Journals / Marmara Medical Journal / 2026 / Volume: 39 Issue: 2

Neuroprotective effects of basil extract (Ocimum gratissimum) on hippocampal neuronal loss and spatial memory in a streptozotocininduced experimental Alzheimer’s disease model in rats using the Eight-arm Radial Maze Test

Danış Aygün(PAMUKKALE UNIVERSITY)0000-0002-6165-3422
Mehmet Bülent Özdemir(Bandırma Onyedi Eylül University)0000-0003-3826-5285
Nuriye Kurbetli(Bandırma Onyedi Eylül University)0000-0002-4267-9299
Pages
—
Publication Date
2026-05-21
🏛️Bibliographic metadata and full text access for this article are provided via DergiPark.
DergiPark Record ↗
✨

AI Summary & Key Takeaways

AI Insight
⚡ TL;DR(Too Long; Didn't Read)

This study may be an important resource for future molecular and clinical studies on the use of O. gratissimum extract in Alzheimer’s disease.

📌 3 Key Takeaways

🎯
Objective & Hypothesis:Objective: Alzheimer’s disease is the most common cause of age-related dementia.
📊
Key Findings & Data:Therefore, Alzheimer’s disease is also called type 3 diabetes.
💡
Conclusion & Impact:This study may be an important resource for future molecular and clinical studies on the use of O. gratissimum extract in Alzheimer’s disease.
🔬Design:Modeling & Simulation
📍Scope:Comprehensive Sample
⚙️Variables:Alzheimer’s disease · Diabetes mellitus · Experimental Alzheimer’s disease

Abstract

Objective: Alzheimer’s disease is the most common cause of age-related dementia. This disease is a progressive, degenerative central nervous system disease. Neuron loss is more pronounced in hippocampal pyramidal cells. Although various agents are known for its treatment, a stronger or definitive treatment has not yet been found. Alzheimer’s disease is seen in more than half of diabetes mellitus patients. The main similarities between these two diseases are insulin resistance and inflammatory pathways. Therefore, Alzheimer’s disease is also called type 3 diabetes. The antidiabetic effect of Ocimum gratissimum (O. gratissimum) extract, commonly known as basil extract are well documented worldwide. However, its behavioral and neuroprotective effects in Alzheimer’s disease have not been sufficiently studied yet. Our aim is to demonstrate the anti-apoptotic effect of O. gratissimum on hippocampal pyramidal cells in an experimental rat model of Alzheimer’s disease induced by streptozotocin (STZ) and in paralel, to test learning-related behaviors in rats. Materials and Methods: Thirty-three 4-month-old male Wistar rats were used and randomly divided into five groups: control, sham, STZ, O. gratissimum, and O. gratissimum+STZ. The eight-arm radial maze test was taught to all animals that were kept under suitable conditions. Finally, STZ and O. Gratissimum extract were given to rats together intraperitoneally. Blood glucose and the weight of all rats were measured regularly. After the eight-arm radial maze test was performed on the rats in all groups, the rats were decapitated, their brains were sectioned by histological methods, and all apoptotic cells in the hippocampus were counted with TUNEL method. All groups were compared by statistical analysis (ANOVA). Results: In rats whose learning was impaired with STZ, learning behavior improved in a statistically significant way with O. gratissimum extract (p <0.05). In parallel, O. gratissimum significantly reduced neuron loss in CA1, CA2, and CA3 areas of hippocampus when compared to STZ (p <0.05). Behavioral tests show that STZ and O. gratissimum have effects on apoptosis in the brain, especially in the hippocampus. There are also studies in parallel with our study showing that O. gratissimum reduces neuronal atrophy in the CA3 region. In our study, it was observed that the number of apoptotic cells was higher in the STZ group, and there was a corrective effect in the O. gratissimum added group. Conclusion: As a result, O. gratissimum extract showed a neuroprotective effect against the loss of hippocampal neurons caused by STZ, similar to that observed in Alzheimer’s disease, and maintained learning behavior accordingly. This study may be an important resource for future molecular and clinical studies on the use of O. gratissimum extract in Alzheimer’s disease.

🔖

Cite This Article

Aygün, D., Özdemir, M. B., Kurbetli, N. (2026). Neuroprotective effects of basil extract (Ocimum gratissimum) on hippocampal neuronal loss and spatial memory in a streptozotocininduced experimental Alzheimer’s disease model in rats using the Eight-arm Radial Maze Test. Marmara Medical Journal, Volume: 39 Issue: 2. https://doi.org/10.5472/marumj.1953925

📄 Full Text PDF Viewer

📄

PDF görüntüleyici hazırlanıyor...

References (37)

  1. Behl C. Alzheimer’s disease research. Cham: Springer 2023:27- 45. doi.org/10.1007/978-3-031-31570-1
  2. Jicha GA, Carr SA. Conceptual evolution in Alzheimer’s disease: implications for understanding the clinical phenotype of progressive neurodegenerative disease. J Alzheimer’s Dis 2010;19:253-72. doi.org/10.3233/JAD-2010-1237
  3. Watanabe T, Iwasaki K, Ishikane S, et al. Spatial memory impairment without apoptosis induced by the combination of beta-amyloid oligomers and cerebral ischemia is related to decreased acetylcholine release in rats. 2008;106:84-91. https://doi.org/10.1254/jphs.FP0071648
  4. Özdemir MB, Erdogan C, Iwasaki K, Watanabe T, Ishikane S, Fujiwara MJNr. Injection of specific amyloid-beta oligomers (beta1-40: beta1-42= 10: 1) into rat medial septum impairs memory retention without inducing hippocampal apoptosis. Neurol Res 2013;35:798-803. doi: 10.1179/1743132813Y.0000000195.
  5. Yonguc G, Ozdemir M, Kucukatay V, et al. Memory function and total pyramidal neuron number of hippocampus in streptozotocin-induced diabetic rats. Journal of Neurological Sciences 2014;31:461-71.
  6. Aisen PS. The potential of anti-inflammatory drugs for the treatment of Alzheimer’s disease. The Lancet Neurology 2002;1:279-84. doi.org/10.1016/S1474-4422(02)00133-3
  7. Antora RA, Salleh RM. Antihyperglycemic effect of Ocimum plants: A short review. Asian Pacific Trop Biomed 2017;7:755- 9. https://doi.org/10.1016/j.apjtb.2017.07.010
  8. Ahmadpour S, Foghi K. The possible neurodegeneration of the CA3 and CA1 of hippocampus in STZ-induced diabetes mellitus type1 on male wistar rats. J Med Histol 2021;5:41-7. doi.org/10.21608/jmh.2021.80629.1090
  9. Şahbaz N, Şahin G, Yücesan B, Verma S K, Gürel E. (2011). In vitro regeneration and analysis of total phenolics in Ocimum basilicum L.(sweet basil). Planta Medica 2011;77:PB13.
  10. Oyem JC, Chris-Ozoko LE, Enaohwo MT, Otabor FO, Okudayo VA, Udi OA. Antioxidative properties of Ocimum gratissimum alters Lead acetate induced oxidative damage in lymphoid tissues and hematological parameters of adult Wistar rats. Toxicol Rep 2021;8:215-22. doi.org/10.1016/j. toxrep.2021.01.003
  11. Ates O, Cayli SR, Altinoz E, et al. Neuroprotective effect of mexiletine in the central nervous system of diabetic rats. Mol Cell Biochem 2006;286:125-31. doi: 10.1007/s11010-005- 9102-6
  12. Tuzcu M, Baydas G. Effect of melatonin and vitamin E on diabetes-induced learning and memory impairment in rats. Eur J Pharmacol 2006;537:106-10. doi.org/10.1016/j. ejphar.2006.03.024
  13. Şavik E, Gültekin F, Karakoyun İ, Doğuç DK, Demirin H, Delibaş N. Klorpirifosun sıçanlarda öğrenmeye etkileri. Med J SDU 2008;15:1-6. doi.org/10.17343/sdutfd.59651
  14. Uygur EE, Ekiz EE, Akyazı İ, Gültekin İG, Arslan M. Investigation of the long term effects of chronic white noise stress on learning in radial arm maze and behaviors in forced swim test. Ankara Univ Vet Fak Derg 2011;58:233-8. doi:10.1501/Vetfak_0000002481
  15. Loo, D T. In situ detection of apoptosis by the TUNEL assay: an overview of techniques. DNA damage detection in situ, ex vivo, and in vivo: methods and protocols Methods Mol Biol 2011;682:3-13. doi.org/:10.1007/978-1-60327-409-8_1.
  16. M. de la Monte S. Brain insulin resistance and deficiency as therapeutic targets in Alzheimer’s disease. Curr Alzheimer Res 2012;9:35-66. doi: 10.2174/156720512799015037.
  17. Butterfield DA, Halliwell B. Oxidative stress, dysfunctional glucose metabolism and Alzheimer disease. Nature Reviews Neuroscience. 2019;20:148-60. doi: 10.1038/s41583-019- 0132-6.
  18. Kosaraju J, Madhunapantula SV, Chinni S, et al. Dipeptidyl peptidase-4 inhibition by Pterocarpus marsupium and Eugenia jambolana ameliorates streptozotocin induced Alzheimer’s disease. 2014;267:55-65. doi.org/10.1016/j.bbr.2014.03.026
  19. Shin M-S, Chung KJ, Ko I-G, Kim S-H, Jin J-J, Kim S-E, et al. Effects of surgical and chemical castration on spatial learning ability in relation to cell proliferation and apoptosis in hippocampus. 2016;48:517-27. doi: 10.1007/s11255-015- 1200-0.
  20. Kim D-Y, Jung S-Y, Kim K, Kim C-J. Treadmill exercise ameliorates Alzheimer disease-associated memory loss through the Wnt signaling pathway in the streptozotocin-induced diabetic rats. J Exerc Rehabil 2016;12:276. doi: 10.12965/ jer.1632678.339
  21. Sarahroodi S, Esmaeili S, Mikaili P, Hemmati Z, Saberi Y. The effects of green Ocimum basilicum hydroalcoholic extract on retention and retrieval of memory in mice. Anc Sci Life 2012;31:185-9. doi.org/10.4103/0257-7941.107354
  22. Udi OA, Oyovwi MO, Adeogun AE. Exploring the cognitive-enhancing effects of Ocimum gratissimum: an ethnopharmacological and phytochemical review. Discov Plant 2025;2:58. doi: 10.1007/s44372-025-00127-1
  23. Bora KS, Arora S, Shri RJJoe. Role of Ocimum basilicum L. in prevention of ischemia and reperfusion-induced cerebral damage, and motor dysfunctions in mice brain. J Ethnopharmacol 2011;137:1360-5. doi.org/10.1016/j. jep.2011.07.066
  24. Nehlig A. The neuroprotective effects of cocoa flavanol and its influence on cognitive performance. Br J Clin Pharmacol 2013;75:716-27. doi.org/10.1111/j.1365-2125.2012.04378.x
  25. ardner AL. Neurobiological effects of the green tea constituent theanine and its potential role in the treatment of psychiatric and neurodegenerative disorders. Nutri Neurosci 2014;17:145-55. doi: 10.1179/1476830513Y.0000000079.
  26. Liu C, Song J, Teng M, et al. Antidiabetic and antinephritic activities of aqueous extract of cordyceps militaris fruit body in diet‐streptozotocin‐induced diabetic sprague dawley rats.Oxid Med Cell Longev 2016;2016:9685257. doi. org/10.1155/2016/9685257
  27. Thomson M, Al-Qattan KK, Js D, Ali MJBC, Medicine A. Anti-diabetic and anti-oxidant potential of aged garlic extract (AGE) in streptozotocin-induced diabetic rats. 2015;16:1-9. doi: 10.1186/s12906-016-0992-5.
  28. Wang J, Teng L, Liu Y, et al. Studies on the antidiabetic and antinephritic activities of paecilomyces hepiali water extract in diet‐streptozotocin‐induced diabetic sprague dawley rats.J Diabetes Res 2016;2016:4368380. doi. org/10.1155/2016/4368380
  29. Taher M, Tg Zakaria TMFS, Susanti D, Zakaria ZA. Hypoglycaemic activity of ethanolic extract of Garcinia mangostana Linn. in normoglycaemic and streptozotocininduced diabetic rats. BMC Complement Med Ther 2016;16:1- 12. doi: 10.1186/s12906-016-1118-9.
  30. Ayuob NN, Firgany AE-DL, El-Mansy AA, Ali S. Can Ocimum basilicum relieve chronic unpredictable mild stressinduced depression in mice? Exp Mol Pathol 2017;103:153-61. doi.org/10.1016/j.yexmp.2017.08.007
  31. Ajibola M, Ibrahim RB, Imam A, Masud M A, Safiriyu A, Etibor AT. Neurodegenerative potential of the aqueous leaf extract of Ocimum gratissimum: A histological and biochemical study. Anat J Afr 2015;4:563-70.
  32. Ali S, Abd El Wahab M, Ayuob N, Suliaman MJB. The antidepressant-like effect of Ocimum basilicum in an animal model of depression. Biothec Histochem 2017;92:390-401. doi: 10.1080/10520295.2017.1323276
  33. Lester-Coll N, Rivera EJ, Soscia SJ, Doiron K, Wands JR, De la Monte SM. Intracerebral streptozotocin model of type 3 diabetes: relevance to sporadic Alzheimer’s disease. J Alzheimer’s Dis 2006;9:13-33. doi.org/10.3233/JAD-2006- 9102
  34. Ajayi GO, Edamisan OM, Obayemi PT, Elegbeleye EN, Obi EU. Phytoconstituents and antidiabetic activity of vernonia amygdalina (asteraceae) in steptozotocin-induced diabetic rats. Int J Biochem Bioinforma Biotech Stud 2021;6:1-16.
  35. Kakkar A, Singh H, Anand A, Chopra H, Mishra AK. Neuroprotective effects of eugenol in Alzheimer’s disease: mitigating oxidative stress, inflammation and amyloid plaques. Curr Pharm Des 2026;32:493-504. doi: 10.2174/011 3816128373290250620054118.
  36. Jamshidzadeh A, Baghban M, Azarpira N, Bardbori AM, Niknahad H. Effects of tomato extract on oxidative stress induced toxicity in different organs of rats. Food Chem Toxicol 2008;46:3612-5. doi.org/10.1016/j.fct.2008.09.006
  37. Irie Y. Effects of eugenol on the central nervous system: its possible application to treatment of Alzheimer’s disease, depression, and Parkinson’s disease. Curr Bioact Compd 2006;2:57-66. doi: 10.2174/1573407210602010057