Eugenol restrains abdominal aortic aneurysm progression with down-regulations on NF-κB and COX-2.

Abdominal aortic aneurysm (AAA) is a lethal disease without available medicine for treatment. This study aimed to evaluate the efficiency of eugenol (4-allyl-2-methoxyphenol) against AAA and the underlying mechanism. Eugenol is the major bioactive component of clove. A mouse AAA model was established through porcine pancreatic elastase (PPE) incubation peri-adventitially and 1% 3-aminopropanonitrile (BAPN) diet. Continuous AAA progression from day 0 to day 15 was observed after PPE plus BAPN treatment, according to the AAA diameter and histopathological evaluation. Accompanying with AAA progression, sustained increased expressions of CD68, COX-2 and NF-κB were observed through immunofluorescence assay. After elucidation the efficiency of eugenol against AAA progression by AAA diameter, hematoxylin-eosin staining and orcein staining, the down-regulations of eugenol on COX-2 and NF-κB were further detected by immunohistochemistry and western blot. Eugenol not only blocked AAA expansion and protected the integrity of aortic structure in a dose-dependent manner, but also held high oral bioavailability. Excellent efficiency, high oral bioavailability and down-regulation on COX-2/NF-κB endowed eugenol great potential for future AAA therapy.

Rosmarinic Acid Suppresses Abdominal Aortic Aneurysm Progression in Apolipoprotein E-deficient Mice.

An abdominal aortic aneurysm is a life-threatening cardiovascular disorder caused by dissection and rupture. No effective medicine is currently available for the > 90% of patients whose aneurysms are below the surgical threshold. The present study investigated the impact of rosmarinic acid, salvianolic acid C, or salvianolic acid B on experimental abdominal aortic aneurysms. Abdominal aortic aneurysms were induced in apolipoprotein E-deficient mice via infusion of angiotensin II for 4 wks. Rosmarinic acid, salvianolic acid C, salvianolic acid B, or doxycycline as a positive control was provided daily through intraperitoneal injection. Administration of rosmarinic acid was found to decrease the thickness of the aortic wall, as determined by histopathological assay. Rosmarinic acid also exhibited protection against elastin fragmentation in aortic media and down-regulated cell apoptosis and proliferation in the aortic adventitia. Infiltration of macrophages, T lymphocytes, and neutrophils in aortic aneurysms was found, especially at the aortic adventitia. Rosmarinic acid, salvianolic acid C, or salvianolic acid B inhibited the infiltration on macrophages specifically, but these compounds did not influence T lymphocytes and neutrophils. Expression of matrix metalloproteinase 9 and macrophage migration inhibitory factor significantly increased in aortic aneurysms. Rosmarinic acid and salvianolic acid C decreased the expression of matrix metalloproteinase-9 in media, and rosmarinic acid also tended to reduce migration inhibitory factor expression. Further then, partial least squares-discriminate analysis was used to classify metabolic changes among different treatments. Rosmarinic acid affected most of the metabolites in the biosynthesis of the citrate cycle, fatty acid pathway significantly. Our present study on mice demonstrated that rosmarinic acid inhibited multiple pathological processes, which were the key features important in abdominal aortic aneurysm formation. Further study on rosmarinic acid, the novel candidate for aneurysmal therapy, should be undertaken to determine its potential for clinical use.

Lipid-Lowering Activities of Cucurbitacins Isolated from Trichosanthes cucumeroides and Their Synthetic Derivatives.

In the ongoing efforts to discover natural cholesterol-lowering compounds, dihydrocucurbitacin B, isolated from Trichosanthes cucumeroides roots, was found to promote LDL uptake by upregulating LDLR protein in a PCSK9-dependent process. In this study, an in-depth investigation of T. cucumeroides roots afforded 27 cucurbitacins (1-27), including seven new cucurbitacins (1-7), and their structures were elucidated by spectroscopic data analyses. In order to gain insight into their structure-activity relationship, cucurbitacin derivatives (B1-11 and DB1-11) were synthesized. Evaluation of lipid-lowering activities of these cucurbitacins by an LDL uptake assay in HepG2 cells revealed that most of the compounds improved the LDL uptake rate, among which hexanorisocucurbitacin D (6) and isocucurbitacin D (21) exhibited the highest activities (rates of 2.53 and 2.47, respectively), which were comparable to that of the positive control, nagilactone B (rate of 2.07). According to a mechanistic study by Western blot analysis, compounds 6 and 21 dose-dependently increased LDLR protein levels and reduced PCSK9 protein levels, representing promising new lipid-lowering drug candidates.

Synthetic derivatives of the natural product 13-amino 2-desoxy-4-epi-pulchellin inhibit STAT3 signaling and induce G2/M arrest and death of colon cancer cells.

2-Desoxy-4-epi-puchellin (PCL) is a sesquiterpene-lactone, which naturally occurs in many traditional Chinese medicinal plants, and has antitumor and anti-inflammatory activities. In this work, a series of 13-amino derivatives of PCL were synthesized through Michael addition reaction. Inhibition of IL-6-induced STAT3 signaling pathway and in vitro cytotoxicity of these compounds were evaluated, and their effect on the cell cycle was also studied. The methyl hydroxyethylamine derivatives showed higher potency than PCL, which could induce significant mitotic arrest via G2/M arrest in HCT116 cancer cells, indicating that these derivatives have the potential to be developed into anti-colon cancer drugs.