Protective Effects of Carnosol on Renal Interstitial Fibrosis in a Murine Model of Unilateral Ureteral Obstruction

Fluorinated 1,7-DO2A-Based Iron(II) Complexes as Sensitive 19F MRI Molecular Probes for Visualizing Renal Dysfunction in Living Mice

Kidney diseases have become an important global health concern due to their high incidence, inefficient diagnosis, and poor prognosis. Devising direct methods, especially imaging means, to assess renal function is the key for better understanding the mechanisms of various kidney diseases and subsequent development of effective treatment. Herein, we developed a fluorinated ferrous chelate-based sensitive probe, 1,7-DO2A-Fe(II)-F18 (Probe 1), for 19F magnetic resonance imaging (MRI). This highly fluorinated probe (containing 18 chemically equivalent 19F atoms with a fluorine content at 35 wt %) achieves a 15-time enhancement in signal intensity compared with the fluorine-containing ligand alone due to the appropriately regulated 19F relaxation times by the ferrous ion, which significantly increases imaging sensitivity and reduces acquisition time. Owing to its high aqueous solubility, biostability, and biocompatibility, this probe could be rapidly cleared by kidneys, which provides a means for monitoring renal dysfunction via 19F MRI. With this probe, we accomplish in vivo imaging of the impaired renal dysfunction caused by various kidney diseases including acute kidney injury, unilateral ureteral obstruction, and renal fibrosis at different stages. Our study illustrates the promising potential of Probe 1 for in vivo real-time visualization of kidney dysfunction, which is beneficial for the study, diagnosis, and even stratification of different kidney diseases. Furthermore, the design strategy of our probe is inspiring for the development of more high-performance 19F MRI probes for monitoring various biological processes.

Carnosol prevents cardiac remodeling and ventricular arrhythmias in pressure overload-induced heart failure mice

Cardiac remodeling is a commonly observed pathophysiological phenomenon associated with the progression of heart failure in various cardiovascular disorders. Carnosol, a phenolic compound extracted from rosemary, possesses noteworthy pharmacological properties including anti-inflammatory, antioxidant, and anti-apoptotic activities. Considering the pivotal involvement of inflammation, oxidative stress, and apoptosis in cardiac remodeling, the present study aims to assess the effects of carnosol on cardiac remodeling and elucidate the underlying mechanisms. In an in vivo model, cardiac remodeling was induced by performing transverse aortic constriction (TAC) surgery on mice, while an in vitro model was established by treating neonatal rat cardiomyocytes (NRCMs) with Ang II. Our results revealed that carnosol treatment effectively ameliorated TAC-induced myocardial hypertrophy and fibrosis, thereby attenuating cardiac dysfunction in mice. Moreover, carnosol improved cardiac electrical remodeling and restored connexin 43 expression, thereby reducing the vulnerability to ventricular fibrillation (VF). Furthermore, carnosol significantly reduced Ang II-induced cardiomyocyte hypertrophy in NRCMs and alleviated the upregulation of hypertrophy and fibrosis markers. Both in vivo and in vitro models of cardiac remodeling exhibited the anti-inflammatory, anti-oxidative, and anti-apoptotic effects of carnosol. Mechanistically, these effects were mediated through the Sirt1/PI3K/AKT pathway, as the protective effects of carnosol were abrogated upon inhibition of Sirt1 or activation of the PI3K/AKT pathway. In summary, our study suggests that carnosol prevents cardiac structural and electrical remodeling by regulating the anti-inflammatory, anti-oxidative, and anti-apoptotic effects mediated by Sirt1/PI3K/AKT signaling pathways, thereby alleviating heart failure and VF.

Palliative effects of carnosol on lung-deposited pollutant particles-induced thrombogenicity and vascular injury in mice

The toxicity of inhaled particulate air pollution perseveres even at lower concentrations than those of the existing air quality limit. Therefore, the identification of safe and effective measures against pollutant particles-induced vascular toxicity is warranted. Carnosol is a bioactive phenolic diterpene found in rosemary herb, with anti-inflammatory and antioxidant actions. However, its possible protective effect on the thrombotic and vascular injury induced by diesel exhaust particles (DEP) has not been studied before. We assessed here the potential alleviating effect of carnosol (20 mg/kg) administered intraperitoneally 1 h before intratracheal (i.t.) instillation of DEP (20 μg/mouse). Twenty-four hours after the administration of DEP, various parameters were assessed. Carnosol administration prevented the increase in the plasma concentrations of C-reactive protein, fibrinogen, and tissue factor induced by DEP exposure. Carnosol inhibited DEP-induced prothrombotic effects in pial microvessels in vivo and platelet aggregation in vitro. The shortening of activated partial thromboplastin time and prothrombin time induced by DEP was abated by carnosol administration. Carnosol inhibited the increase in pro-inflammatory cytokines (interleukin-6 and tumor necrosis factor α) and adhesion molecules (intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin, and P-selectin) in aortic tissue. Moreover, it averted the effects of DEP-induced increase of thiobarbituric acid reactive substances, depletion of antioxidants and DNA damage in the aortic tissue. Likewise, carnosol prevented the decrease in the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) caused by DEP. We conclude that carnosol alleviates DEP-induced thrombogenicity and vascular inflammation, oxidative damage, and DNA injury through Nrf2 and HO-1 activation.

Noninvasive Diagnosis of Kidney Dysfunction Using a Small-Molecule Manganese-Based Magnetic Resonance Imaging Probe

Contrast-enhanced magnetic resonance imaging (CE-MRI) is a promising approach for the diagnosis of kidney diseases. However, safety concerns, including nephrogenic systemic fibrosis, limit the administration of gadolinium (Gd)-based contrast agents (GBCAs) in patients who suffer from renal impairment. Meanwhile, nanomaterials meet biosafety concerns because of their long-term retention in the body. Herein, we propose a small-molecule manganese-based imaging probe Mn-PhDTA as an alternative to GBCAs to assess renal insufficiency for the first time. Mn-PhDTA was synthesized via a simple three-step reaction with a total yield of up to 33.6%, and a gram-scale synthesis can be realized. Mn-PhDTA has an r1 relaxivity of 2.72 mM-1 s-1 at 3.0 T and superior kinetic inertness over Gd-DTPA and Mn-EDTA with a dissociation time of 60 min in the presence of excess Zn2+. In vivo and in vitro experiments demonstrate their good stability and biocompatibility. In the unilateral ureteral obstruction rats, Mn-PhDTA provided significant MR signal enhancement, enabled distinguishing structure changes between the normal and damaged kidneys, and evaluated the renal function at different injured stages. Mn-PhDTA could act as a potential MRI contrast agent candidate for the replacement of GBCAs in the early detection of kidney dysfunction and analysis of kidney disease progression.

6-Shogaol Ameliorates Liver Inflammation and Fibrosis in Mice on a Methionine- and Choline-Deficient Diet by Inhibiting Oxidative Stress, Cell Death, and Endoplasmic Reticulum Stress

Non-alcoholic steatohepatitis (NASH) is becoming an increasingly serious global health threat, distinguished by hepatic lipid accumulation, inflammation, and fibrosis. There is a lack of approved pharmaceutical interventions for this disease, highlighting the urgent need for effective treatment. This study explores the hepatoprotective potential of 6-shogaol, a natural compound derived from ginger, in a methionine- and choline-deficient (MCD) dietary mouse model of NASH. Male C57BL/6J mice were subjected to the MCD diet for 4 weeks to induce NASH, with concurrent intraperitoneal administration of 6-shogaol (20 mg/kg) three times a week. While 6-shogaol did not impact body weight, liver weight, or hepatic lipid accumulation, it effectively mitigated liver injury, inflammation, and fibrosis in MCD diet-fed mice. Mechanistically, 6-shogaol inhibited lipid and DNA oxidation, restored hepatic glutathione levels, and regulated the expression of pro-oxidant and antioxidant enzymes. Furthermore, 6-shogaol inhibited apoptosis and necroptosis, as indicated by a decrease in TUNEL-stained cells and downregulation of apoptosis- and necroptosis-associated proteins. Additionally, 6-shogaol alleviated endoplasmic reticulum (ER) stress, as demonstrated by decreased expression of molecules associated with unfolded protein response pathways. These findings underscore the potential of 6-shogaol as a therapeutic intervention for NASH by targeting pathways related to oxidative stress, cell death, and ER stress.

Nephroprotective Effects of Cardamonin on Renal Ischemia Reperfusion Injury/UUO-Induced Renal Fibrosis

Acute kidney injury and chronic renal fibrosis are intractable pathological processes to resolve, yet limited strategies are able to effectively address them. Cardamonin (CAD) is a flavonoid with talented antioxidant, anti-inflammatory capacity, and satisfactory biosafety. In our study, animal and cellular models of renal ischemia/reperfusion (I/R) and unilateral ureteral obstruction (UUO) were successfully constructed to confirm whether CAD confers protective effects and underlying mechanisms. Animal experiments demonstrated that CAD application (100 mg/kg) distinctly ameliorated tissue damage and improved renal function. Meanwhile, the continuous oral administration of CAD after UUO surgery efficiently inhibited renal fibrosis as confirmed by hematoxylin-eosin (H&E), Sirius red, and Masson staining as well as the downregulated mRNA and protein expression of collagen I, α-smooth muscle actin (α-SMA), collagen III, and fibronectin. Interestingly, in transforming growth factor β1 (TGF-β1)-stimulated and hypoxia/reoxygenation (H/R)-exposed human kidney-2 (HK-2) cells, protective effects of CAD were again authenticated. Meanwhile, we performed bioinformatics analysis and constructed the "ingredient-target-pathway-disease" network to conclude that the potential mechanisms of CAD protection may be through the regulation of oxidative stress, inflammation, apoptosis, and mitogen-activated protein kinase (MAPK) pathway. Furthermore, experimental data validated that CAD evidently decreased the reactive oxygen species (ROS) production and malondialdehyde (MDA) content while depressing the mRNA and protein expression of inflammatory markers (tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and Il-1β) and inhibiting apoptosis as evidenced by decreased levels of P53, BAX, cleaved caspase-3, and apoptotic rate in renal I/R and UUO models. In addition, the impact of CAD on restraining oxidative stress and inflammation was attributed to its ability to elevate antioxidant enzyme activities including catalase, superoxide dismutase 1 (SOD1), and superoxide dismutase 2 (SOD2) and to inhibit the inflammation-associated MARK/nuclear factor-κB (MAPK/NF-κB) signaling pathway. In conclusion, cardamonin restored the antioxidative capacity to block oxidative stress and suppressed the MAPK/NF-κB signaling pathway to alleviate inflammatory response, thus mitigating I/R-generated acute kidney injury/UUO-induced renal fibrosis in vivo and in vitro, which indicated the potential therapeutic advantage of cardamonin in attenuating acute and chronic kidney injuries.

Eupatilin Ameliorates Lipopolysaccharide-Induced Acute Kidney Injury by Inhibiting Inflammation, Oxidative Stress, and Apoptosis in Mice

Acute kidney injury (AKI) is a common complication of sepsis. Eupatilin (EUP) is a natural flavone with multiple biological activities and has beneficial effects against various inflammatory disorders. However, whether EUP has a favorable effect on septic AKI remains unknown. Here, we examined the effect of EUP on lipopolysaccharide (LPS)-evoked AKI in mice. LPS-evoked renal dysfunction was attenuated by EUP, as reflected by reductions in serum creatinine and blood urea nitrogen levels. LPS injection also induced structural damage such as tubular cell detachment, tubular dilatation, brush border loss of proximal tubules, and upregulation of tubular injury markers. However, EUP significantly ameliorated this structural damage. EUP decreased serum and renal cytokine levels, prevented macrophage infiltration, and inhibited mitogen-activated protein kinase and NF-κB signaling cascades. Lipid peroxidation and DNA oxidation were increased after LPS treatment. However, EUP mitigated LPS-evoked oxidative stress through downregulation of NPDPH oxidase 4 and upregulation of antioxidant enzymes. EUP also inhibited p53-mediated apoptosis in LPS-treated mice. Therefore, these results suggest that EUP ameliorates LPS-evoked AKI through inhibiting inflammation, oxidative stress, and apoptosis.

Protective Effects of Apamin on Acetaminophen-Induced Hepatotoxicity in Mice

Acetaminophen (APAP) overdose can cause severe liver damage, but therapeutic options are limited. Apamin is a natural peptide present in bee venom and has antioxidant and anti-inflammatory properties. Accumulating evidence suggests that apamin has favorable actions in rodent models of inflammatory disorders. Here, we examined the effect of apamin on APAP-evoked hepatotoxicity. Intraperitoneal administration of apamin (0.1 mg/kg) alleviated histological abnormalities and reduced serum levels of liver enzymes in mice injected with APAP. Apamin inhibited oxidative stress through an increase in the amount of glutathione and activation of the antioxidant system. Apamin also attenuated apoptosis with inhibition of caspase-3 activation. Moreover, apamin reduced serum and hepatic levels of cytokines in APAP-injected mice. These effects were accompanied by suppression of NF-κB activation. Furthermore, apamin inhibited chemokine expression and inflammatory cell infiltration. Our results suggest that apamin dampens APAP-evoked hepatotoxicity through inhibiting oxidative stress, apoptosis, and inflammation.

Antioxidant, Antiapoptotic, and Anti-Inflammatory Effects of Hesperetin in a Mouse Model of Lipopolysaccharide-Induced Acute Kidney Injury

Sepsis is a severe inflammatory condition that can cause organ dysfunction, including acute kidney injury (AKI). Hesperetin is a flavonoid aglycone that has potent antioxidant and anti-inflammatory properties. However, the effect of hesperetin on septic AKI has not yet been fully investigated. This study examined whether hesperetin has a renoprotective effect on lipopolysaccharide (LPS)-induced septic AKI. Hesperetin treatment ameliorated histological abnormalities and renal dysfunction in LPS-injected mice. Mechanistically, hesperetin attenuated LPS-induced oxidative stress, as evidenced by the suppression of lipid and DNA oxidation. This beneficial effect of hesperetin was accompanied by downregulation of the pro-oxidant NADPH oxidase 4, restoration of glutathione levels, and activation of antioxidant enzymes. This flavonoid compound also inhibited apoptotic cell death via suppression of p53-dependent caspase-3 pathway. Furthermore, hesperetin alleviated Toll-like receptor 4-mediated cytokine production and macrophage infiltration. Our findings suggest that hesperetin ameliorates LPS-induced renal structural and functional injury through suppressing oxidative stress, apoptosis, and inflammation.