This work aimed to investigate whether treatment with the antidiabetic drug metformin would affect adenine-induced chronic kidney disease (CKD) in non-diabetic rats and rats with streptozotocin (STZ)-induced diabetes. Rats were randomly divided into eight groups, and given either normal feed, or feed mixed with adenine (0.25% w/w, for five weeks) to induce CKD. Some of these groups were also simultaneously treated orally with metformin (200 mg/kg/day). Rats given adenine showed the typical signs of CKD that included detrimental changes in several physiological and traditional and novel biochemical biomarkers in plasma urine and kidney homogenates such as albumin/creatinine ratio, N-acetyl-beta-D-glucosaminidase, neutrophil gelatinase-associated lipocalin, 8-isoprostane, adiponectin, cystatin C, as well as plasma urea, creatinine, uric acid, indoxyl sulfate, calcium, and phosphorus. Several indices of inflammation and oxidative stress, and renal nuclear factor-κB and nuclear factor erythroid 2-related factor 2 levels were also measured. Histopathologically, adenine caused renal tubular necrosis and fibrosis. The activation of the intracellular mitogen-activated protein kinase signaling pathway was inhibited in the groups that received metformin and STZ together, with or without adenine induced-CKD. Induction of diabetes worsened most of the actions induced by adenine. Metformin significantly ameliorated the renal actions induced by adenine and STZ when these were given singly, and more so when given together. The results suggest that metformin can be a useful drug in attenuating the progression of CKD in both diabetic and non-diabetic rats.

We investigated some reproductive actions of hookah smoke (HS) exposure (30 min/day, for 30 days) in male mice, and the possible mitigative effect of the prebiotic agent gum acacia (GA) thereon. Control mice were air-exposed (AE). Twenty-four hours after the last exposure, the levels of some plasma reproductive hormones, biochemical markers of inflammation, oxidative and nitrosative stress and testicular histopathology were assessed. The urinary level of cotinine, a major nicotine metabolite, was also measured. HS exposure induced significant decreases in testosterone, estradiol, luteinizing hormone, and androgen binding protein, as well as glutathione reductase activity and levels of nitrite and total nitrite. Plasma inhibin B, alkaline phosphatase, lipopolysaccharide binding protein, uric acid, lactate dehydrogenase, lipid peroxidation, 8-oxo-2’-deoxyguanosine, and cytochrome C were significantly increased following HS exposure. In testicular homogenate, nuclear factor-κB (NF-ĸB), nuclear factor erythroid 2–related factor 2 (Nrf2), interleukin- 6 (IL-6), interleukin-1β (IL-1β), transforming growth factor-β1(TGF- β1), and tumor necrosis factor-α (TNF- α) were all significantly elevated, and the steroidogenic acute regulatory protein (StAR) significantly decreased. Histopathologically, there was slight impairment and disorganization of spermatogenesis. Urinary cotinine concentration was elevated significantly in the HS-exposed group compared with the air-exposed group. GA co-administration mitigated the adverse actions of HS measured. In conclusion, daily exposure to HS at the above dose induced adverse actions on the reproductive system of male mice. GA co-administration significantly mitigated these effects by reducing the inflammation, oxidative and nitrosative stress, via a mechanism involving Nrf2, and reduction of StAR expression.

Riociguat is a soluble guanylate cyclase (sGC) activator that increases the levels of cyclic guanosine monophosphate (cGMP). cGMP is known to play a key role in regulating kidney function. This research sought to investigate the possible protective effects of riociguat on the kidneys in the context of chronic kidney disease (CKD). CKD was induced in male Wistar rats through adenine administration. A total of 24 rats were allocated into four groups and administered treatments over a period of 35 days. Group 1 received a normal diet and a vehicle (carboxymethylcellulose (0.5%)), serving as the control. Group 2 received adenine (0.25% w/w) in the feed and a vehicle. Groups 3 and 4 received adenine in the feed (0.25% w/w) plus riociguat (3 mg/kg/day) and riociguat (10 mg/kg/day), respectively. Adenine administration significantly elevated systolic blood pressure, plasma creatinine, urea, and neutrophil gelatinase-associated lipocalin (NGAL). Furthermore, adenine reduced creatinine clearance and increased the urinary albumin-to-creatinine ratio and urinary N-Acetyl-β-D-Glucosaminidase (NAG). Histopathologically, adenine caused renal tubular necrosis and fibrosis. Furthermore, adenine elevated the plasma concentration of interleukins (IL-1β and IL-6) and tumor necrosis factor-alpha (TNF-α). Adenine significantly increased renal malondialdehyde (MDA) and reduced glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), and total antioxidant capacity (TAC). Treatment with riociguat attenuated adenine-induced hypertension, improved kidney function, and ameliorated histopathological changes. Riociguat also reduced kidney injury markers, inflammation, and renal oxidative stress. The renoprotective effect of riociguat is probably due to anti-inflammatory and antioxidant actions. This indicates that riociguat may have the potential to slow the progression of kidney damage in chronic kidney disease (CKD).

Background: Cisplatin (CP), a platinum-based chemotherapeutic agent, is widely used to treat cancer but causes nephrotoxicity. Riociguat, a soluble guanylate cyclase (sGC) stimulator that enhances the nitric oxide–sGC–cGMP signaling pathway, was investigated for its potential protective effects against cisplatin-induced nephrotoxicity. Materials and Methods: Rats were randomly divided into four equal groups (six rats each) and treated for nine consecutive days. The first and second groups were given oral carboxymethylcellulose 0.5% (vehicle) for 9 days, and on day 6 were injected intraperitoneally with saline or CP, respectively. The third and fourth groups were treated orally with two doses of riociguat (3 and 10 mg/kg/day) for 9 days, and received intraperitoneal injections of CP on day 6. Blood, urine, and kidney tissues were analyzed 24 h after the last treatment. Results: CP significantly elevated the markers of kidney function, including uric acid, serum creatinine, and urea. CP also caused histological kidney damage. Antioxidant markers, including catalase (CAT), glutathione reductase (GR), superoxide dismutase (SOD), and total antioxidant capacity (TAC) were significantly reduced, while inflammatory cytokines (IL-1β, IL-6, and TNF-α) and lipid peroxidation (MDA) were markedly increased. Riociguat improved kidney structure and significantly reduced kidney function markers, MDA, and inflammatory cytokines while restoring GR, TAC, SOD, and CAT activities. Conclusions: These results indicate that riociguat exerts protection of the kidneys from CP-caused kidney damage by antioxidation and anti-inflammation. Riociguat may have potential as an adjunct therapy to mitigate CP-associated nephrotoxicity.

Background: Diabetes mellitus (DM) and chronic kidney disease (CKD) are major contributors to global morbidity and mortality, with disease progression being closely linked to persistent inflammation, oxidative damage, and apoptotic pathways. Icariin (ICA), a bioactive flavonoid compound isolated from Epimedium brevicornum Maxim, has attracted considerable interest because of its diverse pharmacological properties. We evaluated the effect of ICA on streptozotocin (STZ)-induced diabetic rats with or without adenine-induced CKD. This combined model reproduces several key structural and functional characteristics observed in human diabetic kidney disease and advanced CKD. Methods: Male Wistar rats were allocated to five treatment groups and followed for 35 days. Group 1 served as the untreated control and received standard chow; Group 2 was administered streptozotocin (STZ); Group 3 received STZ together with icariin (ICA); Group 4 received a combination of adenine and STZ; and Group 5 was treated with adenine, STZ, and ICA. ICA was administered at a dose of 200 mg/kg by oral gavage. Biochemical, oxidative stress and inflammatory markers were assessed. Results: Rats treated with STZ, with or without adenine, exhibited significant hyperglycemia, elevated plasma levels of cystatin C and indoxyl sulphate, increased urinary levels of N-acetyl-β-D-glucosaminidase (NAG) and NAG/creatinine ratio, and reduced creatinine clearance. Additionally, there were significant decreases in renalase activity and urine osmolality, significant increases in interleukins IL-1β and IL-6 and TNF-alpha levels, and a decrease in IL-10 level. Oxidative stress biomarkers were also significantly impaired in both groups, along with significant renal histopathological changes. ICA significantly ameliorated these alterations in both experimental groups. Conclusions: These findings demonstrate that ICA exerts renoprotective and anti-inflammatory effects in a clinically relevant model of advanced diabetic CKD. Further studies are warranted to elucidate the underlying mechanisms and determine the translational relevance of these findings.