Glucose-rich polysaccharide from dried 'Shixia' longan activates macrophages through Ca2+ and CR3- mediated MAPKs and PI3K-AKT pathways.

A water-soluble glucose-rich polysaccharide from dried 'Shixia' longan pulp (LPsx) has been isolated for the first time, and its structure and immuno-regulatory mechanism were studied. LPsx is a hetero-polysaccharide with the average molecular weight 4102 g/mol. It was mainly consisted of glucose (95.9%), and small proportions of arabinose (2.1%), galactose (1.0%), mannose (0.6%), and xylose (0.4%). As analyzed by NMR, LPsx was mainly composed of (1 â†’ 6)-α-d-glucose and (1 â†’ 6)-ß-d-glucose, branched with α-d-glucose-(1→. The immunomodulatory activity study showed that LPsx significantly increased the phagocytosis of macrophages, and strongly promoted the production of NO, IL-1ß, IL-6 and TNF-α. Moreover, LPsx could inhibit the inflammatory response induced by lipopolysaccharide. The immuno-regulatory mechanism of LPsx was studied using RNA- sequencing and receptors activity analyses. It was found that LPsx induced macrophage activation via Ca2+ and CR3-mediated MAPKs and PI3K-AKT signaling pathways. The results would be helpful for revealing the health promoting mechanism of dried 'Shixia' longan in traditional Chinese medicine.

T cell-derived soluble glycoprotein GPIbα mediates PGE2 production in human monocytes activated with the vaccine adjuvant MDP.

Vaccine adjuvants containing analogs of microbial products activate pattern recognition receptors (PRRs) on antigen-presenting cells, including monocytes and macrophages, which can cause prostaglandin E2 (PGE2) release and consequently undesired inflammatory responses and fever in vaccine recipients. Here, we studied the mechanism of PGE2 production by human monocytes activated with muramyl dipeptide (MDP) adjuvant, which activates cytosolic nucleotide-binding oligomerization domain 2 (NOD2). In rabbits, administration of MDP elicited an early increase in PGE2 followed by fever. In human monocytes, MDP alone did not induce PGE2 production. However, high amounts of PGE2 and the proinflammatory cytokines IL-1ß and IL-6 were secreted by monocytes activated with MDP in the presence of conditioned medium obtained from CD3 bead-isolated T cells (Tc CM) but not from those isolated without CD3 beads. Mass spectrometry and immunoblotting revealed that the costimulatory factor in Tc CM was glycoprotein Ib α (GPIbα). Antibody-mediated blockade of GPIbα or of its receptor, Mac-1 integrin, inhibited the secretion of PGE2, IL-1ß, and IL-6 in MDP + Tc CM-activated monocytes, whereas recombinant GPIbα protein increased PGE2 production by MDP-treated monocytes. In vivo, COX2 mRNA abundance was reduced in the liver and spleen of Mac-1 KO mice after administration of MDP compared with that of treated wild-type mice. Our findings suggest that the production of PGE2 and proinflammatory cytokines by MDP-activated monocytes is mediated by cooperation between two signaling pathways: one delivered by MDP through NOD2 and a second through activation of Mac-1 by T cell-derived GPIbα.

Effects of sinomenine in LPS-associated diseases are related to inhibition of LBP, Mac-1, and L-selectin levels.

The aim of the research was to investigate the anti-endotoxin and anti-inflammatory effects of Sinomenine, an agent commonly found in Chinese herbal medicines. Endotoxin (i.e., 1 mg lipopolysaccharide (LPS)/kg)) was administered via intraperitoneal (IP) injection to piglets in high-, middle-, and low-dose sinomenine groups. Piglets were then treated with 1, 5 or 10 mg/kg sinomenine, intramuscularly (i.m.), 3 hr after LPS. Vehicle was administered, as above, to drug control group piglets followed 3 hr later by 10 mg/kg sinomenine i.m.. LPS control group piglets were challenged with 1 mg/kg LPS IP, followed by vehicle i.m., and naïve control piglets were treated with normal saline IP, followed by normal saline i.m., as above. Temperatures were measured, and blood samples were collected from the precaval veins of piglets at 12, 24, and 48 hr post-LPS or vehicle injection. Clinical signs were recorded, and index levels were analyzed via ELISA. Sinomenine was found to reduce the incidence and severity of LPS-induced toxicities, including body temperature elevation, cell adhesion, and systemic inflammation. These data suggest that sinomenine may be effective for regulating inflammatory responses and has the potential for use as an anti-endotoxin therapy.

Aureobasidium pullulans produced ß-glucan is effective to enhance Kurosengoku soybean extract induced Thrombospondin-1 expression.

Black yeast, Aureobasidium pullulans is extracellularly produced ß-(1,3), (1,6)-D-glucan (ß-glucan) under certain conditions. In this study, using Glycine max cv. Kurosengoku (Kurosengoku soybeans), the production of ß-glucan through fermentation of A. pullulans was evaluated, and the effects of A. pullulans cultured fluid (AP-CF) containing ß-glucan made with Kurosengoku soybeans (kAP-CF) on a human monocyte derived cell line, Mono Mac 6 cells were investigated. Concentration of ß-glucan in kAP-CF reached the same level as normal AP-CF. An anti-angiogenic protein, Thrombospondin-1 (THBS1) was effectively induced after the stimulation with kAP-CF for comparison with AP-CF. The THBS1 is also induced after stimulation with hot water extract of Kurosengoku soybeans (KS-E), while the combined stimulation of ß-glucan with KS-E more effectively induced THBS1 than that with KS-E alone. These results suggest effects of A. pullulans-produced ß-glucan on the enhancement of Kurosengoku soybean-induced THBS1 expression.

Flavonoid-enriched fraction from Echinodorus macrophyllus aqueous extract exhibits high in-vitro and in-vivo anti-inflammatory activity.

OBJECTIVES: Echinodorus macrophyllus (Kunth) Micheli (Alismataceae) is popularly used as an infusion to treat inflammatory diseases. This work fractionated the aqueous extract of E. macrophyllus (AEEm) to improve its anti-inflammatory effects. METHODS: Aqueous extract of E. macrophyllus was fractionated by Sephadex LH-20 and analysed by HPLC-DAD. Anti-inflammatory action was evaluated, in vivo, by air pouch model (total leucocyte, protein and leukotriene B4 (LTB4 )), and, in vitro, by neutrophil migration (transwell assay) and its Mac1 expression (flow cytometry), and RAW 264.7 nitric oxide (NO) production (Griess reaction). KEY FINDINGS: Fr20 reduced total leucocyte at 2.5 mg/kg (29.7%) while ethanolic extract of E. macrophyllus (EAEm) increased it (94.0%). Fr20 showed higher (P < 0.05) inhibition (89.8%) of LTB4 in exudate than EAEm (75.0%). Fr20 and EAEm decreased exudate protein and inflammatory infiltrate in pouch tissues, in-vitro neutrophil migration, and NO production. Otherwise, Fr40 did not reduce leucocytes and exudate protein (until 50 mg/kg) nor tissue inflammation, and increased in-vitro NO production. The inhibition of neutrophil migration by EAEm, but not Fr20, was dependent on reduced Mac-1 expression. CONCLUSIONS: The fractionation of AEEm provided a more potent anti-inflammatory fraction containing flavonoids (Fr20) that reduces the migration of neutrophils and LTB4 release, probably contributing to its mechanism of action.

A simplified approach for efficient isolation of functional microglial cells: Application for modeling neuroinflammatory responses in vitro.

Purified microglial cells in culture are frequently used to model brain inflammatory responses but obtaining large yields of these cells on a routine basis can be quite challenging. Here, we demonstrate that it is possible to achieve high-yield isolation of pure microglial (MAC-1(+) /Fcrls(+) /Ccr2(-) ) cells from postnatal brain tissue through a simple culture procedure that mainly relies on the adhesion preference of these cells to the polycation polyethyleneimine (PEI) in serum-supplemented DMEM medium. Accordingly, other synthetic or biological substrates failed to mimic PEI effects under the same culture conditions. Replacement of DMEM by DMEM/F12 nutrient mixture did not permit microglial cell isolation on PEI coating, indicating that PEI effects were context-dependent. Remarkably, the lack of culture feeding during progression of microglial cell isolation strongly improved cell yield, suggesting that nutritional deprivation was required to optimize this process. When generated in large culture flasks coated with PEI, cultures of microglial cells were easily recovered by trypsin proteolysis to produce subcultures for functional studies. These cultures responded to lipopolysaccharide (LPS, 1-10 ng/ml) treatment by secreting pro-inflammatory cytokines such as TNF-α, IL-6, IL-1ß and by generating nitric oxide and reactive oxygen species. Most interestingly, this response was curtailed by appropriate reference drugs. Microglial cells were also strongly responsive to the mitogenic cytokine GM-CSF, which confirms that the functional repertoire of these cells was well preserved. Because of its high yield and simplicity, we believe that the present method will prove to be especially convenient for mechanistic studies or screening assays. GLIA 2016;64:1912-1924.

Immunosuppressive effects of the standardized extract of Phyllanthus amarus on cellular immune responses in Wistar-Kyoto rats.

Phyllanthus amarus (family: Euphorbiaceae) is of immense interest due to its wide spectrum of biological activities. In the present study, the standardized 80% ethanol extract of P. amarus was investigated for its modulatory activity on various cellular immune parameters, including chemotaxis of neutrophils, engulfment of Escherichia coli by neutrophils, and Mac-1 expression, in leukocytes isolated from treated/nontreated Wistar-Kyoto rats. The detailed cell-mediated activity of P. amarus was also investigated, including analysis of the effects on T- and B-cell proliferation and CD4(+) and CD8(+) T-cell subsets in splenic mononuclear cells, and estimation of serum cytokine production by activated T-cells. The main components of the extract, phyllanthin, hypophyllanthin, corilagin, geraniin, ellagic acid, and gallic acid were identified and quantitatively analyzed in the extracts, using validated reversed-phase high-performance liquid chromatography (HPLC) methods. N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced neutrophils isolated from rats administered with the extract of P. amarus, at doses ranging from 100 to 400 mg/kg for 14 days, revealed a significant dose-dependent reduction in neutrophil migration (P<0.05). Similar patterns of inhibition were also observed in phagocytic activity and in fMLP-induced changes in expression of ß2 integrin polymorphonuclear neutrophils. The results in P. amarus-treated rats also demonstrated a dose-dependent inhibition of both lipopolysaccharide-stimulated B-cell proliferation and concanavalin A-stimulated T-cell proliferation as compared with sensitized control. At a dose of 400 mg/kg (P<0.01), there was a significant decrease in the (%) expression of CD4(+) and CD8(+) in splenocytes and in serum cytokines of T helper (Th1) (IL-2 and IFN-γ) and Th2 (IL-4). In conclusion, P. amarus showed effective immunosuppressive activities in cellular immune response, by various immune regulatory mechanisms, and may be useful for improvement of immune-related disorders.

Attenuation of neuroinflammatory responses and behavioral deficits by Ligusticum officinale (Makino) Kitag in stimulated microglia and MPTP-induced mouse model of Parkinson's disease.

ETHNOPHARMACOLOGICAL RELEVANCE: Ligusticum officinale (Makino) Kitag (L. officinale) is one of the important traditional herbs used in traditional Oriental medicine for the treatment of various disorders including pain and inflammation. However, there is limited scientific basis for its activity and mechanism in brain inflammation. AIM OF THE STUDY: This study aimed to evaluate the effects of L. officinale on microglia-mediated neuroinflammation and behavioral impairments using in vitro cellular and in vivo mouse model of PD, as well as investigate the molecular mechanisms involved including the finger printing analysis of its ethanol extract. MATERIALS AND METHODS: Lipopolysaccharide (LPS) was used to stimulate BV-2 microglial cells. The changes in neuroinflammatory expressional levels were measured by Western blotting and immunofluorescence techniques. 1-methyl-4 phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-intoxicated mice model of PD was developed to evaluate the behavioral impairments and the brain tissues were used for immunohistochemical studies. High performance liquid chromatography (HPLC) technique was performed for finger printing analysis of L. officinale extract used in the study. RESULTS: L. officinale significantly attenuated the LPS-stimulated increase in inflammatory mediators in BV-2 cells. L. officinale also inhibited the LPS-induced activation of nuclear factor-kappa beta by blocking the degradation of IκB-α and suppressing the increase in p38-mitogen-activated protein kinase phosphorylation in BV-2 cells. Furthermore, L. officinale exhibited significant antioxidant properties by inhibiting the 1-diphenyl-2-picrylhydrazyl radicals. An in vivo evaluation in MPTP (20mg/kg, four times, 1 day, i.p.) intoxicated mice resulted in brain microglial activation and significant behavioral deficits. Prophylactic treatment with L. officinale prevented microglial activation and attenuated PD-like behavioral changes as assessed by the pole test. HPLC finger printing analysis revealed that L. officinale extract contained ferulic acid (FA) as one of the major constituents compared with reference standard. FA also inhibited the LPS-stimulated excessive release of NO and suppressed the increased the expressional levels of proinflammatory mediators in BV-2 microglia. CONCLUSIONS: The findings observed in this study indicated that L. officinale extract significantly attenuated the neuroinflammatory processes in stimulated microglia and restored the behavioral impairments in a mouse model of PD providing a scientific basis for its traditional claims.

Integrins LFA-1 and Mac-1 and cytokines IL-6 and IL-10 in high-cancer mice under the influence of phytoadaptogen.

The expression of leukocyte integrins LFA-1 and Mac-1 and cytokines IL-6 and IL-10 was studied in mice predisposed to spontaneous hepatocarcinomas. The efficacy of a phytoadaptogen in correcting these parameters was evaluated. The role of adhesive interactions between immune cells and target cells in the recovery of antitumor regulatory mechanisms was estimated.

Extract from Acanthopanax senticosus prevents LPS-induced monocytic cell adhesion via suppression of LFA-1 and Mac-1.

A crude extract from Acanthopanax senticosus (AS) has drawn increased attention because of its potentially beneficial activities, including anti-fatigue, anti-stress, anti-gastric-ulcer, and immunoenhancing effects. We previously reported that AS crude extract exerts anti-inflammatory activity through blockade of monocytic adhesion to endothelial cells. However, the underlying mechanisms remained unknown, and so this study was designed to investigate the pathways involved. It was confirmed that AS extract inhibited lipopolysaccharide (LPS)-induced adhesion of monocytes to endothelial cells, and we found that whole extract was superior to eleutheroside E, a principal functional component of AS. A series of PCR experiments revealed that AS extract inhibited LPS-induced expression of genes encoding lymphocyte function-associated antigen-1 (LFA-1) and macrophage-1 antigen (Mac-1) in THP-1 cells. Consistently, protein levels and cell surface expression of LFA-1 and Mac-1 were noticeably reduced upon treatment with AS extract. This inhibitory effect was mediated by the suppression of LPS-induced degradation of IκB-α, a known inhibitor of nuclear factor-κB (NF-κB). In conclusion, AS extract exerts anti-inflammatory activity via the suppression of LFA-1 and Mac-1, lending itself as a potential therapeutic galenical for the prevention and treatment of various inflammatory diseases.

Hot water extract of the sclerotium of Polyporus rhinocerus Cooke enhances the immune functions of murine macrophages.

Treatment of hot water extract of the sclerotium of Polyporus rhinocerus (PRW) with murine macrophages including RAW 264.7 cell line and primary macrophages (PMs) could enhance their functional activities. These include a significant up-regulation of pinocytosis; an increase in the production of reactive oxygen species (ROS) and nitric oxide (NO); an increase in tumor necrosis factor alpha (TNF-alpha) production and inducible nitric oxide synthase (iNOS) expression in both RAW 264.7 cells and PMs. Cell surface receptors for yeast-derived beta-glucan, including Dectin-1, CR3, and TLR2, were determined by flow cytometry, and the expression of Dectin-1+ cells on the cell surface decreased in the responses of PMs to PRW. PRW increased phosphorylation of IkappaBalpha, which could trigger the nuclear factor kappa B (NF-kappaB) signal pathway for macrophage activation in RAW 264.7 cells. Therefore, the immunomodulatory effect of PRW could be mediated by macrophage activation via the NF-kappaB signal pathway.

Novel sulfated polysaccharides disrupt cathelicidins, inhibit RAGE and reduce cutaneous inflammation in a mouse model of rosacea.

BACKGROUND: Rosacea is a common disfiguring skin disease of primarily Caucasians characterized by central erythema of the face, with telangiectatic blood vessels, papules and pustules, and can produce skin thickening, especially on the nose of men, creating rhinophyma. Rosacea can also produce dry, itchy eyes with irritation of the lids, keratitis and corneal scarring. The cause of rosacea has been proposed as over-production of the cationic cathelicidin peptide LL-37. METHODOLOGY/PRINCIPAL FINDINGS: We tested a new class of non-anticoagulant sulfated anionic polysaccharides, semi-synthetic glycosaminoglycan ethers (SAGEs) on key elements of the pathogenic pathway leading to rosacea. SAGEs were anti-inflammatory at ng/ml, including inhibition of polymorphonuclear leukocyte (PMN) proteases, P-selectin, and interaction of the receptor for advanced glycation end-products (RAGE) with four representative ligands. SAGEs bound LL-37 and inhibited interleukin-8 production induced by LL-37 in cultured human keratinocytes. When mixed with LL-37 before injection, SAGEs prevented the erythema and PMN infiltration produced by direct intradermal injection of LL-37 into mouse skin. Topical application of a 1% (w/w) SAGE emollient to overlying injected skin also reduced erythema and PMN infiltration from intradermal LL-37. CONCLUSIONS: Anionic polysaccharides, exemplified by SAGEs, offer potential as novel mechanism-based therapies for rosacea and by extension other LL-37-mediated and RAGE-ligand driven skin diseases.

Stress induced morphological microglial activation in the rodent brain: involvement of interleukin-18.

The present study investigated the possibility that acute stress might activate microglial cells. Wistar rats were exposed to 2 h period of restraint combined with water immersion stress prior to brain analysis by immunohistochemistry with OX-42, a marker of complement receptor CR3. A single session of stress provoked robust morphological microglial activation in the thalamus, hypothalamus, hippocampus, substantia nigra and central gray. These effects appeared as early as at 1 h of exposure and were further intensified at 2 h. Morphological activation was not accompanied with changes in markers of functional activation or of inflammation including interleukin-1beta (IL-1beta), interleukin-6 (IL-6) and inducible nitric oxide synthase (iNOS). Similar results were obtained with mice where the effects of stress were compared in animals null for interleukin-18 (IL-18 KO), a cytokine previously demonstrated to be modulated by stress and to contribute to microglia activation. The results demonstrated significant reduction of stress-induced microglial activation in IL-18 KO mice. The present study reports evidence that physical/emotional stress may induce morphological microglial activation in the brain and this activation is in part mediated by interleukin-18.

Acupuncture inhibits microglial activation and inflammatory events in the MPTP-induced mouse model.

Using a mouse model of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease (PD), this study investigated on the neuroprotective effects of acupuncture by examining whether acupuncture contributed to inhibiting microglial activation and inflammatory events. C57BL/6 mice were treated with MPTP (30 mg/kg, i.p.) for 5 consecutive days. Acupuncture was then applied to acupoints Yanglingquan (GB34) and Taichong (LR3) starting 2 h after the first MPTP administration and then at 48 h intervals until the mice were sacrificed for analyses at 1, 3, and 7 days after the last MPTP injection. These experiments demonstrated that acupuncture inhibited the decreased of the tyrosine hydroxylase (TH) immunoreactivity (IR) and generated a neuroprotective effects in the striatum (ST) and the substantia nigra (SN) on days 1, 3, and 7 post-MPTP injections. Acupuncture attenuated the increase of macrophage antigen complex-1 (MAC-1), a marker of microglial activation, at 1 and 3 days and reduced the increases in cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression on days 1, 3, and 7. In MPTP group, striatal dopamine (DA) was measured by 46% at 7 days, whereas DA in the acupuncture group was 78%. On the basis of these results, we suggest that acupuncture could be used as a neuroprotective intervention for the purpose of inhibiting microglial activation and inflammatory events in PD.

Activation of alpha(M)beta(2)-mediated phagocytosis by HF3, a P-III class metalloproteinase isolated from the venom of Bothrops jararaca.

The integrin alpha(M)beta(2) regulates important cell functions in inflammation being the primary phagocytic receptor on macrophages. HF3, a metalloproteinase isolated from Bothrops jararaca venom, is a potent hemorrhagic toxin. A cDNA encoding HF3 indicated that it is a multidomain molecule composed of a pro-domain, a catalytic domain with a zinc binding sequence, followed by disintegrin-like and cysteine-rich domains. It is known that metalloproteinases play a relevant role in the pathogenesis of venom-induced local tissue damage including inflammation. In this study we evaluated the effects of native HF3 and its recombinant disintegrin-like/cysteine-rich domains (DC-HF3) on alpha(M)beta(2)-mediated phagocytosis of opsonized-zymosan particles by macrophages. HF3 and DC-HF3 significantly increased phagocytosis and this activity was inhibited by anti-alpha(M) and anti-beta(2) antibodies. The data show the ability of P-III metalloproteinases to activate macrophages for phagocytosis through integrin alpha(M)beta(2) and suggest that the disintegrin-like/cysteine-rich domains are important for this effect. This is the first report on the activation of phagocytosis via alpha(M)beta(2) integrin by a metalloproteinase containing disintegrin-like/cysteine-rich domains.

Electro-acupuncture stimulation protects dopaminergic neurons from inflammation-mediated damage in medial forebrain bundle-transected rats.

Through producing a variety of cytotoxic factors upon activation, microglia are believed to participate in the mediation of neurodegeneration. Intervention against microglial activation may therefore exert a neuroprotective effect. Our previous study has shown that the electro-acupuncture (EA) stimulation at 100 Hz can protect axotomized dopaminergic neurons from degeneration. To explore the underlying mechanism, the effects of 100 Hz EA stimulation on medial forebrain bundle (MFB) axotomy-induced microglial activation were investigated. Complement receptor 3 (CR3) immunohistochemical staining revealed that 24 sessions of 100 Hz EA stimulation (28 days after MFB transection) significantly inhibited the activation of microglia in the substantia nigra pars compacta (SNpc) induced by MFB transection. Moreover, 100 Hz EA stimulation obviously inhibited the upregulation of the levels of tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta mRNA in the ventral midbrains in MFB-transected rats, as revealed by reverse transcriptase polymerase chain reaction (RT-PCR). ED1 immunohistochemical staining showed that a large number of macrophages appeared in the substantia nigra (SN) 14 days after MFB transection. The number of macrophages decreased by 47% in the rats that received 12 sessions of EA simulation after MFB transection. These data indicate that the neuroprotective role of 100 Hz EA stimulation on dopaminergic neurons in MFB-transected rats is likely to be mediated by suppressing axotomy-induced inflammatory responses. Taken together with our previous results, this study suggests that the neuroprotective effect of EA on the dopaminergic neurons may stem from the collaboration of its anti-inflammatory and neurotrophic actions.

Differential response of lymphocytes and neutrophils to high intensity physical activity and to vitamin C diet supplementation.

We have determined the effects of chronic vitamin C intake on neutrophil and lymphocyte antioxidant defences during the acute phase immune response induced by intense exercise. Blood samples were taken from 16 voluntary athletes in basal conditions, both immediately after and 1 h after a duathlon competition. Sportsmen's nutrient intakes were determined before the competition. After determining the basal plasmatic ascorbate levels, the results were analysed taking into account the vitamin C intake and their plasmatic levels. Two groups were constituted, the vitamin C supplemented group and the control group, with the dietary vitamin C intake as the only statistical difference between groups. The duathlon competition induced a significant neutrophilia, which was higher in the supplemented group. Lymphocyte antioxidant enzyme activities increased after the competition, with a higher increase in SOD activity in the control group than in the supplemented one. The competition decreased neutrophil antioxidant enzyme activities and neutrophil ascorbate concentration. The decrease in the SOD activity in the supplemented group was higher than in the control group. Finally, the duathlon competition increased the expression of MAC-1 neutrophil adhesion molecule in the supplemented group. High vitamin C intake influenced the response of neutrophils and lymphocytes to oxidative stress induced by exercise, increasing the neutrophil activation.

beta2-Integrin and lipid modifications indicate a non-antioxidant mechanism for the anti-atherogenic effect of dietary coenzyme Q10.

Dietary supplementation with coenzyme Q (CoQ) has been proposed to have anti-atherogenic effects by virtue of its antioxidant capacity. To investigate this question, the leukocyte status of 5 males and 5 females (52-68 years) was evaluated before and after supplementation with 200mg CoQ/day for 5 and 10 weeks. CoQ was selectively taken up by mononuclear cells and alpha-tocopherol increased in polynuclear and mononuclear cells. The expression of beta2-integrin CD11b and complement receptor CD35 on the plasma membrane of resting and stimulated monocytes was significantly decreased upon dietary CoQ. Fatty acid and aldehyde analysis revealed that there was a selective increase of arachidonic acid and plasmalogens in only mononuclear cells. These selective lipid changes are not consistent with a general improvement in antioxidant status and indicate that CoQ most likely inhibits a phospholipase A2. Thus, these results strongly suggest that the anti-atherogenic effects of CoQ be mediated by other mechanisms beside its antioxidant protection.

Human monocyte stimulation by experimental whole body hyperthermia.

The thermal effect of fever, an evolutionarily conserved acute-phase response, has been associated with better survival and a shorter duration of disease in cases of infection. The molecular consequence of this beneficial fever response is poorly understood. To determine the influence of hyperthermia on human monocytes, which are important for the recognition and elimination of pathogens, twelve healthy volunteers were immersed in a 39.5 degrees C hot water bath to increase their body temperature. The expression of the endotoxin receptor CD14 and the complement receptor CD11b increased after the hot water bath (P < 0.05), whereas the expression of the selectin CD62L, which mediates the initial attachment of leukocytes at the endothelium during inflammation, was downregulated after hyperthermia (P < 0.05). Comparable changes in monocyte receptor expression were observed after in vitro hyperthermia. Furthermore, 3 hours after in vivo hyperthermia, the response of monocytes to endotoxin was enhanced in an ex vivo lipopolysaccharide stimulation assay, as expressed by a greater TNF-alpha release (P < 0.05). We conclude that the thermal effect of fever directly activates monocytes, which increases their ability to respond to bacterial challenge.

Effects of oral vitamin C on monocyte: endothelial cell adhesion in healthy subjects.

Monocyte recruitment and retention in the vasculature is influenced by oxidative stress and is involved in cardiovascular disease (CVD). Individuals with low plasma ascorbate are at elevated risk of CVD. It is unknown whether vitamin C supplementation affects monocyte adhesion to endothelial cells (ECs) in healthy non-smokers. In a randomised double-blind crossover study the effect of vitamin C supplementation (six weeks, 250 mg/day) was determined in subjects with normal (HIC) and below average (LOC) plasma vitamin C concentration at baseline (mean=67 microM, n=20, mean=32 microM, n=20, respectively). LOC subjects showed 30% greater monocyte adhesion to ECs. This was significantly reduced by 37% (P<0.02) following vitamin C supplementation to levels of HIC monocyte adhesion. No differences in plasma malondialdehyde concentrations were observed between groups or after supplementation. In conclusion, vitamin C supplementation normalises monocyte adhesion in subjects with low plasma vitamin C (LOC). This process may be related to a direct effect on monocytes, independent of lipid peroxidation.