{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T09:17:30Z","timestamp":1787735850798,"version":"build-2784847793"},"reference-count":43,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,8,23]],"date-time":"2026-08-23T00:00:00Z","timestamp":1787443200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Institutes of Health Fogarty International Center","award":["D43TW011403"],"award-info":[{"award-number":["D43TW011403"]}]},{"award":["D43TW011403"],"award-info":[{"award-number":["D43TW011403"]}],"id":[{"id":"https:\/\/ror.org\/02xey9a22","id-type":"ROR","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100005299","name":"Vicerrector\u00eda de Investigaci\u00f3n, Universidad de Costa Rica","doi-asserted-by":"crossref","award":["C4600"],"award-info":[{"award-number":["C4600"]}],"id":[{"id":"10.13039\/501100005299","id-type":"DOI","asserted-by":"crossref"}]},{"award":["C4600"],"award-info":[{"award-number":["C4600"]}],"id":[{"id":"https:\/\/ror.org\/02yzgww51","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Toxins"],"abstract":"<jats:p>Skeletal muscle regeneration is often impaired after acute muscle damage induced by viperid snake venoms, such as that of Bothrops asper, a medically relevant species in Latin America. It has been shown that traces of venom that remain in the damaged muscle affect myogenic cells in culture, raising the possibility of inhibiting these toxins during the regenerative process to improve regeneration. Using a mouse model of myonecrosis and regeneration, we evaluated the effects of Varespladib (a phospholipase A2 inhibitor) or Marimastat (a metalloproteinase inhibitor) on muscle regeneration when administered intravenously 24 h after the onset of myonecrosis, i.e., after muscle damage has occurred. The regenerative process was evaluated 14 and 28 days after venom injection. Marimastat, or a combination of both inhibitors, increased the number and diameter of regenerating muscle fibers and reduced tissue fibrosis compared to tissues from mice receiving only venom, as judged by qualitative and quantitative histological assessment. These initial results underscore the deleterious role of traces of venom components, especially metalloproteinases, in damaged muscles during muscle regeneration.<\/jats:p>","DOI":"10.3390\/toxins18090359","type":"journal-article","created":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T10:07:53Z","timestamp":1787566073000},"page":"359","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Effects of Phospholipase A2 and Metalloproteinase Inhibitors on Skeletal Muscle Regeneration After Myonecrosis Induced by the Venom of Bothrops asper: An Initial Assessment in Mice"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0009-0003-8581-2883","authenticated-orcid":false,"given":"Andr\u00e9s","family":"Zamora","sequence":"first","affiliation":[{"name":"Instituto Clodomiro Picado, Facultad de Microbiolog\u00eda, Universidad de Costa Rica, San Jos\u00e9 11501, Costa Rica"},{"name":"Departamento de Fisiolog\u00eda, Escuela de Medicina, Universidad de Costa Rica, San Jos\u00e9 11501, Costa Rica"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alexandra","family":"Rucavado","sequence":"additional","affiliation":[{"name":"Instituto Clodomiro Picado, Facultad de Microbiolog\u00eda, Universidad de Costa Rica, San Jos\u00e9 11501, Costa Rica"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4140-1620","authenticated-orcid":false,"given":"Teresa","family":"Escalante","sequence":"additional","affiliation":[{"name":"Instituto Clodomiro Picado, Facultad de Microbiolog\u00eda, Universidad de Costa Rica, San Jos\u00e9 11501, Costa Rica"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8385-3081","authenticated-orcid":false,"given":"Jos\u00e9 Mar\u00eda","family":"Guti\u00e9rrez","sequence":"additional","affiliation":[{"name":"Instituto Clodomiro Picado, Facultad de Microbiolog\u00eda, Universidad de Costa Rica, San Jos\u00e9 11501, Costa Rica"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Erika","family":"Camacho","sequence":"additional","affiliation":[{"name":"Instituto Clodomiro Picado, Facultad de Microbiolog\u00eda, Universidad de Costa Rica, San Jos\u00e9 11501, Costa Rica"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"998","DOI":"10.1016\/j.toxicon.2009.07.001","article-title":"Epidemiological, clinical and therapeutic aspects of Bothrops asper bites","volume":"54","year":"2009","journal-title":"Toxicon"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"77","DOI":"10.1016\/S0140-6736(09)61754-2","article-title":"Snake bite","volume":"375","author":"Warrell","year":"2010","journal-title":"Lancet"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"17079","DOI":"10.1038\/nrdp.2017.79","article-title":"Snakebite envenoming","volume":"3","author":"Calvete","year":"2017","journal-title":"Nat. Rev. Dis. Primers"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"958","DOI":"10.1016\/j.toxicon.2009.01.038","article-title":"Experimental pathology of local tissue damage induced by Bothrops asper snake venom","volume":"54","author":"Rucavado","year":"2009","journal-title":"Toxicon"},{"key":"ref_5","first-page":"906","article-title":"Regeneration of mammalian skeletal muscle","volume":"16","author":"Ciciliot","year":"2010","journal-title":"Basic Mech. Clin. Implic. Curr. Pharm. Des."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"719","DOI":"10.1016\/0041-0101(84)90155-7","article-title":"Skeletal muscle regeneration after myonecrosis induced by crude venom and a myotoxin from the snake Bothrops asper (Fer-de-Lance)","volume":"22","author":"Ownby","year":"1984","journal-title":"Toxicon"},{"key":"ref_7","first-page":"211","article-title":"Degenerative and regenerative changes in murine skeletal muscle after injection of venom from the snake Bothrops asper: A histochemical and immunocytochemical Study","volume":"72","author":"Arce","year":"1991","journal-title":"Int. J. Exp. Pathol."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Hern\u00e1ndez, R., Cabalceta, C., Saravia-Otten, P., Chaves, A., Guti\u00e9rrez, J.M., and Rucavado, A. (2011). Poor regenerative outcome after skeletal muscle necrosis induced by Bothrops asper venom: Alterations in microvasculature and nerves. PLoS ONE, 6.","DOI":"10.1371\/annotation\/9caa2be8-b5e6-4553-8575-f0b575442172"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Sonavane, M., Almeida, J.R., Raian, E., Williams, H.F., Townsend, F., Cornish, E., Mitchel, R.D., Patel, K., and Vaiyapuri, S. (2023). Intramuscular Bleeding and Formation of Microthrombi during Skeletal Muscle Damage Caused by a Snake Venom Metalloprotease and a Cardiotoxin. Toxins, 15.","DOI":"10.3390\/toxins15090530"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Arias-Rodr\u00edguez, J., and Guti\u00e9rrez, J.M. (2020). Circumstances and consequences of snakebite envenomings: A qualitative study in South-Eastern Costa Rica. Toxins, 12.","DOI":"10.3390\/toxins12010045"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"587","DOI":"10.1111\/j.1440-1681.1978.tb00714.x","article-title":"Further observations on the pathological responses of rat skeletal muscle to toxins isolated from the venom of the Australian tiger snake, Notechis scutatus scutatus","volume":"5","author":"Harris","year":"1978","journal-title":"Clin. Exp. Pharmacol. Physiol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"565","DOI":"10.1007\/BF00216429","article-title":"Regeneration of mammalian skeletal muscle following the injection of the snake-venom toxin, taipoxin","volume":"232","author":"Maltin","year":"1983","journal-title":"Cell Tissue Res."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Guti\u00e9rrez, J.M., Escalante, T., Hern\u00e1ndez, R., Gastaldello, S., Saravia-Otten, P., and Rucavado, A. (2018). Why Is Skeletal muscle regeneration impaired after myonecrosis induced by viperid snake venoms?. Toxins, 10.","DOI":"10.3390\/toxins10050182"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"202","DOI":"10.1002\/mus.23489","article-title":"Homogenates of skeletal muscle injected with snake venom inhibit myogenic differentiation in cell culture","volume":"47","author":"Robledo","year":"2013","journal-title":"Muscle Nerve"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"36","DOI":"10.1016\/j.toxicon.2022.03.008","article-title":"Traces of Bothrops snake venoms in necrotic muscle preclude myotube formation in vitro","volume":"211","author":"Fusco","year":"2022","journal-title":"Toxicon"},{"key":"ref_16","first-page":"1","article-title":"Differential effects of the venoms of Russell\u2019s viper and Indian cobra on human myoblasts","volume":"14","author":"Almeida","year":"2024","journal-title":"Sci. Rep."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Adeyemi, S.O., Richards, N.J., Alqallaf, A., Bin Haidar, H., Al-Asady, M.J.J., Williams, J., Almeida, J.R., and Patel, K. (2025). Compromised regeneration, damage to blood vessels and the endomysium underpin permanent muscle damage induced by puff adder (Bitis arietans) venom. Toxins, 17.","DOI":"10.3390\/toxins17100496"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1016\/0041-0101(84)90144-2","article-title":"Isolation of a myotoxin from Bothrops asper venom: Partial characterization and action on skeletal muscle","volume":"22","author":"Ownby","year":"1984","journal-title":"Toxicon"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"449","DOI":"10.1002\/mus.10453","article-title":"Neutrophils do not contribute to local tissue damage, but play a key role in skeletal muscle regeneration, in mice injected with Bothrops asper snake venom","volume":"28","author":"Teixeira","year":"2003","journal-title":"Muscle Nerve"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"367","DOI":"10.1016\/0014-4800(84)90054-6","article-title":"Pathogenesis of myonecrosis induced by crude venom and a myotoxin of Bothrops asper","volume":"40","author":"Ownby","year":"1984","journal-title":"Exp. Mol. Pathol."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Lewin, M., Samuel, S., Merkel, J., and Bickler, P. (2016). Varespladib (LY315920) appears to be a potent, broad-spectrum, inhibitor of snake venom phospholipase A2 and a possible pre-referral treatment for envenomation. Toxins, 8.","DOI":"10.3390\/toxins8090248"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1016\/j.toxicon.2017.04.001","article-title":"Peptidomimetic hydroxamate metalloproteinase inhibitors abrogate local and systemic toxicity induced by Echis ocellatus (saw-scaled) snake venom","volume":"132","author":"Arias","year":"2017","journal-title":"Toxicon"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1038\/s41467-020-19981-6","article-title":"A therapeutic combination of two small molecule toxin inhibitors provides broad preclinical efficacy against viper snakebite","volume":"11","author":"Albulescu","year":"2020","journal-title":"Nat. Commun."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Layfield, H.J., Williams, H.F., Ravishankar, D., Mehmi, A., Sonavane, M., Salim, A., Vaiyapuri, R., Lakshminarayanan, K., Vallance, T.M., and Bicknell, A.B. (2020). Repurposing cancer drugs Batimastat and Marimastat to inhibit the activity of a group I metalloprotease from the venom of the Western Diamondback rattlesnake, Crotalus atrox. Toxins, 12.","DOI":"10.3390\/toxins12050309"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Xiao, H., Li, H., Zhang, D., Li, Y., Sun, S., and Huang, C. (2018). Inactivation of venom PLA2 alleviates myonecrosis and facilitates muscle regeneration in envenomed mice: A time course observation. Molecules, 23.","DOI":"10.3390\/molecules23081911"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"100118","DOI":"10.1016\/j.toxcx.2022.100118","article-title":"In vitro and in vivo preclinical venom inhibition assays identify metalloproteinase inhibiting drugs as potential future treatments for snakebite envenoming by Dispholidus typus","volume":"14","author":"Menzies","year":"2022","journal-title":"Toxicon X"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1245","DOI":"10.1517\/13543784.2010.517193","article-title":"Varespladib methyl in cardiovascular disease","volume":"19","author":"Rosenson","year":"2010","journal-title":"Expert Opin. Investig. Drugs"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"(2011). Varespladib. Am. J. Cardiovasc. Drugs, 11, 137\u2013143.","DOI":"10.2165\/11533650-000000000-00000"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"217","DOI":"10.1080\/13543776.2017.1246540","article-title":"Inhibitors of phospholipase A2 and their therapeutic potential: An update on patents (2012-2016)","volume":"27","author":"Kokotou","year":"2017","journal-title":"Expert Opin. Ther. Pat."},{"key":"ref_30","first-page":"209","article-title":"Matrix metalloproteinase inhibitors as investigative tools in the pathogenesis and management of vascular disease","volume":"103","author":"Benjamin","year":"2012","journal-title":"Exp. Suppl."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1016\/S0163-7258(97)00023-5","article-title":"Matrix metalloproteinase inhibition as a novel anticancer strategy: A review with special focus on batimastat and marimastat","volume":"75","author":"Rasmussen","year":"1997","journal-title":"Pharmacol. Ther."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"158","DOI":"10.1006\/dbio.1998.9107","article-title":"Expression of matrix metalloproteinases 2 and 9 in regenerating skeletal muscle: A study in experimentally injured and Mdx Muscles","volume":"205","author":"Kherif","year":"1999","journal-title":"Dev. Biol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"C529","DOI":"10.1152\/ajpcell.00051.2013","article-title":"Matrix metalloproteinase 13 is a new contributor to skeletal muscle regeneration and critical for myoblast migration","volume":"305","author":"Lei","year":"2013","journal-title":"Am. J. Physiol. Cell Physiol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"337","DOI":"10.4161\/cam.3.4.9338","article-title":"Role of matrix metalloproteinases in skeletal muscle","volume":"3","author":"Chen","year":"2009","journal-title":"Cell Adhes. Migr."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1080\/09629350220131980","article-title":"Increments in cytokines and matrix metalloproteinases in skeletal muscle after injection of tissue-damaging toxins from the venom of the snake Bothrops asper","volume":"11","author":"Rucavado","year":"2002","journal-title":"Mediat. Inflamm."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"340","DOI":"10.1016\/j.cell.2017.06.035","article-title":"Ciliary hedgehog signaling restricts injury-induced adipogenesis","volume":"170","author":"Kopinke","year":"2017","journal-title":"Cell"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1359","DOI":"10.1016\/0041-0101(94)90408-1","article-title":"Broad cytolytic specificity of myotoxin II, a lysine-49 phospholipase A2 of Bothrops asper snake venom","volume":"32","author":"Lomonte","year":"1994","journal-title":"Toxicon"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1718","DOI":"10.1007\/s00018-009-9053-2","article-title":"Calcium imaging of muscle cells treated with snake myotoxins reveals toxin synergism and presence of acceptors","volume":"66","author":"Pizzo","year":"2009","journal-title":"Cell. Mol. Life Sci."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Williams, H.F., Mellows, B.A., Mitchell, R., Sfyri, P., Layfield, H.J., Salamah, M., Vaiyapuri, R., Collins-Hooper, H., Bicknell, A.B., and Matsakas, A. (2019). Mechanisms underpinning the permanent muscle damage induced by snake venom metalloprotease. PLoS Negl. Trop. Dis., 13.","DOI":"10.1371\/journal.pntd.0007041"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"46","DOI":"10.1016\/j.toxicon.2021.01.003","article-title":"Changes in basement membrane components in an experimental model of skeletal muscle degeneration and regeneration induced by snake venom and myotoxic phospholipase A2","volume":"192","author":"Escalante","year":"2021","journal-title":"Toxicon"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1781","DOI":"10.1016\/j.jprot.2011.03.026","article-title":"Key Events in microvascular damage induced by snake venom hemorrhagic metalloproteinases","volume":"74","author":"Escalante","year":"2011","journal-title":"J. Proteom."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"858","DOI":"10.1002\/mus.26329","article-title":"Evidence of induced muscle regeneration persists for years in the mouse","volume":"58","author":"Meyer","year":"2018","journal-title":"Muscle Nerve"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"133","DOI":"10.3109\/10520295.2011.570277","article-title":"Certification procedures for Sirius Red F3B (CI 35780, Direct Red 80)","volume":"86","author":"Dapson","year":"2011","journal-title":"Biotech. Histochem."}],"container-title":["Toxins"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-6651\/18\/9\/359\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T08:17:47Z","timestamp":1787732267000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-6651\/18\/9\/359"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,23]]},"references-count":43,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["toxins18090359"],"URL":"https:\/\/doi.org\/10.3390\/toxins18090359","relation":{},"ISSN":["2072-6651"],"issn-type":[{"value":"2072-6651","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,23]]}}}