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Protective effects of wheat germ oil against erectile and endothelial dysfunction in streptozotocin-induced diabetic rats


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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Fig. 1: Study protocol.
Fig. 2: Comparison of in vivo erectile function in control and diabetes mellitus and WGO treated groups.
Fig. 3: Endothelium-dependent and independent relaxation responses.


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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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Correspondence to Hulya Guven.

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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).

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