In vitro Antiurolithiatic activity of the leaves and flowers extracts of Paronychia argentea, a plant used in traditional medicine in Algeria

Plants are a large source of new bioactive molecules with therapeutic potentials. However, only a small amount of worldwide plants has been phytochemically investigated. The ethanolic extracts from leaves and flowers of Paronychia argentea were evaluated for their antilithiasic activity in vitro. The effect of extract (0.1, 0.2, 0.3, 1, 2, and 5mg/mL) was studied by the measurement of turbidity in presence or absence of extract at 620nm using UV/Vis spectrophotometer. Total phenol and flavonoid contents were also evaluated. Polyphenol content was found to be more present in the leaves extract (9.29±0.009mg of Gallic acid equivalent (GAE)/g) compared to the flowers extract (5.92±0.14mg GAE/g). Flavonoids content was also found to be more present in the floral extract that is estimated at 0.18±0.01 mg QE/g compared to the flowers extract (0.47±0.0035mg QE/g). For the antilithiasis activity, the results clearly shown that P. argentia extracts inhibited calcium oxalate crystallization by concentration-dependent manner. The maximum percent inhibition of calcium oxalate by flowers extract was found to be 70.97% at 5mg/mL. Further, P. argentea leaf extract has shown antilithiasic properties and may be used for the prevention of kidneys stones. Plants are a large source of new bioactive molecules with therapeutic potentials. However, only a small amount of worldwide plants has been phytochemically investigated. The ethanolic extracts from leaves and flowers of Paronychia argentea were evaluated for their antilithiasic activity in vitro. The effect of extract (0.1, 0.2, 0.3, 1, 2, and 5mg/mL) was studied by the measurement of turbidity in presence or absence of extract at 620 nm using UV/Vis spectrophotometer. Total phenol and flavonoid contents were also evaluated. Polyphenol content was found to be more present in the leaves extract (9.29±0.009mg of Gallic acid equivalent (GAE)/g) compared to the flowers extract (5.92±0.14mg GAE/g). Flavonoids content was also found to be more present in the floral extract that is estimated at 0.18±0.01mg QE/g compared to the flowers extract (0.47±0.0035mg QE/g). For the antilithiasis activity, the results clearly shown that P. argentia extracts inhibited calcium oxalate crystallization by concentration-dependent manner. The maximum percent inhibition of calcium oxalate by flowers extract was found to be 70.97% at 5mg/mL. Further, P. argentea leaf extract has shown antilithiasic properties and may be used for the prevention of kidneys stones.

Exploring the Molecular Level Interaction of Human Serum Albumin with Calcium Oxalate Monohydrate Crystals

Background: Human serum albumin (HSA) is one of the most abundant proteins in the blood plasma, urine as well as in the organic matrix of renal calculi. Macromolecules present in the urine modulate kidney stone formation either by stimulating or inhibiting crystallization process. Objective: In the present study, effect of HSA protein on the growth of calcium oxalate monohydrate crystal (COM) was investigated. Methods: Crystal growth assay was used to measure oxalate depletion in the crystal seeded solution in the presence of HSA. HSA concentrations exhibiting effect on crystal growth were selected for FTIR and XRD analysis. In silico docking was performed on seven different binding sites of HSA. Results: Albumin is playing dual role in growth of calcium oxalate crystallization. FTIR and XRD studies further revealed HSA exerted strain over crystal thus affecting its structure by interacting with amino acids of its pocket 1. Docking results indicate that out of 7 binding pocket in protein, calcium oxalate interacts with Arg-186 and Lys-190 amino acids of pocket 1. Conclusion: Our study confirms the role of HSA in calcium oxalate crystallization where acidic amino acids arginine and lysine are binding with COM crystals, revealing molecular interaction of macromolecule and crystal in urolithiasis.

Optimization of growth conditions for oxalate decarboxylase production from Pseudomonas sp. OXDC12 and in vitro inhibition of calcium oxalate crystallization by oxalate decarboxylase

Background: Kidney stones have become a common disease worldwide and their incidence and recurrence rates have drastically increased over the past few decades. Oxalate decarboxylase (OxDC) enzyme which catalyzes the disproportionation reaction of oxalate monoanions into formate and CO2 could exhibit significant potential in the treatment of hyperoxaluria. Objective: The present work describes isolation and screening of new OxDC producing bacterial strain from oxalate rich soils and one-factor-at-a-time (OFAT) and response surface methodology (RSM) statistical approaches were used to optimize the production media to obtain an improved intracellular OxDC production. Methods and Results: An OxDC producing bacterial strain isolated from spinach soil sample(s) was identified to be Pseudomonas sp. OXDC12 by 16S rRNA sequencing. The OFAT approach was used to determine the effect of supplementation of carbon, nitrogen and other physical conditions like pH, temperature etc. on intracellular OxDC production by Pseudomonas sp. OXDC12. The three factors screened by Plackett Burman design (PBD) were further used by central composite design (CCD) approach of RSM to determine their interactive effects on OxDC production. The anti-urolithiatic activity of the enzyme OxDC was determined by carrying out in vitro calcium oxalate crystallization in presence and absence of OxDC. The factorial values selected by 23 CCD for OxDC were temperature 30ºC, manganese ion concentration 5 mmol l-1 and innoculum size 3.25% (v/v). The highest predicted value of OxDC was 5.7 U ml-1 while the actual value obtained was 6.7 U ml-1 which was 79.1% and 2.92 fold greater than the initial activity of OxDC produced by Pseudomonas sp. OXDC12. As depicted by the light micrographs, OxDC displayed a significant reduction in the crystallization and formation of calcium oxalate stones as compared to the control under in vitro conditions. Conclusion: OFAT and RSM statistical optimization approaches led to improved OxDC production with a final activity of 6.7 U ml-1 and a 2.92 fold increase in the enzyme activity. The study suggests that OFAT and RSM optimization approaches significantly enhanced OxDC production from Pseudomonas sp. OXDC12. The enzyme may serve as a potential therapeutic agent for hyperoxaluria or kidney stones as it significantly inhibited the formation of calcium oxalate crystals under in vitro conditions.