Nanodelivery of Natural Antioxidants: An Anti-aging Perspective

The aging process is known to be associated with heightened oxidative stress and related systemic inflammation. Therefore, antioxidant supplementation is regarded as a promising strategy to combat aging and associated pathological conditions. Food-grade antioxidants from plant-derived extracts are the most common ingredients of these supplements. Phyto-bioactive compounds such as curcumin, resveratrol, catechins, quercetin are among the most commonly applied natural compounds used as potential modulators of the free radical-induced cellular damages. The therapeutic potential of these compounds is, however, restricted by their low bioavailability related to poor solubility, stability, and absorbance in gastrointestinal tract. Recently, novel nanotechnology-based systems were developed for therapeutic delivery of natural antioxidants with improved bioavailability and, consequently, efficacy in clinical practice. Such systems have provided many benefits in preclinical research over the conventional preparations, including superior solubility and stability, extended half-life, improved epithelium permeability and bioavailability, enhanced tissue targeting, and minimized side effects. The present review summarizes recent developments in nanodelivery of natural antioxidants and its application to combat pathological conditions associated with oxidative stress.

Intrathecal Administration of Nanoclusters for Protecting Neurons against Oxidative Stress in Cerebral Ischemia/Reperfusion Injury

Oxidative stress is one of the important mechanisms in cerebral ischemia/reperfusion (I/R) injury. Antioxidants with high brain accumulation are highly desired to help prevent cerebral I/R injury. Herein, intrathecal injection of polyoxometalate (POM) nanoclusters as nano-antioxidants with preferential brain uptake were applied for neuronal protection in cerebral I/R injury. Using powerful positron emission tomography imaging, the uptake of nano-antioxidants in the brain was non-invasively and real-timely monitored. Our results demonstrated that POM nanoclusters rapidly reached the ischemic penumbra after intrathecal injection and effectively scavenged reactive oxygen species (ROS) for inhibiting oxidative stress. The infarct size was reduced, and neurological function was restored in cerebral I/R injury rat models. As a proof-of-concept, the intrathecal injection of nano-antioxidants is an excellent therapeutic strategy to ameliorate cerebral I/R injury.

Bio-evaluation of the role of chitosan and curcumin nanoparticles in ameliorating genotoxicity and inflammatory responses in rats' gastric tissue followed hydroxyapatite nanoparticles' oral uptake

Hydroxyapatite has been extensively used in tissue engineering due to its osteogenic potency, but its present toxicological facts are relatively insufficient. Here, the possible gastric toxicity of hydroxyapatite nanoparticles was evaluated biochemically to determine oxidant and antioxidant parameters in rats' stomach tissues. At results, hydroxyapatite nanoparticles have declined stomach antioxidant enzymes and reduced glutathione level, while an induction in lipid peroxidation and nitric oxide has been observed. Furthermore, DNA oxidation was analyzed by the suppression of toll-like receptors 2, nuclear factor-kappa B and Forkhead box P3 gene expression and also 8-Oxo-2'-deoxyguanosine level as a genotoxicity indicator. Various pro-inflammatory gene products have been identified that intercede a vital role in proliferation and apoptosis suppression, among these products: tumor suppressor p53, tumor necrosis factor-α and interliukin-6. Moreover, the hydroxyapatite-treated group revealed wide histological alterations and significant elevation in the number of proliferating cell nuclear antigen-positive cells, which has been observed in the mucosal layer of the small intestine, and these alterations are an indication of small intestine injury, while the appearance of chitosan and curcumin nanoparticles in the combination group showed improvement in all the above parameters with inhibition of toxic-oxidant parameters and activation of antioxidant parameters.

Recent Trends in the Development and Application of Nano-Antioxidants for Skin-Related Disease

Skin is a vital barrier for the human body, protecting against external environmental influences and maintaining internal homeostasis. In addition, an imbalance of oxidative stress and antioxidant mechanisms can lead to skin-related diseases. Thus, for treating skin-related diseases, antioxidant therapy may be an important strategy to alleviate these symptoms. However, traditional drug therapies have limitations in treating these conditions, such as lack of lasting effect and insufficient skin permeability. Recently, nano-antioxidants, with their good permeability, sustained-release ability, multifunctionality, and other beneficial characteristics, have showed their advances in the exploration of skin-related diseases from research on safe therapies to clinical practice. Hereby, we review the latest research and advancements in nano-antioxidants for skin-related diseases. We categorize skin-related diseases into four main groups: skin inflammatory diseases, skin damage caused by ultraviolet rays, skin wound healing, and other skin-related conditions. Additionally, we summarize the prospects and potential future directions for nano-antioxidant drugs in treating skin-related diseases.