Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are important signaling molecules that maintain cellular homeostasis. Redox imbalance or production of excess amounts of ROS and RNS, however, is either a cause or an important mediator in the pathogenesis and pathophysiology of many diseases. It results in oxidative damage to various biological macromolecules including DNA, lipids, and proteins, thereby altering several signaling pathways that ultimately promote cellular damage and death.
Natural product-based medicines have been used in medical practices for centuries. Naturally derived compounds have fewer reported side effects than allopathic medicine and may be safer to use over a longer period of time. F. Zhu et al. had reported in 2012 in
Many natural compounds and natural product mimics are potential antioxidants that protect against oxidative damage in chronic diseases. Understanding and validating the bioactivities of the natural compounds and the molecular mechanisms are essential for a solid scientific foundation for their clinical use, improvement in their efficacy, and to meet the regulatory challenges. This special issue on the “Biological Efficacy of Medicinal Plant Extracts in Preventing Oxidative Damage” presents a collection of original reports and review articles on the scientific mechanism of action of some novel as well as traditionally used medicinal extracts in preventing oxidative damage-related diseases.
G.-H. Li et al. describe the bioactive constituents and the mechanism of action of Salviae Miltiorrhizae Radix et Rhizoma (SMRR), which is a traditional Chinese medicine and is commonly used for the therapy of cardiac cerebral diseases. The authors discuss the effect of the SMRR extract as well as the purified constituents tanshinone I, tanshinone IIA, and salvianolic acids A and B on the Nrf2 pathway and the resulting antioxidant therapeutic effects on cardiovascular diseases, neurodegenerative diseases, diabetes, nephropathy, inflammation, liver diseases, and lung diseases.
K. C. dos Santos et al. evaluated the effect of the leaves of Yacon (
Authors D. Guo et al. report that natural
In the review article by M. A. Mendez-Encinas et al., the authors describe the functional properties and potential application as an antioxidant and anticancer agent of ferulated arabinoxylans, which are polysaccharides obtained from the cell walls of cereal grains. They also discuss the gel-forming characteristic of these polysaccharides, which has characteristics such as high water absorption capacity, stability to pH, temperature, and ionic charges, thus making them an excellent drug delivery system.
J. Meng et al. report a potential use of a traditional Tibetan medicine,
The effect of olive leaf extract (OLE) on testicular damage was tested in rats by R. S. Almeer et al. Cisplatin is widely used as an antineoplastic drug for treating various cancers. However, its use is mainly limited by severe toxicity to normal tissues, especially nephrotoxicity, neurotoxicity, and testicular damage. Cisplatin causes disorganization of germinal epithelium and apoptosis. And testicular weights, catalase, serum testosterone, and testicular enzymes are significantly reduced. The authors report that OLE treatment can markedly attenuate both biochemical and histopathological changes and is mediated, at least partly, by inducing the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase 1 (HO-1) pathway.
H. A. Ogaly et al., in their manuscript, have investigated the efficacy of
Lycopene, which is a potent antioxidant carotenoid, has been evaluated by N. Stojiljkovic et al. in methotrexate-induced kidney damage in rats. Lycopene was administered in two different forms: dissolved in corn oil or encapsulated in nanoliposomes. Application of both forms of lycopene concomitantly with methotrexate was found to be effective against changes in serum urea and creatinine and oxidative damage markers and markedly reversed structural changes of kidney tissue, with the nanoliposome-encapsulated form being more effective for recovery.
Resveratrol (RSV), a natural polyphenol, is known for its potent antioxidant and anticancer effects. Authors B. Yan et al. studied the effect of RSV on the biological properties of activated pancreatic stellate cells that initiate pancreatic fibrosis in chronic pancreatitis. The authors report that RSV downregulates miR-21 expression and induces PTEN expression, resulting in impeded reactive oxygen species induction in PSCs. Collectively, the authors conclude that RSV inhibits invasion and migration of pancreatic cancer cells through suppression of ROS/miR-21-mediated activation and glycolysis in PSCs and thus may serve as a new strategy for clinical prevention or treatment of pancreatic ductal adenocarcinoma.
Taken together, the articles in this special issue contributed by the experts in the fields of oxidative stress biology highlight the increasing importance of investigating the effect of natural products on ameliorating oxidative damage and thus identify safe therapeutic treatments for the plethora of oxidative stress-related diseases.
The authors declare that there is no conflict of interest regarding the publication of this article.