Design, synthesis, and in-vivo evaluation of 4,5-diaryloxazole as novel nonsteroidal anti-inflammatory drug.

A series of 4,5-diaryloxazole analogs were designed and the interaction between oxaprozin and cyclooxygenase-2 studied by the docking method to improve the biological activity and reduce the gastrointestinal side effects of oxaprozin. Finally, 3-(4-(4-fluorophenyl)-5-(4-aminosulfonyl-3-fluorophenyl)-oxazole-2-yl) propanoic acid (NC-2142), the best candidate, was selected for synthesis and bioassay based on the screening result. NC-2142 could lower the tumefaction rates of back metatarsus in rats, as well as reduce the writhing times in mice. NC-2142 produced fewer gastric lesions than oxaprozin. After the aminosulfonyl group was introduced into the benzene ring of oxaprozin, its analgesic and anti-inflammatory activities remained unchanged, and it reduced the number of gastric lesions. This provided a feasible method for further structure modification and optimization of oxaprozin.

[Effects of CASI on myocardial ischemia-reperfusion arrhythmia in rats].

OBJECTIVE: To observe the protective effect of compound acanthopanax senticosus injection (CASI) on myocardial ischemia-reperfusion arrhythmia in rats. METHOD: The myocardial ischemia-reperfusion model was induced by 30 min coronary occulusion and 60 min reperfusion in openchest anesthetized rats. The changes of arrhythmia with electrocardiogram lead II, the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), the contents of malondialdehyde (MDA) and Ca2+ in myocardium were determined. RESULT: In rats treated by CASI (in a dosage of 25, 50 and 100 mg x kg(-1) femoral vein infusion at 30 min after coronary occulusion), the incidence of myocardial ischemia-reperfusion ventricular arrhythmias, for instance the ventricular tachycardia (VT) and ventricular fibrillation (Vf), was effectively prevented, the appearing time of arrhythmia was delayed and the duration of arrhythmia was shortened, while the elevated ST segment lowered as well. At the same time, the contents of myocardial Ca2+ and MDA were decreased significantly as well as the activities of myocardial SOD and GSH-Px increased markedly. CONCLUSION: CASI is of protective effect on myocardial ischemia-reperfusion arrhythmia, which may be related to scavenging the oxygen free radicals and Ca2+ overload formed during reperfusion.

[Effects of ginsenoside-Rb on blood lipid metabolism and anti-oxidation in hyperlipidemia rats].

OBJECTIVE: To observe effects of ginsenoside-Rb (G-Rb) on total cholesterol, lipoprotein cholesterol metabolism and anti-oxidation in experimental hyperlipidemia rats. METHOD: Hyperlipidemia rats were respectively given G-Rb 50, 100, 200 mg x kg(-1) x d(-1) ig for twelve days. Total cholesterol, lipoprotein cholesterol and lipid peroxidation (LPO) contents, prostacycline (PGI2), thromboxane (TXA2), superoxide dismutase (SOD) and blood viscosity were measured. Fat accumulation in liver was also observed. RESULT: Triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-c) in serum, TXA2 in plasma, LPO in serum and liver, and blood viscosity were decreased significantly. High density lipoprotein cholesterol (HDLc) in serum, PGI2 in plasma and SOD in serum and liver were significantly increased by G-Rb (100, 200 mg x kg(-1)) in experimental hyperlipidemia rats. In addition, G-Rb could decrease TC/HDL-c, LDLc/HDL-c ratio, increase PGI2/TXA2 ratio and inhibit fat accumulation in liver. CONCLUSION: G-Rb could have anti-arteriosclerosis effect by improving cholesterol and lipoprotein-cholesterol metabolism, suppressing lipid peroxidation, increasing anti-oxidase activity and PGI2/TXA2 ratio.

[Protective effect of ASS on myocardial ischemia-reperfusion injury in rats].

OBJECTIVE: To observe the protective effect of Acanthopanax senticosus saponins (ASS) on myocardial ischemia-reperfusion injury in rats. METHOD: The myocardial ischemia-reperfusion model was induced by 30 min left anterior descending coronary occlusion and 120 min reperfusion in rats. The changes of myocardial infarct size (MIS), the serum creatine phosphokinase (CK) and lactate dehydrogenase (LDH) activity, the serum lipid peroxidation (LPO) content and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity and plasma endothelin (ET), angiotensin II (Ang II), prostacycline (PGI2) and thromboxane A2 (TXA2) levels and myocardial free fatty acid (FFA) content of infarct and noninfarct area were determined. RESULT: In rats treated by ASS (in a dosage of 25, 50 and 100 mg x kg(-1) i.v. at 30 min after coronary occulusion), the MIS was significantly reduced, the serum CK and LDH activity, the plasma ET, Ang II and TXA2 level and myocardial FFA content declined, while plasma PGI2 level and PGI2/TXA2 was increased signficantly. In addition, serum LPO content declined, SOD and GSH-Px activity were increased markedly. CONCLUSION: ASS has protective effect on myocardial ischemia-reperfusion injury, which may be due to its function of improving free radicals and myocardial metabolism, decreasing plasma ET, Ang II and TXA2 levels and increasing plasma PGI2 level and PGI2/TXA2 ratio etc.

20(S)-protopanaxadiol triggers mitochondrial-mediated apoptosis in human lung adenocarcinoma A549 cells via inhibiting the PI3K/Akt signaling pathway.

20(S)-Protopanaxadiol (PPD), an aglycone saponin ginsenoside isolated from Panax quinquefolium L, has been shown to inhibit the growth and proliferation in several cancer lines. However, the underlying molecular mechanisms remain poorly understood. In this study, we investigated the apoptosis-induced effects and the mechanism of 20(S)-PPD on human lung adenocarcinoma A549 cells. 20(S)-PPD showed a potent antiproliferative activity against A549 cells by triggering apoptosis. 20(S)-PPD-induced apoptosis was characterized by a dose-dependent loss of the mitochondrial membrane, release of cytochrome c, second mitochondria-derived activator of caspase (Smac) and apoptosis-inducing factor (AIF), activation of caspase-9/-3, and cleavage of poly (ADP-ribose) polymerase (PARP). Caspase-dependence was indicated by the ability of the pan-caspase inhibitor z-VAD-fmk to attenuate 20(S)-PPD-induced apoptosis. After treatment with 20(S)-PPD, the proportion of A549 cells at the G0/G1 phase increased, while cells at the S and G2/M phases decreased. Furthermore, 20(S)-PPD also triggered down-regulation of phosphorylated Akt (Ser473/Thr308) and glycogen synthase kinase 3ß (GSK 3ß). Knockdown of GSK 3ß with siRNA promoted the apoptotic effects of 20(S)-PPD. These results revealed an unexpected mechanism of action for this unique ginsenoside: triggering a mitochondrial-mediated, caspase-dependent apoptosis via down-regulation of the PI3K/Akt signaling pathway in A549 cells. Our findings encourage further studies of 20(S)-PPD as a promising chemopreventive agent against lung cancer.

Hypolipidemic effects of kaempferide-7-O-(4''-O-acetylrhamnosyl)-3-O-rutinoside in hyperlipidemic rats induced by a high-fat diet.

Kaempferide-7-O-(4''-O-acetylrhamnosyl)-3-O-rutinoside (A-F-B) is a novel flavonoid which is extracted from the leaves of Actinidia kolomikta. The aim of this study was to investigate the hypolipidemic effects of A-F-B in hyperlipidemic rats induced by a high-fat diet. Male Wistar rats were randomly divided into six groups: normal diet group, high-fat diet group, lovastatin (2.5 mg/kg) group and A-F-B (12.5, 25 or 50 mg/kg) groups. To evaluate the lipid-lowering effects of A-F-B, total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), atherogenic index (AI) and coronary risk index (CRI) were investigated. The activities of phosphatidate phosphohydrolase (PAP) and hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase in hepatic tissue were evaluated. Treatment with A-F-B to hyperlipidemic rats resulted in a significant decline in TC, TG, LDL-C, AI and CRI, with an increase in HDL-C level. The results also showed that A-F-B significantly decreased the activities of PAP and HMG-CoA reductase in hepatic tissue. These findings suggest that A-F-B improves lipid profiles. The mechanisms of A-F-B were associated with regulating the activities of PAP and HMG-CoA reductase in hepatic tissue.

Juglone, from Juglans mandshruica Maxim, inhibits growth and induces apoptosis in human leukemia cell HL-60 through a reactive oxygen species-dependent mechanism.

Juglone, a major chemical constituent of Juglans mandshruica Maxim, is a promising anticancer agent that has shown a strong activity against cancer cells in vitro. Our previous study showed that juglone inhibited the proliferation of HL-60 cells with an IC50 value ∼8 µM. To further explore the proapoptotic mechanism of juglone, we investigated the role of the reactive oxygen species (ROS) in the apoptosis induced by juglone in HL-60 cells. The generation of ROS was about 2 to 8-fold as compared to control cell after treatment with juglone (2, 4 and 8 µM) for 24 h. The glutathione (GSH) depletion was consistent with ROS generation after treatment with juglone. Reversal of apoptosis in antioxidants (NAC and catalase) pretreated cells indicated the involvement of ROS in juglone-induced apoptosis. The cleavage of PARP and procaspase-3 and -9, loss of mitochondrial membrane potential (△Ψm), and release of cytochrome c (Cyt c) and Smac induced by juglone were significantly blocked by NAC. NAC also prevented the inhibition the phosphorylation of Akt and mTOR proteins by juglone. Collectively, these results indicated that ROS played a significant role in the apoptosis induced by juglone in human leukemia cell HL-60.

Ginsenoside Rb3 inhibits angiotensin II-induced vascular smooth muscle cells proliferation.

This study was designed to examine the effect of ginsenoside Rb3 on angiotensin (Ang) II-induced proliferation of cultured rat vascular smooth muscle cells (VSMCs). VSMCs proliferation was evaluated by [3H]Thymidine incorporation. The cell cycle was examined by flow cytometry. The expression of mRNA of proto-oncogene c-myc, c-fos and c-jun was observed by RT-PCR. Ginsenoside Rb3 had no effects on VSMCs proliferation in physiological condition. Ang II significantly increased the proliferation of VSMCs and the expression of mRNA of proto-oncogene c-myc, c-fos and c-jun. Ginsenoside Rb3 markedly inhibited Ang II-induced VSMCs proliferation. Concomitantly, ginsenoside Rb3 decreased cell cycle progression from G(0)/G(1) to S phase. Furthermore, ginsenoside Rb3 significantly attenuated the expression of mRNA of proto-oncogene c-myc, c-fos and c-jun. This study showed that ginsenoside Rb3 inhibited Ang II-induced VSMCs proliferation, at least in part by inhibiting Ang II-induced G(0)/G(1) to S phase transition and attenuating the expression of mRNA of c-fos, c-jun and c-myc. The findings may explain the beneficial effects of ginsenoside Rb3 in cardiovascular diseases, and it will be useful to develop prevention and therapeutics of cardiovascular diseases.

Anti-proliferative effect of Juglone from Juglans mandshurica Maxim on human leukemia cell HL-60 by inducing apoptosis through the mitochondria-dependent pathway.

Induction of apoptosis in tumor cells has become the major focus of anti-tumor therapeutics development. Juglone, a major chemical constituent of Juglans mandshurica Maxim, possesses several bioactivities including anti-tumor. Here, for the first time, we studied the molecular mechanism of Juglone-induced apoptosis in human leukemia HL-60 cells. In the present study, HL-60 cells were incubated with Juglone at various concentrations. Occurrence of apoptosis was detected by Hoechst 33342 staining and flow cytometry. Expression of Bcl-2 and Bax mRNA was determined by quantitative polymerase chain reaction (qPCR). The results showed that Juglone inhibits the growth of human leukemia HL-60 cells in dose- and time-dependent manner. Topical morphological changes of apoptotic body formation after Juglone treatment were observed by Hoechst 33342 staining. The percentages of Annexin V-FITC-positive/PI negative cells were 7.81%, 35.46%, 49.11% and 66.02% with the concentrations of Juglone (0, 0.5, 1.0 and 1.5 microg/ml). Juglone could induce the mitochondrial membrane potential (DeltaPsim) loss, which preceded release of cytochrome c (Cyt c), Smac and apoptosis inducing factor (AIF) to cell cytoplasm. A marked increased of Bax mRNA and protein appeared with Juglone treatment, while an evidently decreased of Bcl-2 mRNA and protein appeared at the same time. These events paralleled with activation of caspase-9, -3 and PARP cleavage. And the apoptosis induced by Juglone was blocked by z-LEHD-fmk, a caspase-9 inhibitor. Those results of our studies demonstrated that Juglone-induced mitochondrial dysfunction in HL-60 cells trigger events responsible for mitochondrial-dependent apoptosis pathways and the elevated ratio of Bax/Bcl-2 was also probably involved in this effect.