Urolithiasis is a multifactorial disease and remains a public health problem around the world. Of all types of renal stones, calcium oxalate (CaOx) is the most common composition formed in the urinary system of the patients with urolithiasis. The present study is aimed at evaluating the antiurolithiatic properties of the Tris-Cl extract (TE) of Terminalia arjuna (T. arjuna). The antilithiatic activity of TE of T. arjuna was investigated on nucleation, aggregation, and growth of the CaOx crystals, as well as its protective potency was tested on oxalate-induced cell injury of NRK-52E renal epithelial cells. Also, in vitro antioxidant activity of TE T. arjuna bark was also determined. The TE of T. arjuna exhibited a concentration-dependent inhibition of nucleation and growth of CaOx crystals. Inhibition of aggregation of CaOx crystals remains constant. When NRK-52E cells were injured by exposure to oxalate for 48 h, the TE prevented the cells from injury and CaOx crystal adherence resulting in increased cell viability in a dose-dependent manner. The TE also scavenged the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals with an IC50 at 51.72 µg/mL. The results indicated that T. arjuna is a potential candidate for phytotherapy against urolithiasis as it attains the ability to inhibit CaOx crystallization and scavenge DPPH free radicals in vitro along with a cytoprotective role.

Kidney stone formation during hyperoxaluric condition is inherently dependent on the interaction between renal epithelial cells and calcium oxalate (CaOx) crystals. Although modern medicine has progressed in terms of removal of these stones, recurrence and persistent side effects restricts their use. Strategies involving plant based agents which could be used as adjunct therapy is an area which needs to be explored. Plant proteins having antilithiatic activity is a hitherto unexplored area and therefore, we conducted a detailed identification and characterization of antilithiatic proteins from Terminalia arjuna (T. arjuna). Proteins were isolated from the dried bark of T. arjuna and those having molecular weights > 3 kDa were subjected to anion exchange chromatography followed by gel filtration chromatography. Four proteins were identified exhibiting inhibitory activity against CaOx crystallization and crystal growth kinetics The cytoprotective and anti-apoptotic efficacy of these purified proteins was further investigated on oxalate injured renal epithelial cells (MDCK and NRK-52E) wherein, injury due to oxalate was significantly attenuated and led to a dose dependent increase in viability of these cells. These proteins also prevented the interaction of the CaOx crystals to the cell surface and reduced the number of apoptotic cells. Identification of these 4 anionic proteins from the bark of T. arjuna was carried out by Matrix-assisted laser desorption/ionization-time of flight Mass spectrometry (MALDI-TOF MS). This was followed by database search with the MASCOT server and sequence similarity was found with Nuclear pore anchor, DEAD Box ATP-dependent RNA helicase 45, Lon protease homolog 1 and Heat shock protein 90–3. These novel proteins isolated from T. arjuna have the potential to inhibit CaOx crystallization and promote cell survival and therefore, offer novel avenues which need to be explored further for the medical management of urolithiasis.

Purpose:For most cases, urolithiasis is a condition where excessive oxalate is present in the urine. Many reports have documented free radical generation followed by hyperoxaluria as a consequence of which calcium oxalate (CaOx) deposition occurs in the kidney tissue. The present study is aimed to exam the antilithiatic potency of the aqueous extract (AE) of Terminalia arjuna (T. arjuna).Materials and Methods:The antilithiatic activity of Terminalia arjuna was investigated in vitro nucleation, aggregation and growth of the CaOx crystals as well as the morphology of CaOx crystals using the inbuilt software ‘Image-Pro Plus 7.0’ of Olympus upright microscope (BX53). Antioxidant activity of AE of Terminalia arjuna bark was also determined in vitro.Results:Terminalia arjuna extract exhibited a concentration dependent inhibition of nucleation and aggregation of CaOx crystals. The AE of Terminalia arjuna bark also inhibited the growth of CaOx crystals. At the same time, the AE also modified the morphology of CaOx crystals from hexagonal to spherical shape with increasing concentrations of AE and reduced the dimensions such as area, perimeter, length and width of CaOx crystals in a dose dependent manner. Also, the Terminalia arjuna AE scavenged the DPPH (2, 2-diphenyl-1-picrylhydrazyl) radicals with an IC50 at 13.1µg/mL.Conclusions:The study suggests that Terminalia arjuna bark has the potential to scavenge DPPH radicals and inhibit CaOx crystallization in vitro. In the light of these studies, Terminalia arjuna can be regarded as a promising candidate from natural plant sources of antilithiatic and antioxidant activity with high value.

Urolithiasis is one of the painful multifactorial disorders caused by metabolic abnormalities influencing the composition of body fluids and urine. The bark of Terminalia arjuna (T. arjuna), very well known in Ayurveda for the treatment of cardiovascular diseases, possesses antioxidant and diuretic activity. The present study was undertaken to investigate the antiurolithiatic efficacy of aqueous extract of bark of T. arjuna on oxalate-induced injury to renal tubular epithelial cells. Madin-Darby canine kidney (MDCK) cells were exposed to 2 mM oxalate for 48 h to evaluate the protective effect of T. arjuna aqueous extract on cell viability, CaOx crystal adherence and apoptotic changes caused by oxalate. The results confirmed that oxalate injured MDCK cells were protected by T. arjuna extract. On treatment with a range concentrations, the cell viability increased in a concentration dependent manner. Moreover, the extract prevented the interaction of the calcium oxalate (CaOx) crystals with the cell surface and reduced the number of apoptotic cells. The current data suggests that T. arjuna bark confers a cytoprotective role and based on our results it could be a potential candidate from natural plant sources against urolithiasis.

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formation in renal tubular cells. This is the first study to suggest that Nnt can suppress kidney stone formation. Nnt is a promising candidate for future therapeutic intervention.

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