Anti-inflammatory effects of Neurotoxin-Nna, a peptide separated from the venom of Naja naja atra

Harnessing the Power of Venomous Animal-Derived Toxins against COVID-19

Animal-derived venoms are complex mixtures of toxins triggering important biological effects during envenomings. Although venom-derived toxins are known for their potential of causing harm to victims, toxins can also act as pharmacological agents. During the COVID-19 pandemic, there was observed an increase in in-depth studies on antiviral agents, and since, to date, there has been no completely effective drug against the global disease. This review explores the crosstalk of animal toxins and COVID-19, aiming to map potential therapeutic agents derived from venoms (e.g., bees, snakes, scorpions, etc.) targeting COVID-19.

Biological Effects of Animal Venoms on the Human Immune System

Venoms are products of specialized glands and serve many living organisms to immobilize and kill prey, start digestive processes and act as a defense mechanism. Venoms affect different cells, cellular structures and tissues, such as skin, nervous, hematological, digestive, excretory and immune systems, as well as the heart, among other structures. Components of both the innate and adaptive immune systems can be stimulated or suppressed. Studying the effects on the cells and molecules produced by the immune system has been useful in many biomedical fields. The effects of venoms can be the basis for research and development of therapeutic protocols useful in the modulation of the immunological system, including different autoimmune diseases. This review focuses on the understanding of biological effects of diverse venom on the human immune system and how some of their components can be useful for the study and development of immunomodulatory drugs.

Recent advances on transdermal delivery systems for the treatment of arthritic injuries: From classical treatment to nanomedicines

Arthritic injuries happen frequently during a lifetime due to accidents, sports, aging, diseases, etc. Such injuries can be cartilage/bone injuries, tendon injuries, ligament injuries, inflammation, pain, and/or synovitis. Oral and injective administration of therapeutics are typically used but cause many side effects. Transdermal administration is an alternative route for safe and efficient delivery. Transdermal formulations of non-steroidal anti-inflammatory drugs have been available on market for years and show promising efficacy in pain relieving, inflammation alleviation, infection control, and so on. Innovative transdermal patches, gels/films, and microneedles have also been widely explored as formulations to deliver therapeutics to combat arthritic injuries. However, transdermal formulations that halt disease progression and promote damage repair are translated slowly from lab bench to clinical applications. One major reason is that the skin barrier and synovial capsule barrier limit the efficacy of transdermal delivery. Recently, many nanocarriers, such as nanoparticles, nanolipids, nanoemulsions, nanocrystals, exosomes, etc., have been incorporated into transdermal formulations to advance drug delivery. The combined transdermal formulations show promising safety and efficacy. Therefore, this review will focus on stating the current development of nanomedicine-based transdermal formulations for the treatment of arthritic injuries. The advances, limitations, and future perspectives in this field will also be provided to inspire future studies and accelerate clinical translational studies. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement Biology-Inspired Nanomaterials > Lipid-Based Structures.

Future Directions for the Discovery of Natural Product-Derived Immunomodulating Drugs

Drug discovery from natural sources is going through a renaissance, having spent many decades in the shadow of synthetic molecule drug discovery, despite the fact that natural product-derived compounds occupy a much greater chemical space than those created through synthetic chemistry methods. With this new era comes new possibilities, not least the novel targets that have emerged in recent times and the development of state-of-the-art technologies that can be applied to drug discovery from natural sources. Although progress has been made with some immunomodulating drugs, there remains a pressing need for new agents that can be used to treat the wide variety of conditions that arise from disruption, or over-activation, of the immune system; natural products may therefore be key in filling this gap. Recognising that, at present, there is no authoritative article that details the current state-of-the-art of the immunomodulatory activity of natural products, this in-depth review has arisen from a joint effort between the International Union of Basic and Clinical Pharmacology (IUPHAR) Natural Products and Immunopharmacology, with contributions from a Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation number of world-leading researchers in the field of natural product drug discovery, to provide a "position statement" on what natural products has to offer in the search for new immunomodulatory argents. To this end, we provide a historical look at previous discoveries of naturally occurring immunomodulators, present a picture of the current status of the field and provide insight into the future opportunities and challenges for the discovery of new drugs to treat immune-related diseases.

Analgesic and Anti-Inflammatory Potential of Essential Oil of Eucalyptus camaldulensis Leaf: In Vivo and in Silico Studies

The objective of our present study is to scrutinize the analgesic and anti-inflammatory potentials of essential oil of Eucalyptus camaldulensis leaf using different in vivo assay models at doses of 100, 200, and 400 mg/kg body weight. Twenty chemical compounds, which were isolated from the leaves essential oil of E. camaldulensis, were docked using AutodockVina against cyclooxygenase 2, tumor necrosis factor-α, and interleukin-1β convertase to elucidate the analgesic and anti-inflammatory activity. The essential oil of E. camaldulensis exhibited noteworthy analgesic activities in the writhing test. In the tail immersion and hot-plate test, the essential oil significantly extended the latency period. The number of licks in the formalin-induced paw licking test was markedly reduced following essential oil administration. In addition, E. camaldulensis essential oil revealed notable anti-inflammatory responses in carrageenan-induced paw edema, xylene induced ear edema and cotton pellet induced granuloma methods. Among 20 compounds, 5 ( cis-sabinol, globulol, α-eudesmol, β-eudesmol, and γ-eudesmol) showed better binding for cyclooxygenase-2 while β-eudesmol exhibited higher affinity for TNFα than that of TNF-alpha-IN-1 and standard drug. In the case of interleukin 1β convertase, maximum affinity was shown by α-eudesmol than the synthetic drug belnacasan. Chemical components of the essential oil interacted with diverse amino acid residues which were similar to the natural substrate and standard drugs. In conclusion, E. camaldulensis essential oil can be an effective source of analgesic and anti-inflammatory treatment and additional modification and docking studies will be required to justify the efficiency of globulol, α-eudesmol, β-eudesmol, and γ-eudesmol.

Antiinflammatory peptides: current knowledge and promising prospects

BACKGROUND

Inflammation is part of the regular host reaction to injury or infection caused by toxic factors, pathogens, damaged cells, irritants, and allergens. Antiinflammatory peptides (AIPs) are present in all living organisms, and many peptides from herbal, mammalian, bacterial, and marine origins have been shown to have antimicrobial and/or antiinflammatory properties.

METHODS

In this study, we investigated the effects of antiinflammatory peptides on inflammation, and highlighted the underlying mechanisms responsible for these effects.

RESULTS

In multicellular organisms, including humans, AIPs constitute an essential part of their immune system. In addition, numerous natural and synthetic AIPs are effective immunomodulators and can interfere with signal transduction pathways involved in inflammatory cytokine expression. Among them, some peptides such as antiflammin, N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP), and those derived from velvet antler proteins, bee venom, horse fly salivary gland, and bovine β-casein have received considerable attention over the past few years.

CONCLUSION

This article presents an overview on the major properties and mechanisms of action associated with AIPs as immunomodulatory, chemotactic, antioxidant, and antimicrobial agents. In addition, the results of various studies dealing with effects of AIPs on numerous classical models of inflammation are reviewed and discussed.

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.

Revisiting the Therapeutic Potential of Bothrops jararaca Venom: Screening for Novel Activities Using Connectivity Mapping

Snake venoms are sources of molecules with proven and potential therapeutic applications. However, most activities assayed in venoms (or their components) are of hemorrhagic, hypotensive, edematogenic, neurotoxic or myotoxic natures. Thus, other relevant activities might remain unknown. Using functional genomics coupled to the connectivity map (C-map) approach, we undertook a wide range indirect search for biological activities within the venom of the South American pit viper Bothrops jararaca. For that effect, venom was incubated with human breast adenocarcinoma cell line (MCF7) followed by RNA extraction and gene expression analysis. A list of 90 differentially expressed genes was submitted to biosimilar drug discovery based on pattern recognition. Among the 100 highest-ranked positively correlated drugs, only the antihypertensive, antimicrobial (both antibiotic and antiparasitic), and antitumor classes had been previously reported for B. jararaca venom. The majority of drug classes identified were related to (1) antimicrobial activity; (2) treatment of neuropsychiatric illnesses (Parkinson’s disease, schizophrenia, depression, and epilepsy); (3) treatment of cardiovascular diseases, and (4) anti-inflammatory action. The C-map results also indicated that B. jararaca venom may have components that target G-protein-coupled receptors (muscarinic, serotonergic, histaminergic, dopaminergic, GABA, and adrenergic) and ion channels. Although validation experiments are still necessary, the C-map correlation to drugs with activities previously linked to snake venoms supports the efficacy of this strategy as a broad-spectrum approach for biological activity screening, and rekindles the snake venom-based search for new therapeutic agents.

Cobrotoxin extracted from Naja atra venom relieves arthritis symptoms through anti-inflammation and immunosuppression effects in rat arthritis model

ETHNOPHARMACOLOGICAL RELEVANCE

The Naja atra (Chinese cobra), primarily distributing in the low or medium altitude areas of southern China and Taiwan, was considered as a medicine in traditional Chinese medicine and used to treat pain, inflammation and arthritis.

AIM OF THE STUDY

To study the anti-inflammatory and anti-arthritic activities of cobrotoxin (CTX), an active component of the venom from Naja atra.

MATERIALS AND METHODS

Adjuvant-induced arthritis (AA) rats were used as the animal model of rheumatoid arthritis. The anti-arthritic effects of CTX were evaluated through the arthritis score, paw edema and histopathology changes of joints. The anti-inflammation effects were assayed by the level of IL-6, TNF-α, IL-1β and the number of inflammatory cells in peripheral blood, as well as the proliferation of fibroblast-like synoviocytes (FLS). The immune level was valued by the proliferation of T cells and the level of CD4 and CD8.

RESULTS

CTX alleviated the disease development of AA rats according to the ameliorating arthritis score, paw edema and histopathology character. At the meanwhile, CTX decreased the levels of IL-6, TNF-α, IL-1β and the numbers of inflammatory cells in peripheral blood. CTX also suppressed the abnormal increasing of CD4+ T cells/ CD8+ T cells ratio, and could significantly inhibit T cell proliferation. Consistent with its effects on inhibiting granuloma's formation, CTX inhibited the proliferation of the cultured FLSs. Further studies on inflammatory signaling in FLSs revealed that CTX could inhibit the NF-κB signaling pathway.

CONCLUSIONS

CTX has beneficial effects on rheumatoid arthritis by its immune regulation effects and anti-inflammation effects. The inhibition of NF-κB pathway partly contributes to the anti-inflammatory properties of CTX.

Hydrostatin-TL1, an Anti-Inflammatory Active Peptide from the Venom Gland of Hydrophis cyanocinctus in the South China Sea

Tumor necrosis factor (TNF)-α is a pleiotropic cytokine with intense pro-inflammatory and immunomodulatory properties, and anti-TNF-α biologics are effective therapies for various inflammatory diseases such as inflammatory bowel disease (IBD) and sepsis. Snake venom, as a traditional Chinese medicine, has been used in the treatment of inflammatory diseases in China for centuries. In this research, we constructed a venom gland T7 phage display library of the sea snake Hydrophis cyanocinctus to screen bioactive compounds that antagonize TNF-α and identified a novel nine-amino-acid peptide, termed hydrostatin-TL1 (H-TL1). In enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR) analyses, H-TL1 inhibited the interaction between TNF-α and TNF receptor 1 (TNFR1). Further, H-TL1 attenuated the cytotoxicity of TNF-α in L929 cells as determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. H-TL1 also decreased the mRNA expression of TNF-α/TNFR1 downstream targets and suppressed the phosphorylation of well-characterized proteins of downstream signal transduction pathways in HEK-293 cells. In vivo data demonstrated that H-TL1 protects animals against dextran sodium sulfate (DSS)-induced acute colitis and lipopolysaccharide (LPS)-induced acute shock. Given its significant anti-inflammatory activity in vitro and in vivo, H-TL1 is a potential peptide for the development of new agents to treat TNF-α-associated inflammatory diseases.

Anti-cancer effect of snake venom toxin through down regulation of AP-1 mediated PRDX6 expression

Snake venom toxin (SVT) from Vipera lebetina turanica contains a mixture of different enzymes and proteins. Peroxiredoxin 6 (PRDX6) is known to be a stimulator of lung cancer cell growth. PRDX6 is a member of peroxidases, and has calcium-independent phospholipase A2 (iPLA2) activities. PRDX6 has an AP-1 binding site in its promoter region of the gene. Since AP-1 is implicated in tumor growth and PRDX6 expression, in the present study, we investigated whether SVT inhibits PRDX6, thereby preventing human lung cancer cell growth (A549 and NCI-H460) through inactivation of AP-1. A docking model study and pull down assay showed that SVT completely fits on the basic leucine zipper (bZIP) region of c-Fos of AP-1. SVT (0–10 μg/ml) inhibited lung cancer cell growth in a concentration dependent manner through induction of apoptotic cell death accompanied by induction of cleaved caspase-3, -8, -9, Bax, p21 and p53, but decreased cIAP and Bcl2 expression via inactivation of AP-1. In an xenograft in vivo model, SVT (0.5 mg/kg and 1 mg/kg) also inhibited tumor growth accompanied with the reduction of PRDX6 expression, but increased expression of proapoptotic proteins. These data indicate that SVT inhibits tumor growth via inhibition of PRDX6 activity through interaction with its transcription factor AP-1.

Neurotoxin from Naja naja atra venom inhibits skin allograft rejection in rats

BACKGROUND

Recent studies reported that Naja naja atra venom (NNAV) regulated immune function and had a therapeutic effect on adjunctive arthritis and nephropathy. We hypothesized that NNAV and its active component, neurotoxin (NTX), might inhibit skin allograft rejection.

METHODS

Skin allografts were used to induce immune rejection in rats. In addition, mixed lymphocyte culture (MLC) was used to mimic immune rejection reaction in vitro. Both NNAV and NTX were orally given starting from 5days prior to skin allograft surgery.

RESULTS

The results showed that oral administration of NNAV or NTX prolonged the survival of skin allografts and inhibited inflammatory response. The production of Th1 cytokines (IFN-γ, IL-2) was also suppressed. NTX inhibited T-cell proliferation and CD4(+) T cell division induced by skin allografts. NTX also showed immunosuppressive activity in mixed lymphocyte culture. Atropine alone inhibited Con A-induced proliferation of T cells and potentiated NTX' s inhibitory effects on T cells, while pilocarpine only slightly enhanced Con A-induced T cell proliferation and partially reversed the inhibitory effect of NTX. On the other hand, neither nicotine nor mecamylamine had an influence on NTX's inhibitory effects on Con A-induced T cell proliferation in vitro. NTX inhibited T cell proliferation by arresting the cell cycle at the G0/G1 phase.

CONCLUSIONS

The present study revealed that NNAV and NTX suppressed skin allograft rejection by inhibiting T cell-mediated immune responses. These findings suggest both NNAV and NTX as potential immunosuppressants for preventing the immune response to skin allografts.

Taiwan cobra phospholipase A2 suppresses ERK-mediated ADAM17 maturation, thus reducing secreted TNF-α production in human leukemia U937 cells

The goal of this study was to explore the signaling pathway regulating the processing of proADAM17 into ADAM17 in Taiwan cobra phospholipase A2 (PLA2)-treated human leukemia U937 cells. PLA2 induced reactive oxygen species (ROS)-elicited p38 MAPK activation and ERK inactivation in U937 cells. Catalytically inactive bromophenacylated PLA2 (BPB-PLA2) and PLA2 mutants evoked Ca(2+)-mediated p38 MAPK activation, and the level of phosphorylated ERK remained unchanged. PLA2 treatment reduced mature ADAM17 expression and secreted TNF-α (sTNF-α) production. Co-treatment of SB202190 (p38 MAPK inhibitor) and catalytically inactive PLA2 increased ERK phosphorylation, ADAM17 maturation and sTNF-α production. Nevertheless, mRNA levels of ADAM17 and TNF-α were insignificantly altered after PLA2 and SB202190/BPB-PLA2 treatment. ADAM17 activity assay and knock-down of ADAM17 revealed that ADAM17 was involved in sTNF-α production. Restoration of ERK activation increased the processing of proADAM17 into ADAM17 in PLA2-treated cells, while inactivation of ERK reduced ADAM17 maturation in untreated and SB202190/BPB-PLA2-treated cells. Removal of cell surface heparan sulfate abrogated PLA2 and SB202190/BPB-PLA2 effect on ADAM17 maturation. Taken together, the present data reveal that PLA2 suppresses ERK-mediated ADAM17 maturation, thus reducing sTNF-α production in U937 cells. Moreover, the binding with heparan sulfate is crucial for the PLA2 effect.