Taxifolin inhibits melanoma proliferation/migration impeding USP18/Rac1/JNK/ß-catenin oncogenic signaling.

BACKGROUND: Metastatic melanoma is a fatal cancer. Despite the advances in targeted therapy and immunotherapy for patients with melanoma, drug resistance and low response rates pose a considerable challenge. Taxifolin is a multifunctional natural compound with emerging antitumor potentials. However, its utility in melanoma treatment remains unclear. PURPOSE: The study aimed to investigate the effect of purified Taxifolin from Larix olgensis roots (Changbai Mountain, China) on melanoma and explore the underlying mechanism. METHODS: Purified Taxifolin from Larix olgensis roots was evaluated for its antimelanoma effects in vitro and in vivo settings. RNA-seq analysis was performed to explore the underlying mechanism. RESULTS: Purified Taxifolin (> 99 %) from Larix olgensis roots inhibited the proliferation and migration of B16F10 melanoma cells at 200 and 400 µM, and of A375 cells at 100 and 200 µM. Taxifolin administered at 60 mg/kg suppressed tumor growth and metastasis in mouse models without causing significant toxicity. Taxifolin modulated USP18/Rac1/JNK/ß-catenin axis to exert its antitumor effect. CONCLUSION: These findings indicate that Taxifolin derived from Larix olgensis roots may be a promising antimelanoma therapy.

Reduction in ischemic cerebral infarction is mediated through golgi phosphoprotein 3 and Akt/mTOR signaling following salvianolate administration.

Salvianolate has been reported to possess protective properties. However, its specific mechanisms have yet to be identified. Our study aimed to identify the molecular mechanism of antioxidative stress function of salvianolate on rat ischemia and reperfusion brain tissues. Rats were randomly distributed into three experimental groups: sham, model and intervention . All animal neurobehavioral tests were performed at the end of 72-h reperfusion per Longa's method, and rats with a score of 0 (no neurological deficit) or 4 (severe neurological deficit with impaired consciousness) were excluded. Brain slices were obtained after 72 h of reperfusion and stained with triphenyltetrazolium chloride. Western blot analysis and quantitative real-time polymerase chain reaction (qRT-PCR) were used to determine levels of GOLPH3, Akt/p-Akt, and mTOR/p-mTOR expressions in ischemic cortex. Salvianolate (18mg/kg intraperitoneal injection) significantly decreased the neurological deficit scores of rats in groups of 72 h I/R and reduced the number of TUNELpositive cells in the cerebral cortex when given at onset and at 24 and 48 h after reperfusion, leading to decreased cerebral infarction in rats after ischemia/reperfusion injury. Results of Western blot and qRT-PCR showed that salvianolate could significantly upregulate the expression of Golgi phosphoprotein-3 as well as the phosphorylation of Akt and mTOR. Above findings indicate that salvianolate exerts potent and long-term neuroprotective effects in the model of cerebral I/R, and Golgi phosphoprotein-3 and its downstream activation of Akt/mTOR signaling pathway may provide a new insight for the antioxidative effect of salvianolate.

Salvianolate increases heat shock protein expression in a cerebral ischemia-reperfusion injury model.

Stroke remains a worldwide health problem. Salvianolate exerts a protective effect in various mi-crocirculatory disturbance-related diseases, but studies of the mechanisms underlying its protective action have mainly focused on the myocardium, whereas little research has been carried out in brain tissue following ischemia-reperfusion. We assessed the neuroprotective effects of salvianolate in a rat model of cerebral ischemia-reperfusion injury induced using the suture method. At onset and 24 and 48 hours after reperfusion, rats were intraperitoneally injected with salvianolate (18 mg/kg) or saline. Neurological deficit scores at 72 hours showed that the neurological functions of rats that had received salvianolate were significantly better than those of the rats that had received saline. 2,3,5-Triphenyltetrazolium chloride was used to stain cerebral tissue to determine the extent of the infarct area. A significantly smaller infarct area and a significantly lower number of apoptotic cells were observed after treatment with salvianolate compared with the saline treatment. Expression of heat shock protein 22 and phosphorylated protein kinase B in ischemic brain tissue was significantly greater in rats treated with salvianolate compared with rats treated with saline. Our findings suggest that salvianolate provides neuroprotective effects against cerebral ischemia-reperfusion injury by upregulating heat shock protein 22 and phosphorylated protein kinase B expression.

Study on the pharmacokinetics drug-drug interaction potential of Glycyrrhiza uralensis, a traditional Chinese medicine, with lidocaine in rats.

Drug-drug interaction potentials of an herbal medicine named Glycyrrhiza uralensis was investigated in rats via in vitro and in vivo pharmacokinetic studies. P(450) levels and the metabolic rate of lidocaine in the liver microsomes prepared from different treatment groups were measured. In a separate in vivo pharmacokinetic study, the pharmacokinetic parameters of lidocaine in plasma and urine were estimated. P(450) levels in the rats pretreated by Glycyrrhiza uralensis were significant higher than that in the non-treatment control. The increase in P(450) levels was dose-dependent. Glycyrrhiza uralensis (1 and 3 g/kg) increased P(450) levels by 62% and 91%, respectively, compared with the non-treatment control (0.695 nmol/mg protein). The metabolic rate of lidocaine in the liver microsomes was significantly higher in the herb pretreated rats. The pharmacokinetic profile of lidocaine was significantly modified in the rats with the herbal pretreatment. Elimination half-lives were shortened by 39%, and total clearances were increased by 59% with the pretreatment of Glycyrrhiza uralensis. In conclusion, Glycyrrhiza uralensis showed induction effect on P(450) isozymes. Efficacy and safety profiles of a drug may be affected when the herbal products or herbal prescriptions containing the plant medicine were concomitantly used.

Inhibition of cytochrome P450 enzymes by rhein in rat liver microsomes.

Rhein, an active ingredient extensively found in plants such as Aloe, Cassitora L., rhubarb and so on, has been used for a long time in China. Pharmacological tests revealed that rhein not only had a strong antibacterial action, but also may be useful in cancer chemotherapy as a biochemical modulator. Its therapeutic action and toxicity is still the subject of considerable research. With microsome incubation assays in vitro and HPLC methods, the inhibition of rat liver CYP1A2, CYP2C9, CYP2D6, CYP2E1 and CYP3A enzymes by rhein were studied kinetically. The results showed the most inhibition of CYP2E1 by rhein (K(i) = 10 microm, mixed); CYP3A and CYP2C9 were also inhibited by rhein, K(i) = 30 microm (mixed) and K(i) = 38 microm (mixed), respectively; rhein revealed some inhibition of CYP1A2 (K(i) = 62 microm, uncompetitive) and CYP2D6 (K(i) = 74 microm, mixed). Drug-drug interactions, especially cytochrome P450 (CYP)-mediated interactions, cause an enhancement or attenuation in the efficacy of co-administered drugs. Inhibition of the five major CYP enzymes observed for rhein suggested that changes in pharmacokinetics of co-administered drugs were likely to occur. Therefore, caution should be paid to the possible drug interaction of medicinal plants containing rhein and CYP substrates.

Effect of the water extract and ethanol extract from traditional Chinese medicines Angelica sinensis (Oliv.) Diels, Ligusticum chuanxiong Hort. and Rheum palmatum L. on rat liver cytochrome P450 activity.

Angelica sinensis (Oliv.) Diels (DG), Ligusticum chuanxiong Hort. (CX) and Rheum palmatum L. (DH), three well known traditional Chinese medicines (TCM), have been used widely for the treatment of various types of disorders in China. Herb-drug interactions, especially cytochrome P450 (CYP)-mediated interactions, cause an enhancement or attenuation in the efficacy of co-administered drugs. In this study, to assess the possible interactions between TCM and drugs, the effect of water and ethanol extracts of DG, CX and DH on cytochrome P450 were studied in rats. The activities of various CYP enzymes were determined by HPLC method. Treatment of rats with water extracts or ethanol extracts of DG, CX and DH at daily dosages equivalent to 3 g (dry herbal material)/kg all increased the microsome protein contents and decreased the total CYP levels. The water extract of DG strongly increased the activities of CYP2D6 and 3A and the water extract of DH significantly increased the activity of 2D6. The other water extracts all showed inhibition against CYP isoforms. Only the ethanol extract of DG and DH increased the CYP2D6 and 3A activities, respectively, and the other ethanol extracts all decreased the level of CYP isoforms. All extract treatments had significant effects on CYP isoforms activities, whether induction or inhibition, compared with the blank control. Thus, caution should be paid to possible drug interactions of DG, CX, DH and CYP substrates.

Traditional Chinese medicines Wu Wei Zi (Schisandra chinensis Baill) and Gan Cao (Glycyrrhiza uralensis Fisch) activate pregnane X receptor and increase warfarin clearance in rats.

The traditional Chinese medicines (TCMs) are essential components of alternative medicines. Many TCMs are known to alter the expression of hepatic drug-metabolizing enzymes and transporters. The molecular mechanism by which TCMs and/or their constituents regulate enzyme and transporter expression, however, has remained largely unknown. In this report, we show that two TCMs, Wu Wei Zi (Schisandra chinensis Baill) and Gan Cao (Glycyrrhiza uralensis Fisch), and their selected constituents activate the xenobiotic orphan nuclear receptor pregnane X receptor (PXR). Treatment with TCM extracts and the Schisandrol and Schisandrin constituents of Wu Wei Zi induced the expression of drug-metabolizing enzymes and transporters in reporter gene assays and in primary hepatocyte cultures. The affected enzymes and transporters include CYP3A and 2C isozymes and the multidrug resistance-associated protein 2. In transient transfection and reporter gene assays, the Schisandrin constituents of Wu Wei Zi had an estimated EC50 of 2 and 1.25 microM on hPXR and mPXR, respectively. Interestingly, mutations that were intended to alter the pore of the ligand-binding cavity of PXR had species-specific effects on the activities of the individual Schisandrols and Schisandrins. In rats, the administration of Wu Wei Zi and Gan Cao increased the metabolism of the coadministered warfarin, reinforcing concerns involving the safe use of herbal medicines and other nutraceuticals to avoid PXR-mediated drug-drug interactions. Meanwhile, the activation of PXR and induction of detoxifying enzymes provide a molecular mechanism for the hepatoprotective effects of certain TCMs.

[Effects of almond on D-gal-induced aging rats].

OBJECTIVE: To study the effects of Beijing Almond on D-gal-induced aging rats. METHODS: D-gal-induced aging rats are fed on almond in three different dosages respectively daily (32.5 g/kg feedstuff, 65 g/kg feedstuff, 97.5 g/kg feedstuff). After 30 days, the level of MDA, the activities of SOD, GSH-Px in serum, and the liquid fluidity of erythrocyte membrane were determined. RESULTS: Compared with aging group, the level of MDA in high and middle dose groups decreased significantly (P < 0.01). At the same time, the activities of SOD, GSH-Px and the liquid fluidity of erythrocyte membrane increased evidently (P < 0.01). But the lowest dose group was not significantly difference (P < 0.05). CONCLUSION: Almond in proper has abilities of anti-oxidation and retarding aging process.