Histological, molecular and biochemical detection of renal injury after Echis pyramidum snake envenomation in rats

The renoprotective potential of montelukast: a scoping review

Introduction

Kidney damage can result from various factors, leading to structural and functional changes in the kidney. Acute kidney injury (AKI) refers to a sudden decline in kidney function, while chronic kidney disease involves a gradual deterioration lasting more than 3 months. Mechanisms of renal injury include impaired microcirculation, inflammation, and oxidative stress. Cysteinyl-leukotrienes (CysLTs) are inflammatory substances contributing to tissue damage. Montelukast, a leukotriene receptor antagonist, has shown potential renoprotective effects in experimental models of kidney injury.

Methods

The authors conducted a scoping review using PubMed, Scopus, and Web of Science databases to identify relevant studies investigating the impact of montelukast on renal diseases. Articles published until 2022 were included and evaluated for quality. Data extraction and analysis were performed based on predetermined inclusion criteria.

Results

The scoping review included 30 studies from 8 countries. Montelukast demonstrated therapeutic effects in various experimental models of nephrotoxicity and AKI induced by agents such as cisplatin, lipopolysaccharide, diclofenac, amikacin, Escherichia coli, cyclosporine, methotrexate, cobalt-60 gamma radiation, doxorubicin, and cadmium. Studies involving human subjects with nephrotic syndrome, pyelonephritis, and other renal diseases also reported positive outcomes with montelukast treatment. Montelukast exhibited anti-inflammatory, anti-apoptotic, antioxidant, and neutrophil-inhibiting properties, leading to improved kidney function and histopathological changes.

Conclusions

Montelukast shows promise as a renoprotective medication, particularly in early-stage kidney injury. Its ability to mitigate inflammation, oxidative stress, and neutrophil infiltration contributes to its therapeutic effects. Further research is needed to explore the clinical applications and mechanisms underlying the renoprotective action of montelukast.

Hemodynamic Changes Provoked through Intravascular Injection of the Echis carinatus Venom in Rats

Echis carinatus (E. carinatus) is known for its hematological and nephrotoxic properties in the envenomed patients. Based on the limited data upon the cardiovascular changes associated with this dangerous venomous snake in Iran, the current study purposed to evaluate the venom-induced hemodynamic manifestations in rats. Venom (120 µg/kg) was administered intravenously within one minute through the left femoral vein, and the hemodynamic parameters were continuously recorded using a pressure transducer (MLT844, ADInstruments, Australia). The venom caused prominent hypotension leading to death a few minutes after a transient uprise in blood pressure. It also induced a decrease in heart and pulmonary rates, yet it had no arrhythmogenic properties. Additionally, pre-treatment with the pepsin-derived Iranian polyvalent antivenom (30 µl/Kg) completely neutralized the hemodynamic responses but had no effect when instilled two minutes after venom injection. Heparin (300 IU/kg) and epinephrine (1.5 µg/kg) prevented dramatic hypotension when used 10 minutes before venom instillation; however, atropine (1 mg/kg), dexamethasone (1 mg/kg), and ketorolac (10 mg/ml) had no effects. All treated rats were killed post-injection. Histologically, the lung was the most vulnerable organ with mononuclear infiltration, microcystic formation, and significant capillary congestion. Prominent renal pathological deterioration also occurred, including mesangial cell infiltration and diffuse bleeding, leading to acute tubular necrosis. Modest portal inflammation and vascular congestion were observed in the hepatic tissue of the envenomed rats. The crude venom of Iranian Echis carinatus caused hypotension leading to bradycardia, a decrease in pulmonary rate, and death without significant histological changes to the heart.

Ameliorating effect of Alstonia scholaris L. bark extract on histopathological changes following viper envenomation in animal models

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In the present paper, the histopathological changes of liver and kidney tissues associated with Vipera russelli envenomation and systemic venom neutralization potential of aqueous Alstonia scholaris Linn bark extract in animal models has been discussed.

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Histological alterations observed in liver sections of venom treated groups were mainly pyknosis, karyorrhexis, cytoplasmic vacuolation, necrosis, fatty changes and hepatocytes atrophy.

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Histological changes in venom treated kidney tissues were cell damage, peritubular congestion, degenerating changes in the proximal tubules in the form of cytoplasmic vacuolations, partially destroyed bowman’s capillaries with dilated Bowman’s space after staining with haematoxylin and eosin.

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Both Antivenom and Alstonia scholaris Linn extract could significantly reduce the venom induced histological as well as biochemical changes (serum AST,ALT and creatinine) in the affected tissues.

Objectives

The primary symptoms associated with snake envenomation are both systemic and local. The local symptoms are characterized by pain, swelling, haemorrhage and myonecrosis at the site of bite. The present study investigates the ameliorating effect of the aqueous bark extract of Alstonia scholaris bark on viper venom induced histopathological and biochemical changes in liver and kidney of swiss albino mice models.

Methods & materials

Swiss albino mice (20 ± 2)g were treated with sublethal doses(0.5 μg and 1 μg) of Vipera russelli venom(VRV) intraperitonially The following groups were assigned in the study-Group I(saline control); Group II & III(Venom treated-0.5 μg ie ¼ LD50 and 1 μg ie 1/2 LD50) and Group IV &V(Venom-0.5 μg and 1 μg respectively incubated with Aqueous Alstonia scholaris (AAS) extract; 200 mg/kg bw) and Group VI (Antivenom serum (AVS) (2 mg/ml) followed by 1 μg Vipera russelli venom (VRV). The animals were sacrificed and their organs were immersed in Bouin's fixative for 24 h and stained with haematoxylin/eosin and observed under the microscope. The serum samples were collected from the animals and tested for serum Alanine transaminase (ALT) and Aspartate transaminases (AST) following the method of Reitman & Frankel(1957) and serum creatinine.

Results

The histological alterations observed in Group II and III liver sections were mainly pyknosis, karyorrhexis, cytoplasmic vacuolation, necrosis, fatty changes and hepatocytes atrophy. Sinusoidal dilatation, amyloidosis, portal vein thrombosis which was significantly reduced by AAS extract in Groups IV and V. A venom dose of 1 μg induced tubular cell acidophilia indicating cell damage, peritubular congestion, degenerating changes in the proximal tubules in the form of cytoplasmic vacuolations, partially destroyed bowman’s capillaries with dilated Bowman’s space in Group III that was significantly reduced by Aqueous Alstonia scholaris (AAS) (200 mg/kg bw) extract in Groups IV and Group V.AVS gave significant protection against venom induced action in Group VI.

Conclusion

The present paper thus highlights the histopathological changes associated with Vipera russelli venom and systemic venom neutralization potential of Aqueous Alstonia scholaris (AAS) in animal models.

The Venom of Spectacled Cobra (Elapidae: Naja naja): In Vitro Study from Distinct Geographical Origins in Sri Lanka

Several countries residing envenomation due to Naja naja had revealed a disparity in the venom composition according to their geographic location and Sri Lankan cobra still lacks the evidence to support this. Therefore, the current study was focused on addressing relationship between the histopathological changes according to geographic variation of Sri Lankan N. naja venom. The histopathological changes in vital organs and muscle tissues following intramuscular administration of venom of N. naja were studied using BALB/c mice. The median lethal dose of venom of N. naja in the present study was determined to be 0.55, 0.66, 0.68, 0.62, and 0.7 mg/kg for North (NRP), Central (CRP), Western, Southern, and Sabaragamuwa Regional Population venoms, respectively. Histopathological changes were observed in different levels in vital organs and muscle tissues of mice. NRP accompanied significantly higher infiltration of inflammatory and necrotic cells into skeletal muscle and CRP venom demonstrated high level of cardiotoxic effects comparing to other regions. This study revealed a certain extent of variations in the pathological effects of N. naja venom samples according to their geographical distribution.