<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE root>
<article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:ali="http://www.niso.org/schemas/ali/1.0/" article-type="research-article" dtd-version="1.2" xml:lang="en"><front><journal-meta><journal-id journal-id-type="publisher-id">Kazan medical journal</journal-id><journal-title-group><journal-title xml:lang="en">Kazan medical journal</journal-title><trans-title-group xml:lang="ru"><trans-title>Казанский медицинский журнал</trans-title></trans-title-group></journal-title-group><issn publication-format="print">0368-4814</issn><issn publication-format="electronic">2587-9359</issn><publisher><publisher-name xml:lang="en">Eco-Vector</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="publisher-id">698404</article-id><article-id pub-id-type="doi">10.17816/KMJ698404</article-id><article-id pub-id-type="edn">RNUXVS</article-id><article-categories><subj-group subj-group-type="toc-heading" xml:lang="en"><subject>Theoretical and clinical medicine</subject></subj-group><subj-group subj-group-type="toc-heading" xml:lang="ru"><subject>Теоретическая и клиническая медицина</subject></subj-group><subj-group subj-group-type="article-type"><subject>Research Article</subject></subj-group></article-categories><title-group><article-title xml:lang="en">Melatonin, oxidative stress markers, and microbial profile in periodontal inflammation: a cross-sectional study among residents of the Russian arctic</article-title><trans-title-group xml:lang="ru"><trans-title>Мелатонин, маркёры оксидативного стресса и микробный профиль при воспалительных заболеваниях пародонта: одномоментное исследование среди жителей Арктической зоны Российской Федерации</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-6414-9870</contrib-id><contrib-id contrib-id-type="spin">5230-2125</contrib-id><name-alternatives><name xml:lang="en"><surname>Davidovich</surname><given-names>Natalia V.</given-names></name><name xml:lang="ru"><surname>Давидович</surname><given-names>Наталия Валерьевна</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><bio xml:lang="en"><p>MD, Cand. Sci. (Medicine), Assistant Professor, Depart. of Clinical Biochemistry, Microbiology, and Laboratory Diagnostics</p></bio><bio xml:lang="ru"><p>канд. мед. наук, доцент, каф. клинической биохимии, микробиологии и лабораторной диагностики</p></bio><email>nvdavidovich@gmail.com</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-7037-7730</contrib-id><contrib-id contrib-id-type="spin">3054-9139</contrib-id><name-alternatives><name xml:lang="en"><surname>Galieva</surname><given-names>Alexandra S.</given-names></name><name xml:lang="ru"><surname>Галиева</surname><given-names>Александра Сергеевна</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><bio xml:lang="en"><p>MD, Cand. Sci. (Medicine), Assistant Professor, Depart. of Therapeutic Dentistry</p></bio><bio xml:lang="ru"><p>канд. мед. наук, доцент, каф. терапевтической стоматологии</p></bio><email>alexgalieva@yandex.ru</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0001-5642-3019</contrib-id><contrib-id contrib-id-type="spin">8585-3051</contrib-id><name-alternatives><name xml:lang="en"><surname>Sabanaev</surname><given-names>Michael A.</given-names></name><name xml:lang="ru"><surname>Сабанаев</surname><given-names>Михаил Алексеевич</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><bio xml:lang="en"><p>Assistant Lecturer, Depart. of Clinical Biochemistry, Microbiology, and Laboratory Diagnostics</p></bio><bio xml:lang="ru"><p>ассистент, каф. клинической биохимии, микробиологии и лабораторной диагностики</p></bio><email>mix.sabanaeff@gmail.com</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-9247-6633</contrib-id><contrib-id contrib-id-type="spin">9526-8284</contrib-id><name-alternatives><name xml:lang="en"><surname>Bashilova</surname><given-names>Elena N.</given-names></name><name xml:lang="ru"><surname>Башилова</surname><given-names>Елена Николаевна</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><bio xml:lang="en"><p>MD, Cand. Sci. (Medicine), Assistant Professor, Depart. of Histology, Cytology, and Embryology</p></bio><bio xml:lang="ru"><p>канд. мед. наук, доцент, каф. гистологии, цитологии и эмбриологии</p></bio><email>ebashilova@mail.ru</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0001-7811-7741</contrib-id><contrib-id contrib-id-type="spin">2017-4416</contrib-id><name-alternatives><name xml:lang="en"><surname>Moiseev</surname><given-names>Denis A.</given-names></name><name xml:lang="ru"><surname>Моисеев</surname><given-names>Денис Александрович</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><bio xml:lang="en"><p>MD, Cand. Sci. (Medicine), Head, Lab. of Simulation Technologies in Dentistry, Assistant Professor, Depart. of Therapeutic Dentistry, Institute of Dentistry</p></bio><bio xml:lang="ru"><p>канд. мед. наук, заведующий, лаб. симуляционных технологий в стоматологии, доцент, каф. терапевтической стоматологии Института стоматологии</p></bio><email>moiseeff.den@yandex.ru</email><xref ref-type="aff" rid="aff2"/></contrib><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0003-0793-4749</contrib-id><contrib-id contrib-id-type="spin">8478-5172</contrib-id><name-alternatives><name xml:lang="en"><surname>Pisareva</surname><given-names>Svetlana N.</given-names></name><name xml:lang="ru"><surname>Писарева</surname><given-names>Светлана Николаевна</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><bio xml:lang="en"><p>Senior Lecturer, Depart. of Clinical Biochemistry, Microbiology, and Laboratory Diagnostics</p></bio><bio xml:lang="ru"><p>старший преподаватель, каф. клинической биохимии, микробиологии и лабораторной диагностики</p></bio><email>pisareva.sveta3917@yandex.ru</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0003-3371-1485</contrib-id><contrib-id contrib-id-type="spin">1844-4439</contrib-id><name-alternatives><name xml:lang="en"><surname>Kukalevskaya</surname><given-names>Natalia N.</given-names></name><name xml:lang="ru"><surname>Кукалевская</surname><given-names>Наталья Николаевна</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><bio xml:lang="en"><p>Assistant Lecturer, Depart. of Clinical Biochemistry, Microbiology, and Laboratory Diagnostics</p></bio><bio xml:lang="ru"><p>ассистент, каф. клинической биохимии, микробиологии и лабораторной диагностики</p></bio><email>n.kukalevskaya@yandex.ru</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-0664-4224</contrib-id><contrib-id contrib-id-type="spin">2263-8904</contrib-id><name-alternatives><name xml:lang="en"><surname>Solovyeva</surname><given-names>Natalia V.</given-names></name><name xml:lang="ru"><surname>Соловьева</surname><given-names>Наталия Владиславовна</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><bio xml:lang="en"><p>MD, Dr. Sci. (Medicine), Assistant Professor, Head, Depart. of Pathological Physiology</p></bio><bio xml:lang="ru"><p>д-р мед. наук, доцент, заведующий, каф. патологической физиологии</p></bio><email>patophiz@yandex.ru</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-7890-2341</contrib-id><contrib-id contrib-id-type="spin">2220-2151</contrib-id><name-alternatives><name xml:lang="en"><surname>Bazhukova</surname><given-names>Tatyana A.</given-names></name><name xml:lang="ru"><surname>Бажукова</surname><given-names>Татьяна Александровна</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><bio xml:lang="en"><p>MD, Dr. Sci. (Medicine), Professor, Head, Depart. of Clinical Biochemistry, Microbiology, and Laboratory Diagnostics</p></bio><bio xml:lang="ru"><p>д-р мед. наук, профессор, заведующий, каф. клинической биохимии, микробиологии и лабораторной диагностики</p></bio><email>tbazhukova@yandex.ru</email><xref ref-type="aff" rid="aff1"/></contrib></contrib-group><aff-alternatives id="aff1"><aff><institution xml:lang="en">Northern State Medical University</institution></aff><aff><institution xml:lang="ru">Северный государственный медицинский университет</institution></aff></aff-alternatives><aff-alternatives id="aff2"><aff><institution xml:lang="en">N.I. Pirogov Russian National Research Medical University</institution></aff><aff><institution xml:lang="ru">Российский национальный исследовательский медицинский университет им. Н.И. Пирогова</institution></aff></aff-alternatives><pub-date date-type="preprint" iso-8601-date="2026-05-14" publication-format="electronic"><day>14</day><month>05</month><year>2026</year></pub-date><pub-date date-type="pub" iso-8601-date="2026-06-15" publication-format="electronic"><day>15</day><month>06</month><year>2026</year></pub-date><volume>107</volume><issue>3</issue><issue-title xml:lang="en"/><issue-title xml:lang="ru"/><fpage>335</fpage><lpage>342</lpage><history><date date-type="received" iso-8601-date="2025-12-12"><day>12</day><month>12</month><year>2025</year></date><date date-type="accepted" iso-8601-date="2026-01-30"><day>30</day><month>01</month><year>2026</year></date></history><permissions><copyright-statement xml:lang="en">Copyright ©; 2026, Eco-Vector</copyright-statement><copyright-statement xml:lang="ru">Copyright ©; 2026, Эко-Вектор</copyright-statement><copyright-year>2026</copyright-year><copyright-holder xml:lang="en">Eco-Vector</copyright-holder><copyright-holder xml:lang="ru">Эко-Вектор</copyright-holder><ali:free_to_read xmlns:ali="http://www.niso.org/schemas/ali/1.0/" start_date="2029-06-15"/><license><ali:license_ref xmlns:ali="http://www.niso.org/schemas/ali/1.0/">https://eco-vector.com/for_authors.php#07</ali:license_ref></license></permissions><self-uri xlink:href="https://kazanmedjournal.ru/kazanmedj/article/view/698404">https://kazanmedjournal.ru/kazanmedj/article/view/698404</self-uri><abstract xml:lang="en"><p><bold>Background: </bold>In the Arctic, circadian rhythm disruption, driven by melatonin deficiency, serves as an additional pathogenetic factor in the development and progression of inflammatory periodontal diseases.</p> <p><bold>Aim: </bold>To study the role of melatonin and oxidative stress in the pathogenesis of periodontal inflammation among residents of the Russian Arctic.</p> <p><bold>Methods: </bold>The gingival crevicular fluid was collected from patients with chronic periodontitis (54 samples), chronic gingivitis (46 samples), and with intact periodontium (28 samples). Melatonin and malondialdehyde (an oxidative stress marker) levels were measured by ELISA in the gingival crevicular fluid. Periodontopathogen markers were detected using real-time PCR. Statistical analyses were performed using Stata 14 with nonparametric tests.</p> <p><bold>Results: </bold>In patients with chronic periodontitis and gingivitis, melatonin levels were significantly lower than in individuals with intact periodontium [median: 2.1 (1.4; 2.8) pg/mL and 3.0 (2.2; 3.7) pg/mL vs 5.8 (4.9; 6.5) pg/mL, <italic>p</italic> &lt; 0.001]. Malondialdehyde levels were elevated in inflammatory periodontal diseases. Melatonin correlated negatively with malondialdehyde in periodontitis patients (r = −0.712; <italic>p</italic> &lt; 0.001). Periodontopathogens (<italic>Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Treponema denticola</italic>) were frequently detected in inflamed cases, and melatonin levels correlated negatively with pathogen associations (r = −0.80; <italic>p</italic> &lt; 0.001).</p> <p><bold>Conclusion: </bold>In the Russian Arctic, low oral melatonin levels in chronic periodontitis patients are associated with increased oxidative stress and immune activation, thereby exacerbating periodontal inflammation.</p></abstract><trans-abstract xml:lang="ru"><p><bold>Обоснование</bold>. В условиях Арктики дополнительным патогенетическим фактором развития и прогрессирования воспалительных заболеваний пародонта выступает нарушение циркадных ритмов, ассоциированное с дефицитом мелатонина.</p> <p><bold>Цель исследования</bold>. Изучить роль мелатонина и окислительного стресса в патогенезе воспалительных заболеваний пародонта у жителей Арктической зоны Российской Федерации.</p> <p><bold>Методы</bold>. Клиническим материалом послужила десневая жидкость пациентов с хроническим пародонтитом (54 образца), хроническим гингивитом (46 образцов) и с интактным пародонтом (28 образцов). С помощью иммуноферментного анализа в десневой жидкости определяли содержание мелатонина и маркёра окислительного стресса (малоновый диальдегид). Маркёры пародонтопатогенных бактерий выделяли в ходе полимеразной цепной реакции в режиме реального времени. Статистическую обработку данных проводили с помощью пакета программ Stata 14 с использованием непараметрических методов.</p> <p><bold>Результаты</bold>. В группе пациентов с хроническим пародонтитом и гингивитом уровни мелатонина были значимо ниже, чем у лиц с интактным пародонтом [медиана — 2,1 (1,4; 2,8) пг/мл и 3,0 (2,2; 3,7) пг/мл против 5,8 (4,9; 6,5) пг/мл, <italic>p</italic> &lt;0,001]. Уровни малонового диальдегида, напротив, были повышены при воспалительных заболеваниях пародонта. Выявлена отрицательная корреляция между уровнем мелатонина и малоновым диальдегидом (r=−0,712; <italic>p</italic> &lt;0,001) у пациентов с хроническим пародонтитом. У пациентов с воспалением пародонта также отмечалась высокая частота выделения пародонтопатогенов (<italic>Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Treponema denticola</italic>), а уровень мелатонина отрицательно коррелировал с наличием ассоциаций патогенов (r=−0,80; <italic>p</italic> &lt;0,001).</p> <p><bold>Заключение</bold>. В условиях Арктики дефицит мелатонина в ротовой жидкости у пациентов с хроническим пародонтитом ассоциирован с усилением оксидативного стресса и активацией иммунного ответа, что усугубляет течение воспалительного процесса в пародонте.</p></trans-abstract><kwd-group xml:lang="en"><kwd>melatonin</kwd><kwd>oxidative stress</kwd><kwd>periodontopathogenic bacteria</kwd><kwd>inflammatory periodontal diseases</kwd><kwd>Russian Arctic</kwd></kwd-group><kwd-group xml:lang="ru"><kwd>мелатонин</kwd><kwd>окислительный стресс</kwd><kwd>пародонтопатогенные бактерии</kwd><kwd>воспалительные заболевания пародонта</kwd><kwd>Арктическая зона Российской Федерации</kwd></kwd-group><funding-group/></article-meta></front><body></body><back><ref-list><ref id="B1"><label>1.</label><mixed-citation>Chapple IL, Matthews JB. The role of reactive oxygen and antioxidant species in periodontal tissue destruction. Periodontol 2000. 2007;43:160–232. doi: 10.1111/j.1600-0757.2006.00178.x</mixed-citation></ref><ref id="B2"><label>2.</label><mixed-citation>Bullon P, Newman HN, Battino M. Obesity, diabetes mellitus, atherosclerosis and chronic periodontitis: a shared pathology via oxidative stress and mitochondrial dysfunction? Periodontol 2000. 2014;64(1):139–153. doi: 10.1111/j.1600-0757.2012.00455.x</mixed-citation></ref><ref id="B3"><label>3.</label><mixed-citation>Battino M, Bullon P, Wilson M, Newman H. Oxidative injury and inflammatory periodontal diseases: the challenge of anti-oxidants to free radicals and reactive oxygen species. Crit Rev Oral Biol Med. 1999;10(4):458–476. doi: 10.1177/10454411990100040301</mixed-citation></ref><ref id="B4"><label>4.</label><mixed-citation>Waddington RJ, Moseley R, Embery G. Reactive oxygen species: a potential role in the pathogenesis of periodontal diseases. Oral Dis. 2000;6(3):138–151. doi: 10.1111/j.1601-0825.2000.tb00325.x EDN: XOBBHD</mixed-citation></ref><ref id="B5"><label>5.</label><mixed-citation>Gubin D, Danilenko K, Stefani O, et al. Light Environment of Arctic Solstices is Coupled With Melatonin Phase-Amplitude Changes and Decline of Metabolic Health. J Pineal Res. 2025;77(1):e70023. doi: 10.1111/jpi.70023 EDN: EKIQQA</mixed-citation></ref><ref id="B6"><label>6.</label><mixed-citation>Paul MA, Love RJ, Hawton A, Arendt J. Sleep and the endogenous melatonin rhythm of high arctic residents during the summer and winter. Physiol Behav. 2015;15(141):199–206. doi: 10.1016/j.physbeh.2015.01.021</mixed-citation></ref><ref id="B7"><label>7.</label><mixed-citation>Reiter RJ, Tan DX, Rosales-Corral S, et al. Mitochondria: Central Organelles for Melatonin's Antioxidant and Anti-Aging Actions. Molecules. 2018;23(2):509. doi: 10.3390/molecules23020509 EDN: YHVKMX</mixed-citation></ref><ref id="B8"><label>8.</label><mixed-citation>Manchester LC, Coto-Montes A, Boga JA, et al. Melatonin: an ancient molecule that makes oxygen metabolically tolerable. J Pineal Res. 2015;59(4):403–419. doi: 10.1111/jpi.12267 EDN: XQGHPR</mixed-citation></ref><ref id="B9"><label>9.</label><mixed-citation>Darenskaya MA, Goncharov IS, Kolesnikov SI, et al. Periodontitis and oxidative stress: current trends in studying pathogenetic interactions and approaches to correction. Pathological Physiology and Experimental Therapy. 2025;69(1):81–91. doi: 10.48612/pfiet/0031-2991.2025.01.81-91 EDN: KNXSCM</mixed-citation></ref><ref id="B10"><label>10.</label><mixed-citation>Galieva AS, Davidovich NV, Opravin AS, et al. The role of inflammatory biomarkers in gingival crevicular fluid involved in modulating immune defense mechanisms in chronic periodontitis. I.P. Pavlov Russian Medical Biological. 2023;31(3):451–458. doi: 10.17816/PAVLOVJ321217 EDN: MZRELK</mixed-citation></ref><ref id="B11"><label>11.</label><mixed-citation>Opravin AS, Galieva AS, Davidovich NV, et al. Periodontopathogenic microflora and antibiotic resistance genes in individuals with chronic generalized periodontitis. Periodontology. 2023;28(1):39–47. doi: 10.33925/1683-3759-2023-28-1-39-47 EDN: SXAYPK</mixed-citation></ref><ref id="B12"><label>12.</label><mixed-citation>Sczepanik FSC, Grossi ML, Casati M, et al. Periodontitis is an inflammatory disease of oxidative stress: We should treat it that way. Periodontol 2000. 2020;84(1):45–68. doi: 10.1111/prd.12342 EDN: OJWRBM</mixed-citation></ref><ref id="B13"><label>13.</label><mixed-citation>Moiseev DA, Kopetsky IS, Nikolskaya IA, et al. Treatment, prevention and outcomes of endo-periodontal lesions: a modern view. Clinical Dentistry (Russia). 2023;26(4):18–28. doi: 10.37988/1811-153X_2023_4_18 EDN: RWOQTO</mixed-citation></ref></ref-list></back></article>
