Our aim was to investigate the protective effect of wheat germ oil (WGO) at different doses on diabetes mellitus (DM)-induced erectile and endothelial dysfunction. Twenty-four male Wistar rats weighing 250–300 g were divided into four groups as; control group treated with saline, DM group, DM group treated with 3 ml/kg WGO (DM + 3WGO group), DM group treated with 6 ml/kg WGO. Type 1 DM was induced by intraperitoneal injection of 60 mg/kg streptozotocin (STZ). STZ-induced diabetic rats received saline, 3 ml/kg WGO, and 6 ml/kg WGO via oral gavage daily for 5 weeks. The density of WGO used was 0.92 g/ml. The protective effect of WGO was evaluated by (i) in vitro vascular function, (ii) in vivo erectile function, and (iii) oxidative stress parameters in both aorta and penile tissue. Acetylcholine-mediated relaxation in the aorta and erectile functions decreased significantly in the DM group (p = 0.018 and p = 0.005). WGO (3 and 6 ml/kg) improved vascular functions in the DM groups (p = 0.001 and p = 0.014). The beneficial effect of WGO on erectile function appeared at higher doses of WGO. However, a higher dose of WGO substantially increased the oxidative stress parameters in both aorta and penile tissue. These findings suggest that the improvement in vascular or erectile function by WGO was not related to antioxidant effects, and new studies are needed to clarify the mechanism.
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Association AD. American diabetes association: diagnosis and classification of diabetes mellitus. Diabetes Care. 2014;37:81–90.
Cho NH, Ahn CW, Park JY, Ahn TY, Lee HW, Park TS, et al. Prevalence of erectile dysfunction in Korean men with Type 2 diabetes mellitus. Diabet Med. 2006;23:198–203.
Lue TF, Brant WO, Shindel A, Bella AJ. Sexual dysfunction in diabetes. In: Feingold KR, Anawalt B, Boyce A, et al., editors. Endotext. South Dartmouth (MA): MDText.com, Inc.; 2000.
Tilton RG, Chang K, Hasan KS, Smith SR, Petrash JM, Misko TP, et al. Prevention of diabetic vascular dysfunction by guanidines: inhibition of nitric oxide synthase versus advanced glycation end-product formation. Diabetes. 1993;42:221–32.
Hatzichristou DG. Sildenafil citrate: lessons learned from 3 years of clinical experience. Int J Impot Res. 2002;14:S43–52.
Hackett G, Cole N, Bhartia M, Kennedy D, Raju J, Wilkinson P, et al. The response to testosterone undecanoate in men with type 2 diabetes is dependent on achieving threshold serum levels (the BLAST study). Int J Clin Pract. 2014;68:203–15.
Padma-Nathan H, Yeager JL. An integrated analysis of alprostadil topical cream for the treatment of erectile dysfunction in 1732 patients. Urology. 2006;68:386–91.
Cui K, Tang Z, Li CC, Wang T, Rao K, Wang SG, et al. Lipoxin A4 improves erectile dysfunction in rats with type i diabetes by inhibiting oxidative stress and corporal fibrosis. Asian J Androl. 2018;20:166–72.
Kiasalari Z, Khalili M, Aghaei M. Effect of Withania somnifera on levels of sex hormones in the diabetic male rats. Iran J Reprod Med. 2009;7:163–8.
Eser N, Buyuknacar HS, Cimentepe OO, Gocmen C, Ucar Y, Erdogan S, et al. The effect of Ferula elaeochytris root extract on erectile dysfunction in streptozotocin-induced diabetic rat. Int J Impot Res. 2020;32:186–94.
Shurpalekar SR, Rao PH. Wheat Germ. Adv Food Res. 1977;23:187–304.
Karabacak M, Kanbur M, Eraslan G, Soyer, Sarica Z. The antioxidant effect of wheat germ oil on subchronic coumaphos exposure in mice. Ecotoxicol Environ Saf. 2011;74:2119–25.
Abbasnezhad A, Niazmand S, Mahmoudabady M, Soukhtanloo M, Rezaee SA, Mousavi SM. Nigella sativa seed decreases endothelial dysfunction in streptozotocin-induced diabetic rat aorta. Avicenna J Phytomed. 2016;6:67–76.
Tong YC, Hung YC, Lin SN, Cheng JT. Dark-cycle video surveillance of sexual performances of normal and diabetic rats. Urol Int. 1996;56:207–10.
Barakat IAH, Abbas OA, Ayad S, Hassan AM. Evaluation of radio protective effects of wheat germ oil in male rats. J Am Sci. 2011;7:664–73. http://www.americanscience.org
Bal E, Murat N, Demir O, Soner BC, Can E, Gidener S, et al. Restraint stress impairs erectile responses in rats. Tohoku J Exp Med. 2009;217:239–42.
Quinlan DM, Nelson RJ, Partin AW, Mostwin JL, Walsh PC. The rat as a model for the study of penile erection. J Urol. 1989;141:656–61.
Ding H, Hashem M, Wiehler WB, Lau W, Martin J, Reid J, et al. Endothelial dysfunction in the streptozotocin-induced diabetic apoE-deficient mouse. Br J Pharmacol. 2005;146:1110–8.
Lu CW, Lin Y, Lei YP, Wang L, He ZM, Xiong Y. Pyrrolidine dithiocarbamate ameliorates endothelial dysfunction in thoracic aorta of diabetic rats by preserving vascular DDAH activity. PLoS ONE. 2017;12:1–19.
Kasznicki J, Kosmalski M, Sliwinska A, Mrowicka M, Stanczyk M, Majsterek I, et al. Evaluation of oxidative stress markers in pathogenesis of diabetic neuropathy. Mol Biol Rep 2012;39:8669–78.
Guest JF, Das Gupta R. Health-related quality of life in a UK-based population of men with erectile dysfunction. Pharmacoeconomics. 2002;20:109–17.
Kirby M, Jackson G, Simonsen U. Endothelial dysfunction links erectile dysfunction to heart disease. Int. J Clin Pract. 2005;59:225–9.
Ghaheri M, Miraghaee S, Babaei A, Mohammadi B, Kahrizi D, Haghighi ZMS, et al. Effect of Stevia rebaudiana Bertoni extract on sexual dysfunction in Streptozotocin-induced diabetic male rats. Cell Mol Biol. 2018;64:6–10.
Zhang JL, Hui Y, Zhou F, Hou JQ. Neuroprotective effects of melatonin on erectile dysfunction in streptozotocin-induced diabetic rats. Int Urol Nephrol. 2018;50:1981–8.
Li WJ, Zhou J, Li B, Wang H, Peng YB, Wang Z. PARP inhibition restores erectile function by suppressing corporal smooth muscle apoptosis in diabetic rats. J Sex Med. 2011;8:1072–82.
Ayeleso A, Brooks N, Oguntibeju O. Modulation of antioxidant status in streptozotocin-induced diabetic male wistar rats following intake of red palm oil and/or rooibos. Asian Pac J Trop Med. 2014;7:536–44.
Leenhardt F, Fardet A, Lyan B, Gueux E, Rock E, Mazur A, et al. Wheat germ supplementation of a low vitamin e diet in rats affords effective antioxidant protection in tissues. J Am Coll Nutr. 2008;27:222–8.
Akool ES. Molecular mechanisms of the protective role of wheat germ oil against cyclosporin A-induced hepatotoxicity in rats. Pharm Biol. 2015;53:1311–7.
Hamdi H The preventive role of wheat germ oil against sertraline-induced testicular damage in male albino rats. Andrologia. 2019;51:e13369.
Alessandri C, Pignatelli P, Loffredo L, Lenti L, Del Ben M, Carnevale R, et al. Alpha-linolenic acid-rich wheat germ oil decreases oxidative stress and CD40 ligand in patients with mild hypercholesterolemia. Arterioscler Thromb Vasc Biol. 2006;26:2577–8.
Bai GY, Zhou F, Hui Y, Xu Y DE, Lei HE, Pu JX, et al. Effects of icariside II on corpus cavernosum and major pelvic ganglion neuropathy in streptozotocin-induced diabetic rats. Int J Mol Sci. 2014;15:23294–306.
Wheat Germ Oil was a kind donation of Tabia®, Natural Supplement Products, Research, Industry and Commerce Inc. Aydin. This research was presented as an oral presentation on March 5, 2020, at “Fifth German Pharm-Tox Summit, 86th Annual Meeting of the German Society for Experimental and Clinical Pharmacology and Toxicology”.
This research was supported by the Research Foundation of Dokuz Eylul University (2018.KB.SAG.003). The funding source had no involvement in study design; in the collection, analysis, and interpretation of data; in the writing of the report; and in the decision to submit the article for publication.
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Guven, H., Durmus, N., Hocaoglu, N. et al. Protective effects of wheat germ oil against erectile and endothelial dysfunction in streptozotocin-induced diabetic rats. Int J Impot Res (2021). https://doi.org/10.1038/s41443-021-00453-4