Caffeic Acid Phenethyl Ester Protects Kidney Mitochondria against Ischemia/Reperfusion Induced Injury in an In Vivo Rat Model

Natural products for kidney disease treatment: Focus on targeting mitochondrial dysfunction

The patients with kidney diseases are increasing rapidly all over the world. With the rich abundance of mitochondria, kidney is an organ with a high consumption of energy. Hence, renal failure is highly correlated with the breakup of mitochondrial homeostasis. However, the potential drugs targeting mitochondrial dysfunction are still in mystery. The natural products have the superiorities to explore the potential drugs regulating energy metabolism. However, their roles in targeting mitochondrial dysfunction in kidney diseases have not been extensively reviewed. Herein, we reviewed a series of natural products targeting mitochondrial oxidative stress, mitochondrial biogenesis, mitophagy, and mitochondrial dynamics. We found lots of them with great medicinal values in kidney disease. Our review provides a wide prospect for seeking the effective drugs targeting kidney diseases.

Ketogenic Diet and Ketone Bodies against Ischemic Injury: Targets, Mechanisms, and Therapeutic Potential

The ketogenic diet (KD) has been used as a treatment for epilepsy since the 1920s, and its role in the prevention of many other diseases is now being considered. In recent years, there has been an intensive investigation on using the KD as a therapeutic approach to treat acute pathologies, including ischemic ones. However, contradictory data are observed for the effects of the KD on various organs after ischemic injury. In this review, we provide the first systematic analysis of studies conducted from 1980 to 2022 investigating the effects and main mechanisms of the KD and its mimetics on ischemia-reperfusion injury of the brain, heart, kidneys, liver, gut, and eyes. Our analysis demonstrated a high diversity of both the composition of the used KD and the protocols for the treatment of animals, which could be the reason for contradictory effects in different studies. It can be concluded that a true KD or its mimetics, such as β-hydroxybutyrate, can be considered as positive exposure, protecting the organ from ischemia and its negative consequences, whereas the shift to a rather similar high-calorie or high-fat diet leads to the opposite effect.

The Effect of Polyphenols on Kidney Disease: Targeting Mitochondria

Mitochondrial function, including oxidative phosphorylation (OXPHOS), mitochondrial biogenesis, and mitochondria dynamics, are essential for the maintenance of renal health. Through modulation of mitochondrial function, the kidneys are able to sustain or recover acute kidney injury (AKI), chronic kidney disease (CKD), nephrotoxicity, nephropathy, and ischemia perfusion. Therapeutic improvement in mitochondrial function in the kidneys is related to the regulation of adenosine triphosphate (ATP) production, free radicals scavenging, decline in apoptosis, and inflammation. Dietary antioxidants, notably polyphenols present in fruits, vegetables, and plants, have attracted attention as effective dietary and pharmacological interventions. Considerable evidence shows that polyphenols protect against mitochondrial damage in different experimental models of kidney disease. Mechanistically, polyphenols regulate the mitochondrial redox status, apoptosis, and multiple intercellular signaling pathways. Therefore, this review attempts to focus on the role of polyphenols in the prevention or treatment of kidney disease and explore the molecular mechanisms associated with their pharmacological activity.

Caffeic Acid Phenethyl Ester (CAPE) Improves Boar Sperm Quality and Antioxidant Capacity in Liquid Preservation (17°C) Linked to AMPK Activity Maintenance

Liquid preservation of boar sperm is crucial for artificial insemination application in pig production. However, time-dependent oxidative damage to sperm is one of the major challenges during the liquid preservation period. Caffeic acid phenethyl ester (CAPE) possesses excellent antioxidant properties and has potential therapeutic use in reproductive organ injury linked to oxidative stress. Adenosine monophosphate (AMP)-activated protein kinase (AMPK) involves in modulating the cellular redox state and exerts a beneficial effect on sperm preservation. In the present study, we firstly assessed different concentrations of CAPE that affect sperm quality during liquid storage to determine the appropriate addition. To further investigate whether CAPE exerts protective effects on boar sperm through modulation of AMPK activity, sperm quality parameters, antioxidant capacity, and marker protein expressions were evaluated under co-incubation with H₂O₂. The results showed that sperm treated with 210 μmol/L CAPE exhibited the highest motion parameters (total motility and progressive motility) and best functional integrity (mitochondrial activity, plasma membrane integrity, and acrosomal integrity). Even in the presence of H₂O₂, the addition of 210 μmol/L CAPE not only significantly improved sperm quality parameters, but also elevated CAT, SOD, and GSH-Px activities to enhance sperm antioxidant capacity. In addition, we found that CAPE could affect the protein activities of AMPK, phospho-AMPK α (p-AMPK), SOD, and Caspase-3 regardless of whether H₂O₂ is present or not. Our findings suggested that CAPE has potential application in liquid preservation of boar sperm and preliminary indicated that CAPE-induced improvement of sperm quality and antioxidant capacity should be mediated through conservation of AMPK activity. Further studies are required to illustrate the specific mechanism by which CAPE attenuates oxidative stress-mediated damages dependent on AMPK activity.

Caffeic acid protects against DNA damage, oxidative and inflammatory mediated toxicities, and upregulated caspases activation in the hepatorenal system of rats treated with aflatoxin B1

Aflatoxicosis can induce largescale toxicities in predisposed populations. Food fortification with adequate antioxidant sources may reduce the toxic burden from aflatoxicosis. We examined the individual and combined effect of Caffeic acid (CA) on the aflatoxin B₁ (AFB₁)-induced hepatic and renal injury in male rats. Five experimental rat cohort (n = 6) consisting of the control (2 mL/kg corn oil), AFB₁ alone (50 μg/kg), CA alone (40 mg/kg), AFB₁+CA₁ (50 μg/kg + 20 mg/kg) and AFB₁+CA₂ (50 μg/kg + 40 mg/kg) were so treated for 28 consecutive days. Upon sacrifices, diagnostic markers of hepatorenal functions, oxidative stress, inflammation, oxidative deoxyribonucleic acid -DNA-damage and apoptosis were analysed. Our results showed that CA reduced AFB₁-induced toxicities in rats' liver and kidneys by significantly increasing (p < 0.05) endogenous antioxidant and the anti-inflammatory IL-10 level. Caffeic acid simultaneously reduced hepatic and renal dysfunction biomarkers in the serum, oxidative stress, and lipid peroxidation levels. Besides, CA diminished reactive oxygen and nitrogen species, inflammatory nitric oxide levels, interleukin-1 β and the activities of xanthine oxidase and myeloperoxidase. Additionally, CA reduced DNA damage and caspase-mediated apoptotic responses and preserved the cytoarchitecture of rats' liver and kidneys treated with AFB₁. These data suggest that CA can be used as a food additive to mitigate AFB₁-induced toxicity in the examined organs.

Febuxostat treatment attenuates oxidative stress and inflammation due to ischemia-reperfusion injury through the necrotic pathway in skin flap of animal model

BACKGROUND

Ischemia-reperfusion (I/R) injury is a major contributor to skin flap necrosis, which is a serious complication of reconstructive surgery. The purpose of this study was to evaluate the protective effect of treatment with febuxostat, a selective xanthine oxidase inhibitor, on I/R injury in the skin flap of an animal (rat) model.

METHODS

Superficial epigastric flaps were raised in Sprague-Dawley rats and subjected to ischemia for 3 h. Febuxostat at a dose of 10 mg/kg/day was administered to rats in drinking water from 1 week before the surgery (Feb group). Control animals received no drugs (Con group). The mean ratio of flap survival and contraction was evaluated and compared between animals with and without administration of febuxostat on day 5 after the surgery. In addition, infiltration by polymorphonuclear leukocytes and muscles of the panniculus carnosus in the flap were histologically evaluated using hematoxylin-eosin staining. Furthermore, xanthine oxidase activity, ATP levels, superoxide dismutase activity, and expression of 8-hydroxy-2'-deoxyguanosine (8-OHdG), tumor necrosis factor-α, and interleukin-1β were quantitatively assessed in the skin flap 24 h after the surgery.

RESULTS

In the Feb group, the survival and contraction rates at the 5 d timepoint post-surgery were significantly higher and lower than those in the Con group, respectively. Histological analysis showed significant reduction in polymorphonuclear leukocyte infiltration and muscle injury scores due to I/R injury in the Feb group. The expression of 8-OHdG was also significantly inhibited in animals administered febuxostat. Biochemical analysis showed a significant reduction in xanthine oxidase activity and significant increases in ATP levels and superoxide dismutase activity in the Feb group. Furthermore, the expression of interleukin-1β was significantly lower in the Feb group than in the Con group.

CONCLUSION

Febuxostat, which is clinically used for the treatment of hyperuricemia, was effective against necrosis of the skin flap via inhibition of oxidative stress and inflammation caused by I/R injury.

Antioxidant and Mitochondria-Targeted Activity of Caffeoylquinic-Acid-Rich Fractions of Wormwood (Artemisia absinthium L.) and Silver Wormwood (Artemisia ludoviciana Nutt.)

Caffeoylquinic acids are some of the chemophenetically significant specialized metabolites found in plants of the family Asteraceae Dumort., possessing a broad spectrum of biological activities. As they might be potential mitochondria-targeted antioxidants, effective preparation methods—including extraction, isolation, and purification of caffeoylquinic acids from plant sources—are in great demand. The aim of this study was to fractionate the caffeoylquinic acids from cultivated wormwood (Artemisia absinthium L.) and silver wormwood (Artemisia ludoviciana Nutt.) herb acetone extracts and evaluate their phytochemical profiles, antioxidant activity (radical scavenging and reducing activities), effects on kidney mitochondrial functions, and cytochrome-c-reducing properties. The main findings of our study are as follows: (1) Aqueous fractions purified from wormwood and silver wormwood herb acetone extracts are rich in monocaffeoylquinic acids (chlorogenic acid, neochlorogenic acid, 4-O-caffeoylquinic acid), while methanolic fractions purified from wormwood and silver wormwood herb acetone extracts are rich in dicaffeoylquinic acids (4,5-dicaffeoylquinic acid, 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid). Aqueous fractions purified from wormwood and silver wormwood herb acetone extracts were solely composed of monocaffeoylquinic acids. Methanolic fractions purified from wormwood and silver wormwood herb acetone extracts contained only dicaffeoylquinic acids. (2) Fractions purified from silver wormwood herb acetone extracts stood out as having the greatest content of caffeoylquinic acids. (3) The greatest radical scavenging activity was determined in the dicaffeoylquinic-acid-rich fraction purified from silver wormwood herb acetone extract; the greatest reducing activity was determined in the dicaffeoylquinic-acid-rich fraction purified from wormwood herb acetone extract. (4) The effect of both fractions on mitochondrial functions was dose-dependent; lower concentrations of caffeoylquinic-acid-rich fractions had no effect on mitochondrial functions, whereas higher concentrations of caffeoylquinic-acid-rich fractions reduced the state 3 respiration rate (with the complex-I-dependent substrate glutamate/malate). (5) Both monocaffeoylquinic- and dicaffeoylquinic-acid-rich fractions possessed cytochrome-c-reducing properties; the greatest cytochrome c reduction properties were determined in the dicaffeoylquinic-acid-rich fraction purified from wormwood herb acetone extract. In summary, these findings show that caffeoylquinic acids might be beneficial as promising antioxidant and cytochrome-c-reducing agents for the modulation of mitochondria and treatment of various mitochondrial-pathway-associated pathologies.