Animal toxins and the kidney

Using organ-on-a-chip technology to study haemorrhagic activities of snake venoms on endothelial tubules

Snakebite envenomation is a major public health issue which causes severe morbidity and mortality, affecting millions of people annually. Of a diverse range of clinical manifestations, local and systemic haemorrhage are of particular relevance, as this may result in ischemia, organ failure and even cardiovascular shock. Thus far, in vitro studies have failed to recapitulate the haemorrhagic effects observed in vivo. Here, we present an organ-on-a-chip approach to investigate the effects of four different snake venoms on a perfused microfluidic blood vessel model. We assess the effect of the venoms of four snake species on epithelial barrier function, cell viability, and contraction/delamination. Our findings reveal two different mechanisms by which the microvasculature is being affected, either by disruption of the endothelial cell membrane or by delamination of the endothelial cell monolayer from its matrix. The use of our blood vessel model may shed light on the key mechanisms by which tissue-damaging venoms exert their effects on the capillary vessels, which could be helpful for the development of effective treatments against snakebites.

Tissue damaging toxins in snake venoms: mechanisms of action, pathophysiology and treatment strategies

Snakebite envenoming is an important public health issue responsible for mortality and severe morbidity. Where mortality is mainly caused by venom toxins that induce cardiovascular disturbances, neurotoxicity, and acute kidney injury, morbidity is caused by toxins that directly or indirectly destroy cells and degrade the extracellular matrix. These are referred to as 'tissue-damaging toxins' and have previously been classified in various ways, most of which are based on the tissues being affected (e.g., cardiotoxins, myotoxins). This categorisation, however, is primarily phenomenological and not mechanistic. In this review, we propose an alternative way of classifying cytotoxins based on their mechanistic effects rather than using a description that is organ- or tissue-based. The mechanisms of toxin-induced tissue damage and their clinical implications are discussed. This review contributes to our understanding of fundamental biological processes associated with snakebite envenoming, which may pave the way for a knowledge-based search for novel therapeutic options.

Crosstalk of Inflammation and Coagulation in Bothrops Snakebite Envenoming: Endogenous Signaling Pathways and Pathophysiology

Snakebite envenoming represents a major health problem in tropical and subtropical countries. Considering the elevated number of accidents and high morbidity and mortality rates, the World Health Organization reclassified this disease to category A of neglected diseases. In Latin America, Bothrops genus snakes are mainly responsible for snakebites in humans, whose pathophysiology is characterized by local and systemic inflammatory and degradative processes, triggering prothrombotic and hemorrhagic events, which lead to various complications, organ damage, tissue loss, amputations, and death. The activation of the multicellular blood system, hemostatic alterations, and activation of the inflammatory response are all well-documented in Bothrops envenomings. However, the interface between inflammation and coagulation is still a neglected issue in the toxinology field. Thromboinflammatory pathways can play a significant role in some of the major complications of snakebite envenoming, such as stroke, venous thromboembolism, and acute kidney injury. In addition to exacerbating inflammation and cell interactions that trigger vaso-occlusion, ischemia-reperfusion processes, and, eventually, organic damage and necrosis. In this review, we discuss the role of inflammatory pathways in modulating coagulation and inducing platelet and leukocyte activation, as well as the inflammatory production mediators and induction of innate immune responses, among other mechanisms that are altered by Bothrops venoms.

Monitoring Snake Venom-Induced Extracellular Matrix Degradation and Identifying Proteolytically Active Venom Toxins Using Fluorescently Labeled Substrates

Snakebite envenoming is an important public health issue with devastating consequences and annual mortality rates that range between 81,000 and 138,000. Snake venoms may cause a range of pathophysiological effects affecting the nervous system and the cardiovascular system. Moreover, snake venom may have tissue-damaging activities that result in lifelong morbidities such as amputations, muscle degeneration, and organ malfunctioning. The tissue-damaging components in snake venoms comprise multiple toxin classes with various molecular targets including cellular membranes and the extracellular matrix (ECM). In this study, we present multiple assay formats that enable investigation of snake venom-induced ECM degradation using a variety of (dye-quenched) fluorescently labeled ECM components. Using a combinatorial approach, we were able to characterise different proteolytic profiles for different medically relevant snake venoms, followed by identification of the responsible components within the snake venoms. This workflow could provide valuable insights into the key mechanisms by which proteolytic venom components exert their effects and could therefore prove useful for the development of effective snakebite treatments against this severe pathology.

Varespladib in the Treatment of Snakebite Envenoming: Development History and Preclinical Evidence Supporting Advancement to Clinical Trials in Patients Bitten by Venomous Snakes

The availability of effective, reliably accessible, and affordable treatments for snakebite envenoming is a critical and long unmet medical need. Recently, small, synthetic toxin-specific inhibitors with oral bioavailability used in conjunction with antivenom have been identified as having the potential to greatly improve outcomes after snakebite. Varespladib, a small, synthetic molecule that broadly and potently inhibits secreted phospholipase A2 (sPLA2s) venom toxins has renewed interest in this class of inhibitors due to its potential utility in the treatment of snakebite envenoming. The development of varespladib and its oral dosage form, varespladib-methyl, has been accelerated by previous clinical development campaigns to treat non-envenoming conditions related to ulcerative colitis, rheumatoid arthritis, asthma, sepsis, and acute coronary syndrome. To date, twenty-nine clinical studies evaluating the safety, pharmacokinetics (PK), and efficacy of varespladib for non-snakebite envenoming conditions have been completed in more than 4600 human subjects, and the drugs were generally well-tolerated and considered safe for use in humans. Since 2016, more than 30 publications describing the structure, function, and efficacy of varespladib have directly addressed its potential for the treatment of snakebite. This review summarizes preclinical findings and outlines the scientific support, the potential limitations, and the next steps in the development of varespladib's use as a snakebite treatment, which is now in Phase 2 human clinical trials in the United States and India.

Phospholipase A2 inhibitor varespladib prevents wasp sting-induced nephrotoxicity in rats

This study aimed to clarify whether varespladib, a phospholipase A₂ (PLA₂) inhibitor, can be used as a therapeutic agent for wasp sting-induced acute kidney injury (AKI). Rats were divided into control, AKI, and AKI + varespladib groups. The AKI model was established by subcutaneously injecting wasp venom at five different sites in rats. Varespladib treatment showed a significant inhibitory effect on wasp venom PLA₂in vitro and in vivo. Moreover, we observed that varespladib decreased the levels of rhabdomyolysis and hemolysis markers compared with that in the AKI group. Histopathological changes in the kidney decreased significantly, and rat serum creatinine levels were reduced after varespladib administration. The significantly regulated genes in the kidney of the AKI group were mostly involved in inflammatory response pathway, and the administration of varespladib remarkably attenuated the expression of these genes. Therefore, varespladib inhibited wasp sting-induced functional and pathological damage to the kidneys. We propose that the PLA₂ inhibitor varespladib protects the kidney tissue in a wasp sting-induced AKI model by inhibiting PLA₂ activity.

A rare concurrence: bee venom associated acute tubular necrosis and acute interstitial nephritis

Acute kidney injury (AKI) is generally associated with increased morbidity and mortality and is even more devastating in patients with comorbidities. Although AKI due to multiple bee stings is well established in the literature, it is still a rare entity with complex pathophysiologic mechanisms. The most commonly reported histological findings in AKI due to bee stings is acute tubular necrosis (ATN), with a few studies attributing it to acute interstitial nephritis (AIN), whereas the concurrence of both ATN and AIN is rarely reported. We hereby present a 50-year-old known Type 2 diabetes mellitus patient with a prior normal renal function, who developed AKI following multiple stings from >1000 bees. He had a kidney biopsy on account of non-recovery of his kidney function despite being on intermittent hemodialysis that showed combined features of ATN and AIN. He subsequently had a full recovery of his renal function following appropriate management.

Acute kidney injury caused by venomous animals: inflammatory mechanisms

Either bites or stings of venomous animals comprise relevant public health problems in tropical countries. Acute kidney injury (AKI) induced by animal toxins is related to worse prognostic and outcomes. Being one the most important pathways to induce AKI following envenoming due to animal toxins, inflammation is an essential biological response that eliminates pathogenic bacteria and repairs tissue after injury. However, direct nephrotoxicity (i.e. apoptotic and necrotic mechanisms of toxins), pigmenturia (i.e. rhabdomyolysis and hemolysis), anaphylactic reactions, and coagulopathies could contribute to the renal injury. All these mechanisms are closely integrated, but inflammation is a distinct process. Hence, it is important to improve our understanding on inflammation mechanisms of these syndromes to provide a promising outlook to reduce morbidity and mortality. This literature review highlights the main scientific evidence of acute kidney injury induced by bites or stings from venomous animals and their inflammatory mechanisms. It included observational, cross-sectional, case-control and cohort human studies available up to December 2019. Descriptors were used according to Medical Subject Headings (MeSH), namely: “Acute kidney injury” or “Venom” and “Inflammation” on Medline/Pubmed and Google Scholar; “Kidney disease” or “Acute kidney injury” on Lilacs and SciELO. The present review evidenced that, among the described forms of renal inflammation, it can occur either directly or indirectly on renal cells by means of intravascular, systemic and endothelial hemolysis, activation of inflammatory pathway, as well as direct action of venom cytotoxic components on kidney structures.

Kidney injury following envenoming by hump-nosed pit viper (Genus: Hypnale) in Sri Lanka: proven and probable cases

BACKGROUND

Hump-nosed pit vipers (Hypnale hypnale) are highly venomous snakes found in Sri Lanka and the Western Ghats region of India. They are the most common cause of venomous snakebites in Sri Lanka, mainly causing local envenoming leading to pain, swelling and necrosis. Systemic envenoming causing acute kidney injury and coagulopathy are more commonly recognized following their bites.

METHOD

A series of 465 patients with hump-nosed viper bites was prospectively studied over four years from January 2014. All patients were assessed and the data were collected by the principal investigator (primary data).

RESULTS

Forty-four (9.5%) patients developed acute kidney injury, of which 23 (5%) were proven cases and 21 (4.5%) were probable cases. Of the proven cases, 4 (17%) progressed to chronic kidney disease and 12 (52%) had thrombotic microangiopathy, from which 11 (48%) developed haemolytic uremic syndrome and 1 (4%) had thrombotic thrombocytopenic purpura. Twelve (52%) showed microangiopathic haemolysis and 15 (65%) had thrombocytopenia. Oliguria was observed in 10 (43%) whereas 7 (30%) each had anuria and normal urine output. Ten patients (43%) developed haematuria, from which 6 had microscopic haematuria and 4 had macroscopic haematuria. Proteinuria was observed in 8 (35%). Coagulopathy developed in 3 (13%) patients. In probable cases, 3 (14%) died due to complications of kidney injury.

CONCLUSION

A significant proportion of patients develop acute kidney injury following hump-nosed pit viper bite. Who will develop acute kidney injury or succumb to the venom is unpredictable. Reliable and accessible treatments are a critical unmet need.

Minor Blunt Injury-induced Rhabdomyolysis from a Road Traffic Accident in Nigeria

Rhabdomyolysis, though not a common complication of minor blunt trauma, may result in life-threatening acute kidney injury (AKI). Here is illustrated a case of a young male who sustained minor blunt injuries in a road traffic accident, which he overlooked and presented with features of severe AKI. The patient is a 24-year-old male, who presented with progressive weakness, difficulty in walking, and features of uremia, 14 days after he sustained minor blunt injuries and lacerations in a road traffic accident. Evaluation showed elevated serum creatine kinase, serum myoglobin, and severe azotemia. He was commenced on hemodialysis. He was also commenced on antibiotics, analgesic, and 5% dextrose/saline. He had three sessions of hemodialysis on alternate days. His condition improved remarkably after the first session of dialysis. He was discharged after 18 days on admission. Follow-up in the clinic showed a normal renal function. This case report shows rhabdomyolysis from minor blunt injuries sustained in a road traffic accident and complicated by severe AKI. The patient almost recovered full renal function with management.

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.

Determination of the sub-lethal nephrotoxic dose of Russell's viper (Daboia russelii) venom in Wistar rats

Wistar rats were administered increasing doses of Russell's viper venom (RVV; 0.025-0.4 mg/kg) intraperitoneally to investigate acute kidney injury (AKI) by measuring creatinine (1.5-fold increase in serum creatinine above baseline) and examining kidney histology. Approximately 50% of rats receiving 0.25-0.4 mg/kg venom died within 72 h. An increase in serum creatinine only occurred at a venom dose of 0.4 mg/kg, except in two rats. Acute tubular necrosis, glomerular necrosis, cortical necrosis and interstitial inflammation were observed at venom doses of ≥0.25 mg/kg in 12/36 rats. However, of those 12 rats only four survived to 48 h compared to the 24 rats not developing nephrotoxicity, in which 18 were alive at 48 h. There was poor correlation between histological nephrotoxicity and AKI based on creatinine measurement. The early death in rats with AKI makes this a poor model for studying RVV-induced AKI.

Disseminated intravascular coagulation caused by moojenactivase, a procoagulant snake venom metalloprotease

Snake venom toxins that activate coagulation factors are key players in the process of venom-induced coagulopathy, and account for severe clinical manifestations. The present study applies a variety of biochemical, hematological, and histopathological approaches to broadly investigate the intravascular and systemic effects of moojenactivase (MooA), the first described PIIId subclass metalloprotease isolated from Bothrops sp. venom that activates coagulation factors. MooA induced consumption coagulopathy with high toxic potency, characterized by prolongation of prothrombin and activated partial thromboplastin time, consumption of fibrinogen and the plasma coagulation factors X and II, and thrombocytopenia. MooA promoted leukocytosis and expression of the proinflammatory cytokines interleukin-6 and tumor necrosis factor-α, accompanied by tissue factor-dependent procoagulant activity in peripheral blood mononuclear cells. This metalloprotease also caused intravascular hemolysis, elevated plasma levels of creatine kinase-MB, aspartate transaminase, and urea/creatinine, and induced morphopathological alterations in erythrocytes, heart, kidney, and lungs associated with thrombosis and hemorrhage. Diagnosis of MooA-induced disseminated intravascular coagulation represents an important approach to better understand the pathophysiology of Bothrops envenomation and develop novel therapeutic strategies targeting hemostatic disturbances.

Acute kidney injury due to multiple Hymenoptera stings-a clinicopathological study

Background

Acute kidney injury (AKI) after multiple Hymenoptera stings is well known but still a rare phenomenon.

Methods

We conducted a retrospective study of the clinicopathological spectrum of AKI due to multiple Hymenoptera stings over 13 years (July 2003-June 2016).

Results

A total of 35 patients were diagnosed with AKI due to multiple Hymenoptera stings. The mean age of the patients was 44.7 ± 17.4 years and the majority (60%) were men. Haematological and biochemical laboratory abnormalities included anaemia (97.1%), leucocytosis (54.3%), hyperkalaemia (68.6%), severe metabolic acidosis (51.4%), hepatic dysfunction (74.3%), haemolysis (91.4%) and rhabdomyolysis (62.9%). The main complications included acute respiratory distress syndrome (ARDS) and encephalopathy in four (11.4%) patients each; gastrointestinal bleeding, hypertension and panniculitis in two (5.7%) patients each and one (2.9%) patient each developed intra-abdominal bleeding, stroke and polyserositis. Twenty-nine (83%) patients required dialysis. Ten (29%) patients died. A higher white blood cell count (P = 0.05) and the complications of ARDS (P = 0.004) and encephalopathy (P = 0.004) were associated with mortality. The kidney functions normalized at 5.5 ± 2.6 weeks in patients who survived. Kidney biopsy was done in 13 patients. The predominant lesion was acute tubular necrosis (ATN) with or without pigmented granular cast in 10 (77%) patients. In four (30.8%) patients, the kidney biopsy showed severe ATN and in the other six (46.2%), the kidney biopsy showed features of ATN associated with mild to moderate acute interstitial nephritis (AIN). In three (23%) patients the histopathological examination revealed only moderate AIN and these patients were treated with a short course of steroids.

Conclusions

AKI due to multiple Hymenoptera stings is severe and is associated with high mortality. On renal histology, ATN and AIN are common.

Clinical and laboratory parameters associated with acute kidney injury in patients with snakebite envenomation: a prospective observational study from Myanmar

Background

Snakebite-related acute kidney injury (AKI) is a common community-acquired AKI in tropical countries leading to death and disability. The aims of this study were to (1) determine the occurrence of snakebite-related AKI, (2) assess factors at presentation that are associated with snakebite-related AKI, and (3) determine the outcomes of patients with snakebite-related AKI.

Methods

We conducted a prospective observational study of patients with snake envenomation at the three academic tertiary care hospitals in Yangon, Myanmar between March 2015 and June 2016. Patient data including baseline characteristics, clinical and laboratory findings, hospital management, and outcomes were recorded in a case report form. A stepwise multivariate logistic regression analysis using a backward selection method determined independent factors significantly associated with AKI.

Results

AKI was observed in 140 patients (54.3%), the majority of whom were AKI stage III (110 patients, 78.6%). AKI occurred at presentation and developed during hospitalization in 88 (62.9%) and 52 patients (37.1%), respectively. Twenty-seven patients died (19.3%), and 69 patients (49.3%) required dialysis. On multivariate logistic regression analysis, (1) snakebites from the Viperidae family (odds ratio [OR]: 9.65, 95% confidence interval [CI]: 2.42–38.44; p = 0.001), (2) WBC >10 × 10³ cells/μL (OR: 3.55, 95% CI: 1.35–9.34; p = 0.010), (3) overt disseminated intravascular coagulation (OR: 2.23, 95% CI: 1.02–4.89; p = 0.045), (4) serum creatine kinase >500 IU/L (OR: 4.06, 95% CI: 1.71–9.63; p = 0.001), (5) serum sodium <135 mmol/L (OR: 4.37, 95% CI: 2.04–9.38; p < 0.001), (6) presence of microscopic hematuria (OR: 3.60, 95% CI: 1.45–8.91; p = 0.006), and (7) duration from snakebite to receiving antivenom ≥2 h (OR: 3.73, 95% CI: 1.48–9.37; p = 0.005) were independently associated with AKI. Patients bitten by Viperidae with normal renal function who had serum sodium <135 mmol/L had a significantly higher urine sodium-to-creatinine ratio than those with serum sodium ≥135 mmol/L (p < 0.001).

Conclusions

Identifying factors associated with snakebite-related AKI might help clinicians to be aware of snakebite patients who are at risk of AKI, particularly patients who demonstrate renal tubular dysfunction after Viperidae bites.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-017-0510-0) contains supplementary material, which is available to authorized users.

The Related Risk Factors Analysis of Snake-Bite Induced Acute Kidney Injury

BACKGROUND The pathogenic mechanism of snake-bite induced acute kidney injury (AKI) remains unclear. Analyzing the risk factors for snake-bite induced AKI may provide the guidance needed for AKI prevention and early treatment. MATERIAL AND METHODS This retrospective study included 119 snake-bite patients who were hospitalized at the emergency department of Sichuan Provincial People's Hospital from January 2011 to September 2013. The patients were divided into AKI and non-AKI groups according to the 2012 Kidney Disease: Improving Global Outcomes (KDIGO) guideline. Gender, age, and clinical examination data of the patients were recorded. The Mann-Whitney U test and Fisher exact test were performed to analyze the collected data; preliminary analysis of independent risk factors was performed with multivariate logistic regression. RESULTS Among the snake-bite patients, 98.3% were farmers. The mean age of patients was 46±12 years. Of the 119 patients (13.4%), 16 suffered from AKI. There were statistically significant differences between the AKI and non-AKI groups with respect to age, time interval from snake bite to antivenin therapy, creatine kinase, blood myoglobin, advanced age, regional lymphadenopathy, incision drainage, and hemoglobin. Preliminary analysis with multivariate logistic regression showed that advanced age and increased time interval from snake bite to antivenin therapy might be independent risk factors for snake-bite induced AKI. CONCLUSIONS Age, time interval from snake bite to antivenin therapy, creatine kinase, blood myoglobin, advanced age, regional lymphadenopathy, incision drainage, and hemoglobin were risk factors for snake-bite induced AKI. Advanced age and delayed antivenin therapy might be independent risk factors for snake-bite induced AKI.

Effects of Tityus stigmurus (Thorell 1876) (Scorpiones: Buthidae) venom in isolated perfused rat kidneys

ABSTRACT Scorpions belonging to the Tityus genus are of medical interest in Brazil. Among them, Tityus stigmurus is the main scorpion responsible for stings in the Northeast region. After a sting, the scorpion venom distributes rapidly to the organs, reaching the kidneys quickly. However, there are few studies concerning the renal pathophysiology of scorpion poisoning. In this study, we evaluated the effects of T. stigmurus venom (TsV) on renal parameters in isolated rat kidneys. Wistar rats (n = 6), weighing 250-300 g, were perfused with Krebs-Henseleit solution containing 6 g/100 mL bovine serum albumin. TsV at 0.3 and 1.0 μg/mL was tested, and the effects on perfusion pressure (PP), renal vascular resistance (RVR), urinary flow (UF), glomerular filtration rate (GFR), and electrolyte excretion were analyzed. Effects were observed only at TsV concentration of 1.0 μg/mL, which increased PP (controlPP40' = 92.7 ± 1.95; TsVPP40' = 182.0 ± 4.70* mmHg, *p < 0.05), RVR (controlRVR40' = 3.28 ± 0.23 mmHg; TstRVR40' = 6.76 ± 0.45* mmHg, *p < 0.05), UF (controlUF50' = 0.16 ± 0.04; TstUF50' = 0.60 ± 0.10* mL/g/min,*p < 0.05), GFR and electrolyte excretion, with histological changes that indicate renal tubular injury. In conclusion, T. stigmurus venom induces a transient increase in PP with tubular injury, both of which lead to an augmented electrolyte excretion.

Wasp sting-induced acute kidney injury

Background

Wasp stings are a common form of envenomation in tropical countries, especially in farmers. The aim of this study was to document the clinical presentation, treatment and outcomes of patients with acute kidney injury (AKI) due to multiple wasp stings in a tertiary care hospital.

Methods

We conducted a retrospective observational study of patients with multiple wasp stings and AKI at the Department of Nephrology between July 2011 and August 2015. The clinical features, laboratory data, treatment details and outcomes were noted.

Results

A total of 11 patients were included. All were from rural areas. All of them were males with age ranging from 21 to 70 years, mean age 45 ± 23 years. Six had oliguria and two had hypotension. All 11 patients had evidence of rhabdomyolysis and three also had hemolysis. Ten patients required hemodialysis with a mean number of hemodialysis sessions of 8.7 ± 2.8. Renal biopsy carried out on four patients, showed acute interstitial nephritis (AIN) in one patient, acute tubular necrosis (ATN) in two patients, and one patient had both AIN and ATN. The two patients with AIN were given steroids, while all other patients were managed with supportive measures. One patient died within 48 h of presentation due to shock. At a mean follow-up of 24 months, one had progressed to chronic kidney disease and the remaining nine had normal renal function.

Conclusions

Wasp sting is an occupational hazard. AKI was most commonly due to rhabdomyolysis. Early renal biopsy is indicated in those patients who do not respond to supportive measures. Timely dialysis and steroid in the case of AIN improves renal survival.

Acute Interstitial Nephritis Following Multiple Asian Giant Hornet Stings

Patient: Male, 42

Final Diagnosis: Acute interstitial nephritis

Symptoms: Difficulty breathing • headache • numbness • oliguria

Medication: Methylprednisolone

Clinical Procedure: Plasma exchange

Specialty: Nephrology

Proteomic investigation of Sri Lankan hump-nosed pit viper (Hypnale hypnale) venom

The hump-nosed pit viper, Hypanle hypnale, contributes to snakebite mortality and morbidity in Sri Lanka. Studies showed that the venom is hemotoxic and nephrotoxic, with some biochemical and antigenic properties similar to the venom of Calloselasma rhodostoma (Malayan pit viper). To further characterize the complexity composition of the venom, we investigated the proteome of a pooled venom sample from >10 Sri Lankan H. hypnale with reverse-phase high performance liquid chromatography (rp-HPLC), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and peptide sequencing (tandem mass-spectrometry and/or N-terminal sequencing). The findings ascertained that two phospholipase A2 subtypes (E6-PLA2, W6-PLA2) dominate the toxin composition by 40.1%, followed by snake venom metalloproteases (36.9%), l-amino acid oxidase (11.9%), C-type lectins (5.5%), serine proteases (3.3%) and others (2.3%). The presence of the major toxins correlates with the venom's major pathogenic effects, indicating these to be the principal target toxins for antivenom neutralization. This study supports the previous finding of PLA2 dominance in the venom but diverges from the view that H. hypnale venom has low expression of large enzymatic toxins. The knowledge of the composition and abundance of toxins is essential to elucidate the pathophysiology of H. hypnale envenomation and to optimize antivenom formulation in the future.

Acute kidney injury caused by Crotalus and Bothrops snake venom: a review of epidemiology, clinical manifestations and treatment

SUMMARY

Ophidic accidents are an important public health problem due to their incidence, morbidity and mortality. An increasing number of cases have been registered in Brazil in the last few years. Several studies point to the importance of knowing the clinical complications and adequate approach in these accidents. However, knowledge about the risk factors is not enough and there are an increasing number of deaths due to these accidents in Brazil. In this context, acute kidney injury (AKI) appears as one of the main causes of death and consequences for these victims, which are mainly young males working in rural areas. Snakes of the Bothrops and Crotalus genera are the main responsible for renal involvement in ophidic accidents in South America. The present study is a literature review of AKI caused by Bothrops and Crotalus snake venom regarding diverse characteristics, emphasizing the most appropriate therapeutic approach for these cases. Recent studies have been carried out searching for complementary therapies for the treatment of ophidic accidents, including the use of lipoic acid, simvastatin and allopurinol. Some plants, such as Apocynaceae, Lamiaceae and Rubiaceae seem to have a beneficial role in the treatment of this type of envenomation. Future studies will certainly find new therapeutic measures for ophidic accidents.

Pharmacokinetics of the Sri Lankan hump-nosed pit viper (Hypnale hypnale) venom following intravenous and intramuscular injections of the venom into rabbits

The knowledge of venom pharmacokinetics is essential to improve the understanding of envenomation pathophysiology. Using a double-sandwich ELISA, this study investigated the pharmacokinetics of the venom of hump-nosed pit viper (Hypnale hypnale) following intravenous and intramuscular injections into rabbits. The pharmacokinetics of the venom injected intravenously fitted a three-compartment model. There is a rapid (t1/2π = 0.4 h) and a slow (t1/2α = 0.8 h) distribution phase, followed by a long elimination phase (t1/2β = 19.3 h) with a systemic clearance of 6.8 mL h(-1) kg(-1), consistent with the prolonged abnormal hemostasis reported in H. hypnale envenomation. On intramuscular route, multiple peak concentrations observed in the beginning implied a more complex venom absorption and/or distribution pattern. The terminal half-life, volume of distribution by area and systemic clearance of the venom injected intramuscularly were nevertheless not significantly different (p > 0.05) from that of the venom injected intravenously. The intramuscular bioavailability was exceptionally low (Fi.m. = 4%), accountable for the highly varied median lethal doses between intravenous and intramuscular envenomations in animals. The findings indicate that the intramuscular route of administration does not significantly alter the pharmacokinetics of H. hypnale venom although it significantly reduces the systemic bioavailability of the venom.

Incidence, etiology, and outcomes of rhabdomyolysis in a single tertiary referral center

We have encountered numerous cases of rhabdomyolysis associated with acute pesticide intoxication; however, the cause, incidence, and treatment outcomes of rhabdomyolysis have not been studied. The current study involved 2,125 patients hospitalized with acute chemical poisoning. Based on clinical and laboratory parameters and treatment outcomes, we found that overall incidence of rhabdomyolysis in our hospital was 0.06% (93 of 143,830 patients admitted), but the incidence associated with acute pesticide intoxication was 1.8% (33 of 1,793 cases). The incidence of rhabdomyolysis after pesticide intoxication was significantly higher in men than in women (P = 0.010). The amount of pesticide ingested was significantly higher in rhabdomyolysis patients than that in those who did not develop rhabdomyolysis (mean ± SD, 114.1 ± 79.5 mL vs 74.1 ± 94.2 mL, P = 0.010). Our results show that pesticide intoxication is a frequent cause of rhabdomyolysis and is more common among men than women. The volume of pesticide ingested, and not the degree of human toxicity, is the main factor influencing the incidence of rhabdomyolysis.

In Vitro and In Vivo Evaluation of Polyherbal Formulation against Russell's Viper and Cobra Venom and Screening of Bioactive Components by Docking Studies

The present study emphasizes to reveal the antivenom activity of Aristolochia bracteolata Lam., Tylophora indica (Burm.f.) Merrill, and Leucas aspera S. which were evaluated against venoms of Daboia russelli russelli (Russell's viper) and Naja naja (Indian cobra). The aqueous extracts of leaves and roots of the above-mentioned plants and their polyherbal (1 : 1 : 1) formulation at a dose of 200 mg/kg showed protection against envenomed mice with LD₅₀ doses of 0.44 mg/kg and 0.28 mg/kg against Russell's viper and cobra venom, respectively. In in vitro antioxidant activities sample extracts showed free radical scavenging effects in dose dependent manner. Computational drug design and docking studies were carried out to predict the neutralizing principles of type I phospholipase A₂ (PLA₂) from Indian common krait venom. This confirmed that aristolochic acid and leucasin can neutralize type I PLA₂ enzyme. Results suggest that these plants could serve as a source of natural antioxidants and common antidote for snake bite. However, further studies are needed to identify the lead molecule responsible for antidote activity.

Neurological effects of venomous bites and stings: snakes, spiders, and scorpions

Snake and spider bites, as well as scorpion sting envenoming, are neglected diseases affecting millions of people all over the world. Neurological complications vary according to the offending animal, and are often directly related to toxic effects of the venom, affecting the central nervous system, the neuromuscular transmission, the cardiovascular system, or the coagulation cascade. Snake bite envenoming may result in stroke or muscle paralysis. Metalloproteinases and other substances (common in vipers and colubrids) have anticoagulant or procoagulant activity, and may induce ischemic or hemorrhagic strokes. The venom of elapids is rich in neurotoxins affecting the neuromuscular transmission at either presynaptic or postsynaptic levels. The clinical picture of scorpion sting envenoming is dominated by muscle weakness associated with arterial hypertension, cardiac arrythmias, myocarditis, or pulmonary edema. These manifestations occur as the result of release of catecholamines into the bloodstream or due to direct cardiac toxicity of the venom. Cerebrovascular complications have been reported after the sting of the Indian red scorpion. Intracranial hemorrhages occur in the setting of acute increases in arterial blood pressure related to sympathetic overstimulation, and cerebral infarctions are related to either cerebral hypoperfusion, consumption coagulopathy, vasculitis, or cardiogenic brain embolism. Three main syndromes result from spider bite envenoming: latrodectism, loxoscelism, and funnel-web spider envenoming. Latrodectism is related to neurotoxins present in the venom of widow spiders. Most cases present with headache, lethargy, irritability, myalgia, tremor, fasciculation, or ataxia. Loxoscelism is caused by envenoming by spiders of the family Sicariidae. It may present with a stroke due to a severe coagulopathy. The venom of funnel-web spiders also has neurotoxins that stimulate neurotransmitter release, resulting in sensory disturbances and muscle paralysis. Proper management of the envenomed patient, including prompt transport to the hospital, correction of the hemostatic disorder, ventilatory support, and administration of antivenom, significantly reduce the risk of neurological complications which, in turn, reduce the mortality and improve the functional outcome of survivors.

Typical toxic components in traditional Chinese medicine

INTRODUCTION

Traditional Chinese medicine (TCM) is widely used around the world. However, with its wide use has been the identification of a number of toxicological issues that have severely restricted its use in clinical treatment. The identification of these toxic substances within TCM has become somewhat of a hot topic in recent years.

AREAS COVERED

This article reviews literature published on professional authoritative journals in the last 10 years on the toxic constituents and toxicology of TCM, including chemical structures, absorption and metabolism. The literature search for this article was based, but not limited to, toxic constituents including: alkaloids, glycosides, toxic proteins, polypeptide, amino acids, phenols or organic acids, terpenes and lactones. The authors discuss the toxic substances referring to their toxicity on organs, tissues and systems.

EXPERT OPINION

More and more toxic constituents from different TCMs have been identified, in addition to information on how they act in the body at a molecular level. However, the toxicology of TCMs is very complex, and although some progress has been made, a lot work is still needed in order to put an end to toxic incidents.

Exploiting the nephrotoxic effects of venom from the sea anemone, Phyllodiscus semoni, to create a hemolytic uremic syndrome model in the rat

In the natural world, there are many creatures with venoms that have interesting and varied activities. Although the sea anemone, a member of the phylum Coelenterata, has venom that it uses to capture and immobilise small fishes and shrimp and for protection from predators, most sea anemones are harmless to man. However, a few species are highly toxic; some have venoms containing neurotoxins, recently suggested as potential immune-modulators for therapeutic application in immune diseases. Phyllodiscus semoni is a highly toxic sea anemone; the venom has multiple effects, including lethality, hemolysis and renal injuries. We previously reported that venom extracted from Phyllodiscus semoni induced acute glomerular endothelial injuries in rats resembling hemolytic uremic syndrome (HUS), accompanied with complement dysregulation in glomeruli and suggested that the model might be useful for analyses of pathology and development of therapeutic approaches in HUS. In this mini-review, we describe in detail the venom-induced acute renal injuries in rat and summarize how the venom of Phyllodiscus semoni could have potential as a tool for analyses of complement activation and therapeutic interventions in HUS.

Immunological properties of Hypnale hypnale (hump-nosed pit viper) venom: antibody production with diagnostic and therapeutic potentials

Envenomation by hump-nosed pit viper (Hypnale hypnale, Hh) in Sri Lanka has caused significant morbidity and mortality, attributed to 35% of total venomous snakebites. In Southwestern India (Kerala), H. hypnale was increasingly identified as a dangerous and common source of envenomation, second to the Russell's viper but ahead of the cobra bites. Unfortunately, there is still no specific antivenom to date. This study aims to investigate the immunological properties of the venom and to assess the feasibility of specific Hh antivenom production as well as the development of a diagnostic assay. Hh venom elicited satisfactory titers of anti-Hh IgG in rabbits after 3rd immunization. The anti-Hh IgG, isolated with caprylic acid precipitation method, was effective in neutralizing the venom lethality (potency=48 LD(50) per ml IgG) as well as its procoagulant, hemorrhagic and necrotic effects, indicating the possibility to produce the specific antivenom using the common immunization regime. Cross-reactivity studies using indirect ELISA showed that anti-Hh IgG cross-reacted extensively with several Asiatic crotalid venoms, particularly that of Calloselasma rhodostoma (73.6%), presumably due to the presence of venom antigens common to both snakes. Levels of immunological cross-reactivity were vastly reduced with double-sandwich ELISA. Further work demonstrated that the assay was able to distinguish and quantify venoms of H. hypnale, Daboia russelii and Echis carinatus sinhaleyus (three common local viperid) used to spike human sera at various concentrations. The assay hence may be a useful investigating tool for diagnosing biting species and studying the time course profile of venom concentrations in blood.

Neurological complications of venomous snake bites: a review

Snake bite envenoming is a neglected tropical disease affecting millions of people living in the developing world. According to the offending snake species, the clinical picture may be dominated by swelling and soft tissue necrosis in the bitten limb, or by systemic or neurological manifestations. Serious neurological complications, including stroke and muscle paralysis, are related to the toxic effects of the venom, which contains a complex mixture of toxins affecting the coagulation cascade, the neuromuscular transmission, or both. Metalloproteinases, serine proteases, and C-type lentins (common in viper and colubrid venoms) have anticoagulant or procoagulant activity and may be either agonists or antagonists of platelet aggregation; as a result, ischemic or hemorrhagic strokes may occur. In contrast, the venom of elapids is rich in phospholipase A(2) and three-finger proteins, which are potent neurotoxins affecting the neuromuscular transmission at either presynaptic or post-synaptic levels. Presynaptic-acting neurotoxins (called β-neurotoxins) inhibit the release of acetylcholine, while post-synaptic-acting neurotoxins (called α-neurotoxins) cause a reversible blockage of acetylcholine receptors. Proper management of the envenomed patient, including prompt transport to the hospital, correction of the hemostatic disorder, ventilatory support, and administration of antivenom, significantly reduces the risk of neurological complications which, in turn, reduce the mortality and improve the functional outcome of survivors.

Chronic kidney disease in snake envenomed patients with acute kidney injury in Sri Lanka: a descriptive study

BACKGROUND

Data on the long-term outcomes of acute kidney injury (AKI) in envenomed patients leading to chronic kidney disease (CKD) are scarce. The aim of the study was to investigate this issue and to determine the predictive factors in developing CKD.

METHODS

The records of a series of 54 patients who had AKI following a snakebite during the period 2004-2009 and who had been followed up were reviewed in the nephrology unit, Kandy, Sri Lanka. The primary outcome measure was the failure of renal functions to return to normal within 1 year. The renal histology was studied in seven patients.

RESULTS

The mean age of the group was 50 years (SD 13 years) and 39 (72%) patients were men. The offending snakes were Russell's viper and hump-nosed viper in 15 (28%) and 13 (24%) patients, respectively. At 1 year, 20 patients (37%) had developed CKD (CKD group) and the rest (63%) had recovered (recovered group). The acute stage serum creatinine was high in both groups with no difference (on admission, p=0.134; on discharge, p=0.323), but the CKD group showed significantly high serum creatinine at 2 months after AKI (p=0.004). Mean duration of renal replacement therapy (RRT) of the recovered group and CKD group were 7 (SD 5) and 16 (SD 12) days, respectively (p=0.015). Renal histology of six CKD patients showed predominant glomerular sclerosis and interstitial nephritis.

CONCLUSIONS

CKD is an outcome of severe AKI following snake envenoming probably predicted by the length of RRT.