Protective effects of octacosanol on 6-hydroxydopamine-induced Parkinsonism in rats via regulation of ProNGF and NGF signaling

Aim:

To investigate the protective effects of octacosanol in 6-hydroxydopamine-induced Parkinsonian rats and find whether octacosanol has effects on pro nerve growth factor (pro-NGF), NGF and the downstream effector proteins.

Methods:

Behavioral tests, enzymatic assay, tyrosine hydroxylase immunohistochemistry, TUNEL and Western blot were used to investigate the effects of octacosanol in this rat model of PD.

Results:

Oral administration of octacosanol (35–70 mg/kg, po for 14 d) significantly improved the behavioral impairments in rats induced by 6-OHDA and dose-dependently preserved the free radical scavenging capability of the striatum. Octacosanol treatment also effectively ameliorated morphological appearances of TH-positive neuronal cells in nigrostriatal systems and decreased the apoptotic cells induced by 6-OHDA in striatum. In addition, octacosanol strikingly blocked the 6-OHDA-induced increased expression of proNGF-p75NTR-sortilin death signaling complex and its downstream effector proteins. Meantime, octacosanol prevented the decreased levels of NGF, its receptors TrkA and p-Akt which together mediated the cell survival pathway.

Conclusion:

The findings implicated that the anti-parkinsonism effects afforded by octacosanol might be mediated by its neuro-microenvironment improving potency through retrieving the ratios of proNGF:NGF and the respective receptors p75NTR:TrkA in vivo. Due to its excellent tolerability and non-toxicity, octacosanol may be a promising agent for PD treatment.     

Pharmacokinetic interactions between 20(S)-ginsenoside Rh2 and the HIV protease inhibitor ritonavir in vitro and in vivo

Aim:

20(S)-Ginsenoside Rh2 (Rh2) has shown potent inhibition on P-glycoprotein (P-gp), while most HIV protease inhibitors are both substrates and inhibitors of P-gp and CYP3A4. The aim of this study was to investigate the potential pharmacokinetic interactions between Rh2 and the HIV protease inhibitor ritonavir.

Methods:

The effects of Rh2 on the cellular accumulation and transepithelial transport of ritonavir were studied in Caco-2 and MDCK-MDR1 cells. Male rats were administered Rh2 (25 or 60 mg/kg, po) or Rh2 (5 mg/kg, iv), followed by ritonavir (25 mg/kg, po). The P-gp inhibitors verapamil (20 mg/kg, po) or GF120918 (5 mg/kg, po) were used as positive controls. The concentrations of ritonavir in plasma, bile, urine, feces and tissue homogenates were analyzed using LC-MS.

Results:

Rh2 (10 μmol/L) significantly increased the accumulation and inhibited the efflux of ritonavir in Caco-2 and MDCK-MDR1 cells, as verapamil did. But Rh2 did not significantly alter ritonavir accumulation or transport in MDCK-WT cells. Intravenous Rh2 significantly increased the plasma exposure of ritonavir while reducing its excretion in the bile, and oral verapamil or GF120918 also increased plasma exposure of ritonavir but without changing its excretion in the bile. Interestingly, oral Rh2 at both doses did not significantly change the plasma profile of ritonavir. Moreover, oral Rh2 (25 mg/kg) significantly elevated the ritonavir concentration in the hepatic portal vein, and markedly increased its urinary excretion and tissue distribution, which might counteract the elevated absorption of ritonavir.

Conclusion:

Rh2 inhibits the efflux of ritonavir through P-gp in vitro. The effects of Rh2 on ritonavir exposure in vivo depend on the administration route of Rh2: intravenous, but not oral, administration of Rh2 significantly increased the plasma exposure of ritonavir.     

Effects of ticlopidine on pharmacokinetics of losartan and its main metabolite EXP-3174 in rats

Aim:

Losartan and antiplatelet agent ticlopidine can be prescribed concomitantly for prevention or therapy of cardiovascular diseases. Hence, the effects of ticlopidine on the pharmacokinetics of losartan and its active metabolite EXP-3174 were evaluated in rats.

Methods:

Ticlopidine (4 or 10 mg/kg po) was administered 30 min before administration of losartan (9 mg/kg po or 3 mg/kg iv). The activity of human CYP2C9 and 3A4 were measured using the CYP inhibition assay kit. The activity of P-gp was evaluated using rhodamine-123 retention assay in MCF-7/ADR cells.

Results:

Ticlopidine (10 mg/kg) significantly increased the areas under the plasma concentration-time curves (AUCs) and peak plasma concentration (C_max) of oral losartan (9 mg/kg), as well as the AUCs of the active metabolite EXP-3174. Ticlopidine (10 mg/kg) did not significantly change the pharmacokinetics of intravenous losartan (3 mg/kg). Ticlopidine inhibited CYP2C9 and 3A4 with IC₅₀ values of 26.0 and 32.3 μmol/L, respectively. The relative cellular uptake of rhodamine-123 was unchanged.

Conclusion:

The significant increase in the AUC of losartan (9 mg/kg) by ticlopidine (10 mg/kg) could be attributed to the inhibition of CYP2C9- and 3A4-mediated losartan metabolism in small intestine and/or in liver. The inhibition of P-gp in small intestine and reduction of renal elimination of losartan by ticlopidine are unlikely to be causal factors.     

Phase I study on the pharmacokinetics and tolerance of ZT-1, a prodrug of huperzine A,for the treatment of Alzheimer's disease

Aim:

Huperzine A isolated from the Chinese herb Huperzia serrata (Thunb) Trev is a novel reversible and selective AChE inhibitor. The aim of this study was to evaluate the pharmacokinetics and tolerance of single and multiple doses of ZT-1, a novel analogue of huperzine A, in healthy Chinese subjects.

Methods:

This was a double-blinded, placebo-controlled, randomized, single- and multiple-dose study. For the single-dose study, 9 subjects were randomly divided into 3 groups receiving ZT-1 (0.5, 0.75 or 1 mg, po) according to a Three-way Latin Square Design. For the multiple-dose study, 9 subjects receiving ZT-1 (0.75 mg/d, po) for 8 consecutive days. In the tolerance study, 40 subjects were randomly divided into 5 groups receiving a single dose of ZT-1 (0.5, 0.75, 1, 1.25 or 1.5 mg, po). Plasma and urine concentrations of ZT-1 and Hup A were determined using LC-MS/MS. Pharmacokinetic parameters, including C_max, AUC_{0–72 h} and AUC_0–∞ were calculated. Tolerance assessments were conducted throughout the study.

Results:

ZT-1 was rapidly absorbed and converted into huperzine A, thus the plasma and urine concentrations of ZT-1 were below the limit of quantification (<0.05 ng/mL). After single-dose administration of ZT-1, the mean t_max of huperzine A was 0.76–0.82 h; the AUC_{0–72 h} and C_max of huperzine A showed approximately dose-proportional increase over the dose range of 0.5–1 mg. After the multiple-dose administration of ZT-1, a steady-state level of huperzine A was achieved within 2 d. No serious adverse events were observed.

Conclusion:

ZT-1 is a pro-drug that is rapidly absorbed and converted into huperzine A, and ZT-1 is well tolerated in healthy Chinese volunteers.     

The edaravone and 3-n-butylphthalide ring-opening derivative 10b effectively attenuates cerebral ischemia injury in rats

Aim:

Compound 10b is a hybrid molecule of edaravone and a ring-opening derivative of 3-n-butylphthalide (NBP). The aim of this study was to examine the effects of compound 10b on brain damage in rats after focal cerebral ischemia.

Methods:

SD rats were subjected to 2-h-middle cerebral artery occlusion (MCAO). At the onset of reperfusion, the rats were orally treated with NBP (60 mg/kg), edaravone (3 mg/kg), NBP (60 mg/kg)+edaravone (3 mg/kg), or compound 10b (70, 140 mg/kg). The infarct volume, motor behavior deficits, brain water content, histopathological alterations, and activity of GSH, SOD, and MDA were analyzed 24 h after reperfusion. The levels of relevant proteins in the ipsilateral striatum were examined using immunoblotting.

Results:

Administration of compound 10b (70 or 140 mg/kg) significantly reduced the infarct volume and neurological deficits in MCAO rats. The neuroprotective effects of compound 10b were more pronounced compared to NBP, edaravone or NBP+edaravone. Furthermore, compound 10b significantly upregulated the protein levels of the cytoprotective molecules Bcl-2, HO-1, Nrf2, Trx, P-NF-κB p65, and IκB-α, while decreasing the expression of Bax, caspase 3, caspase 9, Txnip, NF-κB p65, and P-IκB-α.

Conclusion:

Oral administration of compound 10b effectively attenuates rat cerebral ischemia injury.     

A study on the extracts of Cuscuta reflexa Roxb. in treatment of cyclophosphamide induced alopecia

Background

Alopecia is a dermatological disorder with psychosocial implications on patients with hair loss. Hair loss is one of the most feared side effects of chemotherapy. Plants have been widely used for hair growth promotion since ancient times in Ayurveda, Chinese and Unani systems of medicine. The effect of extracts of Cuscuta reflexa Roxb. in testosterone induced alopecia was reported.

Objective

In the present study, the efficacies of the extracts of Cuscuta reflexa in promoting hair growth in cyclophosphamide-induced hair loss have been determined.

Materials and methods

The study was performed by treated with petroleum ether and ethanolic extract of Cuscuta reflexa at the dose 250 mg/kg in male swiss albino rats. Cyclophosphamide (125 mg/kg) was used to induce alopecia.

Results

Groups treated with extracts of plant showed hair regrowth. Histopathology and gross morphologic observations for hair regrowth at shaved sites revealed active follicular proliferation.

Conclusions

It concluded that extracts of Cuscuta reflexa shown to be capable of promoting follicular proliferation or preventing hair loss in cyclophosphamide-induced hair fall.     

Resveratrol effectively attenuates α-naphthyl-isothiocyanate-induced acute cholestasis and liver injury through choleretic and anti-inflammatory mechanisms

Aim:

α-Naphthylisothiocyanate (ANIT) is a well-characterized cholestatic agent for rats. The aim of this study was to examine whether resveratrol could attenuate ANIT-induced acute cholestasis and liver injury in rats.

Methods:

SD rats were treated with resveratrol (15 or 30 mg/kg, ip) or a positive control drug ursodeoxycholic acid (100 mg/kg, po) for 5 consecutive days followed by a single dose of ANIT (60 mg/kg, po). Bile flow, and serum biochemical markers and bile constituents were measured 48 h after ANIT administration. Hepatic levels of oxidative repair enzymes (glutathione peroxidase, catalase and MnSOD), myeloperoxidase activity, TNF-α, IL-6 and ATP content, as well as the expression of liver transporter genes and proteins were assayed.

Results:

ANIT exposure resulted in serious cholestasis and liver injury, as shown by marked neutrophil infiltration in liver, dramatically increased serum levels of ALT, AST, GGT, ALP, TBA, TBIL, IBIL and DBIL, and significantly decreased bile excretion and biliary output of GSH and HCO₃⁻. ANIT significantly increased TNF-α and IL-6 release and myeloperoxidase activity, decreased mitochondrial biogenesis in liver, but had little effect on hepatic oxidative repair enzymes and ATP content. Furthermore, ANIT significantly decreased the expression of Mrp2, FXR and Cyp7a1, markedly increased Mrp3 expression in liver. Pretreatment with resveratrol attenuated ANIT-induced acute cholestasis and liver injury, and other pathological changes. Pretreatment with ursodeoxycholic acid was less effective.

Conclusion:

Resveratrol effectively attenuates ANIT-induced acute cholestasis and liver injury in rats, possibly through suppression of neutrophil infiltration, as well as upregulation of expression of hepatic transporters and enzymes, thus decreasing accumulation of bile acids.     

Protective effects of epigallocatechin gallate following 3-nitropropionic acid-induced brain damage: possible nitric oxide mechanisms

Introduction

The role of oxidative stress has been well known in neurodegenerative disorders. 3-Nitropropionic acid (3-NP) is a plant-based mycotoxin that produces HD like symptoms in animals. Oxidative stress and nitric oxide mechanisms have been recently proposed in the 3-NP-induced neurotoxicity. Epigallocatechin gallate (EGCG) is one of the major components of green tea, known for its potent antioxidant activity. Besides, neuroprotective effect of EGCG has also been suggested in different experimental models.

Objectives

The present study has been designed to examine possible effect of EGCG against 3-NP induced behavioral, oxidative stress, mitochondrial dysfunction, and striatal damage in rats and its possible interaction with nitric oxide modulators.

Material and methods

Systemic 3-NP (10 mg/kg) administration for 14 days significantly reduced locomotor activity, body weight, grip strength, oxidative defense (raised levels of lipid peroxidation, nitrite concentration, depletion of antioxidant enzyme), and mitochondrial enzymes activity in striatum, cortex, and hippocampal regions of the brain.

Results

Fourteen days of EGCG pretreatment (10, 20, and 40 mg/kg) significantly attenuated behavioral alterations, oxidative damage, mitochondrial complex enzymes dysfunction, and striatal damage in 3-NP-treated animals. l-arginine (50 mg/kg) pretreatment with sub-effective dose of EGCG (20 mg/kg) significantly reversed the protective behavioral, biochemical, cellular, and histological effects of EGCG. However, l-NAME (10 mg/kg) pretreatment with EGCG (20 mg/kg) significantly potentiated the protective effect of EGCG which was significant as compared to their effect per se.

Conclusion

The present study shows that EGCG attenuate 3-NP-induced neurotoxicity, and nitric oxide modulation might be involved in its protective action.     

Screening of Bauhinia purpurea Linn. for analgesic and anti-inflammatory activities

Objectives:

Ethanol extract of the stem of Bauhinia purpurea Linn. was subjected to analgesic and anti-inflammatory activities in animal models.

Materials and Methods:

Albino Wistar rats and mice were the experimental animals respectively. Different CNS depressant paradigms like analgesic activity (determined by Eddy''s hot plate method and acetic acid writhing method) and anti-inflammatory activity determined by carrageenan induced paw edema using plethysmometer in albino rats) were carried out, following the intra-peritoneal administration of ethanol extract of Bauhinia purpurea Linn. (BP) at the dose level of 50 mg/kg and 100 mg/kg.

Results:

The analgesic and anti-inflammatory activities of ethanol extracts of BP were significant (P < 0.001). The maximum analgesic effect was observed at 120 min at the dose of 100 mg/kg (i.p.) and was comparable to that of standard analgin (150 mg/kg) and the percentage of edema inhibition effect was 46.4% and 77% for 50 mg/kg and 100 mg/kg (i.p) respectively. Anti-inflammatory activity was compared with standard Diclofenac sodium (5 mg/kg).

Conclusion:

Ethanol extract of Bauhinia purpurea has shown significant analgesic and anti-inflammatory activities at the dose of 100 mg/kg and was comparable with corresponding standard drugs. The activity was attributed to the presence of phytoconstituents in the tested extract.     

Use of atorvastatin as an anti-inflammatory treatment in Crohn's disease

Background and purpose:

Experimental and clinical investigations have revealed that statins can downregulate both acute and chronic inflammatory processes. Whether statins express anti-inflammatory activities in the treatment of Crohn''s disease is unknown.

Experimental approach:

Ten patients were given 80 mg atorvastatin once daily for 13 weeks and then followed up for 8 weeks after the treatment. The anti-inflammatory effects of statin were assessed by measuring levels of plasma C-reactive protein (CRP), soluble (s) CD14, tumour necrosis factor (TNF)-α, sTNFRI and II, CCL2 and 8 and the mucosal inflammation by faecal calprotectin. Circulating monocytes were subgrouped and their chemokine receptor expression of CCR2 and CX₃CR1 were analysed.

Key results:

In 8 of 10 patients, atorvastatin treatment reduced CRP (P=0.008) and sTNFRII (P=0.064). A slight decrease in plasma levels of sCD14, TNF-α and sTNFRI was observed in 7/10 patients and faecal calprotectin was reduced in 8/10 patients. We also observed that the treatment diminished expression of CCR2 and CX₃CR1 on monocyte populations (P=0.014). At the follow-up visit, 8 weeks after the atorvastatin treatment was terminated, CRP levels had returned to those seen before the treatment.

Conclusions and implications:

Our findings imply that atorvastatin therapy reduces inflammation in patients with Crohn''s disease and, therefore, encourage further investigations of statin-mediated protective effects in inflammatory bowel diseases.     

6-Shogaol,an active compound of ginger,protects dopaminergic neurons in Parkinson's disease models via anti-neuroinflammation

Aim:

6-Shogaol [1-(4-hydroxy-methoxyphenyl)-4-decen-one], a pungent compound isolated from ginger, has shown various neurobiological and anti-inflammatory effects. The aim of this study was to examine the effects of 6-shogaol on neuroinflammatory-induced damage of dopaminergic (DA) neurons in Parkinson''s disease (PD) models.

Methods:

Cultured rat mesencephalic cells were treated with 6-shogaol (0.001 and 0.01 μmol/L) for 1 h, then with MPP⁺(10 μmol/L) for another 23 h. The levels of TNF-α and NO in medium were analyzed spectrophotometrically. C57/BL mice were administered 6-shogaol (10 mg·kg⁻¹·d⁻¹, po) for 3 d, and then MPTP (30 mg/kg, ip) for 5 d. Seven days after the last MPTP injection, behavioral testings were performed. The levels of tyrosine hydroxylase (TH) and macrophage antigen (MAC)-1 were determined with immunohistochemistry. The expression of iNOS and COX-2 was measured using RT PCR.

Results:

In MPP⁺-treated rat mesencephalic cultures, 6-shogaol significantly increased the number of TH-IR neurons and suppressed TNF-α and NO levels. In C57/BL mice, treatment with 6-shogaol reversed MPTP-induced changes in motor coordination and bradykinesia. Furthermore, 6-shogaol reversed MPTP-induced reductions in TH-positive cell number in the substantia nigra pars compacta (SNpc) and TH-IR fiber intensity in stratum (ST). Moreover, 6-shogaol significantly inhibited the MPTP-induced microglial activation and increases in the levels of TNF-α, NO, iNOS, and COX-2 in both SNpc and ST.

Conclusion:

6-Shogaol exerts neuroprotective effects on DA neurons in in vitro and in vivo PD models.     

Lactacystin requires reactive oxygen species and Bax redistribution to induce mitochondria-mediated cell death

Background and purpose:

The proteasome inhibitor model of Parkinson''s disease (PD) appears to reproduce many of the important behavioural, imaging, pathological and biochemical features of the human disease. However, the mechanisms involved in the lactacystin-induced, mitochondria-mediated apoptotic pathway remain poorly defined.

Experimental approach:

We have used lactacystin as a specific inhibitor of the 20S proteasome in the dopaminergic neuroblastoma cell line SH-SY5Y. We over-expressed a green fluorescent protein (GFP)–Bax fusion protein in these cells to study localization of Bax. Free radical scavengers were used to assess the role of reactive oxygen species (ROS) in these pathways.

Key results:

Lactacystin triggered a concentration-dependent increase in cell death mediated by the mitochondrial apoptotic pathway, and induced a change in mitochondrial membrane permeability accompanied by cytochrome c release. The participation of Bax protein was more critical than the formation of the permeability transition pore in mitochondria. GFP–Bax over-expression demonstrated Bax redistribution from the cytosol to mitochondria after the addition of lactacystin. ROS, but not p38 mitogen-activated protein kinase, participated in lactacystin-induced mitochondrial Bax translocation. Lactacystin disrupted the intracellular redox state by increasing ROS production and depleting endogenous antioxidant systems such as glutathione (GSH). Pharmacological depletion of GSH, using l-buthionine sulphoxide, potentiated lactacystin-induced cell death. Lactacystin sensitized neuroblastoma cells to oxidative damage, induced by subtoxic concentrations of 6-hydroxydopamine.

Conclusions and implications:

The lactacystin-induced, mitochondrial-mediated apoptotic pathway involved interactions between ROS, GSH and Bax. Lactacystin could constitute a potential factor in the development of sporadic PD.     

Timosaponin A3 induces hepatotoxicity in rats through inducing oxidative stress and down-regulating bile acid transporters

Aim:

To investigate the mechanisms underlying the hepatotoxicity of timosaponin A3 (TA3), a steroidal saponin from Anemarrhena asphodeloides, in rats.

Methods:

Male SD rats were administered TA3 (100 mg·kg⁻¹·d⁻¹, po) for 14 d, and the blood and bile samples were collected after the final administration. The viability of a sandwich configuration of cultured rat hepatocytes (SCRHs) was assessed using WST-1. Accumulation and biliary excretion index (BEI) of d8-TCA in SCRHs were determined with LC-MS/MS. RT-PCR and Western blot were used to analyze the expression of relevant genes and proteins. ROS and ATP levels, and mitochondrial membrane potential (MMP) were measured. F-actin cytoskeletal integrity was assessed under confocal microscopy.

Results:

TA3 administration in rats significantly elevated the total bile acid in serum, and decreased bile acid (BA) component concentrations in bile. TA3 inhibited the viability of the SCRHs with an IC₅₀ value of 15.21±1.73 μmol/L. Treatment of the SCRHs with TA3 (1–10 μmol/L) for 2 and 24 h dose-dependently decreased the accumulation and BEI of d8-TCA. The TA3 treatment dose-dependently decreased the expression of BA transporters Ntcp, Bsep and Mrp2, and BA biosynthesis related Cyp7a1 in hepatocytes. Furthermore, the TA3 treatment dose-dependently increased ROS generation and HO-1 expression, decreased the ATP level and MMP, and disrupted F-actin in the SCRHs. NAC (5 mmol/L) significantly ameliorated TA3-induced effects in the SCRHs, whereas mangiferin (10–200 μg/mL) almost blocked TA3-induced ROS generation.

Conclusion:

TA3 triggers liver injury through inducing ROS generation and suppressing the expression of BA transporters. Mangiferin, an active component in Anemarrhena, may protect hepatocytes from TA3-induced hepatotoxicity.     

Mangiferin activates Nrf2-antioxidant response element signaling without reducing the sensitivity to etoposide of human myeloid leukemia cells in vitro

Aim： Mangiferin is glucosylxanthone extracted from plants of the Anacardiaceae and Gentianaceae families. The aim of this study was to investigate the effects of mangiferin on Nrf2-antioxidant response element （ARE） signaling and the sensitivity to etoposide of human myeloid leukemia cells in vitro. Methods： Human HL-60 myeloid leukemia cells and mononuclear human umbilical cord blood cells （MNCs） were examined. Nrf2 protein was detected using immunofluorescence staining and Western blotting. Binding of Nrf2 to ARE was examined with electrophoretic mobility shift assay. The level of NQ01 was assessed with real-time RT-PCR and Western blotting. DCFH-DA was used to evaluate intracellular ROS level. Cell proliferation and apoptosis were analyzed using MTT and flow cytometry, respectively. Results： Mangiferin （50 pmol/L） significantly increased Nrf2 protein accumulation in HL-60 cells, particularly in the nucleus. Mangiferin also enhanced the binding of Nrf2 to an ARE, significantly up-regulated NQ01 expression and reduced intracellular ROS in HL60 cells. Mangiferin alone dose-dependently inhibited the proliferation of HL-60 cells. Mangiferin （50 mol/L） did not attenuate etoposide-induced cytotoxicity in HL-60 cells, and combined treatment of mangiferin with low concentration of etoposide （0.8 pg/mL） even increased the cell inhibition rate. Nor did mangiferin change the rate of etoposide-induced apoptosis in HL-60 cells. In MNCs, mangiferin significantly relieved oxidative stress, but attenuated etoposide-induced cytotoxicity. Conclusion： Mangiferin is a novel Nrf2 activator that reduces oxidative stress and protects normal cells without reducing the sensitivity to etoposide of HL-60 leukemia Cells in vitro. Mangiferin may be a potential chemotherapy adjuvant.     

Quercetin protects rat dorsal root ganglion neurons against high glucose-induced injury in vitro through Nrf-2/HO-1 activation and NF-κB inhibition

Aim:

To examine the effects of quercetin, a natural antioxidant, on high glucose (HG)-induced apoptosis of cultured dorsal root ganglion (DRG) neurons of rats.

Methods:

DRG neurons exposed to HG (45 mmol/L) for 24 h were employed as an in vitro model of diabetic neuropathy. Cell viability, reactive oxygen species (ROS) level and apoptosis were determined. The expression of NF-кB, IкBα, phosphorylated IкBα and Nrf2 was examined using RT PCR and Western blot assay. The expression of hemeoxygenase-1 (HO-1), IL-6, TNF-α, iNOS, COX-2, and caspase-3 were also examined.

Results:

HG treatment markedly increased DRG neuron apoptosis via increasing intracellular ROS level and activating the NF-κB signaling pathway. Co-treatment with quercetin (2.5, 5, and 10 mmol/L) dose-dependently decreased HG-induced caspase-3 activation and apoptosis. Quercetin could directly scavenge ROS and significantly increased the expression of Nrf-2 and HO-1 in DRG neurons. Quercetin also dose-dependently inhibited the NF-κB signaling pathway and suppressed the expression of iNOS, COX-2, and proinflammatory cytokines IL-6 and TNF-α.

Conclusion:

Quercetin protects rat DRG neurons against HG-induced injury in vitro through Nrf-2/HO-1 activation and NF-κB inhibition, thus may be beneficial for the treatment of diabetic neuropathy.     

Drug-disease interaction: Crohn's disease elevates verapamil plasma concentrations but reduces response to the drug proportional to disease activity

AIM

Inflammation is involved in the pathogenesis of cardiovascular diseases that includes reduced response to pharmacotherapy due to altered pharmacokinetics and pharmacodynamics. It is not known if these effects exist in general in all inflammatory conditions. It also remains unknown whether in a given population the effect is a function of disease severity. We investigated whether pharmacokinetics and pharmacodynamics of a typical calcium channel inhibitor are influenced by Crohn''s disease (CD), a disease for which the disease severity can be readily ranked.

METHODS

We administered 80 mg verapamil orally to (i) healthy control subjects (n = 9), (ii) patients with clinically quiescent CD (n = 22) and (iii) patients with clinically active CD (n = 14). Serial analysis of verapamil enantiomers (total and plasma unbound), blood pressure and electrocardiograms were recorded over 8 h post dose. The severity of CD was measured using the Harvey-Bradshaw Index.

RESULTS

CD substantially and significantly increased plasma verapamil concentration and in a stereoselective fashion (S, 9-fold; R, 2-fold). The elevated verapamil concentration, however, failed to result in an increased verapamil pharmacodynamic effect so that the patients with elevated verapamil concentration demonstrated no significant increase in response measured as PR interval and blood pressure. Instead, the greater the disease severity, the lower was the drug potency to prolong PR interval (r = 0.86, P < 0.0006),

CONCLUSIONS

CD patients with severe disease may not respond to cardiovascular therapy with calcium channel blockers. Reducing the severity increases response despite reduced drug concentration. This observation may have therapeutic implication beyond the disease and the drug studies herein.     

Analgesic and anti-nociceptive activity of hydroethanolic extract of Drymaria cordata Willd

Objectives:

To study the analgesic and anti-nociceptive activity of hydroethanolic extract of Drymaria cordata Willd.

Materials and Methods:

Wistar rats and Swiss albino mice were used for studying analgesic and anti-nociceptive activity of Drymaria cordata hydroethanolic extract (DCHE) at doses 50, 100 and 200 mg/kg p.o. Various models viz. acetic acid induced writhing model (female mice), Eddy''s hot plate (mice) and tail flick model (rat) for analgesic study and formalin-induced paw licking model (mice) were used for anti-nociceptive study.

Results:

In acetic acid induced writhing model, effect of DCHE was better than the standard drug- indomethacin 10 mg/kg (p.o.). In the hot plate model, the maximum effect was observed at 60 min at a dose of 200 mg/kg p.o., which was higher than the standard drug morphine sulfate (1.5 mg/kg i.p.), whereas in the tail flick model, effect was comparable with morphine sulfate. In formalin-induced paw licking model, administration of DCHE completely abolished the early phase at 100 and 200 mg/kg p.o. and in the late phase, the effect of DCHE (200 mg/kg p.o.) was higher than indomethacin (10 mg/kg p.o.).

Conclusion:

DCHE was effective in both non-narcotic and narcotic models of nociception, suggesting its possible action via peripheral and central mechanism. It also abolished the early phase in formalin-induced paw licking model, suggesting complete inactivation of C-fiber at higher dose. The activity can be attributed to the phyto-constituents viz tannins, diterpenes, triterpenes and steroids present in the DCHE extract. In conclusion, DCHE can be developed as a potent analgesic and anti-nociceptive agent in future.     

Pharmacological inhibition of diacylglycerol acyltransferase 1 reduces body weight gain, hyperlipidemia, and hepatic steatosis in db/db mice

Aim:

To test whether pharmacological inhibition of Diacylglycerol acyltransferase 1 (DGAT1) by a small-molecule inhibitor H128 can improve metabolism disorders in leptin receptor-deficient db/db mice.

Methods:

To investigate the effect of H128 on intestinal fat absorption,db/db mice were acutely given a bolus of corn oil by gavage. The mice were further orally administered H128 (3 and 10 mg/kg) for 5 weeks. Blood glucose, lipids, insulin, ALT, and AST as well as hepatic triglycerides were measured. The insulin tolerance test was performed to evaluate insulin sensitivity. The expression of genes involved in fatty acid oxidation was detected by RT-PCR.

Results:

Oral administration of H128 (10 mg/kg) acutely inhibited intestinal fat absorption following a lipid challenge in db/db mice. Chronic treatment with H128 significantly inhibited body weight gain, decreased food intake, and induced a pronounced reduction of serum triglycerides. In addition, H128 treatment markedly ameliorated hepatic steatosis, characterized by decreased liver weight, lipid droplets, and triglyceride content as well as serum ALT and AST levels. Furthermore, H128 treatment increased the expression of the CPT1 and PPARα genes in liver, suggesting that H128 enhanced fatty acid oxidation in db/db mice. However, neither blood glucose nor insulin tolerance was affected by H128 treatment throughout the 5-week experimental period.

Conclusion:

DGAT1 may be an effective therapeutic target for the treatment of obesity, hyperlipidemia and hepatic steatosis.     

Gelsemine alleviates both neuropathic pain and sleep disturbance in partial sciatic nerve ligation mice

Aim:

Gelsemine, an alkaloid from the Chinese herb Gelsemium elegans (Gardn & Champ) Benth., is effective in mitigating chronic pain in rats. In the present study we investigated whether the alkaloid improved sleep disturbance, the most common comorbid symptoms of chronic pain, in a mouse model of neuropathic pain.

Methods:

Mice were subjected to partial sciatic nerve ligation (PSNL). After the mice were injected with gelsemine or pregabalin (the positive control) intraperitoneally, mechanical allodynia and thermal hyperalgesia were assessed, and electroencephalogram (EEG)/electromyogram (EMG) recording was performed. Motor performance of the mice was assessed using rota-rod test. c-Fos expression in the brain was analyzed with immunohistochemical staining.

Results:

In PSNL mice, gelsemine (2 and 4 mg/kg) increased the mechanical threshold for 4 h and prolonged the thermal latencies for 3 h. Furthermore, gelsemine (4 mg/kg, administered at 6:30 AM) increased non-rapid eye movement (non-REM, NREM) sleep, decreased wakefulness, but did not affect REM sleep during the first 3 h in PSNL mice. Sleep architecture analysis showed that gelsemine decreased the mean duration of wakefulness and increased the total number of episodes of NREM sleep during the first 3 h after the dosing. Gelsemine (4 mg/kg) did not impair motor coordination in PSNL mice. Immunohistochemical study showed that PSNL increased c-Fos expression in the neurons of the anterior cingulate cortex, and gelsemine (4 mg/kg) decreased c-Fos expression by 58%. Gelsemine (4 mg/kg, administered at either 6:30 AM or 8:30 PM) did not produce hypnotic effect in normal mice. Pregabalin produced similar antinociceptive and hypnotic effects, but impaired motor coordination in PSNL mice.

Conclusion:

Gelsemine is an effective agent for treatment of both neuropathic pain and sleep disturbance in PSNL mice; anterior cingulate cortex might play a role in the hypnotic effects of gelsemine.