- Antihypertensive effect of caffeic acid and its analogs through dual renin-angiotensin-aldosterone system inhibition
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Hypertension is a crucial risk factor for cardiovascular diseases and contributes to one third of global mortality. In addition to conventional antihypertensive drugs such as captopril, naturally occurring phytochemicals and their analogs are used for red
- Bhullar, Khushwant S.,Lassalle-Claux, Grégoire,Touaibia, Mohamed,Vasantha Rupasinghe
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p. 125 - 132
(2014/04/17)
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- Antiproliferative, antiandrogenic and cytotoxic effects of novel caffeic acid derivatives in LNCaP human androgen-dependent prostate cancer cells
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Caffeic acid and its naturally occurring derivative caffeic acid phenethyl ester (CAPE) have antiproliferative and cytotoxic properties in a variety of cancer cell lines without displaying significant toxicity toward healthy cells, and are considered to be potential anticancer agents. However, little is known about their effects on prostate cancer cells. We synthesized and evaluated the effects of caffeic acid, CAPE (2) and 18 synthetic derivatives on cell viability and androgen-dependent cell proliferation, subcellular localisation and expression of androgen receptor (AR) and secretion of prostate-specific antigen (PSA) in LNCaP human hormone-dependent prostate cancer cells. Several synthetic derivatives of CAPE were strong, concentration-dependent cytotoxic agents in LNCaP cells with IC50 values in the 6.8-26.6 μM range, potencies that were up to five-fold greater than that of CAPE (33.7 ± 4.0 μM). A number of caffeic acid derivatives were inhibitors of androgen-stimulated LNCaP cell proliferation with concomitant inhibition of DHT-stimulated PSA secretion. Compound 24 was the most cytotoxic and antiproliferative caffeic acid derivative (IC50 values of 6.8 ± 0.3 and 2.4 ± 0.8 μM, respectively) inhibiting DHT-stimulated cell proliferation and PSA secretion statistically significantly at concentrations as low as 0.3 μM. Exposure to DHT increased cytoplasmic and nuclear AR levels and co-treatment with increasing concentrations of compound 24 or CAPE (2), notably, further increased these levels. In conclusion, a number of synthetic derivatives of caffeic acid are potent inhibitors of androgen-dependent prostate cancer cell proliferation and viability, acting, at least in part, via an antiandrogenic mechanism that involves increased nuclear accumulation of (presumably inactive) AR.
- Sanderson, J. Thomas,Clabault, Hélène,Patton, Cody,Lassalle-Claux, Grégoire,Jean-Fran?ois, Jacques,Paré, Aurélie F.,Hébert, Martin J.G.,Surette, Marc E.,Touaibia, Mohamed
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p. 7182 - 7193
(2013/11/06)
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- Evaluation of allergens in propolis by ultra-performance liquid chromatography/tandem mass spectrometry
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The purified extract of propolis is used as a traditional remedy for the treatment of several diseases. Its beneficial activities are mainly attributed to the polyphenolic fraction. Nevertheless, propolis can cause allergic dermatitis and the sensitization rate in humans is increasing significantly mainly in younger subjects. The aim of this study was to develop and validate a selective and sensitive ultra-performance liquid chromatography tandem mass spectrometry analysis (UPLC/MS/MS) for the evaluation of the amount of caffeic acid and its esters with allergenic action in raw propolis samples and commercial formulations. The separation was carried out on a 1.7 μm C 18 BEH Shield column and the detection performed by means of electrospray ionization in negative ion mode with multiple reaction monitoring. The confirmation of formulae of the precursor and product ions was accomplished by injection into a high-resolution system (FTICR-MS) using accurate mass measurements. The error was below 1.4 ppm.The range of the standard curves was 0.5-10 μg/mL and dihydrocaffeic acid was used as internal standard (IS). The lower limit of detection (LLOD) for 3-methyl-2-butenyl- (3M2B), 3-methyl-3-butenyl- (3M3B), 2-methyl-2-butenyl- (2M2B), benzyl- (CABE), phenylethylcaffeic acid (CAPE) and for caffeic acid (CA) and the IS was 0.1 and 0.3 μg/mL, respectively. The recoveries were in the range 96-104% and the intra- and inter-day precisions were within 6.2%. In the European (n = 8) and Asiatic (n = 3) propolis the most abundant allergens were CABE>3M2B> CAPE>3M3B>CA>2M2B. These compounds were not found in the red (n = 1) and green (n = 1) Brazilian propolis. Hydroalcoholic extracts (n = 6) and tablets (n = 6) were analyzed by the proposed UPLC/MS/MS method. The results showed that in the commercial products CABE, 3M2B, CAPE and 3M3B were also the most abundant.
- Gardana, Claudio,Simonetti, Paolo
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experimental part
p. 1675 - 1682
(2012/03/12)
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