A natural compound derivative P-13 inhibits STAT3 signaling by covalently inhibiting Janus kinase 2.[Pubmed: 30073465]

We investigated the function and molecular mechanisms of 2-desoxy-4β-propylcarbamate-pulchellin (P-13), a sesquiterpene lactone derivative of 2-desoxy-4-epi-pulchellin from the traditional Chinese medicinal herb Carpesium abrotanoides L, in regulating STAT3 signaling and cancer cell growth. We found that P-13 inhibited the IL-6-induced, as well as the constitutive, STAT3 activation in a dose and time-dependent manner. In vitro kinase activity analyses demonstrated that P-13 directly inhibited JAK2 kinase activity. The inhibitory effects of P-13 on JAK2/STAT3 signaling could be blocked by reducing agents dithiothreitol (DTT) or glutathione (GSH), indicating an involvement of the thiol-reactive α-β unsaturated carbonyl group in P-13. Further analyses with mass spectrograph, as well as molecular docking, revealed that P-13 covalently bound with the C452 in the SH2 domain of JAK2. Furthermore, P-13 inhibited growth and induced death of many cancer cell lines, particularly those expressing constitutively activated STAT3. It also inhibited in vivo growth of human cancer cell xenografts. Taken together, these findings revealed P-13 as a novel covalent inhibitor of JAK2, uncovered a new mechanism to inhibit JAK2, and provided a promising anti-cancer drug candidate.

Caroguaianolide A-E, five new cytotoxic sesquiterpene lactones from Carpesium abrotanoides L.[Pubmed: 29621599]

None

[Killing Effect of Carpesium abrotanoides on Taenia asiatica Cysticercus].[Pubmed: 26541048]

The cysticerci of Taenia asiatica were cultured in vitro with different concentrations of water decoction of Carpesium abrotanoides (20, 40, and 60 mg/ml). The killing effect of C. abrotanoides on T. asiatica and the morphological change of cysticerci were observed under microscope 24 hours post-culture. The water decoction of C. abrotanoides showed significant killing effect on the cysticerci. The mortality of the parasites(95.0%, 57/60) was highest in 60 mg/ml group. The dead body of cysticercus shows shrunken with the enlarged scolex, and sucker tissue degenerated.

[Simultaneous determination of five sesquiterpene lactones in Carpesium abrotanoides by HPLC].[Pubmed: 26323148]

An HPLC method was established to simultaneously determine the five sesquiterpene lactones, carabrone, carabrol, 2-desoxy-4-epi-pulchellin, telekinand 11(13)-dehydroivaxillin in Carpesium abrotanoides. Samples were analyzed on a kromasil C18 column (4.6 mm x 250 mm, 5 µm); mobile phase: A was acetonitrile, B was water, with gradient elution; flow speed: 1.0 mL · min(-1); detection was carried out using a photodiode array detector at 211 nm; temperatureof column: 30 °C. The five sesquiterpene lactones were well separated with good linear correlations in the range of 0.270-2.700 (r = 0.999 7 ), 1.336-13.360 (r = 0.999 6), 0.258-2.580 (r = 0.999 7), 0.238-2.380 (r = 0.999 9), 0.490-4.900 µg (r = 0.999 9) for carabrone, carabrol, 2-desoxy-4-epi-pulchellin, telekin and 11 (13) -dehydroivaxillin. The average recoveries of these five sesquiterpene lactoneswere 96.78%-98.41% (RSD 1.3%-2.9%). The method was simple, repeatable and stable, which could be used for quality control of C. abrotanoide.

Dicarabrol, a new dimeric sesquiterpene from Carpesium abrotanoides L.[Pubmed: 26316467]

A new dimeric sesquiterpene, dicarabrol (1), together with three known sesquiterpenes, carabrol (2), 11(13)-dehydroivaxillin (3), and 2-desoxy-4-epi-pulchellin (4), were isolated from the whole plant of Carpesium abrotanoides L. Their structures were elucidated on the basis of spectroscopic analysis, and single crystal X-ray diffraction analysis. Compound 1 possessed a dimeric sesquiterpene core featured with a cyclopentane ring connecting two sesquiterpene lactone units rarely discovered in nature. Dicarabrol (1), as well as three known sesquiterpenes (2-4), had potent in vitro cytotoxicities against the K562, MCF-7, Hela, DU145, U937, H1975, SGC-7901, A549, MOLT-4, and HL60 cell lines with IC50 values ranging from 0.10 to 46.7 μM, while they showed significant antiviral (H1N1 and H3N2) activities. Furthermore, compounds 1, 3 and 4 displayed significant antimycobacterial activity (IC50 3.7, 6.0, and 7.6 μM, respectively).

[Study on Chemical Constituents from Carpesium abrotanoides].[Pubmed: 26080506]

To study the chemical constituents from Carpesium abrotanoides.

Dicarabrones A and B, a pair of new epimers dimerized from sesquiterpene lactones via a [3 + 2] cycloaddition from Carpesium abrotanoides.[Pubmed: 25794335]

Dicarabrones A and B, a pair of epimers possessing a new skeleton featuring a cyclopentane ring connecting two sesquiterpene lactone units, were isolated from the whole plant of Carpesium abrotanoides L. Their full structures were established on the basis of spectroscopic data and were further confirmed by single-crystal X-ray crystallography. They were presumably biosynthesized from two sesquiterpenoid monomers through a [3 + 2] cycloaddition. Dicarabrones A and B showed moderate effects on HL-60 cells with IC50 values of 9.1 and 8.2 μM, respectively.

The effect of 4α,5α-epoxy-10α,14-dihydro-inuviscolide, a novel immunosuppressant isolated from Carpesium abrotanoides, on the cytokine profile in vitro and in vivo.[Pubmed: 25596339]

The plant Carpesium abrotanoides (CA) is used in Asian herbal medicines as an insecticide and to treat bruises. However, the effect of single compounds from CA blooms and the mechanism of its immunosuppressive effect remain poorly understood. The aim of this study was to investigate the mechanism of the immunosuppressive effect in the three kinds of immune cells, and the immunosuppressive effect of CA bloom extract (CAE) in acute inflammation models (LPS and ConA-induced inflammation). Interleukin-6, IL-4, IL-13, IFNγ, and IL-10-but not TNFα-were significantly reduced in a dose-dependent manner by 4α,5α-epoxy-10α,14-dihydro-inuviscolide (INV). Furthermore, INV inhibited NF-κB transcriptional activation and IL-10 promoter activity in the same manner as for Bay11. Meanwhile, treatment with dexamethasone reduced the levels of IFNγ, but not IL-10, and resulted in no change in NF-κB transcriptional activation or the IL-10 promoter. INV did not affect PMA-induced IκB kinase complex phosphorylation, IκB degradation, or MAPK and the nuclear translocation of p65, as with DEX. The in vivo, CAE has an immunosuppressive effect on the LPS-induced inflammation response model by inhibiting the plasma level of IFNγ and IL-6 levels. CAE treatment also tends to attenuate the plasma level of IFNγ, IL-4, and IL-6 in ConA-induced inflammation. These findings indicate that INV causes the reduction of the cytokine profile by blocking the NF-κB transcription factor activation and the molecular mechanism by which INV operates could provide new insights into the unique mechanisms responsible for NF-κB inhibition, in contrast to established immunosuppressants, as a therapeutic agent for immunopathological treatment.

The chemopreventive effects of Carpesium abrotanoides are mediated by induction of phase II detoxification enzymes and apoptosis in human colorectal cancer cells.[Pubmed: 20136434]

Cancer chemoprevention is thought to occur either by blocking the initiation of or suppressing the promotion of carcinogenesis. Phase II detoxification enzymes are known to play important roles in cancer chemoprevention because they enhance cytoprotection through detoxification and elimination of activated carcinogens at tumor initiation. Apoptosis is one of the most important inhibitory targets for tumor promotion. In this study, we have investigated the cancer chemopreventive activity of the ethanolic extract of Carpesium abrotanoides (CAE). We found that CAE induced quinone reductase [also known as NAD(P)H:quinone oxidoreductase (NQO1)] activity, increased NQO1 mRNA and protein expression, and had a relatively high chemoprevention index (12.04). CAE also significantly activated the antioxidant response element through the nuclear accumulation of NF-E2-related factor 2 in HCT116. Interestingly, we also found that CAE induced apoptosis, as evidenced by the externalization of phosphatidylserine, increased sub-G(0)/G(1) content, chromatin condensation, poly(ADP-ribose) polymerase cleavage, and p53. These data suggest that the chemopreventive effects of C. abrotanoides can result from both the induction of phase II detoxification enzymes and from apoptosis. Thus, CAE could potentially be developed as a cancer chemopreventive agent for prevention or treatment of human cancers.