Isorhamnetin, a flavonol aglycone, isolated from the traditional Chinese medicine H. rhamnoides L., was frequently used in traditional medicine to prevent and treat diverse diseases. Isorhamnetin has been shown to play a variety of roles in anti-oxidation, anti-inflammation, anti-tumor, anti-viral, and neurodegenerative injury protection. Isorhamnetin could inhibit the H2O2-induced activation of the intrinsic apoptotic pathway by scavenging free ROS and extracellular signal-regulated kinase 1/2 (ERK1/2) inactivation. In the type 2 diabetic rat model, isorhamnetin was found to be able to inhibit the NF-κB signaling activity, attenuate oxidative stress, and decrease the production of inflammatory mediators. Isorhamnetin can suppress skin cancer, breast cancer, colon cancer and atherosclerosis by inhibiting PI3K/AKT activation. Isorhamnetin shows inhibitory activity toward CYP1B1 expression and function.

TETRAHYDROPALMATINE, (+)- is an alkaloid found in the plants of the Carydalis species. Tetrahydropalmatine (THP) has two enantiomers with different effects on the brain dopaminergic system. Dopamine (DA) content reduction in the rat striatum induced by d-THP is much more dose-dependent. At a small dose, d-THP predominantly reduced the DA level but left serotonin and noradrenaline level unaffected. d-THP is probably a DA depletor. There were stereoselective differences between the two THP enantiomers on the activity of cytochrome P450 (CYP450) isozymes, i.e., d-THP had the potential to inhibit the activities of CYP2D6 and CYP1A2 isozymes, while l-THP inhibited CYP1A2 isozyme and induced CYP3A4 and CYP2C9 isozymes. The plasma levels of l-THP were always higher than those of d-THP in rats.

Naftopidil,(R)- is an enantiomer of Naftopidil (NAF), a specific subtype selective α1-adrenoceptor blocker. Racemic Naftopidil is frequently used for the treatment of lower urinary tract symptoms/benign prostatic hyperplasia. No significant differences in pharmacokinetic parameters were observed between R(+)- and S(−)-NAF after intravenous administration. However, mean plasma concentrations of R(+)-NAF were lower than those of S(-)-NAF after intragastric administration. R(+)-NAF bioavailability in rats was consistently about two-fold lower than that of S(-)-NAF. The fractions of R(+)- NAF reaching the prostate and metabolized in the liver were higher than those of S(−)-NAF. The major pathways of R(+)- NAF metabolism in vitro were demethylation and hydroxylation. CYP2C9 played the most important role in the demethylation and hydroxylation of both NAF enantiomers. CYP2C19 was another CYP isoform that played a major role in R(+)-NAF metabolism.

Eupatorin is a natural flavonoid isolated from the herbs of Eupatorium semiserratum. It has the anti-inflammatory and anti-proliferative properties, which may be utilized in the development of novel anti-inflammatory and anti-tumor treatments. Eupatorin moderately inhibited human cytochrome P450 1A2 (CYP1A2). Eupatorin showed IC50 values of 0.4 ug/mL on T. cruzi epimastigotes and 61.8 ug/mL on trypomastigotes, respectively. It was demonstrated, that eupatorin exerts a vasorelaxative effect on aortic rings through the NO/sGC/cGMP and PGI2 pathways, calcium and potassium channels, muscarinic and beta-adrenergic receptors.

Sinensetin is a methylated flavone found in certain citrus fruits. pocess potent antiangiogenesis and anti-inflammatory, sinensetin enhances adipogenesis and lipolysis. Sinensetin is a selective inhibitor of α-glucosidase with IC50 value of 0.66 mg/ml. Alpha-glucosidase and α-amylase inhibition could the mechanisms through which sinensetin exert its antidiabetic activity, indicating that it could have potential use in the management of non-insulin-dependent diabetes. Sinensetin inhibits inflammatory gene expression and STAT1 activation. It has meaningful anti-inflammatory properties which may be utilized in the development of novel anti-inflammatory treatments.

Dihydromethysticin is one of the six major kavalactones found in the roots of kava plant. Dihydromethysticin was found to be very effective in producing analgesia in the tail immersion test. Dihydromethysticin kavalactone induces apoptosis in osteosarcoma cells through modulation of PI3K/Akt pathway, disruption of mitochondrial membrane potential and inducing cell cycle arrest. Dihydromethysticin was identified as a promising lung cancer chemopreventive agent. Low concentrations of the kavalactone (+)-dihydromethysticin enhanced the binding of ligands to the GABAA receptors on freeze-dried rat cortex preparations.