## 4 Discussion
Ammonia is produced as a result of the deamination of amino acids and this ammonia is converted into urea in the presence of liver enzymes. Creatinine is also a nonprotein nitrogenous (NPN) waste obtained from the breakdown of creatine and phosphocreatine [51]. As shown in Table 4, EPE extract reduced urea and creatinine levels and maintained AST and ALT levels. AMP-activated protein kinase (AMPK) restores the energy balance and promotes ATP generation [52]. It has an alpha catalytic unit and two isoforms, \(\alpha\)1 and \(\alpha\)2 [53]. It was found that AMPK stimulates glucose uptake and thereby lowered the blood glucose level [52]. Phosphorylated AMPK can regulate lipogenesis [52]. The homeostasis of the adipose tissue is maintained by peroxisome proliferator-activated receptors (PPARs). They are a group of ligand-activated nuclear hormone receptors and have three forms of isomers called PPAR\(\alpha\), PPAR\(\beta\)/\(\delta\), and PPAR\(\gamma\). PPAR\(\alpha\) increases ATP production from \(\beta\)-oxidative phosphorylation under energy-deprived conditions. The expression of PPAR\(\gamma\) is usually found in adipose tissue and stimulates fat storage, adipogenesis, and thermogenesis [54]. Our results showed that the expressions of AMPK\(\alpha\)1/2 and PPAR-\(\alpha\) were increased and PPAR-\(\gamma\) expression was decreased after treated with EPE extract. Kiss1R is the receptor of a neuropeptide called kissepeptin. It is associated with initiating puberty and maintaining the reproductive capacity of the adult [55]. The literature stated that the energy imbalance negatively affects the kissepeptin signaling pathway [55]. Hypothalamic hypogonadism is largely seen under diabetic or obese conditions. They are expressed in peripheral tissues controlling metabolism and the functioning of these tissues are altered under energy imbalanced conditions [56]. The decrease in Kiss1R mRNA expression under obese conditions was mentioned in a previous study [56]. StAR is a labile phosphoprotein known for the regulation of steroid hormones. The activity of StAR is highly enhanced in the adrenal and gonads under the acute steroidogenesis process. So, the inhibition of StAR affects steroid biosynthesis [57]. Testosterone synthesis is catalyzed by an enzyme called 17\(\beta\)-HSD3. This catalyzes the reduction of androstenedione to testosterone [58]. Our results indicated that EPE extracts, especially EPE5, were able to ameliorate the mRNA expression of Kiss1R, StAR, and 17\(\beta\)-HSD3. Seminiferous tubules and interstiti are the functional compartments of the testes, in which spermatogenesis and androgen biosynthesis occur, respectively. Sertoli cells are found in the seminiferous tubules are responsible for nurturing the developing sperm cells. They control the passage of bloodborne nutrients, hormones, and exogenous substances into the tubules. The androgen-secreting Leydis cells find the interstitial space between the seminiferous tubules [59]. Figure 10 reveals that the normal morphology of testes was negatively changed in the HFD group and the administration of EPE significantly improved the morphology (Figure 10). Additionally, the sperm parameters were also improved (Figure 9 and Table 5). MMP is the energy status of mitochondria and it helps to identify the viability of sperm cells. The membrane potential of the sperm is directly proportional to its motility [60]. Sperm DNA was also altered under obese conditions due to oxidative stress [61]. Our results showed that EPE significantly improved sperm DNA damage and sperm MMP (Figures 11 and 12). In conclusion, our in vivo study revealed that the EPE extract can reduce the level of cytokines and further oxidative stress. In addition to this, the sperm parameters, testis structure, sperm DNA damage, and sperm mitochondrial membrane potential were also improved. Additionally, they increased lipid metabolism and testosterone synthesis.