{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,11]],"date-time":"2026-06-11T06:56:26Z","timestamp":1781160986820,"version":"3.54.1"},"reference-count":23,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T00:00:00Z","timestamp":1781049600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100007161","name":"Secretar\u00eda de Investigaci\u00f3n y Posgrado del Instituto Polit\u00e9cnico Nacional","doi-asserted-by":"publisher","award":["SIP 20254002"],"award-info":[{"award-number":["SIP 20254002"]}],"id":[{"id":"10.13039\/501100007161","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pharmaceutics"],"abstract":"<jats:p>Background\/Objectives: Heliotropium indicum (H. indicum) is a medicinal plant traditionally used for conditions associated with inflammation, but its active antinociceptive constituents remain poorly defined. This study evaluated the antinociceptive activity of the aerial parts of H. indicum through a bioassay-guided approach and explored the mechanism of action of the active compound isolated in the formalin test. Methods: Three extracts of H. indicum (hexane, dichloromethane, and methanol) were evaluated in male Swiss albino CD-1 mice using the formalin test. The most active extract was fractionated, and its major fractions were screened for antinociceptive activity. Based on the active fraction and previous phytochemical data, (E)-ethyl-12-cyclohexyl-4,5-dihydroxydodec-2-enoate (ECDE) was selected for further pharmacological evaluation in the same model. Antagonist pretreatments were used to investigate the involvement of opioid, serotonergic, gamma-aminobutyric acid (GABAA), and Nitric Oxide (NO)\u2013soluble Guanylyl Cyclase (sGC) pathways. Results: The three extracts reduced nociceptive behavior, mainly during phase II of the formalin test, whereas the dichloromethane extract showed the broadest activity profile and was selected for fractionation. The six fractions significantly reduced phase II nociception, and fraction F5 was selected for purification. ECDE produced a clear dose-dependent antinociceptive effect in phase II, with minimal effect on phase I, and its efficacy was compared with that of ketorolac, a standard antinociceptive drug. Dose\u2013response analysis estimated a DE50 of 0.76 mg\/kg for ECDE. Pretreatment with N-nitro-L-arginine methyl ester (L-NAME) and [1,2,4]oxadiazolo [4,3-a]quinoxalin-1-one (ODQ) significantly attenuated the effect of ECDE, whereas naloxone, methiothepin, and bicuculline did not. Conclusions: ECDE was identified in H. indicum as one of the compounds contributing to this effect. Its activity appears to be directed mainly toward inflammatory nociception and to depend, at least in part, on the NO\u2013sGC pathway.<\/jats:p>","DOI":"10.3390\/pharmaceutics18060714","type":"journal-article","created":{"date-parts":[[2026,6,11]],"date-time":"2026-06-11T05:50:58Z","timestamp":1781157058000},"page":"714","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Bioguided Isolation of (E)-Ethyl-12-cyclohexyl-4,5-dihydroxydodec-2-enoate from the Aerial Parts of Heliotropium indicum and Evaluation of Its Mechanism of Action Using the Formalin Test"],"prefix":"10.3390","volume":"18","author":[{"given":"Mar\u00eda Elena","family":"S\u00e1nchez-Mendoza","sequence":"first","affiliation":[{"name":"Escuela Superior de Medicina, Instituto Polit\u00e9cnico Nacional, Plan de San Luis y D\u00edaz Mir\u00f3n, Colonia Casco de Santo Tom\u00e1s, Miguel Hidalgo, M\u00e9xico City 11340, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jes\u00fas","family":"Arrieta","sequence":"additional","affiliation":[{"name":"Escuela Superior de Medicina, Instituto Polit\u00e9cnico Nacional, Plan de San Luis y D\u00edaz Mir\u00f3n, Colonia Casco de Santo Tom\u00e1s, Miguel Hidalgo, M\u00e9xico City 11340, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yaraset","family":"L\u00f3pez-Lorenzo","sequence":"additional","affiliation":[{"name":"Escuela Superior de Medicina, Instituto Polit\u00e9cnico Nacional, Plan de San Luis y D\u00edaz Mir\u00f3n, Colonia Casco de Santo Tom\u00e1s, Miguel Hidalgo, M\u00e9xico City 11340, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gisela","family":"Guti\u00e9rrez-Iglesias","sequence":"additional","affiliation":[{"name":"Escuela Superior de Medicina, Instituto Polit\u00e9cnico Nacional, Plan de San Luis y D\u00edaz Mir\u00f3n, Colonia Casco de Santo Tom\u00e1s, Miguel Hidalgo, M\u00e9xico City 11340, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5325-3760","authenticated-orcid":false,"given":"Osmar Antonio","family":"Jaramillo-Morales","sequence":"additional","affiliation":[{"name":"Departamento de Enfermer\u00eda y Obstetricia, Divisi\u00f3n de Ciencias de la Vida, Campus Irapuato-Salamanca, Universidad de Guanajuato, Irapuato 36500, Guanajuato, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8123-6343","authenticated-orcid":false,"given":"Josu\u00e9 Vidal","family":"Espinosa-Ju\u00e1rez","sequence":"additional","affiliation":[{"name":"Escuela de Ciencias Qu\u00edmicas, Universidad Aut\u00f3noma de Chiapas, Ocozocoautla de Espinosa 29140, Chiapas, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,6,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1001","DOI":"10.15585\/mmwr.mm6736a2","article-title":"Prevalence of Chronic Pain and High-Impact Chronic Pain Among Adults\u2014United States, 2016","volume":"67","author":"Dahlhamer","year":"2018","journal-title":"MMWR Morb. 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