Inhibition of snake venom induced sterile inflammation and PLA2 activity by Titanium dioxide Nanoparticles in experimental animals

Antitoxin nanoparticles: design considerations, functional mechanisms, and applications in toxin neutralization

The application of nanotechnology has significantly advanced the development of novel platforms that enhance disease treatment and diagnosis. A key innovation in this field is the creation of antitoxin nanoparticles (ATNs), designed to address toxin exposure. These precision-engineered nanosystems have unique physicochemical properties and selective binding capabilities, allowing them to effectively capture and neutralize toxins from various biological, chemical, and environmental sources. In this review, we thoroughly examine their therapeutic and diagnostic potential for managing toxin-related challenges. We also explore recent advancements and offer critical insights into the design and clinical implementation of ATNs.

Inhibition of the Naja naja venom toxicity by polymeric nanoparticles loaded with Leucas aspera methanolic extract

Background

Snakebite is a neglected tropical disease that affects millions of people worldwide. Developing effective treatments can make a significant contribution to global health efforts and public health initiatives. To reduce mortality due to snakebite, there is an immediate need to explore novel and effective treatment methodologies. In that context, nanoparticle-based drug delivery is gaining a lot of attention. Hydrophilic nanoparticles are suitable for the delivery of therapeutic peptides, proteins, and antigens.

Methods

The present investigation is aimed at evaluating the anti-ophidian potential of the methanolic extract of the ethno-medicinal herb Leucas aspera (Willd.) loaded within chitosan nanoparticles (CNP-LA), against the Indian cobra (Naja naja) venom enzymes. For this purpose, nanoparticles were prepared using the ionic gelation method to enhance the efficacy of the extract. The physicochemical and structural features of nanoparticles were investigated using dynamic light scattering (DLS), Fourier-transform Infrared (FTIR), field emission scanning electron microscopy (FE-SEM), and X-ray diffraction (XRD) techniques.

Results

It was found that CNP-LA has an average size of 260 nm with a polydispersity index of 0.132 (PDI) and zeta potential of 34.7 mV, with an encapsulation efficiency of 92.46%. The in vitro release study was performed at pH 5.0 and 7.4. Furthermore, in vitro studies indicated that CNP-LA inhibited the phospholipase A2, hemolytic, and caseinolytic activities of Naja naja venom with the percentage inhibition of 92.5%, 83.9%, and 94.5%, respectively.

Conclusion

This is the first report on the application of herbal methanolic extract loaded within chitosan nanoparticles for neutralizing snake venom enzymes with increased efficiency.

Phytochemical characterization and phospholipase A2 inhibitory effect of Vitex negundo L. root extracts

ETHNOPHARMACOLOGICAL RELEVANCE

Snake bites are a critical health issue in many parts of the world particularly in Asian countries lacking efficient health facilities in rural areas. Cobra is the most common snake type in Asia and is responsible for a large number of mortalities particularly in rural areas. Plants are usually considered the most effective and easy-to-approach treatment for snake bites in rural areas of various countries. Vitex negundo L. is an important medicinal plant traditionally used to treat snake bite envenomation in many countries of Asia.

AIM OF THE STUDY

From literature survey of plants traditionally used in the treatment of snake bites in Asian countries including India, Pakistan and Sri Lanka, roots of V. negundo were selected for the present study. Anti-snake venom potential of its roots was assessed through various in vitro assays targeting the phospholipase A2 enzyme.

MATERIALS AND METHODS

V. negundo roots were sequentially extracted in different organic solvents to get fractions and in methanol to get total extract. The extracts were evaluated for phospholipase A2 (PLA2) inhibitory potential through inhibition of venom-induced hemolysis, ADP-induced platelet aggregation, PLA2-induced fatty acid hydrolysis and anticoagulant effect of cobra venom. Antioxidant power was determined using DPPH and superoxide radical scavenging assays. GC-MS and HPLC analysis was performed for the total methanol extract.

RESULTS

Strong PLA2 inhibitory effect was observed for all the extracts. The ethyl acetate, acetone and methanol fractions significantly inhibited toxic effects of cobra venom under in vitro conditions. Radical scavenging potential of these fractions was also significantly high as compared to non-polar fractions in both DPPH and superoxide scavenging assays. Phytochemical analysis indicated high phenolic and flavonoid contents in these fractions. GC-MS and HPLC analysis of total methanol extract confirmed the presence of bis(2-ethylhexyl) phthalate, phenol, o-Guaiacol, palmitic acid-methyl ester, methyl stearate, quercetin and kaempferol in the plant.

CONCLUSION

The study concluded that the roots of V. negundo, particularly their polar extracts, have strong PLA2 inhibitory effect against cobra venom confirming their traditional use to manage snake bites. The roots of this plant can be further studied for isolation of plant-based antisera.

Identification of poorly immunodepleted phospholipase A2 (PLA2) proteins of Bungarus fasciatus venom from Assam, India and evaluation of Indian polyvalent antivenom using third-generation antivenomics

Bungarus fasciatus also referred to as the Banded krait is a snake which possesses venom and belongs to the Elapidae family. It is widely distributed across the Indian subcontinent and South East Asian countries and is responsible for numerous snakebites in the population. B. fasciatus possesses a neurotoxic venom and envenomation by the snake results in significant morbidity and occasional morbidity in the victim if not treated appropriately. In this study, the efficacy of Indian polyvalent antivenom (Premium Serums polyvalent antivenom) was evaluated against the venom of B. fasciatus from Guwahati, Assam (India) employing the Third-generation antivenomics technique followed by identification of venom proteins from three poorly immunodepleted peaks (P5, P6 and P7) using LC-MS/MS analysis. Seven proteins were identified from the three peaks and all these venom proteins belonged to the phospholipase A2 (PLA2) superfamily. The identified PLA2 proteins were corroborated by the in vitro enzymatic activities (PLA2 and Anticoagulant activity) exhibited by the three peaks and previous reports of pathological manifestation in the envenomated victims. Neutralization of enzymatic activities by Premium Serums polyvalent antivenom was also assessed in vitro for crude venom, P5, P6 and P7 which revealed moderate to poor inhibition. Inclusion of venom proteins/peptides, which are non-immunodepleted or poorly immunodepleted, into the immunization mixture of venom used for antivenom production may help in enhancing the efficacy of the polyvalent antivenom.

The role of quercetin in the formation of titanium dioxide nanoparticles for nanomedical applications

The current work aimed to synthesize and characterize titanium dioxide nanoparticles (TiO₂NPs) using quercetin (QE) and evaluate their biological activities, i.e., anti-hemolytic, anti-inflammatory, and cytotoxicity effects. The crystallographic phase and morphology of biosynthesized QE-TiO₂NPs were characterized by XRD (X-Ray Diffraction) and TEM/FE-SEM (Transmission/Field-Emission Scanning Electron Microscopy) micrographs. Functional groups involved in the synthesis process were determined by FTIR spectroscopy (Fourier Transform-Infrared Spectroscopy). Based on the characterization results, selected QE-TiO₂NPs showed a rutile phase, spherical shape, and a size range of 7.3-39 nm. The QE-TiO₂NPs did not show a hemolytic effect. They indicated 95.3% red blood cells (RBCs) membrane stabilization activity and 82.6% inhibition of bovine serum albumin (BSA) denaturation, similar to a standard drug, which proved their anti-inflammatory effects. The attained results from cytotoxicity studies revealed the toxic effects of QE-TiO₂NPs with IC50 values below 100 and 50 μg/mL for human breast cancer cells of MCF-7 and melanoma cancer cells of A375, respectively. These NPs did not significantly affect normal skin fibroblast cells up to 50 μg/mL and only showed a 16% inhibition rate on the cell viability at 100 μg/mL. These NPs also induced excessive ROS generation. This work established the blood/biocompatibility and excellent nanomedical applications of biosynthesized QE-TiO₂NPs.

Inflammation and Oxidative Stress in Snakebite Envenomation: A Brief Descriptive Review and Clinical Implications

Snakebite envenoming is a pathological condition which may occur in response to the injection of venom. Snake venoms contain a complex mixture of biologically active molecules which are responsible for a broad spectrum of clinical manifestations, ranging from local tissue injuries to fatal complications. Snake venom administration commonly provokes local tissue injury often associated with systemic effects, including neurotoxic and cardiotoxic manifestations, bleeding, acute kidney injury, and rhabdomyolysis. An important spectrum of pathogenesis of snake envenomation is the generation of reactive oxygen species (ROS), which can directly provoke tissue damage and also potentiate the deleterious consequences of inflammation at the bite site. Snake venom components known to induce oxidative stress include phospholipases A₂, metalloproteinases, three-finger toxins, and L-amino acid oxidase. Clear evidence is mounting suggesting that inflammation and oxidative stress participate in the destructive effects of envenoming, including acute renal failure, tissue necrosis, and unusual susceptibility to bleed (hemorrhage), mostly due to hypocoagulability, neuro/cardio toxicity, and myonecrosis. Impaired regulation of oxidative stress may also set the stage for secondary/long-term complications of snakebite envenomation such as musculoskeletal disabilities. Some aspects of natural antioxidant therapeutic options are discussed in this review.

Development of a Monoclonal scFv against Cytotoxin to Neutralize Cytolytic Activity Induced by Naja atra Venom on Myoblast C2C12 Cells

The Taiwanese cobra, Naja atra, is a clinically significant species of snake observed in the wild in Taiwan. Victims bitten by N. atra usually experience severe pain and local tissue necrosis. Although antivenom is available for treatment of cobra envenomation, its neutralization potency against cobra-induced necrosis is weak, with more than 60% of cobra envenoming patients developing tissue necrosis after antivenom administration. The present study found that cytotoxin (CTX) is a key component of N. atra venom responsible for cytotoxicity against myoblast cells. Anti-CTX IgY was generated in hens, and the spleens of these hens were used to construct libraries for the development of single chain variable fragments (scFv). Two anti-CTX scFv, S1 and 2S7, were selected using phage display technology and biopanning. Both polyclonal IgY and monoclonal scFv S1 reacted specifically with CTX in cobra venom. In a cell model assay, the CTX-induced cytolytic effect was inhibited only by monoclonal scFv S1, not by polyclonal IgY. Moreover, the neutralization potency of scFv S1 was about 3.8 mg/mg, approximately three times higher than that of conventional freeze-dried neurotoxic antivenom (FNAV). Collectively, these results suggest that scFv S1 can effectively neutralize CTX-induced cytotoxicity and, when combined with currently available antivenom, can improve the potency of the latter, thereby preventing tissue damage induced by cobra envenoming.

Engineered titania nanomaterials in advanced clinical applications

Significant advancement in the field of nanotechnology has raised the possibility of applying potent engineered biocompatible nanomaterials within biological systems for theranostic purposes. Titanium dioxide (titanium(IV) oxide/titania/TiO₂) has garnered considerable attention as one of the most extensively studied metal oxides in clinical applications. Owing to the unique properties of titania, such as photocatalytic activity, excellent biocompatibility, corrosion resistance, and low toxicity, titania nanomaterials have revolutionized therapeutic approaches. Additionally, titania provides an exceptional choice for developing innovative medical devices and the integration of functional moieties that can modulate the biological responses. Thus, the current review aims to present a comprehensive and up-to-date overview of TiO₂-based nanotherapeutics and the corresponding future challenges.

Neutralization of Daboxin P activities by rationally designed aptamers

Inefficacy and associated risks of current antivenom has raised the need for alternative approaches of snakebite management. Aptamers are one such alternative which is being pursued for therapeutic interventions as well as for design of diagnostic kits due to its high specificity. Present study focussed on designing and validating nucleic acid aptamers against snake venom PLA_2, a hydrolytic enzyme present in all venomous snakes. The aptamers were designed by adding nucleic acid chain on the surface of Daboxin P, a major PLA₂ enzyme of Daboia russelii venom. Binding characteristics of the aptamers were confirmed by docking to Daboxin P as well as acidic and basic PLA₂s from different snake species using in silico docking. The aptamers folded into different tertiary structures and bound to the active and Ca²⁺ binding site of PLA₂ enzymes. Molecular dynamics simulation analysis of Daboxin P-aptamer complexes showed that the complexes were stable in an aqueous environment. The electrophoretic mobility shift assay further confirmed the binding of the synthetic aptamers to Daboxin P and other snake venom PLA₂ enzymes. The aptamers inhibited the sPLA₂ activity with an IC₅₀ value ranging between 0.52 μM and 0.77 μM as well as the anticoagulant activity of Daboxin P. The aptamers could also inhibit the PLA₂ activity of Echis carinatus crude venom and anti-coagulant activity of Bungarus caeruleus crude venom, members of big four snakes. However, the aptamers didn't inhibit fibrinogenolytic or proteolytic activity of big four venom as well as the coagulation and hemolytic activities. Thus, aptamers can be rationally designed to inhibit the biochemical and biological activities of snake venom proteins.

The Influence of Silver Nanoparticles Against Toxic Effects of Philodryas olfersii Venom

Purpose

A silver nanoparticle obtained by reducing salts with solid dispersion of curcumin (130 nm, 0.081 mg mL⁻¹) was used to counteract against the toxic – edematogenic, myotoxic, and neurotoxic – effects of Philodryas olfersii venom.

Methods

The edematogenic effect was evaluated by plasma extravasation in rat dorsal skin after injection of 50 µg per site of venom alone or preincubated with 1, 10, and 100 µL of AgNPs; the myotoxicity was evaluated by measuring the creatine kinase released into the organ-bath before the treatment and at the end of each experiment; and neurotoxicity was evaluated in chick biventer cervicis using the conventional myographic technique, face to the exogenous acetylcholine (ACh) and potassium chloride (KCl) added into the bath before the treatment and after each experiment. Preliminarily, a concentration-response curve of AgNPs was carried out to select the concentration to be used for neutralizing assays, which consists of neutralizing the venom-induced neuromuscular paralysis and edema by preincubating AgNPs with venom for 30 min.

Results

The P. olfersii venom-induced edema (n=6) and a complete neuromuscular blockade (n=4) that includes the total and unrecovered block of ACh and KCl contractures. AgNPs produced a concentration-dependent decrease the venom-induced edema (n=6) from 223.3% to 134.4% and to 100.5% after 10 and 100 µL AgNPs-preincubation, respectively. The preincubation of venom with AgNPs (1 µL; n=6) was able to maintain 46.5 ± 10.9% of neuromuscular response under indirect stimuli, 39.2 ± 9.7% of extrinsic nicotinic receptors functioning in absence of electrical stimulus and 28.3 ± 8.1% of responsiveness to potassium on the sarcolemmal membrane. The CK release was not affected by any experimental protocol which was like control.

Conclusion

AgNPs interact with constituents of P. olfersii venom responsible for the edema-forming activity and neuromuscular blockade, but not on the sarcolemma membrane-acting constituents. The protective effect of the studied AgNPs on avian preparation points out to molecular targets as intrinsic and extrinsic nicotinic receptors.