The Protective Effects of Cobra Venom from Naja naja atra on Acute and Chronic Nephropathy

The effect of Iranian snake, Naja naja oxiana venom on the blood glucose concentration and some biochemical parameters of experimental diabetic rats

Diabetes is a chronic disease resulting from impaired insulin production and function; leading to hyperglycaemia and long-term complications. The treatment for Type I diabetes treatment involves insulin injections while Type II diabetes treatments include drugs such as metformin and sulfonylureas, along with lifestyle changes. These medicines can be expensive and may have adverse effects. Therefore, the search for new therapeutic agents continues. Venoms from various animals yield numerous pharmacologically active compounds. In this study, we investigated the effects of the venom from an Iranian snake, Naja naja oxiana, on blood glucose concentration and certain serum biochemical parameters in male rats with induced diabetes. Diabetes was induced in male rats using either a single injection of streptozotocin (STZ) alone (55 mg/kg i. p.) or STZ (65 mg/kg i. p.) preceded by nicotinamide (230/kg i. p.) administered 15 min earlier. The diabetic rats produced by either method received a single injection of either vehicle or venom (0.2 or 0.4 mg/kg i. p.). In the STZ rats, this was done 13 days after diabetes induction, while in the STZ-nicotinamide rats, venom was injected 3 days after diabetes induction. The venom from Naja naja oxiana significantly reduced blood glucose levels in male rats with diabetes induced by either method. Additionally, the venom decreased serum cholesterol and triglycerides concentrations. However, the venom had no effect on the blood glucose levels of healthy male rats. Pretreatment with the venom did not prevent the induction of diabetes by STZ. These findings suggest that Naja naja oxiana venom exhibits an anti-diabetic effect and could be a potential candidate for effectively controlling diabetes.

Anti-Inflammatory and Immune Regulatory Actions of Naja naja atra Venom

Naja naja atra venom (NNAV) is composed of various proteins, peptides, and enzymes with different biological and pharmacological functions. A number of previous studies have reported that NNAV exerts potent analgesic effects on various animal models of pain. The clinical studies using whole venom or active components have confirmed that NNAV is an effective and safe medicine for treatment of chronic pain. Furthermore, recent studies have demonstrated that NNAV has anti-inflammatory and immune regulatory actions in vitro and in vivo. In this review article, we summarize recent studies of NNAV and its components on inflammation and immunity. The main new findings in NNAV research show that it may enhance innate and humoral immune responses while suppressing T lymphocytes-mediated cellular immunity, thus suggesting that NNAV and its active components may have therapeutic values in the treatment of inflammatory and autoimmune diseases.

Cobrotoxin from Naja naja atra Venom Ameliorates Adriamycin Nephropathy in Rats

Chronic kidney disease (CKD) becomes a global health problem with high morbidity and mortality. Adriamycin- (ADR-) induced rodent chronic nephropathy is a classic experimental model of human minimal lesion nephrotic syndrome. The present study investigated the effect of cobrotoxin (CTX) on ADR-induced nephropathy. Rats were given 6 mg/kg ADR once through the tail vein to replicate ADR nephropathy model. CTX was administered to rats daily by placing a fast dissolving CTX membrane strip under the tongue starting from 5 days prior to ADR administration until the end of experiment. The results showed that CTX ameliorated the symptoms of ADR nephropathy syndrome with reduced body weight loss, proteinuria, hypoalbuminemia, dyslipidemia, serum electrolyte imbalance, oxidative stress, renal function abnormities, and kidney pathological lesions. Anti-inflammatory cytokine IL-10 expression was elevated after CTX administration in ADR nephropathy model. CTX inhibited the phosphorylation of IκB-α and NF-κB p65 nuclear translocation. Meanwhile, CTX upregulated the protein level of podocyte-specific nephrin and downregulated the level of fibrosis-related TGF-β. These findings suggest that CTX may be a potential drug for chronic kidney diseases.

Naja naja atra venom ameliorates pulmonary fibrosis by inhibiting inflammatory response and oxidative stress

BACKGROUND

Naja naja atra venom (NNAV) displays diverse pharmacological actions including analgesia, anti-inflammation and immune regulation.In this study, we investigated the effects of NNAV on pulmonary fibrosis and its mechanisms of action.

METHODS

To determine if Naja naja atra venom (NNAV) can produce beneficial effects on pulmonary fibrosis, two marine models of pulmonary fibrosis were produced with bleomycin (BLM) and lipopolysaccharide (LPS). NNAV (30, 90, 270 μg/kg) was orally administered once a day started five days before BLM and LPS until to the end of experiment. The effects of NNAV treatment on pulmonary injury were evaluated with arterial blood gas analysis, hydroxyproline (HYP) content assessment and HE/Masson staining. The effects of NNAV treatment on inflammatory related cytokines, fibrosis related TGF-β/Smad signaling pathway and oxidative stress were examined.

RESULTS

The results showed that NNAV improved the lung gas-exchange function and attenuated the fibrotic lesions in lung. NNAV decreased IL-1β and TNF-α levels in serum in both pulmonary fibrosis models. NNAV inhibited the activation of NF-κB in LPS-induced and TGF-β/Smad pathway in BLM-induced pulmonary fibrosis. Additionally, NNAV also increased the levels of SOD and GSH and reduced the levels of MDA in BLM-induced pulmonary fibrosis model.

CONCLUSIONS

The present study indicates that NNAV attenuates LPS- and BLM-induced lung fibrosis. Its mechanisms of action are associated with inhibiting inflammatory response and oxidative stress. The study suggests that NNAV might be a potential therapeutic drug for treatment of pulmonary fibrosis.

Naja naja atra Venom Protects against Manifestations of Systemic Lupus Erythematosus in MRL/lpr Mice

Systemic lupus erythematosus (SLE) is an autoimmune disease and effective therapy for this pathology is currently unavailable. We previously reported that oral administration of Naja naja atra venom (NNAV) had anti-inflammatory and immune regulatory actions. We speculated that NNAV may have therapeutic effects in MRL/lpr SLE mice. Twelve-week-old MRL/lpr mice received oral administration of NNAV (20, 40, and 80 μg/kg) or Tripterygium wilfordii polyglycosidium (10 mg/kg) daily for 16 weeks. The effects of NNAV on SLE manifestations, including skin erythema, proteinuria, and anxiety-like behaviors, were assessed with visual inspection and Multistix 8 SG strips and open field test, respectively. The pathology of spleen and kidney was examined with H&E staining. The changes in autoimmune antibodies and cytokines were determined with ELISA kits. The results showed that NNAV protected against the manifestation of SLE, including skin erythema and proteinuria. In addition, although no apparent histological change was found in liver and heart in MRL/lpr SLE mice, NNAV reduced the levels of glutamate pyruvate transaminase and creatine kinase. Furthermore, NNAV increased serum C3 and reduced concentrations of circulating globulin, anti-dsDNA antibody, and inflammatory cytokines IL-6 and TNF-α. NNAV also reduced lymphadenopathy and renal injury. These results suggest that NNAV may have therapeutic values in the treatment of SLE by inhibiting autoimmune responses.

Differential Effects of Naja naja atra Venom on Immune Activity

Previous studies reported that Naja naja atra venom (NNAV) inhibited inflammation and adjuvant arthritis. Here we investigated the role of NNAV in regulation of immune responses in mice. Oral administration of NNAV to normal mice showed significant increase in natural killer cell activity, B lymphocyte proliferation stimulated by lipopolysaccharides, and antibody production in response to sheep red blood cells. Meanwhile, NNAV markedly decreased T lymphocyte proliferation stimulated by concanavalin A, arrested the cell cycle at G₀/G₁ phase, and suppressed CD4 and CD8 T cell divisions. Furthermore, NNAV inhibited the dinitrofluorobenzene-induced delayed-type hypersensitivity reaction. This modulation of immune responses may be partly attributed to the selective increase in Th1 and Th2 cytokines (IFN-γ, IL-4) secretion and inhibition of Th17 cytokine (IL-17) production. In dexamethasone-induced immunosuppressed mice, NNAV restored the concentration of serum IgG and IgM, while decreasing the percentage of CD4 and CD8 T-cell subsets. These results indicate that NNAV enhances the innate and humoral immune responses while inhibiting CD4 Th17 and CD8 T cell actions, suggesting that NNAV could be a potential therapeutic agent for autoimmune diseases.

Ameliorating Adriamycin-Induced Chronic Kidney Disease in Rats by Orally Administrated Cardiotoxin from Naja naja atra Venom

Previous studies reported the oral administration of Naja naja atra venom (NNAV) reduced adriamycin-induced chronic kidney damage. This study investigated the effects of intragastric administrated cardiotoxin from Naja naja atra venom on chronic kidney disease in rats. Wistar rats were injected with adriamycin (ADR; 6 mg/kg body weight) via the tail vein to induce chronic kidney disease. The cardiotoxin was administrated daily by intragastric injection at doses of 45, 90, and 180  μ g/kg body weight until the end of the protocol. The rats were placed in metabolic cages for 24 hours to collect urine, for determination of proteinuria, once a week. After 6 weeks, the rats were sacrificed to determine serum profiles relevant to chronic kidney disease, including albumin, total cholesterol, phosphorus, blood urea nitrogen, and serum creatinine. Kidney histology was examined with hematoxylin and eosin, periodic acid-Schiff, and Masson's trichrome staining. The levels of kidney podocin were analyzed by Western blot analysis and immunofluorescence. We found that cardiotoxin reduced proteinuria and can improve biological parameters in the adriamycin-induced kidney disease model. Cardiotoxin also reduced adriamycin-induced kidney pathology, suggesting that cardiotoxin is an active component of NNAV for ameliorating adriamycin-induced kidney damage and may have a potential therapeutic value on chronic kidney disease.