Molecular recognition of long chain fatty acids by peroxisome proliferator-activated receptor α

In the present study, flexible ligand docking and multiple scoring were used to study the binding of long-chain fatty acid (LCFAs) to the peroxisome proliferator-activated receptor α (PPARα). The calculations indicated that LCFAs bind PPARα in nanomolar affinities, which is in agreement with the intracellular concentrations of LCFAs. Calculated binding affinities were linearly related with the chain length up to 20 carbon atoms. The best correlation between the rank order of experimentally detected binding affinities and the predicted scores was found with the internal coordinate mechanics (ICM) binding energy method. This study contributes molecular insight into the binding process, which is of pivotal importance for designing new ligands interfering with lipid and glucose homeostasis.     

Induction of systemic lupus erythematosus syndrome in BALB／c mice by immunization with active chromatin

AIM: To establish an animal model for systemic lupus erythematosus (SLE)-like syndrome in mice. METHODS:BALB/c mice were immunized with active chromatin isolated from ConA-actived syngeneic spleno-lymphocytes.Plasma samples of mice were tested by enzyme-linked immunosorbent assays (ELISA) for the presence of IgG anti-dsDNA, -ssDNA, and anti-histone antibodies. Tumor necrosis factor-α(TNF-α) in serum was measured by ELISA. Spleno-lymphocyte proliferation assays and the levels of interferon-γ(IFN-γ) in supematants were tested respectively. Proteinuria was measured. Kidneys were examined by direct immunohistochemical method and fight microscopy. RESULTS： Anti-ds DNA, ssDNA, and histone antibodies were induced in active chromatin-immunized mice, the proliferation response of splenocytes to ConA and LPS were reduced, levels of interferon-γ in supernatants and TNF-at in serum were lowered. Lupus nephritis was assessed by the presence of Ig deposits,glomerular pathology and proteinuria. CONCLUSION: The active chromatin-induced SLE-like mouse model was similar to idiopathic SLE in human.     

Arsenic trioxide (As₂O₃) inhibits murine WEHI-3 leukemia in BALB/c mice in vivo

Arsenic trioxide (As₂O₃) is used clinically to treat acute promyelocytic leukemia (APL) and has activity in vitro for induction of apoptosis in several solid tumor cell lines. To investigate the potential therapeutic application of As₂O₃ for leukemia, we analyzed the effects of As₂O₃ on the WEHI‐3 cells‐induced orthotopic leukemia animal model in vivo in this study. We established the WEHI‐3 cells leukemia mice through the injection of murine WEHI‐3 cells into BALB/c mice, and they were then treated with As₂O₃ (0.9 and 4.5 mg kg^?1; p.o.) and/or combined with all‐trans‐retinoic acid (ATRA), (30 mg kg^?1; i.p.). The results indicated that (1) As₂O₃ alone or As₂O₃ combined with ATRA promoted the total survival rate of leukemia mice and these effects are dose‐dependent; (2) As₂O₃ did not affect the body weight but decreased the spleen weight; however, it did not affect liver weight; (3) As₂O₃ alone or As₂O₃ combined with ATRA increased the levels of CD3 and CD19, indicating that the differentiation of T and B cells were promoted; and (4) As₂O₃ alone or As₂O₃ combined with ATRA did not change the levels of Mac‐3 and CD11b markers, indicating that the differentiation of the precursor of macrophage were not inhibited. Based on these observations, As₂O₃ alone or As₂O₃ combined with ATRA have efficacious antileukemia activity in WEHI‐3 cells leukemia in vivo. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2012.     

Dominant lethal study of α-asarone in male mice

α-Asarone is a hypolipidaemic agent obtained from Guatteria gaumeri, a medical plant used in Mexico to treat hypercholesteraemia and cholelithiasis. α-Asarone has been shown to be hepatocarcinogenic and mutagenic in a human lymphocyte assay, a murine bone marrow cell assay and in an unscheduled DNA synthesis assay. In this study, α-asarone was tested for dominant lethal effects in male CF1 mice. The drug was given orally at doses of 0, 10 and 30 mg/kg per day for 5 days. Males were mated weekly with eight consecutive batches of naive, nulliparous female mice. Repeated matings revealed no perceptible effect of α-asarone on the incidence of pregnancy. Examination of surgically exposed uteri and ovaries of pregnant females on day 13–15 of gestation revealed an increased incidence of post-implantation loss. Semen examination of a separate group of mice showed a decreased concentration and motility of spermatozoa. These results suggest a dominant lethal mutation as well as direct α-asarone toxicity to spermatozoa by in treated mice.     

Occurrence, pharmacology and function of presynaptic α2-autoreceptors in α2 A/D-adrenoceptor-deficient mice

The occurrence, pharmacological properties and function of alpha2-autoreceptors were studied in hippocampal slices, occipito-parietal cortex slices, segments of heart atria and segments of the vas deferens of wildtype (WT) mice and mice in which the alpha2 A/D-adrenoceptor gene had been disrupted (alpha2 A/D(KO)). Tissues were preincubated with [3H]-noradrenaline and then superfused and stimulated electrically. Stimulation periods for brain slices consisted either of 1 pulse or of 2-64 pulses delivered at 1-s intervals; stimulation periods for peripheral tissues consisted either of 1 POP (pseudo-one-pulse; brief burst of 20 pulses/50 Hz) or of 2-4 POPs delivered at 1-s intervals. Single pulses or POPs were used to study the effect of medetomidine and its interaction with antagonists. One or more pulses or POPs per stimulation period were used to study alpha2-autoinhibition. Medetomidine decreased the evoked overflow of tritium in WT tissues. In alpha2 A/D(KO) tissues, the inhibition was slightly (peripheral tissues) or greatly (brain slices) attenuated but not abolished. Phentolamine, rauwolscine, spiroxatrine, 2-(2,6-dimethoxyphenoxyethyl)aminomethyl-1,4-benzodioxane (WB 4101), tolazoline and prazosin antagonized the effect of medetomidine in all tissues. Their pKd values against medetomidine were compared with pKd values at prototypical alpha2 binding sites by means of a correlation analysis. For WT brain and atrial autoreceptors, the correlations indicated an alpha2D pharmacology, whereas for WT vas deferens autoreceptors they favoured an alpha2B pharmacology. In the KO tissues, any correlation with alpha2D was lost, and the non-alpha2 A/D-autoreceptors displayed alpha2B or alpha2C pharmacology. When 2 or more pulses or POPs were applied to WT tissues per stimulation period, the pulse number-overflow curve (POP number-overflow curve) was flat, indicating that overflow elicited by p pulses (POPs) was much smaller than p times the overflow elicited by a single pulse (POP); moreover, rauwolscine caused a pulse (POP) number-dependent and, at high pulse (POP) numbers, large increase in evoked tritium overflow. In alpha2 A/D(KO) tissues, the pulse (POP) number-overflow curve was much steeper, indicating that overflow elicited by p pulses (POPs) was closer to p times the overflow elicited by a single pulse (POP); moreover, rauwolscine caused no (atria) or only a small increase in overflow, and did so in brain slices only at high pulse numbers (16 and 64). In conclusion, the predominant alpha2D pharmacology of the autoreceptors in WT tissues supports the idea that the main mammalian presynaptic alpha2-autoreceptors belong to the alpha2 A/D subtype. However, alpha2 A/D-deficient animals also possess autoreceptors. As expected, these non-alpha2 A/D-autoreceptors display alpha2B or alpha2C pharmacology. In WT animals, alpha2B- or alpha2C-autoreceptors or both may coexist with alpha2 A/D-autoreceptors, at least in peripheral tissues. Little autoinhibition by released noradrenaline in trains of pulses remains when the alpha2 A/D-adrenoceptor is lacking, again in accord with a predominance of alpha2 A/D-autoreceptors.     

Modulation of motor activity by α1 and α2 stimulation in mice

Summary The influence of two -adrenoceptor agonists, clonidine and B-HT 920, on motor activity was tested in mice. Both, clonidine and B-HT 920 (2-amino-6-allyl-5,6,7,8-tetrahydro-4H-thiazolo-[4,5-d]-azepine) in the dose range 30–300 g/kg s.c. equieffectively inhibited exploratory activity. On the other hand only clonidine, which stimulates ₂- and ₂-adrenoceptors increased locomotor activity in mice treated with reserpine (5 mg/kg) and apomorphine (3 mg/kg) in the doses of 0.3 and 1 mg/kg i.p. The highly selective ₂-agonist B-HT 920 was ineffective under these conditions up to 30 mg/kg i.p. It is concluded, that in mice sedative -adrenoceptors are of the ₂- and excitatory of the ₁-type.     

Effects of Ganoderma sterols （GS） on hepatic cytochrome P450 in BCG-induced immunological hepatic injury in BALB／c mice

AIM: To investigate effects of Ganoderma sterols (GS) isolated from Ganoderma lucidum (Leyss ex fr) Karst on hepatic cytochrome P450 in BCG-induced immunological hepatic injury in BALB/c mice and its possible mechanism. METHODS: Immunological liver injury was induced by one intravenous injection of BCG (125 mg/kg) in BALB/c mice. One week later, successiveintragastric administration of GS (20, 40, 80 mg/kg, per day) and     

The effects of sexual maturation on α-adrenoceptors in female rabbits

α-Adrenoceptor number and function were examined in brain, platelets, and other peripheral tissues of young (2–3 months) and mature (6–8 months) non pregnant female rabbits. α₁-Adrenoceptor number was significantly higher in forebrain, hindbrain, spleen and heart of mature rabbits. α₂-Adrenoceptor number, on the other hand, was found to be significantly lower in platelets, forebrain and spleen but not changed in hindbrain and kidney of mature animals compared to young females. There was a significant reduction in platelet aggregation with maturation. However, no change in in vivo pressor or depressor responses to α-adrenoceptor agonists was observed in vivo.     

Role of ω3 long-chain polyunsaturated fatty acids in reducing cardio-metabolic risk factors

Cardiovascular disease is the leading cause of mortality in many economically developed nations, and its incidence is increasing at a rapid rate in emerging economies. Diet and lifestyle issues are closely associated with a myriad of cardiovascular disease risk factors including abnormal plasma lipids, hypertension, insulin resistance, diabetes and obesity, suggesting that diet-based approaches may be of benefit. Omega-3 longchain-polyunsaturated fatty acids (ω3 LC-PUFA) are increasingly being used in the prevention and management of several cardiovascular risk factors. Both the ω3 and ω6 PUFA families are considered essential, as the human body is itself unable to synthesize them. The conversion of the two precursor fatty acids - linoleic acid (18:2ω6) and α-linoleic acid (α18:3ω3) - of these two pathways to longer (≥C(20)) PUFA is inefficient. Although there is an abundance of ω6 PUFA in the food supply; in many populations the relative intake of ω3 LC-PUFA is low with health authorities advocating increased consumption. Fish oil, rich in eicosapentaenoic (EPA, 20:5ω3) and docosahexaenoic (DHA, 22:6ω3) acids, has been found to cause a modest reduction in blood pressure at a dose level of >3g/d both in untreated and treated hypertensives. Whilst a multitude of mechanisms may contribute to the blood pressure lowering action of ω3 LC-PUFA, improved vascular endothelial cell function appears to play a central role. Recent studies which evaluated the potential benefits of fish oil in type-2 diabetes have helped to alleviate concerns raised in some previous studies which used relatively large dose (5-8 g/d) and reported a worsening of glycemic control. Several meta-analyses have confirmed that the most consistent action of ω3 LC-PUFA in insulin resistance and type-2 diabetes is the reduction in triglycerides. In some studies, fish oil has been found to cause a small rise in LDL-cholesterol, but a change in the LDL particle size, from the smaller more atherogenic form to the larger, less damaging particle size, have also been noted. ω3 LC-PUFA are effective modulators of the inflammation that accompanies several cardio-metabolic abnormalities. Taking into consideration the pleiotropic nature of their actions, it can be concluded that dietary supplementation with ω3 LC-PUFA will lead to improvements in cardio-metabolic health parameters. These fatty acids pose only minor side effects and more importantly, do not interact adversely with the common drug therapies used in the management and treatment of hypertension, dyslipidemia, type-2 diabetes, and obesity/metabolic syndrome, but in some instances work synergistically, thereby providing additional cardiovascular benefits.     

The involvement of α2-adrenoceptors in the anticonvulsive effect of swim stress in mice

RATIONALE: Various studies have shown that stressful manipulations in rats and mice lower the convulsant potency of GABA-related, but also some GABA-unrelated convulsants. The mechanism of this anticonvulsive effect of stress is still unknown. OBJECTIVES: We tested the possible involvement of alpha2-adrenoceptors in the previously observed anticonvulsive effect of swim stress. METHODS: The mice were, prior to exposure to swim stress and the IV infusion of picrotoxin, pre-treated with clonidine (an alpha2-adrenoceptor agonist), yohimbine (a non-selective alpha2-adrenoceptor antagonist), idazoxan (a selective alpha2-adrenoceptor antagonist), or niguldipine (an alpha1-adrenoceptor antagonist), and the latency to the onset of two convulsant signs was registered. RESULTS: In control unstressed animals clonidine (0.1 and 1 mg/kg IP), yohimbine (2 mg/kg IP) and idazoxan (1 mg/kg IP) failed to affect the doses of picrotoxin needed to produce convulsant signs, while niguldipine (5 mg/kg IP) prolonged the latency, i.e. it enhanced the doses of picrotoxin producing running/bouncing clonus and tonic hindlimb extension. In swim stressed mice clonidine enhanced, while idazoxan decreased doses of picrotoxin needed to produce two convulsive signs. Yohimbine decreased the dose of convulsant needed to produce tonic hindlimb extension, while niguldipine enhanced doses of picrotoxin needed to produce both symptoms. CONCLUSIONS: The results demonstrate the alpha2-adrenoceptor agonist-induced potentiation and alpha2-adrenoceptor antagonist-induced diminution of the anticonvulsive effect of stress. Additionally, they show the anticonvulsive effect of niguldipine in unstressed and stressed animals. Hence, the results suggest that alpha2-adrenoceptors are involved in the anticonvulsive effect of swim stress in mice.     

Hemostatic effects of bezafibrate and ω-3 fatty acids in isolated hypertriglyceridemic patients

This study aimed to compare the effects of ω-3 fatty acids and fibrate treatment on plasma levels and activities of hemostatic risk factors on glucose and lipid metabolism in subjects with isolated hypertriglyceridemia. Seventy-three subjects with elevated triglyceride levels were allocated into one of the following treatment options: bezafibrate (200 mg twice daily), ω-3 fatty acids (1 g twice daily) or placebo. Plasma lipids, glucose homeostasis markers (fasting and 2-h post-glucose load plasma glucose levels and HOMA), as well as plasma levels/activities of fibrinogen, factor VII and PAI-1 were determined at baseline, on the day of randomization, and after 4 and 12 weeks of the treatment. Not only did bezafibrate improve plasma lipids, but it also increased glucose sensitivity and tended to reduce post-glucose loads of plasma glucose. Except for the reduction in plasma triglycerides, ω-3 fatty acids produced no effect on the lipid profile and insulin sensitivity. Both treatment options reduced, to similar extents, plasma levels of fibrinogen and PAI-1 and factor VII coagulant activity. Our study indicates that, although fibrates exhibit more-pronounced metabolic effects than do ω-3 fatty acids, both these treatment options are equipotent in producing a complex beneficial effect on hemostasis in isolated hypertriglyceridemic subjects.     

Does context influence the duration of locomotor sensitization to ethanol in female DBA/2J mice?

Rationale Repeated exposure to ethanol produces a progressive increase in locomotor sensitivity, referred to as locomotor sensitization. Locomotor sensitization may persist for some time after termination of repeated drug exposure, and context appears to facilitate expression of the behavioral phenomenon. However, many unanswered questions remain concerning the persistence of and degree to which context influences locomotor sensitization to alcohol (ethanol). Objectives The goal of the present work was to determine the duration of locomotor sensitization to ethanol and the degree to which context dependence positively influences the induction, expression, and persistence of the behavioral phenomenon in female DBA/2J mice. Materials and methods Sensitized (with or without ethanol-paired exposure to the testing chamber) and non-sensitized saline control mice were left undisturbed in their home cages until subsequent ethanol challenge and testing in the locomotor activity testing chambers 7, 14, 21, 28, 42, 56, and/or 70 days after cessation of the ethanol sensitization procedure. Retro-orbital sinus bloods were sampled to determine whether the sensitization procedure had altered blood ethanol clearance rates. Results Locomotor sensitization persisted through post-sensitization day 14, and repeated paring of the drug and testing context prolonged the expression of this phenomenon through at least post-sensitization day 28. Blood ethanol concentrations did not differ. Conclusions Locomotor sensitization to ethanol persists for some time after cessation of repeated ethanol exposure, and the association of contextual cues with the ethanol experience lengthens this persistence. The present data lay the groundwork for investigations into the neuroadaptive changes that underlie locomotor sensitization to ethanol in mice.     

Chronic ritodrine treatment induces refractoriness of glucose-lowering β2 adrenoceptor signal in female mice

Adverse events in tocolytic therapy with β2-adrenergic agents compromise cardiovascular and non-cardiovascular functions, including blood glucose regulation and liver function. Here, we have examined the effects of the β2 agonist ritodrine on glucose metabolism and liver injury in mice. Under fasting conditions, ritodrine significantly increased serum insulin levels and decreased glucose concentrations. This contrasts with the β2 agonist-induced hyperglycemia observed in previous studies on humans and other animals. After 14 days of ritodrine treatment, the mice showed a decrease in the total mass of epididymal fat pads, whereas their body weights increased significantly. Chronic ritodrine treatment attenuated the glucose-lowering effect observed during acute administration. Ritodrine also significantly increased serum levels of liver enzymes, which returned to control levels after 14 days of treatment. Thus, ritodrine responsiveness changes between acute and chronic treatment, indicating that close monitoring of blood glucose and serum liver enzymes is necessary in patients with reduced glucose tolerance. The findings reported here of glucose homeostasis in mice provide a unique opportunity to understand refractoriness of β2-adrenoceptor signaling in response to β2 agonists during the course of treatment.     

Avoidance facilitation by chlordiazepoxide-amphetamine combinations in mice: Effect of α-methyl-p-tyrosine

Chlordiazepoxide (CDP) and amphetamine (AMPH) were tested, alone or in combination, in BALB/c mice pretreated with -methyl-p-tyrosine (AMT) and subjected to shuttle-box avoidance training.CDP and AMPH, given alone, partly reversed avoidance depression induced by 50 mg/kg of AMT, but were ineffective in mice pretreated with 100 mg/kg of AMT. Stronger effects were produced by CDP-AMPH combinations, which also improved avoidance performance in mice pretreated with the higher dose of AMT.The results suggest that catecholamines may play a role in the facilitation of avoidance induced by CDP, especially when given in combination with AMPH.     

Exploring the pharmacology of the pro-convulsant effects of α2-adrenoceptor antagonists in mice

The effects of selective and specific ₂-adrenoceptor antagonists on electroshock seizure threshold in mice were investigated. Idazoxan, at low doses, efaroxan, RX811059 and RX821002 significantly lowered seizure threshold. The ₁-agonist St 587 and the -agonist isoprenaline were also pro-convulsant. On the other hand the ₂-agonists clonidine and UK 14,304 produced small increases in seizure threshold. Anticonvulsant effects were also produced by low doses of the noradrenaline uptake inhibitor desipramine. This compound increases levels of noradrenaline in the synaptic cleft which could subsequently act at post-synaptic ₂-adrenoceptors. The pro-convulsant action of ₂-adrenoceptor antagonists could be explained in terms of two mechanisms: a) blockade of endogenous noradrenaline which may normally exert a tonic anti-convulsant influence on seizure threshold, through post-synaptic ₂-receptors and/or b) increased activation of ₁- and -adrenoceptors by elevated synaptic noradrenaline levels following blockade of pre-synaptic ₂-adrenoceptors. Of the ₂-antagonists tested, idazoxan was unusual in that high doses were not pro-convulsant; this difference may be explained by ₁-adrenoceptor mediated actions or be related to its recently described affinity at a non-adrenoceptor site — a function for which is currently unknown.     

α2-Adrenoceptor-mediated inhibition of cultured sympathetic neurons: changes in α2A/D-adrenoceptor-deficient mice

Alpha2-Adrenoceptor-mediated inhibition of [3H]noradrenaline release and alpha2-adrenoceptor-mediated inhibition of voltage-activated Ca2+ currents were compared in cultured thoracolumbar postganglionic sympathetic neurons from newborn wildtype (WT) mice and mice in which the alpha2A/D-adrenoceptor gene had been disrupted (alpha2A/DKO). In cultures prepared from WT mice and preincubated with [3H]noradrenaline, the alpha2-adrenoceptor agonist 5-bromo-6-(2-imidazolidinylidenamino)quinoxaline (UK 14,304) reduced the (autoinhibition-free) release of [3H]noradrenaline elicited by single electrical pulses or trains of 8 pulses at 100 Hz. The maximal inhibition by UK 14,304 amounted to 70%-85%. Its concentration-response curve was shifted to the right by phentolamine (0.3 microM) and, to a smaller extent, rauwolscine (0.3 microM). Pretreatment of the cultures with pertussis toxin abolished the effect of UK 14,304. Phentolamine and rauwolscine increased the (alpha2-autoinhibited) release of [3H]noradrenaline elicited by 18, 36 or 72 pulses at 3 Hz. In cultures from alpha2A/DKO mice, UK 14,304 failed to reduce the release of [3H]noradrenaline elicited by single pulses and phentolamine and rauwolscine failed to increase the release of [3H]noradrenaline elicited by 18-72 pulses at 3 Hz. In neurons from WT mice examined with the amphotericin B-perforated configuration of the patch clamp method, UK 14,304 reduced depolarisation-evoked Ca2+ currents. The inhibition was voltage-dependent as shown by a decline at strong depolarisation during ramp-like voltage commands and by an attenuation briefly after a conditioning depolarising pulse. The maximal inhibition by UK 14,304 was 39%. Its concentration-response curve was shifted to the right by phentolamine (0.3 microM) but not significantly changed by rauwolscine (0.3 microM) and prazosin (1 microM). Pretreatment with pertussis toxin abolished the effect of UK 14,304. In neurons from alpha2A/DKO mice, UK 14,304 also reduced depolarisation-evoked Ca2+ currents, but with a smaller maximal effect, namely 18% inhibition. Its concentration-response curve was shifted to the right by rauwolscine (0.3 microM) and prazosin (1 microM) but not significantly changed by phentolamine (0.3 microM). Pretreatment with pertussis toxin abolished the effect of UK 14,304 also in cultures from alpha2A/DKO mice. It is concluded that the only presynaptic alpha2-autoreceptors that detectably depress transmitter release from cultured thoracolumbar sympathetic neurons taken from newborn mice are alpha2A/D. In contrast, the soma-dendritic alpha2-autoreceptors that inhibit voltage-gated Ca2+ channels are both alpha2A/D and non-alpha2A/D (i.e. alpha2B or alpha2c). Both presynaptic alpha2A/D- and soma-dendritic alpha2A/D- and non-alpha2A/D-autoreceptors operate through pertussis toxin-sensitive G proteins in these neurons.     

Antinociceptive and anti-inflammatory effects of the monoterpene α,β-epoxy-carvone in mice

α,β-Epoxy-carvone (EC) is a monoterpene found in the essential oils of many species of plants. It can also be obtained by organic synthesis. EC exerts a depressant effect on the central nervous system and is also known to have anticonvulsant, antimicrobial and antioxidant effects. The present study investigated the antinociceptive and anti-inflammatory effects of EC. Intraperitoneal administration of EC at doses of 100, 200 or 300 mg/kg promoted a significant antinociceptive effect, as shown in the acetic acid-induced abdominal writhing test. EC also provoked a reduction in formalin-induced nociception in the first (300 mg/kg) and second phases (200 and 300 mg/kg). In the hot-plate test, an increase in response latency was found at 30 min (at 100, 200 and 300 mg/kg), and at 60 and 120 min (at 300 mg/kg) following administration of EC, an effect that was reversed by naloxone. Intraperitoneal administration of EC (300 mg/kg) inhibited the increased vascular permeability provoked by acetic acid. These findings suggest that EC inhibited the acute inflammatory reaction, with a pronounced peripheral and central antinociceptive effect in mice that is probably associated with activation of the opioidergic system, which appears to play a role in the antinociceptive activity induced by EC.     

Safety evaluation of Mucor rouxii CFR-G15 biomass containing ω-6 fatty acids in rats

Mucor rouxii CFR-G15 is an oleaginous zygomycetous fungus. The mycelia of the fungus accumulate 35.0±0.8% total lipid of which, 18.55±0.46% is gamma linolenic acid. Acute and subchronic studies were conducted by feeding rats with dry biomass of M. rouxii CFR-G15 to assess the safety of the oils in the fungal mycelium. For acute toxicity studies, adult male rats fed with diet at 0, 5000, 10,000, 25,000, 50,000 mg/kg bw for 1 day, and the animals were monitored for 14 days. Rats weighing 35±2.5 g were fed for 13 weeks with a diet incorporating 2500, 5000, 10,000 and 20,000 mg/kg (w/w) dry biomass for subchronic toxicity studies. Control consists of the diet without the dry biomass. Dietary feeding of M. rouxii biomass at any level showed no significant changes (p>0.05) in food intake, body weight, organs weight and serum enzymes. Macroscopic and microscopic observations revealed that the vital organs were unaffected by the feed containing the dry biomass. However, triglycerides and cholesterol levels in serum were decreased significantly (p<0.05) in the test rats. The results of this study suggests that feeding fungal mycelia containing oil is safe when fed to rats and also shows positive effects on controlling triglycerides and cholesterol.     

Alteration of neuropathic and visceral pain in female C57BL/6J mice lacking the PPAR-α gene

Rationale

Peroxisome proliferator-activated receptors (PPARs) participate in the control of chronic neuropathic and inflammatory pain, and these receptors could play a role on acute pain.

Objectives

We used null (PPAR-?? ?/?) and wild-type female mice and the PPAR-?? blocker GW6471 to evaluate (1) the role of PPAR-?? on neuropathic pain, (2) the involvement of PPAR-?? on visceral and acute thermal nociception, and (3) tissue levels of pro-inflammatory factors.

Methods

Neuropathic pain was induced by sciatic nerve ligature. Acute thermal nociception was evaluated through hot-plate, tail-immersion, and writhing tests. The pro-inflammatory factors nitric oxide, TNF-??, and interleukins-1?? and -3 were measured.

Results

Regarding neuropathic pain, higher sensitivity to thermal and mechanical non-noxious and noxious stimuli was observed in mice lacking PPAR-??. Cold and mechanical allodynia and heat hyperalgesia were augmented in null mice. With respect to visceral nociception, writhes after acetic acid were enhanced in mutant mice. Although basal thermal sensitivity was enhanced in PPAR-?? ?/? mice, cutaneous thermal nociception did not differ between genotypes. Blockade of PPAR-?? was devoid of effects on acute thermal and writhing tests. Finally, nerve ligature enhanced pro-inflammatory factors in plantar tissue, levels being higher in null mice. No changes in pro-inflammatory factors were observed in the hot-plate test.

Conclusions

Genetic ablation of PPAR-?? is involved in neuropathic and visceral nociception. Lack of PPAR-?? is not involved in acute thermal pain, but it is involved in basal thermal reaction. Changes are biological adaptations to receptor deletion because blockade of PPAR-?? does not affect inflammatory pain or thermal reactions.