Bioactive flavonoids in medicinal plants: Structure, activity and biological fate

Functional mechanism of tracheal relaxation, antiasthmatic, and toxicological studies of 6‐hydroxyflavone

“…Natural products are an important source for discovery and development of new drugs with novel therapeutic targets for more specific treatments and less adverse effects. Within this context, flavonoids are privileged scaffolds that possess several activities and mechanisms of action (Goszcz, Duthie, Stewart, Leslie, & Megson, ; Harborne & Williams, ; Wang et al, ). In previous reports, the potential effect of flavonoids as antiasthmatic drugs, especially those possessing powerful antioxidant, anti‐allergic, anti‐inflammatory, immune‐modulating, and airway smooth muscle relaxant effects, have been described (Flores‐Flores et al, ; Goszcz et al, ; Tanaka & Takahashi, ; Wang et al, ).…”

“…Within this context, flavonoids are privileged scaffolds that possess several activities and mechanisms of action (Goszcz, Duthie, Stewart, Leslie, & Megson, ; Harborne & Williams, ; Wang et al, ). In previous reports, the potential effect of flavonoids as antiasthmatic drugs, especially those possessing powerful antioxidant, anti‐allergic, anti‐inflammatory, immune‐modulating, and airway smooth muscle relaxant effects, have been described (Flores‐Flores et al, ; Goszcz et al, ; Tanaka & Takahashi, ; Wang et al, ). The majority of these induce their antiasthmatic effect via the inhibition of the release of chemical mediators, the synthesis of Th2 type cytokines such as interleukin (IL)‐4 and IL‐13, and CD40 ligand expression by high‐affinity IgE receptor‐expressing cells such as mast cells and basophils (Tanaka & Takahashi, ).…”

“…Taking in account previous reports in which the efficacy of flavonoids as experimental antiasthmatic drugs was described (Goszcz et al, ; Tanaka & Takahashi, ; Wang et al, ) and the relaxant effect that was exhibited by 6‐HOF (Flores‐Flores et al, ), we decided to explore the potential antiasthmatic effect of this flavonoid in allergic OVA‐induced bronchoconstriction in a guinea pig model. Animals exposed to OVA three times for 15 days (at Days 0, 8, and 15) were treated with 6‐HOF at 30, 50, and 90 mg/kg i.p.…”

Potent antioxidant activity of Kigelia africana flower fractions on cell-free systems.

“…The qualitative phytochemical analysis reveals that quinones are not present (or in a few amount only) in BF, however triterpens/steroids were detected only in this fraction but not in EF and EAF (table 1). Phenols and flavonoids are plant secondary products that may contribute to the natural antioxidant system against negative redox balance in human diseases (19). The total amount and particular chemical characteristics of these metabolites are relevant at this point, including the role as prooxidant agent (4,(19)(20)(21)(22).…”

“…Phenols and flavonoids are plant secondary products that may contribute to the natural antioxidant system against negative redox balance in human diseases (19). The total amount and particular chemical characteristics of these metabolites are relevant at this point, including the role as prooxidant agent (4,(19)(20)(21)(22). The total phenolic content (TPC) and total flavonoids content (TFC) found for EAF (µGAE/mgdE = 523.31±23.40; µQE/mgdE = 43.57±3.46) were highest (p<0.05) than BF (µGAE/mgdE = 290.66±35.15; µQE/mgdE = 32.29±1.41) and EF (µAGE/mgdE = 116.02±13.47; µQE/mgdE = 14.25±1.36).…”