The first report on coagulation and phospholipase A2 activities of Persian Gulf lionfish, Pterois russelli, an Iranian venomous fish

Antimalarial Effects of Nano Chloroquine Loaded Curcumin In vivo

BACKGROUND

Malaria is still the deadliest parasitic disease caused by Plasmodium spp. Due to drug resistance and their unpleasant side effects, of conventional researchers are enormously seeking to achieve antimalarial drugs with more curative effective, less toxic and cost-affordable drugs using more advanced technology such as nanodrugs.

PURPOSE

The present study aimed to examine the antimalarial effects of a novel synthesized nonochloroquine-loaded curcumin relying on dendrimer G2 in susceptible mice.

METHODS

Antimalarial activity and toxicity of the nanocomposite were examined on BALB/C mice with microscopy, checking RBCs morphology and related enzymatic activity rate.

RESULTS

The maximum inhibitory effect of the nanocomposite was seen at 10 mg/kg, killing 98% of P. berghei compared to sole chloroquine, whereas ED50 was reported at 5.5 mg/kg. The safety of the synthesized nanocomposite was confirmed with biochemical tests with no detrimental effects on mice. The sustainability and longevity of the nanodrug increased significantly with the NDC-CQ assay compared to the control groups.

CONCLUSION

The study showed that nonochloroquine-loaded curcumin had a promising inhibitory effect on P. berghei growth in infected mice compared to standard drugs. However, further studies and clinical trials with large samples are recommended to study different aspects of using nanodrug.

Unveiling the Venom Composition of the Colombian Coral Snakes Micrurus helleri, M. medemi, and M. sangilensis

Little is known of the biochemical composition and functional features of the venoms of poorly known Colombian coral snakes. Here, we provide a preliminary characterization of the venom of two Colombian endemic coral snake species, Micrurus medemi and M. sangilensis, as well as Colombian populations of M. helleri. Electrophoresis and RP-HPLC techniques were used to identify venom components, and assays were conducted to detect enzyme activities, including phospholipase A2, hyaluronidase, and protease activities. The median lethal dose was determined using murine models. Cytotoxic activities in primary cultures from hippocampal neurons and cancer cell lines were evaluated. The venom profiles revealed similarities in electrophoretic separation among proteins under 20 kDa. The differences in chromatographic profiles were significant, mainly between the fractions containing medium-/large-sized and hydrophobic proteins; this was corroborated by a proteomic analysis which showed the expected composition of neurotoxins from the PLA2 (~38%) and 3FTx (~17%) families; however, a considerable quantity of metalloproteinases (~12%) was detected. PLA2 activity and protease activity were higher in M. helleri venom according to qualitative and quantitative assays. M. medemi venom had the highest lethality. All venoms decreased cell viability when tested on tumoral cell cultures, and M. helleri venom had the highest activity in neuronal primary culture. These preliminary studies shed light on the venoms of understudied coral snakes and broaden the range of sources that could be used for subsequent investigations of components with applications to specific diseases. Our findings also have implications for the clinical manifestations of snake envenoming and improvements in its medical management.

Polypharmacological Cell-Penetrating Peptides from Venomous Marine Animals Based on Immunomodulating, Antimicrobial, and Anticancer Properties

Complex pathological diseases, such as cancer, infection, and Alzheimer's, need to be targeted by multipronged curative. Various omics technologies, with a high rate of data generation, demand artificial intelligence to translate these data into druggable targets. In this study, 82 marine venomous animal species were retrieved, and 3505 cryptic cell-penetrating peptides (CPPs) were identified in their toxins. A total of 279 safe peptides were further analyzed for antimicrobial, anticancer, and immunomodulatory characteristics. Protease-resistant CPPs with endosomal-escape ability in Hydrophis hardwickii, nuclear-localizing peptides in Scorpaena plumieri, and mitochondrial-targeting peptides from Synanceia horrida were suitable for compartmental drug delivery. A broad-spectrum S. horrida-derived antimicrobial peptide with a high binding-affinity to bacterial membranes was an antigen-presenting cell (APC) stimulator that primes cytokine release and naïve T-cell maturation simultaneously. While antibiofilm and wound-healing peptides were detected in Synanceia verrucosa, APC epitopes as universal adjuvants for antiviral vaccination were in Pterois volitans and Conus monile. Conus pennaceus-derived anticancer peptides showed antiangiogenic and IL-2-inducing properties with moderate BBB-permeation and were defined to be a tumor-homing peptide (THP) with the ability to inhibit programmed death ligand-1 (PDL-1). Isoforms of RGD-containing peptides with innate antiangiogenic characteristics were in Conus tessulatus for tumor targeting. Inhibitors of neuropilin-1 in C. pennaceus are proposed for imaging probes or therapeutic delivery. A Conus betulinus cryptic peptide, with BBB-permeation, mitochondrial-targeting, and antioxidant capacity, was a stimulator of anti-inflammatory cytokines and non-inducer of proinflammation proposed for Alzheimer's. Conclusively, we have considered the dynamic interaction of cells, their microenvironment, and proportional-orchestrating-host- immune pathways by multi-target-directed CPPs resembling single-molecule polypharmacology. This strategy might fill the therapeutic gap in complex resistant disorders and increase the candidates' clinical-translation chance.

Oxilipin, a New Anti-cancer Phospholipase A2-like Protein from Iranian Caspian Cobra, Naja Naja Oxiana

The discovery of novel anti-cancer agents from natural resources is highly necessary. Concerning the above problem, the purpose of this study was to discover an anti-cancer compound from Caspian cobra venom. Fractionation of Caspian cobra venom was performed by gel filtration and IEX chromatography. The results showed an anti-cancer protein nominated as Oxilipin. Activity and toxicity of Oxilipin were studied on the colon SW480 cancer cell line using MTT, LDH release, PI staining, morphological cell analysis, hemolysis, and anti-proliferation assays. Oxilipin, an 11kDa protein purified from the venom of the Caspian cobra. LC/MS/MS analysis of obtained protein showed homology with Phospholipase A2 from ‎Naja naja oxiana. 40 µg/ml of Oxilipin can induce an apoptotic effect in SW480 cell line up to 90%; meanwhile, this amount can induce only one-third of cytotoxicity on a normal cell. In this study, Iranian cobra venom was found to have cytotoxic effects on SW480 colon cancer tumor cells, with the least cytotoxicity on normal cells on HEK-293. Given that Oxilipin has slight toxicity on normal cells, it can be hypothesized that the obtained peptide can be considered as a drug lead in an animal model study of colon cancer.

Intraspecific Differences in the Venom of Crotalus durissus cumanensis from Colombia

Biochemical and biological differences in the venom of Crotalus durissus cumanensis from three ecoregions of Colombia were evaluated. Rattlesnakes were collected from the geographic areas of Magdalena Medio (MM), Caribe (CA) and Orinoquía (OR). All three regionally distributed venoms contain proteases, PLA₂s and the basic subunit of crotoxin. However, only crotamine was detected in the CA venom. The highest lethality, coagulant, phospholipase A₂ and hyaluronidase activities were found in the MM venom. Also, some differences, observed by western blot and immunoaffinity, were found in all three venoms when using commercial antivenoms. Furthermore, all three eco-regional venoms showed intraspecific variability, considering the differences in the abundance and intensity of their components, in addition to the activity and response to commercial antivenoms.

Fast killing kinetics, significant therapeutic index, and high stability of melittin-derived antimicrobial peptide

The emergence of multidrug-resistant (MDR) bacteria is a major challenge for antimicrobial chemotherapy. Concerning this issue, antimicrobial peptides (AMPs) have been presented as novel promising antibiotics. Our previous de novo designed melittin-derived peptides (MDP1 and MDP2) indicated their potential as peptide drug leads. Accordingly, this study was aimed to evaluate the kinetics of activity, toxicity, and stability of MDP1 and MDP2 as well as determination of their structures. The killing kinetics of MDP1 and MDP2 demonstrate that all bacterial strains were rapidly killed. MDP1 and MDP2 were ca. 100- and 26.6-fold less hemolytic than melittin and found to be respectively 72.9- and 41.6-fold less cytotoxic than melittin on the HEK293 cell line. MDP1 and MDP2 showed 252- and 132-fold improvement in their therapeutic index in comparison to melittin. MDP1 and MDP2 sustained their activities in the presence of human plasma and were found to be ca. four to eightfold more stable than melittin. Spectropolarimetry analysis of MDP1 and MDP2 indicates that the peptides adopt an alpha-helical structure predominantly. According to the fast killing kinetics, significant therapeutic index, and high stability of MDP1, it could be considered as a drug lead in a mouse model of septicemia infections.

Discovery of Leptulipin, a New Anticancer Protein from theIranian Scorpion, Hemiscorpius lepturus

Cancer is one of the leading causes of mortality in the world. Unfortunately, the present anticancer chemotherapeutics display high cytotoxicity. Accordingly, the discovery of new anticancer agents with lower side effects is highly necessitated. This study aimed to discover an anticancer compound from Hemiscorpius lepturus scorpion venom. Bioactivity-guided chromatography was performed to isolate an active compound against colon and breast cancer cell lines. 2D electrophoresis and MALDI-TOF were performed to identify the molecule. A partial protein sequence was obtained by mass spectrometry, while the full-length was deciphered using a cDNA library of the venom gland by bioinformatics analyses and was designated as leptulipin. The gene was cloned in pET-26b, expressed, and purified. The anticancer effect and mechanism action of leptulipin were evaluated by MTT, apoptosis, and cell cycle assays, as well as by gene expression analysis of apoptosis-related genes. The treated cells displayed inhibition of cell proliferation, altered morphology, DNA fragmentation, and cell cycle arrest. Furthermore, the treated cells showed a decrease in BCL-2 expression and an increase in Bax and Caspase 9 genes. In this study, we discovered a new anticancer protein from H. lepturus scorpion venom. Leptulipin showed significant anticancer activity against breast and colon cancer cell lines.

Utilisation of compounds from venoms in drug discovery

Difficult drug targets are becoming the normal course of business in drug discovery, sometimes due to large interacting surfaces or only small differences in selectivity regions. For these, a different approach is merited: compounds lying somewhere between the small molecule and the large antibody in terms of many properties including stability, biodistribution and pharmacokinetics. Venoms have evolved over millions of years to be complex mixtures of stable molecules derived from other somatic molecules, the stability comes from the pressure to be ready for delivery at a moment's notice. Snakes, spiders, scorpions, jellyfish, wasps, fish and even mammals have evolved independent venom systems with complex mixtures in their chemical arsenal. These venom-derived molecules have been proven to be useful tools, such as for the development of antihypotensive angiotensin converting enzyme (ACE) inhibitors and have also made successful drugs such as Byetta® (Exenatide), Integrilin® (Eptifibatide) and Echistatin. Only a small percentage of the available chemical space from venoms has been investigated so far and this is growing. In a new era of biological therapeutics, venom peptides present opportunities for larger target engagement surface with greater stability than antibodies or human peptides. There are challenges for oral absorption and target engagement, but there are venom structures that overcome these and thus provide substrate for engineering novel molecules that combine all desired properties. Venom researchers are characterising new venoms, species, and functions all the time, these provide great substrate for solving the challenges presented by today's difficult targets.

Discovery of a New Analgesic Peptide, Leptucin, from the Iranian Scorpion, Hemiscorpius lepturus

Hemiscorpius lepturus scorpion stings do not induce considerable pain based on epidemiological surveys conducted in the southwest part of Iran. Accordingly, this study was aimed to identify the analgesic molecule in H. lepturus venom by analyzing a cDNA library of the scorpion venom gland looking for sequences having homology with known animal venom analgesic peptides. The analgesic molecule is a cysteine rich peptide of 55 amino acids. the synthetic peptide was deprotected and refolded. RP-HPLC, Ellman's, and DLS assays confirmed the refolding accuracy. Circular dichroism (CD) showed helix and beta sheet contents. This peptide, called leptucin, demonstrated 95% analgesic activity at the dose of 0.48 mg/kg in hot plate assay. Leptucin at the doses of 0.32, 0.48, and 0.64 mg/kg showed 100% activity in thermal tail flick test. No hemolysis or cytotoxicity was observed at 8 and 16 µg. Histopathology evaluations indicated no hepatotoxicity, nephrotoxicity, and cardiotoxicity. We thus report that leptucin is the analgesic agent of H. lepturus venom. Regarding the high in vivo efficacy of leptucin and the fact it shows no observable toxicity, it could be suggested as a drug lead in a preclinical study of acute pain as well as the study of its mechanism of action.

Getting stoned: Characterisation of the coagulotoxic and neurotoxic effects of reef stonefish (Synanceia verrucosa) venom

The reef stonefish (Synanceia verrucosa) is a venomous fish which causes excruciatingly painful envenomations. While some research on the pathophysiology and functions of the venom have been conducted, there are still some gaps in the understanding of the venom effects due to the extreme lability of fish venom toxins and the lack of available testing platforms. Here we set out to assess new functions of the venom whilst also attempting to address some unclear pathophysiological effects from previous literature. Utilising a biolayer interferometry assay, our results highlight that the venom binds to the orthosteric site of the α-1 nicotinic acetylcholine receptor as well as the domain IV of voltage-gated Ca²⁺ (Ca_V1.2) channel mimotopes. Both these results add some clarity to the previously ambiguous literature. We further assessed the coagulotoxic effects of the venom using thromboelastography and Stago STA-R Max coagulation analyser assays. We reveal that the venom produced anticoagulant activity and significantly delayed time until clot formation of recalcified human plasma which is likely through the degradation of phospholipids. There was a difference between fresh and lyophilised venom activity toward the nicotinic acetylcholine receptor mimotopes and coagulation assays, whilst no difference was observed in the activity toward the domain IV of Ca_V1.2 mimotopes. This research adds further insights into the neglected area of fish venom whilst also highlighting the extreme labile nature of fish venom toxins.

A comparative analysis of the proteomes and biological activities of the venoms from two sea snakes, Hydrophis curtus and Hydrophis cyanocinctus, from Hainan, China

We characterized and compared the venom protein profiles of Hydrophis curtus (synonyms: Lapemis hardwickii, Lapemis curtus and Hydrophis hardwickii) and Hydrophis cyanocinctus, the two representatives of medically important venomous sea snakes in Chinese waters using proteomic approaches. A total of 47 and 38 putative toxins were identified in H. curtus venom (HcuV) and H. cyanocinctus venom (HcyV), respectively, and these toxins could be grouped into 15 functional categories, mainly proteinases, phospholipases, three-finger toxins (3FTxs), lectins, protease inhibitors, ion channel inhibitors, cysteine-rich venom proteins (CRVPs) and snake venom metalloproteases (SVMPs). The constituent ratio of each toxin category varied between HcuV and HcyV with 3FTx (54% in HcuV/69% in HcyV) and PLA2 (38% in HcuV/22% in HcyV) unanimously ranked as the top two most abundant families. Both HcuV and HcyV exhibited relatively high lethality (LD₅₀ values in mice of 0.34 μg/g and 0.24 μg/g, respectively), specific PLA2 activity and hemolytic activity. On the basis of several previous reports of HcuV and HcyV collected from other areas, these findings greatly expand our understanding of geographical variation and interspecies diversity of the two sea snake venoms and can provide a scientific basis for the development of specific sea snake antivenom in the future.

Novel chloroquine loaded curcumin based anionic linear globular dendrimer G2: a metabolomics study on Plasmodium falciparum in vitro using 1H NMR spectroscopy

Due to side-effects and inefficiency of the drugs used in malaria treatment, finding alternative medicine with less side-effects has attracted much attention. In this regard, in the present study, nanocomposite synthesized and its effects on the metabolites of P. falciparum were investigated. Subsequent to synthesis of nanocomposites, characterization was carried out using nuclear magnetic resonance (NMR), liquid chromatography-mass spectrometry (LC-MS), scanning electron microscopy, dynamic light scattering and Fourier-transform infrared tests. Solubility and drug release were measured and its toxicity on Vero cell was assessed using the MTT assay. The antiparasitic effect of the nanocomposite on the metabolites of P. falciparum was investigated by 1H NMR spectroscopy. Among synthesized nanocomposites, the average size of 239 nm showed suitable solubility in water as well as slow drug release. The MTT assay showed no toxicity for Vero cell lines. Concentrations of 2.5 μg mL-1 of nanocomposite eliminated 82.6% of the total parasites. The most effected metabolic cycles were glyoxylate and dicarboxylate metabolism. In this study, 1H NMR spectroscopy was used with untargeted metabolomics to study the effect of the nanocomposite on P. falciparum. Playing an essential role in understanding drug-target interactions and characterization of mechanism of action or resistance exhibited by novel antiprotozoal drugs, can be achieved by targeting metabolic using LC-MS.

Antiretroviral activity of Pterois volitans (red lionfish) venom in the early development of human immunodeficiency virus/acquired immunodeficiency syndrome antiretroviral alternative source

Aim

This study aimed to investigate the antiviral activity of Pterois volitans phospholipase A2 (PV-PLA2) from Indonesia to human immunodeficiency virus (HIV).

Materials and Methods

Fresh venomous fin parts of wild PV specimens were collected from Java Sea waters. Then, it washed using phosphate buffer pH 7.0 and immersed in phosphate buffer pH 7.0 0.01 m containing CaCl₂ 0.001 m for 24 h. The immersed fin then allowed for extraction process by sonicating for 2×8 min with 80% pulse and 20 kHz output with temperature controlling to avoid denaturation. The crude venom (CV) extracted from the fin is allowed for purification by 80% ethanol (ET) precipitation and ammonium sulfate fractionation method. The purified PV-PLA2 then analyzed using Lowry's method, Marinette's method, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and 3-(4, 5-dimethyl thiazol-2yl)-2, 5-diphenyl tetrazolium bromide assay. After determining the purest and safest sample of six samples analyzed, the chosen sample then tested into simian retrovirus-2 (SRV2)-A549 culture (48×10⁴ cells/mL at 1-4 ppm), and compared to the CV sample (1-4 ppm) and lamivudine (100 ppm). The culture then is analyzed using a quantitative real time-polymerase chain reaction to find out the copy number of SRV-2 virus in each culture.

Results

The protein's activity, concentration, and purity analysis revealed that the PV-PLA2 purified using ammonium sulfate fractionation has the highest activity (1.81 times higher than the CV at 80% fractionation) and has higher purity than the sample from ET fractionation. The testing of the sample purified using ammonium sulfate fractionation at 80% saturation level shown that it has a 97.78% inhibition level toward SRV2-A549 culture at 4 ppm. However, in comparison to lamivudine which has 99.55% inhibition level at 100 ppm, it needs much lower concentration to achieve the same result.

Conclusion

The significant inhibition of SRV2-A549 culture shown that the PV-PLA2 extracted from PV venom has the potential to become anti-HIV substances. It would be worthwhile to further evaluate the antiretroviral activity of PV-PLA2 in the in vivo studies.

Action mechanism of melittin-derived antimicrobial peptides, MDP1 and MDP2, de novo designed against multidrug resistant bacteria

The emergence and dissemination of multidrug resistant (MDR) bacteria are major challenges for antimicrobial chemotherapy of bacterial infections. In this critical condition, cationic antimicrobial peptides are 'novel' promising candidate antibiotics to overcome the issue. In this study, we investigated the antibacterial mechanism of new melittin-derived peptides (i.e., MDP1 and MDP2) against multidrug resistant Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. MDP1 was designed with deletion of three amino acid residues, i.e., S₁₈, W₁₉, and I₂₀, from the end of second hydrophobic motif of melittin. In the next step, VLTTG in MDP1 sequence was substituted with tryptophan residue. MDP1 and MDP2 had a high-antibacterial activity against MDR and reference strains of S. aureus, E. coli, and P. aeruginosa. DNA and calcein release and flow cytometry assays indicate a time-dependent antibacterial activity on the examined bacteria affected by both MDP1 and MDP2. Finally, SEM analyses highlighted dose- and time-dependent effects of MDP1 and MDP2 on S. aureus and E. coli bacteria by induction of vesicle or pore formation as well as cell lysis. In this study we successfully showed that rational truncation of large hydrophobic motifs can lead to significant reduction in toxicity against human RBCs and improving the antibacterial activity as well. Analyses of data from DNA release, fluorometry, flow cytometry, and morphological assays demonstrated that the MDP1 and MDP2 altered the integrity of both Gram-positive and Gram-negative bacterial membranes and killed the bacteria via membrane damages.

Characteristics and Lethality of a Novel Recombinant Dermonecrotic Venom Phospholipase D from Hemiscorpius lepturus

Hemoscorpius lepturus is the most medically important scorpion in Iran. The clinical signs of H. lepturus envenomation are remarkably similar to those reported for brown spiders, including dermonecrosis, hematuria, renal failure and even death. The lethality and toxicity of brown spiders’ venom have been attributed to its phospholipase D activity. This study aims to identify a phospholipase D with possible lethality and dermonecrotic activity in H. lepturus venom. In this study, a cDNA library of the venom glands was generated by Illumina RNA sequencing. Phospholipase D (PLD) from H. lepturus was characterized according to its significant similarity with PLDs from brown spiders. The main chain designated as Hl-RecPLD1 (the first recombinant isoform of H. lepturus PLD) was cloned, expressed and purified. Sphingomyelinase, dermonecrotic and lethal activities were examined. Hl-PLD1 showed remarkable sequence similarity and structural homology with PLDs of brown spiders. The conformation of Hl-PLD1 was predicted as a “TIM beta/alpha-barrel”. The lethal dose 50 (LD₅₀) and dermonecrotic activities of Hl-RecPLD1 were determined as 3.1 µg/mouse and 0.7 cm² at 1 µg respectively. It is the first report indicating that a similar molecular evolutionary mechanism has occurred in both American brown spiders and this Iranian scorpion. In conclusion, Hl-RecPLD1 is a highly active phospholipase D, which would be considered as the lethal dermonecrotic toxin in H. lepturus venom.

Description of histopathological changes induced by the venom of the Persian Gulf Lionfish (Pterois russelli) in a mouse model of multiorgan toxicity

Pterois russelli is a venomous fish belongs to Scorpaenidae family. Envenomation by the Persian Gulf lionfish is associated with local pain, marked inflammation and local heat. The present study was aimed to document the histopathological changes in liver, heart, lung, kidney and alterations in release of critical enzymes such as LDH, CK. AST, ALT and ALP induced by the administration of various doses of P. russelli venom in a mouse model. LD50 of venom was determined by intravenous injection in Balb/c mice. Histopathological alterations of lung, liver, heart and kidney following injection of one LD50, 1/2 and 1/3 LD50 doses of the venom were evaluated. Simultaneously, release of LDH, CK, AST, ALT and ALP were measured in serum following administration of 1/2 and1/3 LD50 doses of the venom too. LD50 was calculated as 10.5 mg/kg. The level of all enzymes were increased after 3 h and significantly raised after 24 h and rapidly reduced after 48 h. Histological studies showed that one LD50 and 1/2 LD50 doses of the venom induced significant histological alterations in the lungs, liver, heart and kidneys including congestion, hemorrhage, necrosis, apoptosis, edema, and infiltration of inflammatory cells. The results indicate that the venom of P. russelli has nephrotoxic, hepatotoxic, cardiotoxic and pneumotoxic effects in mouse model. Among four examined vital organs, the highest critical events were seen in liver. The findings are useful to give new insight in the fish's venom studies. Gathering the data resulted from this study together will be directed us toward a good aspect concerning the toxicity of potential therapeutic molecules in the venom of lionfish.

From Mollusks to Medicine: A Venomics Approach for the Discovery and Characterization of Therapeutics from Terebridae Peptide Toxins

Animal venoms comprise a diversity of peptide toxins that manipulate molecular targets such as ion channels and receptors, making venom peptides attractive candidates for the development of therapeutics to benefit human health. However, identifying bioactive venom peptides remains a significant challenge. In this review we describe our particular venomics strategy for the discovery, characterization, and optimization of Terebridae venom peptides, teretoxins. Our strategy reflects the scientific path from mollusks to medicine in an integrative sequential approach with the following steps: (1) delimitation of venomous Terebridae lineages through taxonomic and phylogenetic analyses; (2) identification and classification of putative teretoxins through omics methodologies, including genomics, transcriptomics, and proteomics; (3) chemical and recombinant synthesis of promising peptide toxins; (4) structural characterization through experimental and computational methods; (5) determination of teretoxin bioactivity and molecular function through biological assays and computational modeling; (6) optimization of peptide toxin affinity and selectivity to molecular target; and (7) development of strategies for effective delivery of venom peptide therapeutics. While our research focuses on terebrids, the venomics approach outlined here can be applied to the discovery and characterization of peptide toxins from any venomous taxa.