Herbacetin

Eur J Pharmacol. 2015 Oct 15;765:115-23.

Herbacetin inhibits inducible nitric oxide synthase via JNK and nuclear factor-κB in LPS-stimulated RAW264.7 cells.[Pubmed: 26297979 ]

Herbacetin (3,4',5,7,8-pentahydroxyflavone), an active flavonol compound within flavonoid, has been shown to induce apoptosis in HepG2 cells and suppress hepatocyte growth factor-induced motility of human breast cancer MDA-MB-231 cells. However, the anti-inflammatory mechanisms of Herbacetin have not been researched.
METHODS AND RESULTS:
In this study, we examined the inflammatory responses stimulated by lipopolysaccharide (LPS) in RAW264.7 macrophage cells after pretreatment with different concentrations of Herbacetin. We found that Herbacetin decreased nitric oxide (NO) production in LPS-induced RAW264.7 and mouse bone marrow-derived macrophages. In addition, Herbacetin inhibited the LPS-induced expression of inducible nitric oxide synthase mRNA and protein in RAW264.7 cells. Treatment with Herbacetin decreased the release of proinflammatory cytokines, including TNF-α and IL-1β. Moreover, Herbacetin inhibited the activity of JNK kinase and nuclear factor-κB, signaling molecules involved in NO production. Cell signaling analysis using Bay 11-7082 (an inhibitory κB kinase 2 inhibitor) and mitogen-activated protein kinase (MAPK) inhibitors (SB203580 for p38, SP600125 for JNK, and PD 98059 for ERK) suggested that LPS induced iNOS expression via activation of the JNK and NF-κB pathway, but not the p38 and ERK pathway.
CONCLUSIONS:
These findings suggest that Herbacetin exerts an anti-inflammatory effect through suppression of LPS-induced JNK and NF-κB signaling pathways and diminished production of proinflammatory cytokines and mediators.

Planta Med. 2013 Nov;79(16):1525-30.

Herbacetin, a constituent of ephedrae herba, suppresses the HGF-induced motility of human breast cancer MDA-MB-231 cells by inhibiting c-Met and Akt phosphorylation.[Pubmed: 24081687]

Ephedrae herba suppresses hepatocyte growth factor-induced cancer cell motility by inhibiting tyrosine phosphorylation of the hepatocyte growth factor receptor, c-Met, and the PI3K/Akt pathway. Moreover, Ephedrae herba directly inhibits the tyrosine-kinase activity of c-Met. Ephedrine-type alkaloids, which are the active component of Ephedrae herba, do not affect hepatocyte growth factor-c-Met-Akt signalling, prompting us to study other active molecules in the herb.
METHODS AND RESULTS:
We recently discovered Herbacetin glycosides and found that their aglycon, Herbacetin, inhibits hepatocyte growth factor-c-Met-Akt signalling. This study revealed a novel biological activity of Herbacetin. Herbacetin suppressed hepatocyte growth factor-induced motility in human breast cancer MDA-MB-231 cells by inhibiting c-Met and Akt phosphorylation and directly inhibiting c-Met tyrosine kinase activity. The effects of Herbacetin were compared to those of kaempferol, apigenin, and isoscutellarein, all of which have similar structures. Herbacetin inhibition of hepatocyte growth factor-induced motility was the strongest of those for the tested flavonols, and only Herbacetin inhibited the hepatocyte growth factor-induced phosphorylation of c-Met.
CONCLUSIONS:
These data suggest that Herbacetin is a novel Met inhibitor with a potential utility in cancer therapeutics.

Food Science, 2013, 34(17):106-10.

In vitro Free Radical Scavenging and Protein Oxidation Inhibitory Effects of Herbacetin[Reference: WebLink]

METHODS AND RESULTS:
The in vitro antioxidant activity of Herbacetin was investigated in terms of scavenging activities against DPPH and hydroxyl free radicals and inhibitory effects against oxidative protein damage and carbonylation induced by Cu 2+-H 2 O 2 or AAPH. At a concentration between 10 μ mol/L and 100 μ mol/L, Herbacetin exerted a marked scavenging effect on DPPH and hydroxyl free radicals, with respective IC 50 values of 49.28 μ mol/L and 219.2 μ mol/L. Meanwhile, Herbacetin could significantly inhibit oxidative protein damage and carbonylation induced by Cu 2+-H 2 O 2 or AAPH in a dose-dependent manner.
CONCLUSIONS:
This study concludes that Herbacetin has a strong ability to scavenge free radical and inhibit oxidative protein damage.

Food Chem Toxicol. 2013 Jan;51:426-33.

Herbacetin induces apoptosis in HepG2 cells: Involvements of ROS and PI3K/Akt pathway.[Pubmed: 23063593]

Herbacetin (HER) is a natural flavonoid compound that can be extracted from Ramose Scouring Rush Herb, and its biological and pharmacological activities lack of corresponding attention.
METHODS AND RESULTS:
In this study, the apoptotic effect of Herbacetin against the human hepatoma cell line (HepG2) was investigated. The results showed that HepG2 cells apoptosis occurred in a dose-dependent manner within 48h incubated with Herbacetin, which was confirmed by DNA fragmentation, nuclear shrinkage, and poly (ADP-ribose) polymerase (PARP) cleavage. Herbacetin at 25-100μM induced a mitochondria-dependent apoptotic pathway associated with Bcl-2/Bax ratio decrease, mitochondrial membrane potential (ΔΨ) collapse, cytochrome c release, and caspase-3 activation. Increasing expression of peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α) was also observed in Herbacetin-treated cells. Furthermore, the addition of a ROS inhibitor (N-Acetyl-l-cysteine, NAC) significantly attenuated the apoptosis induced by Herbacetin and also blocked the expression of PGC-1α protein. Additionally, Herbacetin effectively inhibited the phosphorylation of Akt and the phosphatidylinositol-3 kinase (PI3K) inhibitor LY294002 increased the inhibition effect of Herbacetin on Akt phosphorylation.
CONCLUSIONS:
These findings provide evidences that Herbacetin induces HepG2 apoptosis in a ROS-mediated mitochondria-dependent manner that correlate with the inactivation of the PI3K/Akt pathway.

Phytochemistry, 1969, 8(1):177-83.

Gossypetin and Herbacetin as taxonomic markers in higher plants.[Reference: WebLink]

Four yellow flavonol pigments earlier reported in the Leguminosae, Ericaceae and Papaveraceae as quercetagetin glycosides have now been found to be the isomeric gossypetin derivatives.
METHODS AND RESULTS:
Reliable methods are outlined for distinguishing between these isomeric 6- and 8-hydroxyquercetin derivatives on a microscale, including a simple colour test which can be carried out on chromatograms. The yellow flavonol monomethyl ether reported in Lotus corniculatus flower is now shown to be gossypetin 7-methyl ether. Gossypetin, besides occurring in Rhododendron petals, is also widespread in the leaves of this (in 76 of 103 species examined) and nine related genera of the Ericaceae. It also occurs as a leaf constituent in the related Empetrum (Empetraceae). In a survey of legume leaves, gossypetin was only detected once, in Acacia constricta.
CONCLUSIONS:
Surveys indicate that Herbacetin, the kaempferol analogue of gossypetin, is much less common, but it has been detected as principal flower pigment in Meconopsis paniculata (Papaveraceae). Consideration of the known natural distribution of the two yellow flavonols indicates that they are of most interest as taxonomic markers at the generic and subfamilial levels.