2-(3,4-dihydroxyphenyl)-2-hydroxypropanoic acid

Danshensu protects against 6-hydroxydopamine-induced damage of PC12 cells in vitro and dopaminergic neurons in zebrafish.[Pubmed: 23562886]

Neurosci Lett. 2013 May 24;543:121-5.

The overproduction of reactive oxygen species (ROS) has been implicated in the development of neurodegenerative diseases such as Parkinson's disease (PD) and Alzheimer's disease (AD). Previous studies have indicated that Danshensu (beta-3,4-dihydroxyphenyl-lactic acid), a main hydrophilic component of the Chinese materia medica Radix Salviae Miltiorrhizae (Danshen, Pharmacopoeia of PR China), has ROS scavenging and antioxidant activities, however its mechanism of action was not clear.
METHODS AND RESULTS:
In this study, we investigated whether the protective effects of Danshensu against neurotoxin 6-hydroxydopamine (6-OHDA)-induced oxidative stress involved the Nrf2/HO-1 pathways. Pretreatment with Danshensu in PC12 cells significantly attenuated 6-OHDA-induced cytotoxicity and the production of ROS. Danshensu activated the nuclear translocation of Nrf2 to increase heme oxygenase-1 (HO-1), conferring protection against ROS. Danshensu induced the phosphorylation of Akt, and its cytoprotective effect was abolished by PI3K, Akt and HO-1 inhibitors. These results confirmed the crucial role of PI3K/Akt and HO-1 signaling pathways as the underlying mechanistic action of Danshensu.
CONCLUSIONS:
Taken together, the results suggest that Danshensu enhances HO-1 expression to suppress 6-OHDA-induced oxidative damage via PI3K/Akt/Nrf2 signaling pathways. Moreover, 6-OHDA-induced dopaminergic neuronal loss in zebrafish could be reduced by Danshensu, further supporting the neuroprotective potential of Danshensu.

Anxiolytic-like effect of danshensu [(3-(3,4-dihydroxyphenyl)-lactic acid)] in mice.[Pubmed: 24582592]

Life Sci. 2014 Apr 17;101(1-2):73-8.

Danshensu [3-(3,4-dihydroxyphenyl)-lactic acid], a phenylpropanoid compound isolated from Prunella vulgaris var. lilacina, is a well-known antioxidant. Although its antioxidant activity and cardioprotective effect have been reported, the pharmacological properties of Danshensu in the central nervous system remain unclear. We investigated whether Danshensu exerts anxiolytic-like activity in mice.
METHODS AND RESULTS:
We conducted monoamine oxidase A (MAO-A) inhibition assay on Danshensu in vitro, and behavioral tests including the elevated plus-maze test (EPM), the hole-board test, the rotarod test and the open field test were employed. We found that Danshensu significantly inhibited the activity of MAO-A in vitro. The administration of Danshensu (3 or 10mg/kg) produced a significant anxiolytic-like effect in the EPM and hole-board test. In addition, no changes in the spontaneous locomotor activity and no myorelaxant effects were observed compared to the control group; these effects were confirmed with the open field test and the rotarod test. Moreover, the anxiolytic-like properties of Danshensu were antagonized by a dopamine D1 receptor antagonist (SCH 23390) but not by a 5-HT1A receptor antagonist (WAY 100635) or an α1-adrenergic receptor antagonist (prazosin).
CONCLUSIONS:
These results indicate that Danshensu exerts its anxiolytic-like properties, in part, through dopaminergic neurotransmitter signaling.

Danshensu protects vascular endothelia in a rat model of hyperhomocysteinemia.[Pubmed: 20871618 ]

Acta Pharmacol Sin. 2010 Oct;31(10):1395-400.

To examine whether Danshensu could protect vascular endothelia in a rat model of hyperhomocysteinemia.
METHODS AND RESULTS:
The model was established by feeding rats with a methionine-rich diet (1 g·kg⁻1·d⁻1) for 3 months. Immediately following the discontinuation of methionine-rich diet, rats were treated with Danshensu (67.5 mg·kg⁻1·d⁻1, po) or saline for 3 additional months. One group of rats receiving vitamin mixture (folic acid, vitamin B12 and vitamin B6) was included as a positive control. One group of rats not exposed to methionine-rich diet was also included as a blank control. The expression of tumor necrosis factor-alpha (TNF-alpha) and intercellular adhesion molecule-1 (ICAM-1) protein in the descending aorta was examined using immunohistochemistry and Western blot. Homocysteine and blood concentration of endothelin and nitric oxide (NO) was also examined. Methionine-rich diet resulted in accumulation of "foam cells", up-regulated expression of TNF-alpha and ICAM-1 in the descending aorta, and significantly increased serum homocysteine. Plasma endothelin concentration was significantly increased; NO was decreased. Danshensu treatment, either simultaneous to methionine-rich diet or afterwards, attenuated the above mentioned changes.
CONCLUSIONS:
Chronic treatment with Danshensu could prevent/attenuate the formation of atherosclerosis. Potential mechanisms include inhibited expression of representative proinflammatory cytokines and adhesion molecules in arterial endothelia. Changes in homocysteine and circulating molecules that control vascular contraction/relaxation via endothelial cells (eg, endothelin and NO) were also implicated.

Design, synthesis, and preliminary cardioprotective effect evaluation of danshensu derivatives.[Pubmed: 24581174]

Chem Biol Drug Des. 2014 Sep;84(3):282-91.

A series of (R)-3,4-dihydroxyphenyllactic acid Danshensu (DSS) derivatives were synthesized, and their cardioprotective effects were evaluated in vitro and in vivo.
METHODS AND RESULTS:
Among the new derivatives, compound 14 showed significant protective effects in cultured myocardial cells and in the rat model of myocardial ischemia. The therapeutic efficacy of compound 14 was significantly higher than that of its parent compound DSS, and amlodipine, a first-line treatment for angina pain. Compound 14 potently scavenged free radicals, significantly decreased the levels of LDH and MDA, and inhibited the leakage of CK in animal model of ischemia. We had previously found that compound 14 activated PI3K/Akt/GSK-3β and Nrf2//Keap1/heme oxygenase-1 (HO-1) signaling pathways in H9c2 cells.
CONCLUSIONS:
These results suggest that compound 14 has a unique mechanism of action, that is, multifunctional. Compound 14 may be a new potential therapy for ischemic heart diseases.

Drug Test Anal. 2014 Dec 29.

Identification of a major metabolite of danshensu in rat urine and simultaneous determination of danshensu and its metabolite in plasma: application to a pharmacokinetic study in rats.[Pubmed: 25557831]

Danshensu, as the effective component of Salvia miltiorrhiza (Danshen), has been widely used in clinical studies for treatment of cardiovascular diseases in China.
METHODS AND RESULTS:
A new metabolite, 4-hydroxy-3-methoxyphenyllactic acid was isolated from the urine of rats, and its chemical structure was identified by ultraviolet (UV), Infrared Spectroscopy (IR), mass spectrometry (MS) and nuclear magnetic resonance (NMR). Furthermore, a selective and sensitive high performance liquid chromatography-tandem mass spectrometric (HPLC-MS/MS) method was developed for the simultaneous quantification of Danshensu and its major metabolite, 4-hydroxy-3-methoxyphenyllactic acid, in rat plasma after oral and intravenous administration of Danshensu. The separation was performed on a Hypersil Gold C18 column (150 × 2.1 mm i.d., 3.0 μm, Thermo, San jose CA, USA) with gradient elution using a mobile phase composed of methanol and water (containing 0.1% formic acid) at a flow rate of 0.2 mL/min. Linear detection responses were obtained for Danshensu and 4-hydroxy-3-methoxyphenyllactic acid ranging from 5 to 10000 ng/mL and 5 to 4000 ng/mL, respectively. The lower limits of quantification (LLOQs) for the two compounds were both 5 ng/mL. The intra-and inter-day precision (R.S.D %) were within 5.61% for the two analytes. The average recoveries of the analytes were greater than 72.43%. The method was proved to be stable during all sample storage, preparation and analytic procedures.
CONCLUSIONS:
This method was successfully applied to the pharmacokinetic studies of Danshensu and 4-hydroxy-3-methoxyphenyllactic acid after oral and intravenous administration of Danshensu in rats.