The combined effect of zinc oxide nanoparticles and milrinone on acute renal ischemia/reperfusion injury in rats: Potential underlying mechanisms

Nanotherapeutics in Kidney Disease: Innovations, Challenges, and Future Directions

The treatment and management of kidney diseases present a significant global challenge, affecting over 800 million individuals and necessitating innovative therapeutic strategies that transcend symptomatic relief. The application of nanotechnology to therapies for kidney diseases, while still in its early stages, holds transformative potential for improving treatment outcomes. Recent advancements in nanoparticle-based drug delivery leverage the unique physicochemical properties of nanoparticles for targeted and controlled therapeutic delivery to the kidneys. Current research is focused on understanding the functional and phenotypic changes in kidney cells during both acute and chronic conditions, allowing for the identification of optimal target cells. In addition, the development of tailored nanomedicines enhances their retention and binding to key renal membranes and cell populations, ultimately improving localization, tolerability, and efficacy. However, significant barriers remain, including inconsistent nanoparticle synthesis and the complexity of kidney-specific targeting. To overcome these challenges, the field requires advanced synthesis techniques, refined targeting strategies, and the establishment of animal models that accurately reflect human kidney diseases. These efforts are critical for the clinical application of nanotherapeutics, which promise novel solutions for kidney disease management. This review evaluates a substantial body of in vivo research, highlighting the prospects, challenges, and opportunities presented by nanotechnology-mediated therapies and their potential to transform kidney disease treatment.

Synergy of zinc oxide nanoparticles to losartan attenuates kidney injury induced by unilateral ureteral obstruction through modulation of the TNF-α/IL6 and BAX/BCL2 signaling pathways

AIM

Although the relief of ureteral obstruction seems to be a radical treatment for obstructive uropathy (OU), progressive kidney damage is the result because of the associated increased apoptosis and fibrosis. Therefore, it is urgent to find a complementary renoprotective therapy against partially obstructed uropathy cascades. Thus, this study investigated the renoprotective effects of both losartan (LOS) and zinc oxide nanoparticles (ZnONPs) in partial unilateral ureteral obstruction (PUUO).

MAIN METHODS

In controlled (n = 16) and shamed (n = 16) study, 64 healthy male Sprague-Dawley rats, both PUUO and right nephrectomy (RNX) were induced. The rats were equally allocated into four groups according to treatment protocol: (1) PUUO group (no treatment), (2) ZnONPs group, (3) LOS group and (4) ZnONPs/LOS group. Antioxidant status and gene expression were assessed in renal tissues. Moreover, histologic and immunohistochemical examinations were performed.

KEY FINDINGS

LOS and ZnONPs significantly mitigated the PUUO-induced renal injury, by significant (P < 0.0001) suppressing of oxidative stress (MDA and TOS), upregulating of antioxidant gene (SOD) and antiapoptotic gene (BCL2), and downregulating the expression of inflammatory cytokines (TNF-α, and IL6), apoptotic gene (Bax) and fibrotic marker (β-Catenin). The combination of both agents offered a more powerful renoprotective effect with additional significant upregulation of the antioxidant marker (TAC, P < 0.0001).

SIGNIFICANCE

Both losartan and ZnONPs and specially their combination have synergistic action in protecting the kidney against PUUO-induced chronic renal cascades through improvement the renal function tests, amelioration of oxidative stress, inhibition of induced apoptosis and fibrosis with marked renal regeneration which highlights the possible application of these drugs as a complementary therapies for different chronic renal degenerative diseases.

Water extract of earthworms mitigates kidney injury triggered by oxidative stress via activating intrarenal Sirt1/Nrf2 cascade and ameliorating mitochondrial damage

ETHNOPHARMACOLOGICAL RELEVANCE

Ischemia-reperfusion (IR) injury can result in acute renal failure. Oxidative stress is a major factor in IR-induced cell death in the kidneys. According to traditional Chinese medicine, earthworms (Pheretima aspergillum) can be used to treat various kidney diseases.

AIM OF THE STUDY

The present study was designed to understand the protective effects of the water extract of earthworms (WEE) against oxidative stress on the kidneys and the crucial molecular events associated with its nephroprotective activity.

MATERIALS AND METHODS

Cytotoxicity caused by H2O2 in HEK293, HK2, and primary mouse renal tubular epithelial cells (TECs) was used to investigate the effect of WEE on oxidative stress-induced renal injury in vitro. IR-induced kidney injury was established using rats as an in vivo model. The WEE-mediated protection of the kidneys against oxidative stress was compared with that of glutathione, a common antioxidant used as a positive control.

RESULTS

In HEK293 cells, HK2 cells, and primary mouse TECs, WEE relieved H2O2-induced mitochondrial damage, apoptosis, and ferroptosis. In kidney cells, WEE increased the expression of Sirt1, boosted LKB1 and AMPK phosphorylation, and upregulated nuclear Nrf2. Suppression of Sirt1 and LKB1 knock down abrogated WEE-induced protection against H2O2. WEE ameliorated IR-induced kidney injury and intrarenal inflammation in rats. In rat kidneys, WEE mitigated mitochondrial damage and suppressed IR-induced apoptosis and ferroptosis. Mechanistically, WEE increased Sirt1 expression, enhanced the phosphorylation of LKB1 and AMPK, and increased intranuclear Nrf2 levels in IR kidneys. IR treatment resulted in considerable increase in renal MDA levels and a prominent decrease in antioxidative enzyme activity. These lesions were significantly alleviated by WEE.

CONCLUSIONS

WEE mitigated H2O2-induced cytotoxicity in kidney cells in vitro and improved IR-induced kidney damage in rats. Mechanistically, WEE potentiated the Sirt1/Nrf2 axis and relieved mitochondrial damage in the kidney cells. These events inhibited the apoptosis and ferroptosis induced by oxidative stress. Our findings support the potential application of WEE for the clinical treatment of kidney diseases caused by intrarenal oxidative stress.

Examining the Influence of Zinc Oxide Nanoparticles and Bulk Zinc Oxide on Rat Brain Functions: a Comprehensive Neurobehavioral, Antioxidant, Gene Expression, and Histopathological Investigation

The study aimed to assess the impact of zinc oxide nanoparticles (ZnONPs) on rats' neurobehavior compared to bulk zinc oxide (BZnO). Thirty male Sprague-Dawley rats were randomly assigned to five groups. The control group received Tween 80 (10%), while the ZnONP groups were given ZnONPs at 5 and 10 mg/kg body weight dosages, and the bulk zinc oxide (BZnO) groups received BZnO at the same dosages. Behavioral observations, neurobehavioral examinations, and assessments of brain tissue oxidative markers, neurotransmitter levels, and histopathological changes were performed. The results indicated that ZnONP at a dosage of 5 mg/kg improved general behavior, locomotor activity, memory, and recognition and reduced fearfulness in rats. Conversely, the higher dosage of 10 mg/kg and the bulk form had adverse effects on general behavior, locomotor activity, and learning ability, with the bulk form demonstrating the most severe impact-znONP-5 treatment increased antioxidant enzyme levels and decreased inflammatory markers. BZnO-5 exhibited lower oxidative stress markers, although still higher than BZnO-10. Furthermore, ZnONP-5 and BZnO-5 increased neurotransmitter levels compared to higher dosages. ZnONP-5 upregulated the expression of brain-derived neurotrophic factor (BDNF) mRNA, while BZnO-5 showed increased BDNF mRNA expression and decreased expression of genes related to apoptosis and inflammation. In summary, ZnONPs at 5 mg/kg demonstrated positive effects on rat brain function and behavior, while higher dosages and the bulk form had detrimental effects. In conclusion, the studies emphasized the importance of further assessing various doses and forms of zinc oxide on brain health, highlighting the significance of dosage considerations when using nanomaterials.

Zn2+ improves sepsis-induced acute kidney injury by upregulating SIRT7-mediated Parkin acetylation

Zn2+ levels are reported to be correlated with kidney function. We explored the significance of Zn2+ in sepsis-induced acute kidney injury (SI-AKI) through the regulation of sirtuin 7 (SIRT7) activity. The sepsis rat model was established by cecal ligation and perforation (CLP) and intraperitoneally injected with ZnSO4 or SIRT7 inhibitor 97491 (SIRT7i), with renal tubular injury assessed by hematoxylin and eosin staining. In vitro, human renal tubular epithelial cells (HK-2) were induced with lipopolysaccharide to obtain a renal injury cell model, followed by ZnSO4 or SIRT7i and autophagy inhibitor (3-methyladenine) treatment. Interleukin (IL)-1β, IL-18, reactive oxygen species (ROS), Parkin acetylation level, kidney injury molecule-1 (KIM-1), and neutrophil gelatinase-associated lipocalin (NGAL) expression levels were determined. The renal tubule injury, inflammation condition, and pyroptosis-related and autophagy-related protein levels were assessed. The pyroptosis in kidney tissues and autophagosome formation were observed by transmission electron microscopy. Zn2+ alleviated renal injury in CLP rats and inhibited pyroptosis and its related protein levels by inhibiting SIRT7 activity in septic rat renal tissues. In vitro, Zn2+ increased HK-2 cell viability and reduced KIM-1, NGAL, IL-1β, IL-18, NLRP3 inflammasome, cleaved caspase-1, gasdermin D-N levels, and pyroptotic cell number. Zn2+ increased autophagosome number and LC3BII/LC3BI ratio and decreased TOM20, TIM23, P62, and mitochondrial ROS levels. Zn2+ increased Parkin acetylation by repressing SIRT7 activity. Inhibiting mitophagy partially averted Zn2+-inhibited NLRP3 inflammasome activation and apoptosis in HK-2 cells. Zn2+ upregulated Parkin acetylation by repressing SIRT7 activity to promote mitophagy and inhibit NLRP3 inflammasome activation and pyroptosis, thus improving SI-AKI.NEW & NOTEWORTHY Zn2+ upregulated Parkin acetylation by repressing sirtuin 7 activity to promote mitophagy and inhibit NLRP3 inflammasome activation and pyroptosis, thus improving sepsis-induced acute kidney injury.

Tailoring of an anti-diabetic drug empagliflozin onto zinc oxide nanoparticles: characterization and in vitro evaluation of anti-hyperglycemic potential

Diabetes is a serious health issue that can be a great risk factor related to numerous physical problems. A class of drugs "Gliflozin" especially Sodium Glucose Co. Transporter 2 was inhibited by a novel drug, which is known as "empagliflozin". While ZnO nanoparticles (NPs) had considerable promise for combating diabetes, it was employed in the treatment and management of type-2 diabetes mellitus. The new drug empagliflozin was initially incorporated into Zinc Oxide NPs in this study using the surface physio-sorption technique, and the degree of drug adsorption was assessed using the HPLC method. The tailored product was characterized by using the FTIR, EDX, Ultraviolet-Visible, XRD and SEM techniques. With an average particle size of 17 nm, SEM revealed mono-dispersion of NPs and sphere-like form. The Freundlich isotherm model best fits and explains the data for the physio-sorption investigation, which examined adsorption capabilities using adsorption isotherms. The enzymes α-amylase and α-glucosidase, which are involved in the human metabolism of carbohydrates, were used in the in-vitro anti-diabetic assays. It was discovered that the composite showed the highest levels of 81.72 and 92.77% inhibition of -α-amylase and -glucosidase at an absolute concentration of 1000 μg per ml with IC50 values of 30.6 μg per ml and 72 μg per ml.