The pharmacokinetic study on the interaction between nobiletin and anemarsaponin BII in vivo and in vitro

ContextThe interaction between nobiletin and anemarsaponin BII could affect the pharmacological activity of these two drugs during their combination.ObjectiveThe co-administration of nobiletin and anemarsaponin BII was investigated to explore the interaction and the potential mechanism.Materials and methodsMale Sprague-Dawley rats were only orally administrated with 50 mg/kg nobiletin as the control and another six rats were pre-treated with 100 mg/kg anemarsaponin BII for 7 d followed by the administration of nobiletin. The transport and metabolic stability of nobiletin were evaluated in vitro, and the effect of anemarsaponin BII on the activity of CYP3A4 was also assessed to explore the potential mechanism underlying the interaction.ResultsThe increasing C_max (2309.67 ± 68.06 μg/L vs. 1767.67 ± 68.86 μg/L), AUC (28.84 ± 1.34 mg/L × h vs. 19.57 ± 2.76 mg/L × h), prolonged t_1/2 (9.80 ± 2.33 h vs. 6.24 ± 1.53 h), and decreased clearance rate (1.46 ± 0.26 vs. 2.42 ± 0.40) of nobilein was observed in rats. Anemarsaponin BII significantly enhanced the metabolic stability of nobiletin in rat liver microsomes (half-life increased from 31.56 min to 39.44 min) and suppressed the transport of nobiletin in Caco-2 cells (efflux rate decreased from 1.57 ± 0.04 to 1.30 ± 0.03). The inhibitory effect of anemarsaponin BII on CYP3A4 was also found with an IC₅₀ value of 10.23 μM.Discussion and conclusionsThe interaction between anemarsaponin BII and nobiletin was induced by the inhibition of CYP3A4, which should draw special attention in their clinical co-administration.     

Pharmacokinetic study on the interaction between pachymic acid and bavachin and its potential mechanism

ContextPachymic acid and bavachin are commonly used drugs in the therapy of lung cancer.ObjectiveThe co-administration of pachymic acid and bavachin was investigated to evaluate their potential drug-drug interaction.Materials and methodsThe pharmacokinetics of bavachin (10 mg/kg) was studied in male Sprague-Dawley (SD) rats in the presence of pachymic acid (5 mg/kg) (n = 6). The rats without pre-treatment of pachymic acid were set as the control and the pre-treatment of pachymic acid was conducted for 7 days before the administration of bavachin. The effect of pachymic acid on the activity of CYP2C9 was also estimated in rat liver microsomes with corresponding probe substrates.ResultsPachymic acid influenced the pharmacokinetic profile of bavachin with the increased AUC (32.82 ± 4.61 vs. 19.43 ± 3.26 μg/L/h), the prolonged t_1/2 (3.21 ± 0.65 vs. 2.32 ± 0.28 h), and the decreased CLz/F (307.25 ± 44.35 vs. 523.81 ± 88.67 L/h/kg) in vivo. The metabolic stability of bavachin was enhanced by pachymic acid and the transport of bavachin was inhibited by pachymic acid. Pachymic acid was found to inhibit the activity of CYP2C9 with the IC₅₀ of 21.25 µM as well as the activity of P-gp.Discussion and conclusionThe interaction between pachymic acid and bavachin results from the inhibition of CYP2C9 and P-gp. The dose of bavachin should be adjusted when combining with pachymic acid. The study design can be generalized to a broader study population with adjustment in the dose.     

Baicalein inhibits the pharmacokinetics of simvastatin in rats via regulating the activity of CYP3A4

ContextBaicalein and simvastatin possess similar pharmacological activities and indications. The risk of their co-administration was unclear.ObjectiveThe interaction between baicalein and simvastatin was investigated to provide reference and guidance for the clinical application of the combination of these two drugs.Materials and methodsThe pharmacokinetics of simvastatin was investigated in Sprague–Dawley rats (n = 6). The rats were pre-treated with 20 mg/kg baicalein for 10 days and then administrated with 40 mg/kg simvastatin. The single administration of simvastatin was set as the control group. The rat liver microsomes were employed to assess the metabolic stability and the effect of baicalein on the activity of CYP3A4.ResultsBaicalein significantly increased the AUC_(0–t) (2018.58 ± 483.11 vs. 653.05 ± 160.10 μg/L × h) and C_max (173.69 ± 35.49 vs. 85.63 ± 13.28 μg/L) of simvastatin. The t_1/2 of simvastatin was prolonged by baicalein in vivo and in vitro. The metabolic stability of simvastatin was also improved by the co-administration of baicalein. Baicalein showed an inhibitory effect on the activity of CYP3A4 with the IC₅₀ value of 12.03 μM, which is responsible for the metabolism of simvastatin.Discussion and conclusionThe co-administration of baicalein and simvastatin may induce drug-drug interaction through inhibiting CYP3A4. The dose of baicalein and simvastatin should be adjusted when they are co-administrated.     

Effects of ginkgo leaf tablet on the pharmacokinetics of rosiglitazone in rats and its potential mechanism

ContextGinkgo leaf tablet (GLT), a traditional Chinese herbal formula, is often combined with rosiglitazone (ROS) for type 2 diabetes mellitus treatment. However, the drug-drug interaction between GLT and ROS remains unknown.ObjectiveTo investigate the effects of GLT on the pharmacokinetics of ROS and its potential mechanism.Materials and methodsThe pharmacokinetics of 10 mg/kg ROS with 100/200 mg/kg GLT as single-dose and 10-day multiple-dose administration were investigated in Sprague-Dawley rats. In vitro, the effects of GLT on the activity of CYP2C8 and CYP2C9 were determined in recombinant human yeast microsomes and rat liver microsomes with probe substrates.ResultsThe t_1/2 of ROS increased from 2.14 ± 0.38 (control) to 2.79 ± 0.37 (100 mg/kg) and 3.26 ± 1.08 h (200 mg/kg) in the single-dose GLT administration. The AUC_0-t (139.69 ± 45.46 vs. 84.58 ± 39.87 vs. 66.60 ± 15.90 h·μg/mL) and t_1/2 (2.75 ± 0.70 vs. 1.99 ± 0.44 vs. 1.68 ± 0.35 h) decreased significantly after multiple-dose GLT treatment. The IC₅₀ values of quercetin, kaempferol, and isorhamnetin, GLT main constituents, were 9.32, 7.67, and 11.90 μmol/L for CYP2C8, and 27.31, 7.57, and 4.59 μmol/L for CYP2C9. The multiple-dose GLT increased rat CYP2C8 activity by 44% and 88%, respectively.Discussion and conclusionsThe metabolism of ROS is attenuated in the single dose of GLT by inhibiting CYP2C8 and CYP2C9 activity, and accelerated after the multiple-dose GLT treatment via inducing CYP2C8 activity in rats, indicating that the clinical dose of ROS should be adjusted when co-administrated with GLT.     

In vitro differences in toddalolactone metabolism in various species and its effect on cytochrome P450 expression

ContextToddalolactone, the main component of Toddalia asiatica (L.) Lam. (Rutaceae), has anticancer, antihypertension, anti-inflammatory, and antifungal activities.ObjectiveThis study investigated the metabolic characteristics of toddalolactone.Materials and methodsToddalolactone metabolic stabilities were investigated by incubating toddalolactone (20 μM) with liver microsomes from humans, rabbits, mice, rats, dogs, minipigs, and monkeys for 0, 30, 60, and 90 min. The CYP isoforms involved in toddalolactone metabolism were characterized based on chemical inhibition studies and screening assays. The effects of toddalolactone (0, 10, and 50 µM) on CYP1A1 and CYP3A5 protein expression were investigated by immunoblotting. After injecting toddalolactone (10 mg/kg), in vivo pharmacokinetic profiles using six Sprague–Dawley rats were investigated by taking 9-time points, including 0, 0.25, 0.5, 0.75, 1, 2, 4, 6 and 8 h.ResultsMonkeys showed the greatest metabolic capacity in CYP-mediated and UGT-mediated reaction systems with short half-lives (T_1/2) of 245 and 66 min, respectively, while T_1/2 of humans in two reaction systems were 673 and 83 min, respectively. CYP1A1 and CYP3A5 were the major CYP isoforms involved in toddalolactone biotransformation. Induction of CYP1A1 protein expression by 50 μM toddalolactone was approximately 50% greater than that of the control (0 μM). Peak plasma concentration (C_max) for toddalolactone was 0.42 μg/mL, and T_max occurred at 0.25 h post-dosing. The elimination t_1/2 was 1.05 h, and the AUC_0–t was 0.46 μg/mL/h.ConclusionsThese findings demonstrated the significant species differences of toddalolactone metabolic profiles, which will promote appropriate species selection in further toddalolactone studies.     

Influence of verapamil on the pharmacokinetics of rotundic acid in rats and its potential mechanism

ContextRotundic acid (RA), a plant-derived pentacyclic triterpene acid, has been reported to possess extensive pharmacological activities. The poor bioavailability limits its further development and potential clinic application.ObjectiveTo clarify the potential mechanism for poor oral bioavailability.Materials and methodsThe single-dose pharmacokinetics of orally administered RA (10 mg/kg) in Sprague–Dawley rats without or with verapamil (25 or 50 mg/kg) were investigated. Additionally, MDCKII-MDR1 and Caco-2 cell monolayers, five recombinant human cytochrome P450 (rhCYP) enzymes (1A2, 2C8, 2C9, 2D6 and 3A4), and rat liver microsomes were also conducted to investigate its potential mechanism.ResultsVerapamil could significantly affect the plasma concentration of RA. Co-administered verapamil at 25 and 50 mg/kg, the AUC_0–∞ increased from 432 ± 64.2 to 539 ± 53.6 and 836 ± 116 ng × h/mL, respectively, and the oral clearance decreased from 23.6 ± 3.50 to 18.7 ± 1.85 and 12.2 ± 1.85 L/h/kg, respectively. The MDCKII-MDR1 cell assay showed that RA might be a P-gp substrate. The rhCYPs experiments indicated that RA was mainly metabolized by CYP3A4. Additionally, verapamil could increase the absorption of RA by inhibiting the activity of P-gp, and slow down the intrinsic clearance of RA from 48.5 ± 3.18 to 12.0 ± 1.06 µL/min/mg protein.Discussion and conclusionsThese findings indicated that verapamil could significantly affect the pharmacokinetic profiles of RA in rats. It was demonstrated that P-gp and CYP3A were involved in the transport and metabolism of RA, which might contribute to the low oral bioavailability of RA.     

Berberine alleviates myocardial ischemia–reperfusion injury by inhibiting inflammatory response and oxidative stress: the key function of miR-26b-5p-mediated PTGS2/MAPK signal transduction

ContextBerberine has myocardial protective effects.ObjectivesThe protective effects of berberine on heart ischemia–reperfusion (I/R) injury were explored.Materials and methodsHuman cardiomyocytes were divided into control group, oxygen-glucose deprivation/re-oxygen (OGD/R) (2 h OGD with 24 h reoxygenation) group, OGD/R + low group (5 μM berberine for 24 h) and OGD/R + high group (10 μM berberine for 24 h). Twenty-four Wistar rats were divided into sham group, I/R group (45 min occlusion with 2 h reperfusion), I/R + berberine group (50 mg/kg berberine 1 h before I/R surgery) and I/R + berberine + antagomir (intraperitoneally injected with miR-26b-5p antagomir). MicroRNA profile, effects of berberine on I/R or OGD/R-induced injuries, and the role of miR-26b-5p in the function of berberine were explored.ResultsOGD/R treatment suppressed viability (0.41 ± 0.05 vs. 0.87 ± 0.13, p< 0.05), while induced apoptosis (6.6 ± 1.0% vs. 26.3 ± 4.8%, p< 0.05) in cardiomyocytes, which was restored by berberine (viability: 0.64 ± 0.01 for 5 μM and 0.72 ± 0.01 for 10 μM, p< 0.05; apoptosis: 10.9 ± 2.2 for 5 μM and 7.9 ± 1.3 for 10 μM). Berberine induced miR-26b-5p and inhibited PTGS2/MAPK pathway. MiR-26b-5p inhibition counteracted the protective function of berberine. In rats, berberine (50 mg/kg) improved heart histological structure and suppressed inflammatory response, which was impaired by miR-26b-5p inhibition.Discussion and conclusionsBerberine exerted anti-I/R function in heart by inducing miR-26b-5p and suppressing the PTGS2/MAPK pathway. These data promote the application of berberine as an anti-I/R agent.     

Deciphering the molecular mechanism of tetrandrine in inhibiting hepatocellular carcinoma and increasing sorafenib sensitivity by combining network pharmacology and experimental evaluation

ContextThe mechanism of tetrandrine (TET) in hepatocellular carcinoma (HCC) progression and sorafenib (Sora) chemosensitivity deserves investigation.ObjectiveUsing network pharmacology approaches to elucidate the mechanisms of TET in HCC.Materials and methodsCCK-8, colony formation, and flow cytometry assays were used to measure cell phenotypes. BALB/c nude mice were divided into Control, Sora (10 mg/kg), TET (50 mg/kg), and TET + Sora (10 mg/kg Sora plus 50 mg/kg TET) groups to evaluate the antitumor effects of TET for 21 days. Sora and TET were given by intraperitoneal injection or oral gavage.ResultsFor SMMC7721 (IC₅₀ = 22.5 μM) and PLC8024 (IC₅₀ = 18.4 μM), TET (10, 20 μM) reduced colony number (0.68 ± 0.04- and 0.50 ± 0.04-fold, 0.56 ± 0.04- and 0.42 ± 0.02-fold), induced cell cycle arrest at G0/G1 stage (1.22 ± 0.03- and 1.39 ± 0.07-fold, 1.37 ± 0.06- and 1.55 ± 0.05-fold), promoted apoptosis (2.49 ± 0.26- and 3.63 ± 0.33-fold, 2.74 ± 0.42- and 3.73 ± 0.61-fold), and inactivated PI3K/AKT/mTOR signalling. Sora (10 μM) decreased cell proliferation, enhanced apoptosis, and inhibited PI3K/AKT/mTOR signalling, and these effects were further aggravated in the combination group. Activating PI3K/AKT/mTOR reversed the effects of TET on cell proliferation and Sora sensitivity. In the combination group, tumour volumes and weights were decreased to 202.3 ± 17.4 mm³ and 151.5 ± 25.8 mg compared with Sora (510.6 ± 48.2 mm³ and 396.7 ± 33.5 mg).Discussion and conclusionsTET enhances Sora sensitivity by inactivating PI3K/AKT/mTOR, suggesting the potential of TET as a chemosensitizer in HCC.     

Gambogic amide inhibits angiogenesis by suppressing VEGF/VEGFR2 in endothelial cells in a TrkA-independent manner

ContextGambogic amide (GA-amide) is a non-peptide molecule that has high affinity for tropomyosin receptor kinase A (TrkA) and possesses robust neurotrophic activity, but its effect on angiogenesis is unclear.ObjectiveThe study investigates the antiangiogenic effect of GA-amide on endothelial cells (ECs).Materials and methodsThe viability of endothelial cells (ECs) treated with 0.1, 0.15, 0.2, 0.3, 0.4, and 0.5 μM GA-amide for 48 h was detected by MTS assay. Wound healing and angiogenesis assays were performed on cells treated with 0.2 μM GA-amide. Chicken eggs at day 7 post-fertilization were divided into the dimethyl sulfoxide (DMSO), bevacizumab (40 μg), and GA-amide (18.8 and 62.8 ng) groups to assess the antiangiogenic effect for 3 days. mRNA and protein expression in cells treated with 0.1, 0.2, 0.4, 0.8, and 1.2 μM GA-amide for 6 h was detected by qRT-PCR and Western blots, respectively.ResultsGA-amide inhibited HUVEC (IC₅₀ = 0.1269 μM) and NhEC (IC₅₀ = 0.1740 μM) proliferation, induced cell apoptosis, and inhibited the migration and angiogenesis at a relatively safe dose (0.2 μM) in vitro. GA-amide reduced the number of capillaries from 56 ± 14.67 (DMSO) to 20.3 ± 5.12 (62.8 ng) in chick chorioallantoic membrane (CAM) assay. However, inactivation of TrkA couldn’t reverse the antiangiogenic effect of GA-amide. Moreover, GA-amide suppressed the expression of VEGF and VEGFR2, and decreased activation of the AKT/mTOR and PLCγ/Erk1/2 pathways.ConclusionsConsidering the antiangiogenic effect of GA-amide, it might be developed as a useful agent for use in clinical combination therapies.     

Antiproliferative activity,cell-cycle arrest,apoptotic induction and LC-HRMS/MS analyses of extracts from two Linum species

ContextLinum is the largest genus of the Linaceae family; the species of this genus are known to have anticancer activity.ObjectiveIn this study, ethyl acetate extracts of L. numidicum Murb. (EAELN) and L. trigynum L. (EAELT) were examined, for the first time, for their anticancer capacity. The secondary metabolites compositions were analysed by LC-HRMS/MS.Materials and methodsThe antiproliferative effect of EAELN and EAELT (0–10.000 μg/mL) against PC3 and MDA-MB-231 cell lines were  evaluated by the MTT assay after 72 h of treatment. Flow cytometer analysis of apoptosis (Annexin V-FITC/PI) and cell cycle (PI/RNase) was also performed after treatment with EAELN and EAELT at 250, 500, and 1000 μg/mL, for 24 h.ResultsEAELN had the highest antiproliferative activity against PC3 (IC₅₀ 133.2 ± 5.73 μg/mL) and MDA-MB-231 (IC₅₀ 156.9 ± 2.83 μg/mL) lines, EAELN had also shown better apoptotic activity with 19 ± 2.47% (250 μg/mL), 87.5 ± 0.21% (500 μg/mL), and 92 ± 0.07% (1000 μg/mL), respectively, causing cell cycle arrest of PC3 cells in G2/M phase, whereas arrest in G0/G1 and G2/M phases was observed after treatment with EAELT. LC-HRMS/MS profiling of the extracts revealed the presence of known compounds that might be responsible for the observed anticancer activity such as chicoric acid, vicenin-2, vitexin and podophyllotoxin-β-d-glucoside.Discussion and conclusionsWe have shown, for the first time, that EAELN and EAELT exert anticancer activity through cell cycle arrest and induction of apoptosis. EAELN can be considered as a source to treat cancer. Further studies will be required to evaluate the effect of the active compounds, once identified, on other cancer cell lines.     

Taxifolin,a novel food,attenuates acute alcohol-induced liver injury in mice through regulating the NF-κB-mediated inflammation and PI3K/Akt signalling pathways

ContextTaxifolin (TAX) has effective anti-inflammatory, antioxidant and hepatoprotective activities, but its potential mechanism has not been revealed.ObjectiveTo evaluate the potential protective effect of TAX on acute alcohol-induced liver injury in mice.Materials and methodsAlcoholic liver injury model was established by oral alcohol in mice, and randomly distributed in five groups (n = 10): Normal group (oral saline only); Alcohol group (concentration of fermented alcohol: 56%, 6 mL/kg); TAX groups, mice were orally administered with alcohol, and then TAX with doses of 20, 40, 80 mg/kg, respectively. Oral administration was conducted for 6 weeks.ResultsTAX treatment illustrated that the level of alanine aminotransferase (ALT) was reduced to 65.90 ± 2.26 U/L and aspartate aminotransferase (AST) to 33.28 ± 5.62 U/L compared with alcohol group (ALT 124.51 ± 4.40 U/L, AST 61.70 ± 4.09 U/L), while superoxide dismutase (SOD) was increased to 49.81 ± 2.39 U/mg and glutathione (GSH) to 8.16 ± 0.44 μmol/g, but MDA was reversed to 2.53 ± 0.24 nmol/mg. Histopathological examination showed TAX treatment alleviated alcohol-induced hepatocyte necrosis and inflammatory infiltration. Meanwhile, Western blot and rt-PCR indicated TAX reduced IL-6 to 2.49 ± 0.25 pg/mL and TNF-α to 1.79 ± 0.20 pg/mL, and inhibiting NF-κB activation in liver. Moreover, TAX reversed alcohol-induced apoptosis by regulating the expression of PI3K/Akt and its downstream apoptotic factors.ConclusionsThe research provides novel evidence of the hepatoprotective effect of TAX on alcohol-induced liver injury, while also providing the possibility for future treatment of alcoholic liver disease.     

Inosine induces acute hyperuricaemia in rhesus monkey (Macaca mulatta) as a potential disease animal model

ContextThe uric acid metabolism pathway is more similar in primates and humans than in rodents. However, there are no reports of using primates to establish animal models of hyperuricaemia (HUA).ObjectivesTo establish an animal model highly related to HUA in humans.Materials and methodsInosine (75, 100 and 200 mg/kg) was intraperitoneally administered to adult male rhesus monkeys (n = 5/group). Blood samples were collected over 8 h, and serum uric acid (SUA) level was determined using commercial assay kits. XO and PNP expression in the liver and URAT1, OAT4 and ABCG2 expression in the kidneys were examined by qPCR and Western blotting to assess the effects of inosine on purine and uric acid metabolism. The validity of the acute HUA model was assessed using ulodesine, allopurinol and febuxostat.ResultsInosine (200 mg/kg) effectively increased the SUA level in rhesus monkeys from 51.77 ± 14.48 at 0 h to 178.32 ± 14.47 μmol/L within 30 min and to peak levels (201.41 ± 42.73 μmol/L) at 1 h. PNP mRNA level was increased, whereas XO mRNA and protein levels in the liver were decreased by the inosine group compared with those in the control group. No changes in mRNA and protein levels of the renal uric acid transporter were observed. Ulodesine, allopurinol and febuxostat eliminated the inosine-induced elevation in SUA in tested monkeys.ConclusionsAn acute HUA animal model with high reproducibility was induced; it can be applied to evaluate new anti-HUA drugs in vivo and explore the disease pathogenesis.     

The influence of antibodies to TNF-α and IL-1β on haemodynamic responses to the cytokines,and to lipopolysaccharide,in conscious rats

1. Male, Long Evans rats (350–450 g) were anaesthetized and had pulsed Doppler probes and intravascular catheters implanted to allow monitoring of regional (renal, mesenteric and hindquarters) haemodynamics in the conscious state. Our main objectives were to:- assess the effects of administering human recombinant tumour necrosis factor (TNF)-α and human recombinant interleukin-1 (IL-1)β, alone and together; determine the influence of pretreatment with a mixture of antibodies to TNF-α and IL-1β on responses to co-administration of the cytokines; ascertain if pretreatment with a mixture of the antibodies to TNF-α and IL-1β had any influence on the responses to lipopolysaccharide (LPS).
2. TNF-α (10, 100 and 250 μg kg⁻¹, in separate groups, n=3, 9 and 8, respectively) caused tachycardia (maximum Δ, +101±9 beats min⁻¹) and modest hypotension (maximum Δ, −10±2 mmHg), accompanied by variable changes in renal and mesenteric vascular conductance, but clear increases in hindquarters vascular conductance; only the latter were dose-related (maximum Δ, +6±6, +27±9, and +61±12% at 10, 100 and 250 μg kg⁻¹, respectively).
3. IL-1β (1, 10, and 100 μg kg⁻¹ in separate groups, n=8, 8 and 9, respectively) evoked changes similar to those of TNF-α (maximum Δ heart rate, +69±15 beats min⁻¹; maximum Δ mean blood pressure, −14±2 mmHg; maximum Δ hindquarters vascular conductance, +49±17%), but with no clear dose-dependency.
4. TNF-α (250 μg kg⁻¹) and IL-1β (10 μg kg⁻¹) together caused tachycardia (maximum Δ, +76±15 beats min⁻¹) and hypotension (maximum Δ, −24±2 mmHg) accompanied by increases in renal, mesenteric and hindquarters vascular conductances (+52±6%, +23±8%, and +52±11%, respectively). Thereafter, blood pressure recovered, in association with marked reductions in mesenteric and hindquarters vascular conductances (maximum Δ, −50±3% and −58±3%, respectively). Although bolus injection of LPS (3.5 mg kg⁻¹) caused an initial hypotension (maximum Δ, −27±11 mmHg) similar to that seen with co-administration of the cytokines, it did not cause mesenteric or hindquarters vasodilatation, and there was only a slow onset renal vasodilatation. The recovery in blood pressure following LPS was less than after the cytokines, and in the former condition there was no mesenteric vasoconstriction. By 24 h after co-administration of TNF-α and IL-1β or after bolus injection of LPS, the secondary reduction in blood pressure was similar (−16±2 and −13±3 mmHg, respectively), but in the former group the tachycardia (+117±14 beats min⁻¹) and increase in hindquarters vascular conductance (+99±21%) were greater than after bolus injection of LPS (+54±16 beats min⁻¹ and +43±9%, respectively).
5. Pretreatment with antibodies to TNF-α and IL-1β (300 mg kg⁻¹) blocked the initial hypotensive and mesenteric and hindquarters vasodilator responses to co-administration of the cytokines subsequently. However, tachycardia and renal vasodilatation were still apparent. Premixing antibodies and cytokines before administration prevented most of the effects of the latter, but tachycardia was still present at 24 h.
6. Pretreatment with antibodies to TNF-α and IL-1β before infusion of LPS (150 μg kg⁻¹ h⁻¹ for 24 h) did not affect the initial fall in blood pressure, but suppressed the hindquarters vasodilatation and caused a slight improvement in the recovery of blood pressure. However, pretreatment with the antibodies had no effect on the subsequent cardiovascular sequelae of LPS infusion.
7. The results indicate that although co-administration of TNF-α and IL-1β can evoke cardiovascular responses which, in some respects, mimic those of LPS, and although antibodies to the cytokines can suppress most of the cardiovascular effects of the cytokines, the antibodies have little influence on the haemodynamic responses to LPS, possibly because, during infusion of LPS, the sites of production and local action of endogenous cytokines, are not accessible to exogenous antibodies.

     

Pogostone inhibits the activity of CYP3A4, 2C9, and 2E1 in vitro

ContextPogostone possesses various pharmacological activities, which makes it widely used in the clinic. Its effect on the activity of cytochrome P450 enzymes (CYP450s) could guide its clinical combination.ObjectiveTo investigate the effect of pogostone on the activity of human CYP450s.Materials and methodsThe effect of pogostone on the activity of CYP450s was evaluated in human liver microsomes (HLMs) compared with blank HLMs (negative control) and specific inhibitors (positive control). The corresponding parameters were obtained with 0–100 μM pogostone and various concentrations of substrates.ResultsPogostone was found to inhibit the activity of CYP3A4, 2C9, and 2E1 with the IC₅₀ values of 11.41, 12.11, and 14.90 μM, respectively. The inhibition of CYP3A4 by pogostone was revealed to be performed in a non-competitive and time-dependent manner with the K_i value of 5.69 μM and the KI/K_inact value of 5.86/0.056/(μM/min). For the inhibition of CYP2C9 and 2E1, pogostone acted as a competitive inhibitor with the K_i value of 6.46 and 7.67 μM and was not affected by the incubation time.Discussion and conclusionsThe inhibitory effect of pogostone on the activity of CYP3A4, 2C9, and 2E1 has been disclosed in this study, implying the potential risk during the co-administration of pogostone and drugs metabolized by these CYP450s. The study design provides a reference for further in vivo investigations to validate the potential interaction.     

Salidroside orchestrates metabolic reprogramming by regulating the Hif-1α signalling pathway in acute mountain sickness

ContextRhodiola crenulata (Hook. f. et Thoms.) H. Ohba (Crassulaceae) is used to prevent and treat acute mountain sickness. However, the mechanisms underlying its effects on the central nervous system remain unclear.ObjectiveTo investigate the effect of Rhodiola crenulata on cellular metabolism in the central nervous system.Materials and methodsThe viability and Hif-1α levels of microglia and neurons at 5% O₂ for 1, 3, 5 and 24 h were examined. We performed the binding of salidroside (Sal), rhodiosin, tyrosol and p-hydroxybenzyl alcohol to Hif-1α, Hif-1α, lactate, oxidative phosphorylation and glycolysis assays. Forty male C57BL/6J mice were divided into control and Sal (25, 50 and 100 mg/kg) groups to measure the levels of Hif-1α and lactate.ResultsMicroglia sensed low oxygen levels earlier than neurons, accompanied by elevated expression of Hif-1α protein. Salidroside, rhodiosin, tyrosol, and p-hydroxybenzyl alcohol decreased BV-2 (IC₅₀=1.93 ± 0.34 mM, 959.74 ± 10.24 μM, 7.47 ± 1.03 and 8.42 ± 1.63 mM) and PC-12 (IC₅₀=6.89 ± 0.57 mM, 159.28 ± 8.89 μM, 8.65 ± 1.20 and 8.64 ± 1.42 mM) viability. They (10 μM) reduced Hif-1α degradation in BV-2 (3.7-, 2.5-, 2.9- and 2.5-fold) and PC-12 cells (2.8-, 2.8-, 2.3- and 2.0-fold) under normoxia. Salidroside increased glycolytic capacity but attenuated oxidative phosphorylation. Salidroside (50 and 100 mg/kg) treatment increased the protein expression of Hif-1α and the release of lactate in the brain tissue of mice.ConclusionsThese results suggest that Sal induces metabolic reprogramming by regulating the Hif-1α signalling pathway to activate compensatory responses, which may be the core mechanism underlying the effect of Rhodiola crenulata on the central nervous system.     

Cytotoxic furanosesquiterpenoids and steroids from Ircinia mutans sponges

ContextIrcinia mutans Wilson (Irciniidae) is a sponge with antimicrobial and cytotoxic constituents.ObjectiveOur objective was to characterise the cytotoxic constituents of two seasonal collections of I. mutans.Materials and methodsThe sponges were extracted in methanol-dichloromethane and their constituents were purified and characterised using column chromatography, GC-MS, 1 D and 2 D NMR. Anti-proliferative activities of the compounds, were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay (0.25–100 μg/mL, 72 h) against leukaemia (MOLT-4), breast (MCF-7) and colon cancer (HT-29) human cells.ResultsThree furanosesquiterpoids; furodysin (1), ent-furodysinin (2) and furoircin (3) and ten sterols were characterised in I. mutans, for the first time. Cholesterol (4), cholesta-5, 7-dien-3β-ol (5) and ergosterol (6) were determined in the sponge from the winter collections, while cholesta-5, 22-dien-3β-ol (7), 24-methyldesmosterol (8), campesterol (9), stigmasterol (10), γ-ergostenol (11), chondrillasterol (12) and γ-sitosterol (13) were detected in the summer samples. The steroids from the winter collection exhibited cytotoxic activity with IC₅₀ values of 13.0 ± 0.9, 11.1 ± 1.7 and 1.1 ± 0.4 µg/mL, against the mentioned cancer cell lines, respectively, while those from the summer sample, showed greater activity, IC₅₀ = 1.1 ± 0.2 μg/mL against MOLT-4. The purified steroids showed potent MOLT-4 cytotoxic activity, IC₅₀ values = 2.3–7.8 µg/mL.Discussion and conclusionThe present study suggests that I. mutans is a rich source of cytotoxic steroids, and introduces 3 as new natural product. Considering the high cytotoxic activity of the steroids, these structures could be candidates for anticancer drug development in future research.     

Biological activity and microscopic characterization of Lythrum salicaria L

Background

There are several plants have been used worldwide in the folk medicine with high incidence for treatment of human disorders, of which Lythrum salicaria belongs to the Lythraceae family has traditionally reputation for some medicinal usage and recently many biological and pharmacological activity of the plant have been studied.

Methods

In this study, microscopic characterizations of the aerial parts of the plant were determined. Moreover, the plant extract (aqueous methanol 80%) was subjected to an anti-diabetic activity test (in a rat model of streptozocin induced diabetes), anti-Helicobacter pylori (using disc diffusion method) along with antioxidant activity against DPPH (stable free radical) tests. Besides, total flavonoids, phenols, tannins, as well as polysaccharides contents have been assessed using spectroscopic methods.

Results

The microscopic properties of the plant fragments revealed anomocytic stomata, conical shape trichomes, and abundant spherical pollen grains as a characteristic pattern for the aerial parts of the plant. The extract of the plant at concentration of 15 g/kg showed mild lowering activity on blood glucose level to 12.6% and 7.3% after 2 and 3 h of administration. Additionally, clinically isolated H. pylori strain was inhibited with the plant extract at concentration of 500 mg/mL (zone of inhibition: 17 ± 0.08 mm). Moreover, IC₅₀ values for DPPH inhibition of the plant extract, vitamin E, BHA were examined as 13.5, 14.2, and 7.8 μg/mL, respectively. Total flavonoids, phenols, tannin, and polysaccharides contents of the extract were successfully evaluated as 5.8 ± 0.4 μg QE/mg EXT, 331 ± 3.7 μg GAE/mg EXT, 340 ± 2.3 μg TAE/mg EXT, 21 ± 0.2 μg GE/mg EXT, respectively.

Conclusions

The results suggested that L. salicaria has low anti-diabetic and anti-Helicobacter pylori effects, but high antioxidant activity, just the same as positive standard (vitamin E), which might be attributed to the high content of phenolic compounds in the extract.     

Esculin protects against methionine choline-deficient diet-induced non-alcoholic steatohepatitis by regulating the Sirt1/NF-[... formula ...]B p65 pathway

ContextEsculin, an active coumarin compound, has been demonstrated to exert anti-inflammatory effects. However, its potential role in non-alcoholic steatohepatitis (NASH) remains unclear.ObjectiveThis study explored the hepatoprotective effect and the molecular mechanism of esculin in methionine choline-deficient (MCD) diet-induced NASH.Materials and methodsFifty C57BL/6J mice were divided into five groups: control, model, low dosage esculin (oral, 20 mg/kg), high dosage esculin (oral, 40 mg/kg), and silybin (oral, 105 mg/kg). All animals were fed a MCD diet, except those in the control group (control diet), for 6 weeks.ResultsEsculin (20 and 40 mg/kg) inhibited MCD diet-induced hepatic lipid content (triglyceride: 16.95 ± 0.67 and 14.85 ± 0.78 vs. 21.21 ± 1.13 mg/g; total cholesterol: 5.10 ± 0.34 and 4.08 ± 0.47 vs. 7.31 ± 0.58 mg/g), fibrosis, and inflammation (ALT: 379.61 ± 40.30 and 312.72 ± 21.45 vs. 559.51 ± 37.01 U/L; AST: 428.22 ± 34.29 and 328.23 ± 23.21 vs. 579.36 ± 31.93 U/L). In vitro, esculin reduced tumour necrosis factor-α, interleukin-6, fibronectin, and collagen 4A1 levels, but had no effect on lipid levels in HepG2 cells induced by free fatty acid. Esculin increased Sirt1 expression levels and decreased NF-κB acetylation levels in vivo and in vitro. Interfering with Sirt1 expression attenuated the beneficial effect of esculin on inflammatory and fibrotic factor production in HepG2 cells.ConclusionsThese findings demonstrate that esculin ameliorates MCD diet-induced NASH by regulating the Sirt1/ac-NF-κB signalling pathway. Esculin could thus be employed as a therapy for NASH.