Search

Several neurodegenerative diseases, such as multiple sclerosis and Parkinson's disease, are linked to alterations in myelin content or structure. Transmembrane receptors such as integrins could be involved in these alterations. In the present study, we investigated the role of αv-integrins in experimental models of neuroinflammation and demyelination with the use of lebecetin (LCT), a C-lectin protein purified from Macrovipera lebetina viper venom, as an αv-integrin modulator. In a model of neuroinflammation, LCT inhibited the upregulation of αv, β3, β5, α5, and β1 integrins, as well as the associated release of pro-inflammatory factor IL-6 and chemokine CXCL-10, and decreased the expression of phosphorylated NfκB. The subsequent "indirect culture" between reactive astrocytes and oligodendrocytes showed a down-regulation of αv and β3 integrins versus upregulation of β1 one, accompanied by a reduced expression of myelin basic protein (MBP). Treatment of oligodendrocytes with LCT rectified the changes in integrin and MBP expression. Through Western blot quantification, LCT was shown to upregulate the expression levels of PI3K and p-mTOR while downregulating expression levels of p-AKT in oligodendrocytes, suggesting the neuroprotective and pro-myelinating effects of LCT may be related to the PI3K/mTor/AKT pathway. Concomitantly, we found that LCT promoted remyelination by tracking the increased expression of MBP in the brains of cuprizone-intoxicated mice. These results point to an involvement of integrins in not only neuroinflammation but demyelination as well. Thus, targeting αv integrins could offer potential therapeutic avenues for the treatment of demyelinating diseases., (© 2024. The Author(s).)

Two bases-decavanadates coordination compounds [(C 6 H 13 N 4 ) 2 ][Mg(H 2 O) 6 ] 2 [O 28 V 10 ].6H 2 O (1) and [(C 7 H 11 N 2 ) 4 ][Mg(H 2 O) 6 ][O 28 V 10 ].4H 2 O (2) have been synthesized and well characterized using vibrational spectroscopy (infrared), UV-Visible analysis and single crystal X-ray diffraction technique. The formula unit, for both compounds, is composed by the decavanadate [V 10 O 28 ] 6- , hydrated magnesium ion, a counter anion and free water molecules. The transition metal adopts octahedral geometries in both compound (1) and (2). The existence of a multitude of hydrogen bonding interactions for both compounds provides a stable three-dimensional supramolecular structure. Optical absorption reveals a band gap energy indicating the semi-conductive nature of the compound. In this study, the cytotoxic and the anti-proliferative activities of compounds (1) and (2) on human cancer cells (U87 and MDA-MB-231) were investigated. Both compounds demonstrated dose-dependent anti-proliferative activity on U87 and MDA-MB-231 with respective IC 50 values of 0.82 and 0.31 μM and 1.4 and 1.75 μM. These data provide evidence on the potential anticancer activity of [(C 6 H 13 N 4 ) 2 ][Mg(H 2 O) 6 ] 2 [O 28 V 10 ].6H 2 O and [(C 7 H 11 N 2 ) 4 ][Mg(H 2 O) 2 ][O 28 V 10 ].4H 2 O. Molecular docking of the compounds was also examined. Molecular docking studies were performed for both compounds against four target receptors and revealed better binding affinity with these targets in comparison to Cisplatin. Moreover, molecular docking investigations suggest that these compounds may function as potential inhibitors of proteins in brain and breast cells, exhibiting greater efficiency compared to Cisplatin., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Inflammation and oxidative stress are two interconnected processes that play a role in cancer development and progression. In the present research, we aimed to evaluate the anticancer effect of Pistacia lentiscus L. (PL) essential oil (EO) in vitro against MCF-7 breast cancer cells and in vivo in DMBA-mammary cancer induction on female C57BL/6 mice model as well as to investigate its anti-inflammatory and antioxidant potential as implicated mechanism. Our results revealed a new chemotypes-profile of 39 bio-compounds of PL EO. The main chemotypes were terpenoid and ketone compounds. In vitro, PL EO had a potent anti-proliferative activity against MCF-7 cells. In vivo, PL reduced the tumor number, volume, weight and burden values as compared to the DMBA-positive control group (p<0.05). Histopathology data confirmed the protective effect of PL traduced by the presence of necrosis area. PL EO revealed improvement on inflammatory perturbation in the C-RP levels and the complete blood cell count. Finally, PL improved oxidative disorders of lipid peroxidation, thiol groups, hydrogen peroxide and antioxidant enzymes depletion in plasma and mammary tissues. Also, a potent plasma scavenging capacity has been detected. Our data suggested that PL chemotypes inhibited cell proliferation, exerting a potential protective effect against DMBA-mammary cancer through anti-inflammatory and antioxidant enhancements. Targeting inflammation and oxidative stress may represent a promising strategy for breast cancer prevention and treatment., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright: © 2024 Abidi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Inflammation is associated with many pathology disorders and the malignant progression of most cancers. Therefore, targeting inflammatory pathways could provide a promising strategy for disease prevention and treatment. In this study, we experimentally investigated the anti-inflammatory effect of CC5 and CC8, two disintegrin isoforms isolated from Cerastes cerastes snake venom, on LPS-stimulated macrophages, both on human THP-1 and mouse RAW264.7 cell adherence and their underlying mechanisms by measuring cytokine release levels and Western blot assay. Equally, both molecules were evaluated on a carrageenan-induced edema rat model. Our findings suggest that CC5 and CC8 were able to reduce adhesion of LPS-stimulated macrophages both on human THP-1 and mouse RAW264.7 cells to fibrinogen and vitronectin through the interaction with the αvβ3 integrin receptor. Moreover, CC5 and CC8 reduced the levels of reactive oxygen species (ROS) mediated by the NF-κB, MAPK and AKT signaling pathways that lead to decreased production of the pro-inflammatory cytokines TNF-α, IL-6 and IL-8 and increased secretion of IL-10 in LPS-stimulated THP-1 and RAW264.7 cells. Interestingly, both molecules potently exhibited an anti-inflammatory effect in vivo by reducing paw swelling in rats. In light of these results, we can propose the CC5 and CC8 disintegrins as interesting tools to design potential candidates against inflammatory-related diseases.

In the present study, we assess tyrosol derivatives bearing 3,5-disubstituted isoxazoles and 1,4-disubstituted triazoles for their ability to inhibit the proliferation of K562 cells derived from leukemia as well as primary chronic myeloid leukemia (CML) cells obtained from the peripheral blood of 15 CML patients including 10 patients with untreated chronic phase and 5 patients with resistance against imatinib or multiple TKI. Our results showed that most derivatives displayed significant anti-proliferative activity against K562 cells in a dose-dependent manner. Among them, compounds 3d and 4a exhibited greater potent anticancer activity with respective IC 50 values of 16 and 18 µg/mL (45 µM and 61 µM). Interestingly, compound 3d inhibited CML cell proliferation not only in newly diagnosed but also in imatinib-resistant patients. We demonstrated that the anti-proliferative effect of this compound is mediated by a pro-apoptotic activity by promoting oxidative stress and modulating the activity of the Akt, p38 MAPK and Erk 1/2 pathways. In conclusion, our data highlight the potential of this class of derivative as a novel promising therapeutic agent for CML therapy.

Glioblastoma is the most aggressive and invasive form of central nervous system tumors due to the complexity of the intracellular mechanisms and molecular alterations involved in its progression. Unfortunately, current therapies are unable to stop its neoplastic development. In this context, we previously identified and characterized AaTs-1, a tetrapeptide (IWKS) from Androctonus autralis scorpion venom, which displayed an anti-proliferative effect against U87 cells with an IC 50 value of 0.57 mM. This peptide affects the MAPK pathway, enhancing the expression of p53 and altering the cytosolic calcium concentration balance, likely via FPRL-1 receptor modulation. In this work, we designed and synthesized new dendrimers multi-branched molecules based on the sequence of AaTs-1 and showed that the di-branched (AaTs-1-2B), tetra-branched (AaTs-1-4B) and octo-branched (AaTs-1-8B) dendrimers displayed 10- to 25-fold higher effects on the proliferation of U87 cells than AaTs-1. We also found that the effects of the newly designed molecules are mediated by the enhancement of the ERK1/2 and AKT phosphorylated forms and by the increase in p53 expression. Unlike AaTs-1, AaTs-1-8B and especially AaTs-1-4B affected the migration of the U87 cells. Thus, the multi-branched peptide synthesis strategy allowed us to make molecules more active than the linear peptide against the proliferation of U87 glioblastoma cells.

Snake venom proteins, which are responsible for deadly snakebite envenomation, induce severe injuries including neurotoxicity, myotoxicity, cardiotoxicity, hemorrhage, and the disruption of blood homeostasis. Yet, many snake-venom proteins have been developed as potential drugs for treating human diseases due to their pharmacological effects. In this study, we evaluated the use of, an L-amino acid oxidase isolated from Cerastes cerastes snake venom CC-LAAO, as a potential anti-glioblastoma drug, by investigating its in vivo and in vitro pharmacological effects. Our results showed that acute exposure to CC-LAAO at 1 and 2.5 µg/mL does not induce significant toxicity on vital organs, as indicated by the murine blood parameters including aspartate transaminase (AST), alanine transaminase (ALT), lactate dehydrogenase (LDH) activities, and creatinine levels. The histopathological examination demonstrated that only at high concentrations did CC-LAAO induce inflammation and necrosis in several organs of the test subjects. Interestingly, when tested on human glioblastoma U87 cells, CC-LAAO induced a dose-dependent apoptotic effect through the H 2 O 2 generated during the enzymatic reaction. Taken altogether, our data indicated that low concentration of CC-LAAO may be safe and may have potential in the development of anti-glioblastoma agents.

Glioblastoma is an aggressive cancer, against which medical professionals are still quite helpless, due to its resistance to current treatments. Scorpion toxins have been proposed as a promising alternative for the development of effective targeted glioblastoma therapy and diagnostic. However, the exploitation of the long peptides could present disadvantages. In this work, we identified and synthetized AaTs-1, the first tetrapeptide from Androctonus australis scorpion venom (Aa), which exhibited an antiproliferative effect specifically against human glioblastoma cells. Both the native and synthetic AaTs-1 were endowed with the same inhibiting effect on the proliferation of U87 cells with an IC 50 of 0.56 mM. Interestingly, AaTs-1 was about two times more active than the anti-glioblastoma conventional chemotherapeutic drug, temozolomide (TMZ), and enhanced its efficacy on U87 cells. AaTs-1 showed a significant similarity with the synthetic peptide WKYMVm, an agonist of a G-coupled formyl-peptide receptor, FPRL-1, known to be involved in the proliferation of glioma cells. Interestingly, the tetrapeptide triggered the dephosphorylation of ERK, p38, and JNK kinases. It also enhanced the expression of p53 and FPRL-1, likely leading to the inhibition of the store operated calcium entry. Overall, our work uncovered AaTs-1 as a first natural potential FPRL-1 antagonist, which could be proposed as a promising target to develop new generation of innovative molecules used alone or in combination with TMZ to improve glioblastoma treatment response. Its chemical synthesis in non-limiting quantity represents a valuable advantage to design and develop low-cost active analogues to treat glioblastoma cancer.

Two series of 3,5-disubstituted isoxazoles (6a-e) and 1,4-disubstituted triazoles (8a-e) derivatives have been synthesized from tyrosol (1), a natural phenolic compound, detected in several natural sources such as olive oil, and well-known by its wide spectrum of biological activities. Copper-catalyzed microwave-assisted 1,3-dipolar cycloaddition reactions between tyrosol-alkyne derivative 2 and two series of aryl nitrile oxides (5a-e) and azides (7a-e) regiospecifically afforded 3,5-disubstituted isoxazoles (6a-e) and 1,4-triazole derivatives (8a-e), respectively in quantitative yields. Synthesized compounds were purified and characterized by spectroscopic means including 1D and 2D NMR techniques and HRMS analysis. The newly prepared hybrid molecules have been evaluated for their anticancer and hemolytic activities. Results showed that most derivatives displayed significant antiproliferative activity against human glioblastoma cancer cells (U87) in a dose-dependent manner. Compounds 6d (IC 50  = 15.2 ± 1.0 μg/mL) and 8e (IC 50  = 21.0 ± 0.9 μg/mL) exhibited more potent anticancer activity. Moreover, most derivatives displayed low hemolytic activity, even at higher concentrations which suggested that these classes of compounds are suitable candidates for further in vivo investigations. The obtained results allow us to consider the newly synthesized isoxazole- and triazole-linked tyrosol derivatives as promising scaffolds for the development of effective anticancer agents., (Copyright © 2021 Elsevier Inc. All rights reserved.)

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.

The excessive production of inflammatory mediators results in an overactive immune response leading to the worsening of various human diseases. Thus, there is a still need to identify molecules able to regulate the inflammatory response. Lebecetin, a C-type lectin protein isolated from Macrovipera lebetina snake venom, was previously characterized as a platelet aggregation inhibitor and antitumor active biomolecule. In the present work, we investigated its effect on the production of some cytokines linked to inflammatory response and the underlying mechanisms in lipopolysaccharide (LPS)-induced THP1 macrophages. Interestingly, we found that lebecetin reduced the levels of the pro-inflammatory cytokines TNF-α, IL-6, and IL-8 while it partially increased LPS-induced secretion of the immunomodulatory cytokine IL-10. Furthermore, this modulatory effect was accompanied by decreased activation of ERK1/2, p38, AKT kinases and NF-κB along with reduced expression of αvβ3 integrin. Thus, this study highlights the promising role of lebecetin as a natural biomolecule that could manage the inflammatory response involved in the development and progression of inflammatory diseases., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Prostate cancer is the most highly diagnosed cancer in men worldwide. It is characterized by high proliferation, great invasion and metastatic potential. Sodium channel subtypes have been identified as highly expressed in different prostate cancer cell lines. In this study, we have screened the negatively charged fractions of Androctonus australis (Aa) scorpion venom to identify active peptides on DU145 prostate cancer cells proliferation. The most active compound was identified to be the sodium channel peptide AaHIV with an IC 50 value of 15 μM. At this concentration, AaHIV had low effect on the adhesion of DU145 cells to fibronectin. When compared to other Na + channel Aa toxins, AaHIV was found to be 2 times more active than AaHI and AaHII on DU145 cells proliferation and slightly less active than AaHII on their adhesion. The three peptides are inactive on DU145 cells migration. AaHIV was found to be 16 times more active than veratridine, asteroidal alkaloid from plants of the lily family widely used as a sodium channel activator. Electrophysiological experiments showed that the AaHIV toxin activates Nav1.6 channel, suggesting that this sodium channel subtype is implicated in the proliferation of DU145 prostate cancer cells., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Through the recent development of knowledge in biotechnology and bioinformatics, snake venoms are widely used to develop new drugs to treat diseases such as hypertension and cancer. We have previously reported that Lebetin 2 isolated from Macrovipera lebetina transmediterranea venom displays a potent anti-platelet activity and exerts a cardioprotective effect in ischemia-reperfusion (IR) injury model. Here, we report that Lebetin 2 possess an anti-tumor effect by targeting the integrin receptor function. It was thus able to inhibit both adhesion and migration of pheochromocytoma cells (PC12) and α1β1 integrin-expressing CHO cells (CHO-α1) to type I and IV collagens. Moreover, this peptide affects proliferation of PC12 cells by modulating AKT phosphorylation. Furthermore, Lebetin 2 exhibits a potent anti-angiogenic effect as assessed in vitro and ex vivo, using both the embryo chick chorioallantoic membrane model (CAM) and rat aortic ring assay. Interestingly, the interaction mode of Lebetin 2 with the integrin α1β1, assessed in silico, showed that the peptide represents a steric obstruction preventing the collagen from enforcing the interactions with the integrin., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The aim of this study was to evaluate the antioxidant, the anti-inflammatory, and the antitumoral activities of the aqueous ethanolic extract from Phoenix dactylifera L. parthenocarpic dates. The antioxidant activity was carried using DPPH radical scavenging activity. The result showed that parthenocarpic dates had strongly scavenging activity on DPPH reaching 94% with an IC 50 value of 0.15 ± 0.011 mg/mL (p < 0.05). The anti-inflammatory potential was determined by the inhibitory effect of the aqueous ethanolic extract on phospholipase A 2 activity as well as on carrageenan-induced paw oedema in mice. The in vitro study showed that the extract inhibited the phospholipase A 2 activity with an IC 50 value of 130  μ g/mL and the in vivo study showed a significantly decrease in the paw oedema after 1 h compared to the control group. Finally, the antiproliferative activity of the aqueous ethanolic extract was assessed by MTT test against MCF-7 and MDA-MB-231 cancer cell lines. This extract was effective in inhibiting MDA-MB-231 and MCF-7 cancer cells growth with IC 50 values of 8 and 18 mg/mL, respectively, after 72 h treatment. These results confirm the ethnopharmacological significance of Phoenix dactylifera L. parthenocarpic dates, which could add support for its pharmaceutical use.

Voltage-gated potassium (Kv) channels are known to play a pivotal role in the progression of various cancer types and considered as new targets for designing anti-cancer therapy. However, the fact that many Kv channels are expressed in different cell lines makes it difficult to ascribe a functional role for a given Kv channel on a specific aspect of the tumorogenesis. In this work, we showed that although both Kv1.1 and Kv1.3 channels are expressed in U87 (glioblastoma), MDA-MB-231 (breast cancer) and LS174 (colon adenocarcinoma) cells, these respond differently to KAaH1 or KAaH2, two homologous Kv1 blockers from scorpion venom. KAaH1 is active on Kv1.1 and Kv1.3 and was found to inhibit migration and adhesion of U87 cells whereas KAaH2 which is slightly active only on Kv1.1 channel, inhibits their proliferation via the EGFR signaling pathway. The correlation between the electro-physiological activity of the scorpion peptides and their anti-migratory effects suggests the involvement of the Kv1.1 and Kv1.3 channels in the mobility of the three cancer cell lines. Our results showed that besides they can elucidate the implication of Kv1.1 and Kv1.3 channels in molecular mechanisms of neoplastic progression, KAaH1 and KAaH2 may be used as therapeutic tools against glioblastoma., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Hard ticks (Acari: Ixodidae) are blood-sucking ectoparasites characterized by the extended period of their attachment to their host. To access their bloodmeal, ticks secrete saliva containing a range of molecules that target the host's inflammation, immune system, and hemostatic components. Some of these molecules reportedly possess antiangiogenic and antitumor properties. The present study describes our investigation, the first of its kind, of the antiangiogenic and antitumoral effects of the Hyalomma dromedarii Koch, 1844 (Acari: Ixodidae), salivary gland extract (SGE), which inhibited the adhesion and migration of Human Umbilical Vein Endothelial Cells (HUVECs) in a dose-dependent manner, as well as angiogenesis in the Chick Chorioallantoic Membrane model. Interestingly, H. dromedarii SGE exerted an antiproliferative effect on U87 glioblastoma cells and inhibited their adhesion and migration to fibrinogen. These results open up new possibilities for characterizing and developing new molecules involved in the key steps of tumor progression., (© The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

The present study investigated the kinetic and interfacial properties of two secreted phospholipases isolated from Tunisian vipers'venoms: Cerastes cerastes (CC-PLA2) and Macrovipera lebetina transmediterranea (MVL-PLA2). Results show that these enzymes have great different abilities to bind and hydrolyse phospholipids. Using egg-yolk emulsions as substrate at pH 8, we found that MVL-PLA2 has a specific activity of 1473U/mg at 37°C in presence of 1mM CaCl2. Furthermore the interfacial kinetic and binding data indicate that MVL-PLA2 has a preference to the zwitterionic phosphatidylcholine monolayers (PC). Conversely, CC-PLA2 was found to be able to hydrolyse preferentially negatively charged head group phospholipids (PG and PS) and exhibits a specific activity 9 times more important (13333U/mg at 60°C in presence of 3mM CaCl2). Molecular models of both CC-PLA2 and MVL-PLA2 3D structures have been built and their electrostatic potentials surfaces have been calculated. A marked anisotropy of the overall electrostatic charge distribution leads to a significantly difference in the dipole moment intensity between the two enzymes explaining the great differences in catalytic and binding properties, which seems to be governed by the electrostatic and hydrophobic forces operative at the surface of the two phospholipases., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Snake venom l-amino acid oxidases are multifunctional enzymes that exhibited a wide range of pharmacological activities. Although it has been established that these activities are primarily caused by the H2O2 generated in the enzymatic reaction, the molecular mechanism, however, has not been fully investigated. In this work, LAAO interaction with cytoplasmic membranes using different cell types and Langmuir interfacial monolayers was evaluated. The Cerastes cerastes venom LAAO (CC-LAAO) did not exhibit cytotoxic activities against erythrocytes and peripheral blood mononuclear cells (PBMC). However, CC-LAAO caused cytotoxicity on several cancer cell lines and induced platelet aggregation in dose-dependent manner. Furthermore, the enzyme showed remarkable effect against Gram-positive and Gram-negative bacteria. These activities were inhibited on the addition of catalase or substrate analogs, suggesting that H2O2 liberation× is required for these effects. Binding studies revealed that CC-LAAO binds to the cell surface and enables the production of highly localized concentration of H2O2 in or near the binding interfaces. On another hand, the interaction of CC-LAAO with a mimetic phospholipid film was evaluated, for the first time, using a monomolecular film technique. Results indicated that phospholipid/CC-LAAO interactions are not involved in their binding to membrane and in their pharmacological activities., (Copyright © 2015 Elsevier B.V. All rights reserved.)

A new L-amino acid oxidase (LAAO) from Cerastes cerastes snake venom, named CC-LAAO, was purified to homogeneity using a combination of size-exclusion, ion-exchange and affinity chromatography. CC-LAAO is a homodimeric glycosylated flavoprotein with a molecular mass around 58 kDa under reducing conditions and about 115 kDa in its native form when analyzed by SDS-PAGE and gel filtration chromatography, respectively. This enzyme displayed a Michaelis-Menten behavior with an optimal pH at 7.8. However, unlike known SV-LAAOs which display their maximum activity at 37 °C, CC-LAAO has an optimal temperature at 50 °C. Kinetic studies showed that the enzyme displayed high specificity towards hydrophobic L-amino acids. The best substrates were L-Phe, L-Met and L-Leu. CC-LAAO activity was inhibited by the substrate analog N-acetyl tryptophan. The N-terminal amino acid sequence of this protein was determined by automated Edman degradation. The CC-LAAO cDNA was cloned from the venom gland total RNA preparation. The cDNA sequence contained an open-reading frame (ORF) of 1551-bp, which encoded a protein of 516 amino acids comprising a signal peptide of 18 amino acids and 498-residues mature protein. CC-LAAO sequence and its tertiary model shared high similarity with other snake venom LAAOs., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Development and homeostasis of the vascular system requires integrin-promoting endothelial cell adhesion, migration and survival. Nowadays, integrins represent potential targets for pharmacological agents and open new avenues for the control of metastatic spread in the treatment of tumor malignancies. We have already reported that PIVL, a serine protease inhibitor isolated from Macrovipera lebetina venom, displays an anti-tumor effect through interference with integrin receptor function. Here, we report that PIVL inhibits human vascular endothelial cell adhesion and migration onto fibrinogen and fibronectin in a dose-dependent manner without any cytotoxicity. Furthermore, we show that PIVL increases microtubule dynamic instability in HMEC-1 transfected with EGFP-tagged α-tubulin. Using Matrigel™ and chick chorioallantoic membrane assays, we demonstrate that PIVL exhibits a strong anti-angiogenic effect both in vitro and in vivo. Interestingly, results herein reveal that the potent anti-angiogenic properties of PIVL are mediated by its RGD-like motif ((41)RGN(43))., (Copyright © 2014 Elsevier Inc. All rights reserved.)