Effects of vipoxin and its components on HepG2 cells

Therapeutic applications of snake venoms: An invaluable potential of new drug candidates

Animal venoms and their chemical compounds have aroused both empirical and scientific attention for ages. However, there has been a significant increase in scientific investigations in recent decades, allowing the production of various formulations that are helping in the development of many important tools for biotechnological, diagnostic, or therapeutic use, both in human and animal health, as well as in plants. Venoms are composed of biomolecules and inorganic compounds that may have physiological and pharmacological activities that are not related to their principal actions (prey immobilization, digestion, and defense). Snake venom toxins, mainly enzymatic and non-enzymatic proteins, and peptides have been identified as potential prototypes for new drugs and/or models for the development of pharmacologically active structural domains for the treatment of cancer, cardiovascular diseases, neurodegenerative and autoimmune diseases, pain, and infectious-parasitic diseases. This minireview aims to provide an overview of the biotechnological potential of animal venoms, with a focus on snakes, and to introduce the reader to the fascinating world of Applied Toxinology, where animal biodiversity can be used to develop therapeutic and diagnostic applications for humans.

A Review on Genotoxic and Genoprotective Effects of Biologically Active Compounds of Animal Origin

Envenomation by animal venoms remains a serious medical and social problem, especially in tropical countries. On the other hand, animal venoms are widely used as a source of biologically active compounds for the development of novel drugs. Numerous derivatives of animal venoms are already used in clinical practice. When analysing the mechanisms of action of animal venoms, attention is usually focused on the main target of the venom's enzymes and peptides such as neurotoxic, cytotoxic or haemorrhagic effects. In the present review, we would like to draw attention to the "hidden" effects of animal venoms and their derivatives in regard to DNA damage and/or protection against DNA damage. Alkaloids and terpenoids isolated from sponges such as avarol, ingenamine G or variolin B manifest the capability to bind DNA in vitro and produce DNA breaks. Trabectidin, isolated from a sea squirt, also binds and damages DNA. A similar action is possible for peptides isolated from bee and wasp venoms such as mastoparan, melectin and melittin. However, DNA lesions produced by the crude venoms of jellyfish, scorpions, spiders and snakes arise as a consequence of cell membrane damage and the subsequent oxidative stress, whereas certain animal venoms or their components produce a genoprotective effect. Current research data point to the possibility of using animal venoms and their components in the development of various potential therapeutic agents; however, before their possible clinical use the route of injection, molecular target, mechanism of action, exact dosage, possible side effects and other fundamental parameters should be further investigated.

Anti-Cancer Effect of Moroccan Cobra Naja haje Venom and Its Fractions against Hepatocellular Carcinoma in 3D Cell Culture

Hepatocellular carcinoma (HCC) is the most common primary liver cancer in adults, the fifth most common malignancy worldwide and the third leading cause of cancer related death. An alternative to the surgical treatments and drugs, such as sorafenib, commonly used in medicine is necessary to overcome this public health problem. In this study, we determine the anticancer effect on HCC of Moroccan cobra Naja haje venom and its fraction obtained by gel filtration chromatography against Huh7.5 cancer cell line. Cells were grown together with WI38 human fibroblast cells, LX2 human hepatic stellate cell line, and human endothelial cells (HUVEC) in MCTS (multi-cellular tumor spheroids) models. The hepatotoxicity of venom and its fractions were also evaluated using the normal hepatocytes cell line (Fa2N-4 cells). Our results showed that an anti HCC activity of Moroccan cobra Naja haje venom and, more specifically, the F7 fraction of gel filtration chromatography exhibited the greatest anti-hepatocellular carcinoma effect by decreasing the size of MCTS. This effect is associated with a low toxicity against normal hepatocytes. These results strongly suggest that the F7 fraction of Moroccan cobra Naja haje venom obtained by gel filtration chromatography possesses the ability to inhibit cancer cells proliferation. More research is needed to identify the specific molecule(s) responsible for the anticancer effect and investigate their mechanism of action.

Viper toxins affect membrane characteristics of human erythrocytes

Elucidating electrokinetic stability by which surface charges regulate toxins interaction with erythrocytes is crucial for understanding the cell functionality. Electrokinetic properties of human erythrocytes upon treatment of Vipoxin, phospholipase A₂ (PLA₂) and Vipoxin acidic component (VAC), isolated from Vipera ammodytes meridionalis venom were studied using particle microelectrophoresis. PLA₂ and Vipoxin treatments alter the osmotic fragility of erythrocyte membranes. The increased stability of cells upon viper toxins is presented by the increased zeta potential of erythrocytes before sedimentation of cells during electric field applied preventing the aggregation of cells. Lipid peroxidation of low dose toxin-treated erythrocytes shows reduced LP products compared to untreated cells. The apparent proton efflux and conductivity assays are performed and the effectiveness PLA₂ > Vipoxin>VAC is discussed. The reported results open perspectives to a further investigation of the electrokinetic properties of the membrane after viper toxins treatment to shed light on the molecular mechanisms driving the mechanisms of inflammation and neurodegenerative diseases.

Miscibility of hBest1 and sphingomyelin in surface films - A prerequisite for interaction with membrane domains

Human bestrophin-1 (hBest1) is a transmembrane Ca²⁺- dependent anion channel, associated with the transport of Cl^-, HCO^3- ions, γ-aminobutiric acid (GABA), glutamate (Glu), and regulation of retinal homeostasis. Its mutant forms cause retinal degenerative diseases, defined as Bestrophinopathies. Using both physicochemical - surface pressure/mean molecular area (π/A) isotherms, hysteresis, compressibility moduli of hBest1/sphingomyelin (SM) monolayers, Brewster angle microscopy (BAM) studies, and biological approaches - detergent membrane fractionation, Laurdan (6-dodecanoyl-N,N-dimethyl-2-naphthylamine) and immunofluorescence staining of stably transfected MDCK-hBest1 and MDCK II cells, we report: 1) Ca²⁺, Glu and GABA interact with binary hBest1/SM monolayers at 35 °C, resulting in changes in hBest1 surface conformation, structure, self-organization and surface dynamics. The process of mixing in hBest1/SM monolayers is spontaneous and the effect of protein on binary films was defined as "fluidizing", hindering the phase-transition of monolayer from liquid-expanded to intermediate (LE-M) state; 2) in stably transfected MDCK-hBest1 cells, bestrophin-1 was distributed between detergent resistant (DRM) and detergent-soluble membranes (DSM) - up to 30 % and 70 %, respectively; in alive cells, hBest1 was visualized in both liquid-ordered (L_o) and liquid-disordered (L_d) fractions, quantifying protein association up to 35 % and 65 % with L_o and L_d. Our results indicate that the spontaneous miscibility of hBest1 and SM is a prerequisite to diverse protein interactions with membrane domains, different structural conformations and biological functions.

Antitumor potential of the myotoxin BthTX-I from Bothrops jararacussu snake venom: evaluation of cell cycle alterations and death mechanisms induced in tumor cell lines

Background

Phospholipases A₂ (PLA₂s) are abundant components of snake venoms that have been extensively studied due to their pharmacological and pathophysiological effects on living organisms. This study aimed to assess the antitumor potential of BthTX-I, a basic myotoxic PLA₂ isolated from Bothrops jararacussu venom, by evaluating in vitro processes of cytotoxicity, modulation of the cell cycle and induction of apoptosis in human (HL-60 and HepG2) and murine (PC-12 and B16F10) tumor cell lines.

Methods

The cytotoxic effects of BthTX-I were evaluated on the tumor cell lines HL-60 (promyelocytic leukemia), HepG2 (human hepatocellular carcinoma), PC-12 (murine pheochromocytoma) and B16F10 (murine melanoma) using the MTT method. Flow cytometry technique was used for the analysis of cell cycle alterations and death mechanisms (apoptosis and/or necrosis) induced in tumor cells after treatment with BthTX-I.

Results

It was observed that BthTX-I was cytotoxic to all evaluated tumor cell lines, reducing their viability in 40 to 50 %. The myotoxin showed modulating effects on the cell cycle of PC-12 and B16F10 cells, promoting delay in the G0/G1 phase. Additionally, flow cytometry analysis indicated cell death mainly by apoptosis. B16F10 was more susceptible to the effects of BthTX-I, with ~40 % of the cells analyzed in apoptosis, followed by HepG2 (~35 %), PC-12 (~25 %) and HL-60 (~4 %).

Conclusions

These results suggest that BthTX-I presents antitumor properties that may be useful for developing new therapeutic strategies against cancer.