Recently, natural bioactive ingredients of oxidative medicines have been a focus of many studies owing to their low toxicity and side effects as well as their excellent efficacy. Bioactive ingredients are the main components extracted from herbs that have therapeutic properties. Bioactive ingredients have multilevel effects on numerous chronic diseases, such as the treatment of asthma, anti-inflammation, anti-infection, antimicrobial activity, and the treatment of diabetes mellitus. Usually, the bioactive ingredients of conventional oxidative medicines have been divided into six categories consisting of flavonoids, saponins, terpenoids, alkaloids, polysaccharides, and other organic acids. In addition, studies found that curcumin, magnolol, animal protein, photosensitizers, and reactive oxide species with antimicrobial activity have positive effects in chronic disease treatment. Especially, active polyphenol curcumin as a pro-drug via oxidative activation into reactive metabolites showed excellent anti-inflammatory activities and antibacterial activities.

Although considerable efforts have been made to apply these bioactive ingredients to chronic disease treatment, the lack of systematic studies on therapeutic mechanisms of these bioactive ingredients for disease treatment impedes the extensive application of these oxidative medicines in vivo. For example, the bioactivation of curcumin will occur in vitro, while bioactivation is insufficient in vivo. Therefore, the evaluation and design of clinical trials of curcumin and other medicinal polyphenols should be considered. In addition, the functional mechanism of bioactive ingredients must be highlighted in future research. The safety evaluation and bioavailability of bioactive ingredients are also important indexes for the development of oxidative medicines. The physicochemical and biological properties of curcumin and other bioactive ingredients should also be further discussed before their clinical usage. Furthermore, the industrial production of natural bioactive ingredients is still a huge challenge at present.

This Special Issue aims to summarize the knowledge of underlying mechanisms and physicochemical properties of bioactive ingredients in chronic disease treatment and provide a fully integrated, reliable source of information for the clinical application of bioactive ingredients as oxidative medicines. Original research and review articles are welcome.

Potential topics include but are not limited to the following:

• Therapeutic properties of natural bioactive ingredients
• Multilevel effects of bioactive ingredients on treatment of chronic disease
• Application of bioactive ingredients
• Safety evaluation of bioactive ingredients
• Bioavailability of natural bioactive ingredients
• Functional mechanism of bioactive ingredients for disease treatment
• Synthesized methods and instrumental analysis of natural bioactive ingredients
• Chemical engineering and industrial production