chemical form of Ca in spinach. The spectra obtained by XAFS measurements show direct evidence that Ca exists in the chemical form of calcium oxalate in spinach, which is an insoluble salt. This result can explain the low bioavailability of Ca in spinach. The bioavailability is discussed from the viewpoint of the solubility of calcium oxalate in the stomach.

Prophylactic effects of quercetin and hyperoside in a calcium oxalate stone forming rat model.

Quercetin and hyperoside (QH) are the two main constituents of the total flavone glycosides of Flos Abelmoschus manihot, which has been prescribed for treating chronic kidney disease for decades. This study aimed to investigate the effect of QH on calcium oxalate (CaOx) formation in ethylene glycol (EG)-fed rats. Rats were divided into three groups: an untreated stone-forming group, a QH-treated stone-forming group (20 mg/kg/day) and a potassium citrate-treated stone-forming group (potassium citrate was a worldwide-recognized calculi-prophylactic medicine). Ethylene glycol (0.5 %) was administered to the rats during the last week, and vitamin D3 was force-fed to induce hyperoxaluria and kidney calcium oxalate crystal deposition. 24 h urine samples were collected before and after inducing crystal deposits. Rats were killed and both kidneys were harvested after 3 weeks. Bisected kidneys were examined under a polarized light microscope for semi-quantification of the crystal-formation. The renal tissue superoxide dismutase and catalase levels were measured by Western blot. QH and potassium citrate have the ability to alkalinize urine. The number of crystal deposits decreased significantly in the QH-treated stone-forming group as compared to the other groups. Superoxide dismutase and catalase levels also increased significantly in the QH-treated stone-forming group, as compared with the untreated stone-forming group. QH administration has an inhibitory effect on the deposition of CaOx crystal in EG-fed rats and may be effective for preventing stone-forming disease.

Short term effects of increasing dietary salt concentrations on urine composition in healthy cats

High dietary salt (NaCl) concentrations are assumed to be beneficial in preventing the formation of calcium oxalate (CaOx) uroliths in cats, since increased water intake and urine volume have been observed subsequent to intake. In human beings, dietary NaCl restriction is recommended for the prevention of CaOx urolith formation, since high NaCl intake is associated with increased urinary Ca excretion. The aim of the present study was to clarify the role of dietary NaCl in the formation of CaOx uroliths in cats. Eight cats received four diets that differed in Na and Cl concentrations (0.38–1.43% Na and 0.56–2.52% Cl dry matter, DM). Each feeding period consisted of a 21 day adaptation period, followed by a 7 day sampling period for urine collection. Higher dietary NaCl concentrations were associated with increased urine volume and renal Na excretion. Urinary Ca concentration was constant, but renal Ca excretion increased from 0.62 to 1.05 mg/kg bodyweight (BW)/day with higher dietary NaCl concentrations (P ≤ 0.05). Urinary oxalate (Ox), citrate, P and K concentrations decreased when NaCl intake was high (P ≤ 0.05), and urinary pH was low in all groups (6.33–6.45; P > 0.05). Relative supersaturation of CaOx in the urine was unaffected by dietary NaCl concentrations. In conclusion, the present study demonstrated several beneficial effects of high dietary NaCl intake over a relatively short time period. In particular, urinary Ca concentration remained unchanged because of increased urine volume. Decreased urinary Ox concentrations might help to prevent the formation of CaOx uroliths, but this should be verified in future studies in diseased or predisposed cats.

Cloning, localization and characterization of a Zn transporter (Zip10) from fly, dog, and human (893.39)

Background: Zn is implicated as having a role in the formation of calcium oxalate (CaOx) kidney stones. Our studies indicate that Slc39a10 (Zip10) may be important in this process. Zip10 has identifiable sequences in human, dog and fly (Drosophila). As we are interested in a translational model of kidney stones, we examined Zip10 from all 3 species.Methods: Zip10 cDNAs were cloned from human &amp; dog (kidney) and fly (whole fly) using gene specific primers and RT‐PCR. Clones were put into a Xenopus oocyte expression vector so that Zip10 function could be measured. Three days post‐injection, oocytes were pre‐incubated in ND96, followed by 30 min in ND96 + 10 μM ZnCl + the PET isotope 63Zn, with varying pHs and ion concentrations. 63Zn uptake was measured in each oocyte using a gamma counter. Zip10 oocytes were also checked using electrophysiology (ion selective electrodes &amp; voltage clamping).Results: Zip10 mRNA &amp; protein are found in gut and kidney. In mouse kidney, Zip10 antibodies stained the apical membrane of proximal tubules. All clones transported 63Zn (nmol/oocyte/hr): hZip10 = 70±8; cZip10= 44 ±7; dZip10= 64 ±8; water = 0.4 ±0.1. These clones seem to be most active at pH 7.5 as uptakes decreased at 5.5 and 8.5. Replacement of either all Cl‐ (with HCO3舉) or all Na+ (with choline) reduced Zn‐uptake. Electrophysiology revealed no evidence of I or V changes with addition of Zn (electroneutral).Conclusions: Our results indicated that all three Zip10 clones transport Zn2+. Understanding the detailed mechanisms of these Zn transporters in oocytes presents the opportunity to better use our Drosophila model in the study of CaOx stone formation and absorption.Grant Funding Source: Supported by DK83007, DK92408

MP25-07 DEVELOPMENT OF A NEW BIOMARKER AND TREATMENT STRATEGY FOR KIDNEY STONE DISEASE TARGETING MITOCHONDRIAL CYCLOPHILIN D ACTIVITY

the kidneys were harvested and examined calcium oxalate stones/crystals were suspected. Histopathological analysis on H&E stainings, fluorescent microscopy and stone analysis by infrared spectrum analysis confirmed calcium oxalate stones/crystal formation within the renal cortex and medulla. No crystal deposition was observed in the control group. CONCLUSIONS: Pigs fed ethylene glycol in combination with vitamin D, ammonium chloride, gentamycin, or Lasix formed calcium oxalate stones/crystals. The use of the above feeding substrate is inexpensive and effective at producing a novel porcine calcium oxalate stone forming model.

Antifungal activity of Ca[Zn(OH)3]2·2H2O coatings for the preservation of limestone monuments: An in vitro study

The antifungal properties of protective coatings based on Ca[Zn(OH)3]2·2H2O have been evaluated both on glass slides and on three different limestone materials, which have regional significance as the most commonly used building and restoration materials in the region, including for historic Mayan monuments and artifacts. The protective coatings were found to have excellent antifungal properties, inhibiting the growth of Penicillium oxalicum and Aspergillus niger, both in the dark and under illumination.Experiments were carried out at a laboratory test site under simulated photoperiod conditions, consisting of 24-h cycles of 12 h in the dark and 12 h under illumination: 21 days after inoculation and exposure to photoperiod conditions, no fungal growth was observed for any type of limestone, for both fungi. X-ray diffraction illustrated that the formation of calcium oxalate in the weddellite structure is an indicator of the fungal activity. Close inspection of samples with scanning electron microscopy (SEM) revealed that for all limestone substrates without protective coating, fungal growth was observed as well as fungal penetration into the limestone material. SEM images also show that the Ca[Zn(OH)3]2·2H2O coating is well-adhered to all substrates, without the presence of significant cracks in the coating. For the three limestone substrates with the protective coating, no fungal growth was observed, illustrating the excellent antifungal properties of the calcium zinc hydroxide dihydrate material.

In Vitro Anti‐Inflammatory Activity of Selected Oxalate‐Degrading Probiotic Bacteria: Potential Applications in the Prevention and Treatment of Hyperoxaluria

Oxalate (Ox) is a very common component of the human diet, capable to collect in the renal tissue and bind calcium to form calcium oxalate (CaOx) crystals. A supersaturation of CaOx crystal may cause nephrocalcinosis and nephrolithiasis. The inflammation derived from the CaOx crystal accumulation, together with innate or secondary renal alterations, could strongly affect the renal function. In this case a consumption of probiotics with either oxalate-degrading activity at intestinal level and systemic anti-inflammatory activity could be an alternative approach to treat the subjects with excess of urinary oxalate excretion. 11 strains of lactic acid bacteria (Lactobacilli and Bifidobacteria), already included in the list of bacteria safe for the human use, were investigated for their capability to degrade oxalate by mean of RP-HPLC-UV method and modulate inflammation in an in vitro model system based on peripheral blood mononuclear cells. Four promising bacterial strains (Lactobacillus plantarum PBS067, Lactobacillus acidophilus LA-14, Bifidobacterium breve PBS077, Bifidobacterium longum PBS078) were identified as innovative biological tools for the prevention and the therapeutic treatment of hyperoxaluria and the inflammatory events associated to the Ox accumulation. The oxalate-degrading activity of some probiotics and their capability to modulate the release of inflammation mediators could be exploited as a new nutraceutical and therapeutic approach for the treatment of oxalate accumulation and the related inflammatory state.

An emerging translational model to screen potential medicinal plants for nephrolithiasis, an independent risk factor for chronic kidney disease.

Pharmacological therapy for urolithiasis using medicinal plants has been increasingly adopted for the prevention of its recurrence. A Drosophila melanogaster model developed for translational research of urolithiasis was applied to evaluate agents with potential antilithic effects and calcium oxalate (CaOx) formation. Potential antilithic herbs were prepared in a mixture of food in a diluted concentration of 5,000 from the original extract with 0.5% ethylene glycol (EG) as the lithogenic agent. The control group was fed with food only. After 3 weeks, flies (n ≥ 150 for each group) were killed using CO2 narcotization, and the Malpighian tubules were dissected, removed, and processed for polarized light microscopy examination of the crystals. The crystal formation rate in the EG group was 100.0%. In the study, 16 tested herbal drugs reached the crystal formation rate of 0.0%, including Salviae miltiorrhizae, Paeonia lactiflora, and Carthami flos. Scutellaria baicalensis enhanced CaOx crystal formation. Two herbal drugs Commiphora molmol and Natrii sulfas caused the death of all flies. Our rapid screening methods provided evidence that some medicinal plants have potential antilithic effects. These useful medicinal plants can be further studied using other animal or human models to verify their effects.