Flavonoids are a family of polyphenolic compounds which are widespread in nature (vegetables) and are consumed as part of the human diet in significant amounts. There are other types of polyphenols, including, for example, tannins and resveratrol. Flavonoids and related polyphenolic compounds have significant antiinflammatory activity, among others. This short review summarizes the current knowledge on the effects of flavonoids and related polyphenolic compounds on inflammation, with a focus on structural requirements, the mechanisms involved, and pharmacokinetic considerations. Different molecular (cyclooxygenase, lipoxygenase) and cellular targets (macrophages, lymphocytes, epithelial cells, endothelium) have been identified. In addition, many flavonoids display significant antioxidant/radical scavenging properties. There is substantial structural variation in these compounds, which is bound to have an impact on their biological profile, and specifically on their effects on inflammatory conditions. However, in general terms there is substantial consistency in the effects of these compounds despite considerable structural variations. The mechanisms have been studied mainly in myeloid cells, where the predominant effect is an inhibition of NF-κB signaling and the downregulation of the expression of proinflammatory markers. At present there is a gap in knowledge of in vitro and in vivo effects, although the pharmacokinetics of flavonoids has advanced considerably in the last decade. Many flavonoids have been studied for their intestinal antiinflammatory activity which is only logical, since the gastrointestinal tract is naturally exposed to them. However, their potential therapeutic application in inflammation is not restricted to this organ and extends to other sites and conditions, including arthritis, asthma, encephalomyelitis, and atherosclerosis, among others.

Effects of Flavonoids and other Polyphenols on Inflammation

Artemisia annua is currently the only commercial source of the sesquiterpene lactone artemisinin.Since artemisinin was discovered as the active component of A. annua in early 1970s, hundreds of papers have focused on the anti-parasitic effects of artemisinin and its semi-synthetic analogs dihydroartemisinin, artemether, arteether, and artesunate. Artemisinin per se has not been used in mainstream clinical practice due to its poor bioavailability when compared to its analogs. In the past decade, the work with artemisinin-based compounds has expanded to their anti-cancer properties. Although artemisinin is a major bioactive component present in the traditional Chinese herbal preparations (tea), leaf flavonoids, also present in the tea, have shown a variety of biological activities and may synergize the effects of artemisinin against malaria and cancer. However, only a few studies have focused on the potential synergistic effects between flavonoids and artemisinin. The resurgent idea that multi-component drug therapy might be better than monotherapy is illustrated by the recent resolution of the World Health Organization to support artemisinin-based combination therapies (ACT), instead of the previously used monotherapy with artemisinins. In this critical review we will discuss the possibility that artemisinin and its semi-synthetic analogs might become more effective to treat parasitic diseases (such as malaria) and cancer if simultaneously delivered with flavonoids. The flavonoids present in A. annua leaves have been linked to suppression of CYP450 enzymes responsible for altering the absorption and metabolism of artemisinin in the body, but also have been linked to a beneficial immunomodulatory activity in subjects afflicted with parasitic and chronic diseases.

https://www.mdpi.com/1420-3049/15/5/3135/pdf

Flavonoids from Artemisia annua L. as antioxidants and their potential synergism with artemisinin against malaria and cancer.

Recovery, concentration and purification of phenolic compounds by adsorption: A review

Context: Medicinal plants are nature′s gift to human beings to make disease free healthy life, and play a vital role to preserve our health. They are believed to be much safer and proven elixir in the treatment of various ailments. The genus Artemisia (Astraceae) consists of about 500 species, occurring throughout the world. The present review comprises the ethnopharmacological, phytochemical and therapeutic potential of various species of Artemisia.Objective: The aim of this this review is to bring together most of the available scientific research conducted on the genus Artemisia, which is currently scattered across various publications. Through this review the authors hope to attract the attention of natural product researchers throughout the world to focus on the unexplored potential of Artemisia species.Methods: This review has been compiled using references from major databases such as Chemical Abstracts, Medicinal and Aromatic Plants Abstracts, ScienceDirect, SciFinder, PubMed, King′s American Disp...

https://www.tandfonline.com/doi/pdf/10.3109/13880209.2010.497815

The genus Artemisia: a comprehensive review.

Sodium Butyrate Inhibits Inflammation and Maintains Epithelium Barrier Integrity in a TNBS-induced Inflammatory Bowel Disease Mice Model.

Anti-inflammatory and immunosuppressive effect of flavones isolated from Artemisia vestita.

Simultaneous quantification of five major bioactive flavonoids in Rhizoma Smilacis Glabrae by high-performance liquid chromatography

Novel immunomodulatory properties of cirsilineol through selective inhibition of IFN-γ signaling in a murine model of inflammatory bowel disease☆

Cirsilineol (4',5-dihydroxy-3',6,7-trimethoxyflavone) is a compound isolated from the herb of Artemisia vestita Wall (Compositae). In this study, we aimed at examining the anti-proliferative activity of cirsilineol against multiple types of cancer cells and the underlying mechanisms. Cirsilineol significantly inhibited proliferation of Caov-3, Skov-3, PC3 and Hela cells in a concentration-dependent manner. The compound also dose-dependently induced apoptosis in Caov-3 cells, as determined by annexin V/propidium iodide staining. Besides, cirsilineol induced a remarkable change in mitochondrial membrane potential and caused release of cytochrome c to cytosol. Furthermore, the compound caused a marked activation of capase-3, caspase-9 and poly (ADP-ribose) polymerase (PARP). These results suggested that the induction of apoptosis via the mitochondrial pathway was involved in the anti-proliferative activity of cirsilineol against cancer cells.

Ye Yin

Papers

Anti-inflammatory and immunosuppressive effect of flavones isolated from Artemisia vestita.

Simultaneous quantification of five major bioactive flavonoids in Rhizoma Smilacis Glabrae by high-performance liquid chromatography

Novel immunomodulatory properties of cirsilineol through selective inhibition of IFN-γ signaling in a murine model of inflammatory bowel disease☆

Cirsilineol inhibits proliferation of cancer cells by inducing apoptosis via mitochondrial pathway.

Jaceosidin inhibits contact hypersensitivity in mice via down-regulating IFN-γ/STAT1/T-bet signaling in T cells.