Diabetes Mellitus (DM) is a chronic disease characterized by hyperglycemia caused by insulin deficiency or insulin resistance
(Mishra et al., 2024). STZ is a naturally occurring alkylating antineoplastic agent that is particularly toxic to the insulin-producing beta cells of the pancreas in mammals. The formation of diabetes by STZ is formed as a result of destroying the b-cells of the pancreas. STZ is one of the most commonly used agents to induce experimental diabetes
(Cardinal et al., 1999). Adipokines are biomolecules secreted from adipose tissue that play a role in many physiological processes in the body
(Bayraktar, 2020) such as nutrition
(Romacho et al., 2015), appetite
(Silveira et al., 2009), energy balance
(Trayhurn et al., 2006), insulin and glucose metabolism, lipid metabolism
(Rabe et al., 2008), blood pressure regulation
(Yiannikouris et al., 2010), coagulation, inflammation
(Romacho et al., 2015).
Adipokines have a role in the development of diabetes and diabetes-related complications
(Al-Hamodi et al., 2014). Visfatin is an adipocytokine with a pro-inflammatory effect that is also secreted from adipose tissue. It is thought that visfatin may be a promising molecule due to its potential role in the pathogenesis of metabolic diseases and related complications, especially DM. Visfatin levels are reported to be increased in T2 DM
(Berndt et al., 2005).The mean serum visfatin levels on day 0 of the study in the C, R100, R200, R300 control groups were found to be 40.3, 40.75, 40.98 and 41.15 ng/ml. In the same way, diabetic groups DC, DR100, DR200 and DR300 were determined to be 53.11, 52.36, 53.84 and 52.59 ng/ml, respectively. The mean serum visfatin levels on day 21 of the study in the C, R100, R200 and R300 control groups were found to be 41.51, 42.48, 42.45 and 43.41 ng/ml. In the same way, diabetic groups DC, DR100, DR200 and D300 were determined to be 57.33, 51.14, 50.09 and 48.33 ng/ml, respectively (Table 3). When the current results were examined, a statistical difference was observed between the groups (p<0.01). While the increase in mean serum visfatin levels due to diabetes was mostly seen in DC groups, similarly, in DR groups, mean serum visfatin levels decreased in all groups due to the addition of antioxidant-effective RPE, while the most significant decrease was determined in DR300 groups (p<0.01). Although the current results of our study are limited in terms of the studies examining the effect of RPE on serum visfatin levels, they differ from studies reporting that it does not change
(Akbarzadeh et al., 2015), which is consistent with similar research literature
(Han et al., 2013; Berndt et al., 2005; Tond et al., 2016). Our data also showed that treating diabetic rats with RPE could lead to a decrease in visfatin levels. We think that this is due to the phytochemicals contained in RPE, which have antioxidant effects.
Cardiovascular diseases are among the leading causes of death worldwide. DM has an active role in the development of cardiovascular diseases.Cardiac troponins (cTn) are cardiospecific markers of ischemic myocardial damage used in diagnosing acute coronary syndrome and myocardial damage with different etiology and pathogenesis. cTnI is a highly specific biomarker for cardiac injury
(Adams et al., 1993). It is the gold standard for screening for acute coronary syndrome or rapid diagnosis of acute myocardial infarction
(Anand and Mills, 2019). The mean serum cTnI levels on day 0 of the study in the C, R100, R200 and R300 control groups were found to be 0.41, 0.43, 0.44 and 0.43 ng/ml. In the same way, diabetic groups DC, DR100, DR200 and DR300 were determined to be 0.70, 0.69, 0.70 and 0.74 ng/ml, respectively. The mean serum cTnI levels on day 21 of the study in the C, R100, R200 and R300 control groups were found to be 0.44, 0.45, 0.46 and 0.48 ng/ml. In the same way, diabetic groups DC, DR100, DR200 and DR300 were determined to be 0.78, 0.73, 0.79 and 0.78 ng/ml, respectively (Table 4). When the current results were examined, a statistical difference was observed between the groups (p<0.01). The highest mean serum cTnI level was determined in the DC and DR300 groups due to increased cardiac damage due to diabetes. Similarly, the most significant decrease in the mean serum cTnI level on day 21 compared to day 0 was determined in the DR100 groups due to the addition of different amounts of RPE, which has been reported to have a cardioprotective effect in the diabetes groups (p<0.01). The current results of our study are consistent with research results reporting that serum cTnI levels increase in diabetes
(Berndt et al., 2005; Brouwers et al., 2013). On the other hand, although studies examining the effect of RPE, which has been reported to have a cardioprotective effect, on mean serum cTnI levels are limited, they are consistent with similar research results in the literature
(Afzaal et al., 2023; Miraghaee et al., 2024). We think that the reason for this situation is due to the cardioprotective effect of RPE.