Antimicrobial Peptides for Diabetic Wound Healing: Preclinical and Clinical Studies.

The purpose of this review is to provide verified data on the current knowledge acquired from preclinical and clinical studies regarding topically used antimicrobial peptides (AMPs) with diabetic wound healing activity. The electronic databases were searched for articles published from 2012 to 2022. The 20 articles comparing topically used AMPs in diabetic wound healing treatment versus control treatments (placebo or active therapy) were selected. AMPs have several unique advantages in diabetic wound healing, such as a broad spectrum of antimicrobial activity even against antibiotic-resistant strains, and the capability to modulate the host's immune response and affect wound healing processes through various mechanisms of action. AMPs through antioxidant activity, stimulation of angiogenesis, keratinocytes, and fibroblast migration and proliferation may be considered an important support during conventional therapy used for diabetic wound treatment.

Herbal Products and Their Active Constituents Used Alone and in Combination with Antibiotics against Multidrug-Resistant Bacteria.

The purpose of this review is to summarize the current knowledge acquired on herbal products and their active constituents with antimicrobial activity used alone and in combination with antibiotics against multidrug-resistant bacteria. The most promising herbal products and active constituents used alone against multidrug-resistant bacteria are Piper betle (methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, extended-spectrum beta-lactamase, Acinetobacter baumannii, Pseudomonas aeruginosa), Glycyrrhiza glabra (methicillin-resistant S. aureus, vancomycin-resistant Enterococcus, P. aeruginosa), and berberine (methicillin-resistant S. aureus, A. baumannii, P. aeruginosa), respectively. The synergistic effect of the combination of herbal products and their active constituents with antibiotics against multidrug-resistant bacteria are also described. These natural antibacterial agents can be promising sources of inhibitors, which can modulate antibiotic activity against multidrug-resistant bacteria, especially as efflux pump inhibitors. Other possible mechanisms of action of herbal therapy against multidrug-resistant bacteria including modification of the bacterial cell wall and/or membrane, inhibition of the cell division protein filamenting temperature sensitive Z-ring, and inhibition of protein synthesis and gene expression, all of which will also be discussed. Our review suggests that combination herbal therapy and antibiotics can be effectively used to expand the spectrum of their antimicrobial action. Therefore, combination therapy against multidrug-resistant bacteria may enable new choices for the treatment of infectious diseases and represents a potential area for future research.

Anandamide Influences Interleukin-1ß Synthesis and IL-1 System Gene Expressions in the Ovine Hypothalamus during Endo-Toxin-Induced Inflammation.

This study evaluated the effect of anandamide (AEA) on interleukin (IL)-1ß synthesis and gene expression of IL-1ß, its type I (IL-1R1) and II (IL-1R2) receptors, and IL-1 receptor antagonist (IL-1RN) in the hypothalamic structures, involved in the central control of reproduction, during inflammation. Animals were intravenously (i.v.) injected with bacterial endotoxin-lipopolysaccharide (LPS) (400 ng/kg) or saline, and two hours after LPS administration., a third group received i.v. injection of AEA (10 µg/kg). Ewes were euthanized one hour later. AEA injection (p < 0.05) suppressed LPS-induced expression of IL-1ß protein in the hypothalamus. The gene expression of IL-1ß, IL-1RN, and IL-1R2 in the hypothalamic structures was higher (p < 0.05) in animals treated with both LPS and AEA in comparison to other experimental groups. AEA administration did not influence LPS-stimulated IL-1R1 gene expression. Our study shows that AEA suppressed IL-1ß synthesis in the hypothalamus, likely affecting posttranscriptional levels of this cytokine synthesis. However, anti-inflammatory effect of AEA might also result from its stimulating action on IL-1RN and IL-1R2 gene expression. These results indicate the potential of endocannabinoids and/or their metabolites in the inhibition of inflammatory process at the level of central nervous system, and therefore their usefulness in the therapy of inflammation-induced neuroendocrine disorders.

Photoperiod Affects Leptin Action on the Choroid Plexus in Ewes Challenged with Lipopolysaccharide-Study on the mRNA Level.

The ovine choroid plexus (ChP) expresses the long isoform of the leptin receptor, which makes this structure a potential target for leptin action. In sheep, leptin concentration in plasma is higher during long days (LD) than short days (SD). This study evaluates the influence a of photoperiod on leptin impact on the gene expression of Toll-like receptor 4 (TLR4), proinflammatory cytokines (IL1B, IL6), their receptors (IL1R1, IL1R2, ILRN, IL6R, IL6ST) and inflammasome components necessary for pro-IL-1ß activation (NLRP3, PYCARD, CASP1), chemokine (CCL2), leptin receptor isoforms (LEPRa, LEPRb) and a suppressor of cytokine signalling (SOCS3) in the ChP of ewes treated or not with lipopolysaccharide (LPS). Studies were conducted on adult female sheep divided into four groups (n = 6 in each): control, leptin (20 µg/kg), LPS (400 ng/kg), and LPS and leptin injected under SD and LD photoperiods. The leptin alone did not affect the gene expression but in co-treatment with LPS increased (p < 0.05) IL1B but only during SD, and SOCS3, IL1R2, IL1RN, IL6ST and CCL2 only during LD, and decreased (p < 0.05) the IL1R1 expression only during SD photoperiod. This indicates that the immunomodulatory action of leptin on the ChP is manifested only under the LPS challenge and is photoperiodically dependent.

Effect of Acute and Prolonged Inflammation on the Gene Expression of Proinflammatory Cytokines and Their Receptors in the Anterior Pituitary Gland of Ewes.

An acute and prolonged inflammation inhibits the reproduction process by the disruption of the neurohormonal activity of the hypothalamic-pituitary-gonadal axis. It is thought that these changes may be caused by proinflammatory cytokines, i.e., interleukin (IL) -1ß, IL-6 and tumor necrosis factor (TNF) α. The aim of this study was to determine the effect of an acute and prolonged inflammation on the expression of genes encoding cytokine and their receptors, gonadotropin releasing hormone receptor (GnRHR), beta subunits of luteinizing hormone (LHß) and follicle-stimulating (FSHß) in the anterior pituitary (AP). Moreover, the circulating concentration of LH and FSH was also assayed. Two experiments were carried out on adult ewes which were divided into two control groups and treated with lipopolysaccharide (LPS; 400 ng / kg). Acute inflammation was caused by a single injection of LPS into the external jugular vein, while the chronic inflammation was induced by seven times LPS injection (one a day). In both experiments, animals were euthanized 3h after the last LPS / NaCl injection and the blood samples collected 15 min before euthanasia. An acute inflammation stimulates the expression of the IL-1ß, IL-6 and TNFα genes and their receptors in the AP of sheep. Prolonged inflammation increased TNFα gene expression and both types of TNFα and IL-6 receptors. Both an acute and prolonged inflammation inhibited LHß gene expression in the AP and reduced LH level in blood. A sevenfold LPS injection raises FSH concentration. The gene expression of GnRHR was reduced in the ovine AP only after a single injection of endotoxin. Our results suggest that there are important differences in the way how an acute and prolonged inflammation influence proinflammatory cytokines and their receptors gene expression in the AP of anestrous ewes, which could be reflected by differences in the AP secretory activity during these states.

Herbal Products in Postsurgical Wound Healing - Incision, Excision and Dead Space Wound Models.

The purpose of this review is to summarize current knowledge acquired on preclinical (incision, excision, and dead space wound models) and clinical studies regarding topically used herbal products with wound healing activity. The antimicrobial, anti-inflammatory, and antioxidant mechanisms of their action as well as the adverse effects of herbal therapy will be described. Numerous preclinical and few clinical trials have confirmed the activity of herbal products in the stimulation of wound healing. In contrast to synthetic drugs, for which chemical compositions, purity, efficacy, minimal active concentration, and toxicity are well specified, several herbal formulations require further investigations. Nevertheless, it cannot be precluded that herbal products may be considered as an important support during conventional wound healing therapy or even as synthetic medicament replacements.

Herbal Products for Treatment of Burn Wounds.

The purpose of this review is to summarize the current knowledge acquired during preclinical and clinical studies regarding topically used herbal products with burn wound-healing activity. Moreover, antimicrobial, anti-inflammatory, and antioxidant mechanisms of their action as well as adverse effects of herbal therapy will be also described.

The Influence of Photoperiod on the Action of Exogenous Leptin on Gene Expression of Proinflammatory Cytokines and Their Receptors in the Thoracic Perivascular Adipose Tissue (PVAT) in Ewes.

Leptin resistance is either a condition induced by human obesity or a natural phenomenon associated with seasonality in ruminants. In the cardiovascular system, the leptin resistance state presence is a complex issue. Moreover, the perivascular adipose tissue (PVAT) appears to be crucial as a source of proinflammatory cytokines and as a site of interaction for leptin contributing to endothelium dysfunction and atherosclerosis progression. So the aim of this study was to examine the influence of the photoperiod on the action of exogenous leptin on gene expression of selected proinflammatory cytokines and their receptors in thoracic PVAT of ewe with or without prior lipopolysaccharide (LPS) stimulation. The experiment was conducted on 48 adult, female ewes divided into 4 group (n = 6 in each): control, with LPS intravenous (iv.) injection (400 ng/kg of BW), with leptin iv. injection (20 µg/kg BW), and with LPS and 30-minute-later leptin injection, during short-day (SD) and long-day (LD) seasons. Three hours after LPS/control treatment, animals were euthanized to collect the PVAT adherent to the aorta wall. The leptin injection enhanced IL1B gene expression only in the LD season; however, in both seasons leptin injection intensified LPS-induced increase in IL1B gene expression. IL1R2 gene expression was increased by leptin injection only in the SD season. Neither IL6 nor its receptor and signal transducer gene expressions were influenced by leptin administration. Leptin injection increased TNFA gene expression regardless of photoperiodic conditions. Only in the SD season did leptin treatment increase the gene expression of both TNFα receptors. To conclude, leptin may modulate the inflammatory reaction progress in PVAT. In ewe, the sensitivity of PVAT on leptin action is dependent upon the photoperiodic condition with stronger effects stated in the SD season.

Antimicrobial peptides activity in the skin.

This review presents the current state of knowledge regarding multifunctional role of human skin antimicrobial peptides (AMPs), including (a) protection from microbial infection, (b) improvement of skin barrier homoeostasis, (c) modulation of inflammation responses, and (d) promotion of wound healing. In addition, association of AMPs with skin diseases as well as challenges and future prospects for AMP therapeutics has also been discussed.

Neostigmine Attenuates Proinflammatory Cytokine Expression in Preoptic Area but Not Choroid Plexus during Lipopolysaccharide-Induced Systemic Inflammation.

The study was designed to examine whether the administration of neostigmine (0.5 mg/animal), a peripheral inhibitor of acetylcholinesterase (AChE), during an immune/inflammatory challenge provoked by intravenous injection of bacterial endotoxin-lipopolysaccharide (LPS; 400 ng/kg)-attenuates the synthesis of proinflammatory cytokines in the ovine preoptic area (POA), the hypothalamic structure playing an essential role in the control of the reproduction process, and in the choroid plexus (CP), a multifunctional organ sited at the interface between the blood and cerebrospinal fluid in the ewe. Neostigmine suppressed (p < 0.05) LPS-stimulated synthesis of cytokines such as interleukin- (IL-) 1ß, IL-6, and tumor necrosis factor (TNF) α in the POA, and this effect was similar to that induced by the treatment with systemic AChE inhibitor-donepezil (2.5 mg/animal). On the other hand, both AChE inhibitors did not influence the gene expression of these cytokines and their corresponding receptors in the CP. It was found that this structure seems to not express the neuronal acetylcholine (ACh) receptor subunit alpha-7, required for anti-inflammatory action of ACh. The mechanism of action involves inhibition of the proinflammatory cytokine synthesis on the periphery as well as inhibition of their de novo synthesis rather in brain microvessels and not in the CP. In conclusion, it is suggested that the AChE inhibitors incapable of reaching brain parenchyma might be used in the treatment of neuroinflammatory processes induced by peripheral inflammation.

Inflammation and LPS-Binding Protein Enable the Stimulatory Effect of Endotoxin on Prolactin Secretion in the Ovine Anterior Pituitary: Ex Vivo Study.

Prolactin is a hormone that plays an important role in the regulation of many physiological processes including lactation, reproduction, fat metabolism, and immune response. The secretion of prolactin could be disturbed by an immune stress commonly accompanying infection. This study was designed to determine the influence of bacterial endotoxin-lipopolysaccharide (LPS)-on prolactin gene (PRL) expression and prolactin release from the ovine anterior pituitary (AP) explants collected from saline- and LPS-treated ewes in the follicular phase. The expressions of toll-like receptor 4 (TLR4) and proinflammatory cytokines interleukin- (IL-) 1ß, IL-6, and tumor necrosis factor- (TNF-) α genes were also assayed. The results of the study showed that LPS stimulates prolactin secretion and IL-6 gene expression in the AP explants, but its action on lactotrophs depends on the immunological status of animal. It was demonstrated that an important role in enhancing the effect of LPS on the pituitary in the saline-treated ewes is played by LPS-binding protein (LBP)- "adapter molecule" for LPS binding to the cell surface receptor CD14 and then to TLR4. Also, it was found that bacterial endotoxin acting on the anterior pituitary cells may enhance prolactin secretion, and this effect of LPS could be mediated by IL-6 which is known as prolactin-releasing factor. Identification of the neuroendocrine and immune interactions in the regulation of prolactin secretion could be helpful in developing newer and more effective treatments for dysfunctions connected with disorders in this hormone secretion.

Plasma and cerebrospinal fluid interleukin-1ß during lipopolysaccharide-induced systemic inflammation in ewes implanted or not with slow-release melatonin.

BACKGROUND: Interleukin-1ß (IL-1ß) is important mediator of inflammatory-induced suppression of reproductive axis at the hypothalamic level. At the beginning of inflammation, the main source of cytokines in the cerebrospinal fluid (CSF) is peripheral circulation, while over time, cytokines produced in the brain are more important. Melatonin has been shown to decrease pro-inflammatory cytokines concentration in the brain. In ewes, melatonin is used to advance the onset of a breading season. Little is known about CSF concentration of IL-1ß in ewes and its correlation with plasma during inflammation as well as melatonin action on the concentration of IL-1ß in blood plasma and the CSF, and brain barriers permeability in early stage of lipopolysaccharide (LPS)-induced inflammation. METHODS: Systemic inflammation was induced through LPS administration in melatonin- and sham-implanted ewes. Blood and CSF samples were collected before and after LPS administration and IL-1ß and albumin concentration were measured. To assess the functions of brain barriers albumin quotient (QAlb) was used. Expression of IL-1ß (Il1B) and its receptor type I (Il1r1) and type II (Il1r2) and matrix metalloproteinase (Mmp) 3 and 9 was evaluated in the choroid plexus (CP). RESULTS: Before LPS administration, IL-1ß was on the level of 62.0 ± 29.7 pg/mL and 66.4 ± 32.1 pg/mL in plasma and 26.2 ± 5.4 pg/mL and 21.3 ± 8.7 pg/mL in the CSF in sham- and melatonin-implanted group, respectively. Following LPS it increased to 159.3 ± 53.1 pg/mL and 197.8 ± 42.8 pg/mL in plasma and 129.8 ± 54.2 pg/mL and 139.6 ± 51.5 pg/mL in the CSF. No correlations was found between plasma and CSF IL-1ß concentration after LPS in both groups. The QAlb calculated before LPS and 6 h after was similar in all groups. Melatonin did not affected mRNA expression of Il1B, Il1r1 and Il1r2 in the CP. The mRNA expression of Mmp3 and Mmp9 was not detected. CONCLUSIONS: The lack of correlation between plasma and CSF IL-1ß concentration indicates that at the beginning of inflammation the local synthesis of IL-1ß in the CP is an important source of IL-1ß in the CSF. Melatonin from slow-release implants does not affect IL-1ß concentration in plasma and CSF in early stage of systemic inflammation.

Peripheral Inhibitor of AChE, Neostigmine, Prevents the Inflammatory Dependent Suppression of GnRH/LH Secretion during the Follicular Phase of the Estrous Cycle.

The study was designed to test the hypothesis that the inhibition of acetylcholinesterase (AChE) activity at the periphery by Neostigmine (0.5 mg/animal) will be sufficient to prevent inflammatory dependent suppression of the gonadotropin-releasing hormone (GnRH)/luteinising hormone (LH) secretion in ewes in the follicular phase of the estrous cycle, and this effect will be comparable with the systemic AChE inhibitor, Donepezil (2.5 mg/animal). An immune/inflammatory challenge was induced by peripheral administration of lipopolysaccharide (LPS; 400 ng/kg). Peripheral treatment with Donepezil and Neostigmine prevented the LPS-induced decrease (P < 0.05) in LHß gene expression in the anterior pituitary gland (AP) and in LH release. Moreover, Donepezil completely abolished (P < 0.05) the suppressory effect of inflammation on GnRH synthesis in the preoptic area, when pretreatment with Neostigmine reduced (P < 0.05) the decrease in GnRH content in this hypothalamic structure. Moreover, administration of both AChE inhibitors diminished (P < 0.05) the inhibitory effect of LPS treatment on the expression of GnRH receptor in the AP. Our study shows that inflammatory dependent changes in the GnRH/LH secretion may be eliminated or reduced by AChE inhibitors suppressing inflammatory reaction only at the periphery such as Neostigmine, without the need for interfering in the central nervous system.

Topically used herbal products for the treatment of hair loss: preclinical and clinical studies.

Currently available conventional therapies of hair loss using synthetic drugs are still imperfect and have a number of limitations. Their effectiveness as well as the safety of their use is often questioned. It has led to an increased interest in alternative treatments with fewer side-effects such as formulations containing herbs and/or their active constituents. For this purpose several electronic databases and hand-searched references were used to summarize current knowledge regarding topically used herbal products for the treatment of hair loss acquired on the basis of preclinical and clinical studies. Moreover, mechanism of their action, follicular penetration and possible adverse effect of herbal products will be also described.

Modifications of Western-type diet regarding protein, fat and sucrose levels as modulators of steroid metabolism and activity in liver.

The aim of the study was to evaluate whether the modification of the Western-type diet (high-fat, high-sucrose diet rich in saturated fatty acids) considering macronutrients content would influence hepatic metabolism and activity of steroids. For 3 weeks Wistar rat were fed the Western-type diet (21% fat, 35% sucrose, 19% protein, lard) and its modifications regarding dietary protein (10 and 19%), fat (5 and 21%) and sucrose (0 and 35%) levels. The steroid 5α-reductase type 1 (Srd5a1) and androgen receptor (Ar) gene expression as well as testosterone (T) conversion towards 5α-reduced derivatives in liver were positively correlated with body weight gain. The Western-type diets with decreased protein content regardless of the sucrose level exerted the most negative effect on the antioxidant system decreasing catalase (Cat), sodium dismutase (Sod1) and glutathione peroxidase (Gpx1) gene expression as well as Cat and Gpx activity and total antioxidant status, simultaneously intensifying lipid peroxidation. The impaired antioxidant system was accompanied by decreased level of hepatic T metabolism towards estrogens: 17ß-estradiol (E2) and estriol, and increased estrogen receptor type 1 (Esr1) gene expression. Liver Esr1 mRNA level was differently correlated with T (positively) and E2 (negatively) plasma levels. Whereas the fat reduction in Western-type diet restored the plasma proportion between T and E2. In conclusion it could be stated that Western-type diet modification relating to protein, sucrose and fat content can influence hepatic steroid metabolism and activity; however the estrogens and androgens metabolism in liver would be connected with impairment of liver function or catabolic activity, respectively.

Topically Used Herbal Products for the Treatment of Psoriasis - Mechanism of Action, Drug Delivery, Clinical Studies.

Psoriasis is a chronic inflammatory skin disease characterized histologically by hyperproliferation and aberrant differentiation of epidermal keratinocytes. A wide range of conventional medical therapies to treat psoriasis is established, from topical therapies and systemic medications through to phototherapy or combinations of those. However, most of these therapies have a limited efficacy and may cause a number of side effects, including cutaneous atrophy, organ toxicity, carcinogenicity, and broadband immunosuppression, which are restricting their long-term use. Therefore, it would be desirable to use herbal products as an alternative treatment for psoriasis that causes fewer side effects. For this purpose, several electronic databases and literature references were used to summarize the current knowledge acquired on the basis of animal studies and clinical trials regarding herbal products used to treat psoriasis topically. This review discusses the mechanisms of herbal products activities through (1) inhibition of the keratinocyte hyperproliferation and inducing apoptosis, (2) inhibition of immune-inflammatory reaction, (3) suppression of phosphorylase kinase (PhK) activity, and (4) inhibition of the hedgehog (Hh) signaling pathway. Moreover, the penetration of herbal products through the psoriatic skin barrier, novel herbal drug delivery systems in psoriasis treatment, and possible adverse effects of herbal therapy are discussed.

Mechanism of action of herbs and their active constituents used in hair loss treatment.

This article discusses the mechanisms via topically applied products containing herbs and their active constituents affect the hair growth process. It was reported that the mechanisms involving (1) insulin-like growth factor-I (IGF-I), (2) vascular endothelial growth factor (VEGF), (3) epidermal growth factor (EGF), (4) fibroblast growth factor 2 (FGF-2), (5) endothelial nitric oxide synthase (eNOS), (6) Wnt/ß-catenin signalling pathway, (7) prostaglandin E (PGE), (8) prostaglandin F (PGF) stimulate hair growth, whereas the mechanisms engaging (1) 5α-reductase and dihydrotestosterone (DHT), (2) transforming growth factor beta (TGF-ß), (3) fibroblast growth factor 5 (FGF-5), (4) prostaglandin D2 (PGD2) inhibit hair growth. The knowledge summarized in the paper may be an inspiration to create new preparations for the treatment of hair loss.

Involvement of prolactin in the meloxicam-dependent inflammatory response of the gonadotropic axis to prolonged lipopolysaccharide treatment in anoestrous ewes.

An immune challenge can affect the reproductive process in females. Peripheral administration of bacterial endotoxin (lipopolysaccharide; LPS) decreases LH secretion and disrupts ovarian cyclicity. The aim of the present study was to determine the effects of a cyclo-oxygenase (COX)-2 inhibitor (meloxicam) on gonadotropin-releasing hormone (GnRH) and LH secretion in anoestrous ewes during systemic inflammation induced by LPS. LPS (400ngkg-1 per day) suppressed LH release. In three individuals, meloxicam (500µgkg-1, i.v.) abolished LPS-induced LH suppression. In another three ewes LH was ineffective. Similar changes were observed in hypothalamic GnRH expression. The effect of meloxicam depended on the circulating level of prolactin: meloxicam abolished inflammatory-dependent suppression of GnRH and LH secretion when plasma prolactin levels were similar to those in untreated animals, but was ineffective in those with elevated levels of prolactin. We conclude that COX-2 inhibitors minimise the negative effect of inflammation on the reproductive system but that this effect may be antagonised by prolactin.

Essential oils and their constituents as skin penetration enhancer for transdermal drug delivery: a review.

OBJECTIVES: In this paper, we focused on essential oils and their constituents as skin penetration enhancers for transdermal drug delivery, mechanism of their action as well as their possible toxicity. KEY FINDINGS: Essential oils and their volatile constituents can penetrate through the skin as well as enhance penetration of different drug from topical formulation into the lower skin layers using different mechanisms of action based on (1) disintegration of the highly ordered intercellular lipid structure between corneocytes in stratum corneum, (2) interaction with intercellular domain of protein, which induces their conformational modification, (3) increase the partitioning of a drug. After application to the skin, essential oils and their components are rapidly metabolized, not accumulated in the organism and fast excreted what strongly suggest that they can be successfully use as safe penetration enhancers. SUMMARY: Essential oils and their constituents may be preferred over the traditionally used synthetics materials as safe and suitable permeation enhancers to promote the percutaneous absorption of hydrophilic and lipophilic drugs from topical formulation into the lower skin layers.

Profile of toll-like receptor mRNA expression in the choroid plexus in adult ewes.

The blood-cerebrospinal fluid barrier (BCSFB) located in the epithelial cells of the choroid plexus (CP) forms the interface between the cerebrospinal fluid (CSF) and pathogen components circulating in the blood. The CP is also implicated in the passage of peripheral immune signals and circulation of immune cells into the central nervous system. Toll-like receptors (TLRs) are patternrecognition receptors that play a crucial role in the recognition of pathogens and triggering of the innate immune response. In sheep, ten members of the TLR family have been identified and cloned. We used real-time PCR analyses to examine the profiles of TLR mRNA expression in the CP of cerebral ventricles in healthy adult ewes. The transcripts for all ten TLRs except TLR8 were present; however, we observed a high variation in the degree of expression of the TLR5 and TLR1 genes (coefficient of variation: 61% and 46%, respectively) as well as a moderate variation in the expression of the TLR4 (34%), TLR2 (27%) and TLR6 (26%) genes. The TLR9, TLR7, TLR3 and TLR10 genes were the four receptors with relatively invariable expression levels (coefficient of variation: 7%, 8%, 16% and 17%, respectively) across the six adult ewes. The concentration of cortisol in blood collected prior to sacrificing the ewes ranged from 0.18 to 78.9 ng/ml. There was no correlation between cortisol concentration and mRNA expression of any of the examined TLRs. These data suggest that the CP has the potential to sense the presence of many bacterial and viral components and mediate responses for the elimination of invading microorganisms, thereby protecting the brain.