{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T11:03:25Z","timestamp":1785409405441,"version":"3.56.0"},"reference-count":50,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2026,6,17]],"date-time":"2026-06-17T00:00:00Z","timestamp":1781654400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004473","name":"Scientific Research Projects Unit of Sakarya University","doi-asserted-by":"publisher","award":["2022-7-25-9"],"award-info":[{"award-number":["2022-7-25-9"]}],"id":[{"id":"10.13039\/501100004473","id-type":"DOI","asserted-by":"publisher"}]},{"award":["2022-7-25-9"],"award-info":[{"award-number":["2022-7-25-9"]}],"id":[{"id":"https:\/\/ror.org\/04ttnw109","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Metabolites"],"abstract":"<jats:p>Background\/Objectives: Although vitamin K has been implicated in osteoarthritis pathophysiology, the specific effects of vitamin K2 (menaquinone) on cartilage degeneration remain poorly characterized. This study aimed to investigate the effect of oral vitamin K2 supplementation in a monosodium iodoacetate-induced osteoarthritis model. Methods: Twenty-four male Sprague Dawley rats were included in the study and divided into 3 equal groups: sham group, control (osteoarthritis) group, and treatment group. Saline was applied to the right knee of the sham group, and MIA was applied intra-articularly to the right knee of the control and treatment groups to create an osteoarthritis model. Rats in the treatment group were given 8 micrograms (\u03bcg)\/day of vitamin K2 orally in addition to the standard diet. After 28 days of follow-up, all rats were euthanized. The right knee articular cartilage was examined histologically with Hematoxylin\u2013Eosin and Safranin O and immunohistochemically with type II collagen alpha 1 and Matrix Metalloproteinase-13. Results: Histological evaluation demonstrated significantly lower Mankin scores in the treatment group (4.25 \u00b1 0.83) compared with the control group (11.10 \u00b1 0.83). Immunohistochemical analysis showed more intense type II collagen staining and reduced matrix metalloproteinase-13 staining in the treatment group relative to the control group. Conclusions: Oral vitamin K2 administration was associated with reduced cartilage degeneration and improved matrix preservation at the 28-day endpoint in an induced MIA osteoarthritis rat model.<\/jats:p>","DOI":"10.3390\/metabo16060425","type":"journal-article","created":{"date-parts":[[2026,6,17]],"date-time":"2026-06-17T08:22:56Z","timestamp":1781684576000},"page":"425","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Efficacy of Oral Vitamin K2 Supplementation in Experimental Knee Osteoarthritis"],"prefix":"10.3390","volume":"16","author":[{"given":"Emre","family":"Uzun","sequence":"first","affiliation":[{"name":"Department of Physical Medicine and Rehabilitation, Sakarya Training and Research Hospital, Sakarya 54290, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"\u0130brahim","family":"Tekeo\u011flu","sequence":"additional","affiliation":[{"name":"Department of Physical Medicine and Rehabilitation, Kutahya Health Sciences University, Kutahya 43020, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"H\u00fcseyin","family":"\u00c7ak\u0131ro\u011flu","sequence":"additional","affiliation":[{"name":"Experimental Animal Unit, Faculty of Medicine, Sakarya University, Sakarya 54290, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2617-3175","authenticated-orcid":false,"given":"\u00d6zcan","family":"Budak","sequence":"additional","affiliation":[{"name":"Department of Histology and Embryology, Faculty of Medicine, Sakarya University, Sakarya 54290, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Elvan","family":"\u015eahin","sequence":"additional","affiliation":[{"name":"Department of Histology and Embryology, Faculty of Medicine, Sakarya University, Sakarya 54290, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kemal","family":"Nas","sequence":"additional","affiliation":[{"name":"Department of Physical Medicine and Rehabilitation, Faculty of Medicine, Sakarya University, Sakarya 54290, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-8639-2742","authenticated-orcid":false,"given":"Muhammed Zahid","family":"Sahin","sequence":"additional","affiliation":[{"name":"Department of Physical Medicine and Rehabilitation, Faculty of Medicine, Sakarya University, Sakarya 54290, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ayhan","family":"Kamanl\u0131","sequence":"additional","affiliation":[{"name":"Department of Physical Medicine and Rehabilitation, Faculty of Medicine, Sakarya University, Sakarya 54290, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,6,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"184","DOI":"10.1016\/j.joca.2021.04.020","article-title":"Epidemiology of osteoarthritis","volume":"30","author":"Allen","year":"2022","journal-title":"Osteoarthr. 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