Peptides with antimicrobial and anti-inflammatory activities that have therapeutic potential for treatment of acne vulgaris

The pathogenesis of acne vulgaris is multifactorial involving infection of the pilosebaceous unit with Propionibacterium acnes and a cytokine-mediated inflammatory response. Five frog skin-derived antimicrobial peptides ([D4k]ascaphin-8, [G4K]XT-7, [T5k]temporin-DRa, brevinin-2GU, and B2RP-ERa), chosen for their low hemolytic activity against human erythrocytes, were assessed for their effects on the growth of clinical isolates of P. acnes and on the release of pro-inflammatory and anti-inflammatory cytokines from peripheral blood mononuclear (PBM) cells. All peptides inhibited the growth of P. acnes with the highest potency exhibited by [D4k]ascaphin-8 (minimum inhibitory concentration, MIC=3-12.5 μM). Release of TNF-α from concanavalin A (ConA)-stimulated PBM cells was significantly reduced by [D4k]ascaphin-8, [G4K]XT-7, brevinin-2GU, and B2RP-ERa (1 and 20 μg/ml) and by [T5k]temporin-DRa (20 μg/ml). Release of IFN-γ from unstimulated PBM cells was significantly reduced by [D4k]ascaphin-8 and brevinin-2GU (1 and 20 μg/ml). No peptide showed significant effects on Il-17 release. Release of the anti-inflammatory cytokines TGF-β, IL-4, and IL-10 from both unstimulated and ConA-treated PBM cells was significantly increased by [T5k]temporin-DRa and B2RP-ERa (1 and 20μg/ml). The potent activities of [D4k]ascaphin-8 and [T5k]temporin-DRa in inhibiting the growth of P. acnes and the release of pro-inflammatory cytokines, and in stimulating the release of anti-inflammatory cytokines suggest a possible therapeutic role in the treatment of acne vulgaris.     

CD209(+) macrophages mediate host defense against Propionibacterium acnes

Propionibacterium acnes is a major etiological factor of acne, triggering an inflammatory response in part through the activation of TLR2. In this study, we demonstrate that activation of peripheral blood monocytes with P. acnes in vitro induced their differentiation into two distinct innate immune cell subsets, CD209(+) macrophages and CD1b(+) dendritic cells. Furthermore, P. acnes induced expression of mRNA for the cytokines IL-15 and GM-CSF, which differentiate CD209(+) and CD1b(+) cells, respectively. The CD209(+) cells were more effective in uptake of P. acnes, compared with the CD1b(+) cells, and demonstrated a 2-fold greater antimicrobial activity against the phagocytosed bacteria. Although CD1b(+) cells secreted inflammatory cytokines in response to both P. acnes and a TLR2 ligand control, the CD209(+) cells responded only to P. acnes. The addition of all-trans retinoic acid, a commonly used agent for the treatment of acne, directly induced differentiation of monocytes into CD209(+) macrophages and enhanced the P. acnes-mediated differentiation of the CD209(+) subset. Therefore, the differentiation of monocytes into CD209(+) macrophages and CD1b(+) dendritic cells distinctly mediate the innate immune response to P. acnes.     

Antibody response to crude cell lysate of propionibacterium acnes and induction of pro-inflammatory cytokines in patients with acne and normal healthy subjects

Propionibacterium acnes (P. acnes) plays an important role in the disease pathogenesis of acne vulgaris, a disorder of pilosebaceous follicles, seen primarily in the adolescent age group. In the present study, the presence of antibodies against P. acnes (MTCC1951) were detected in acne patient (n=50) and disease free controls (n=25) using dot-ELISA and Western blot assay. The ability of P. acnes to induce pro-inflammatory cytokines by human peripheral blood mononuclear cells (PBMCs), obtained from acne patients and healthy subjects, were also analysed. The patients (n=26) who were culture positive for skin swab culture, were found to have a more advanced disease and higher antibody titres (1:4000 to > 1:16000) compared to the P. acnes negative patients (n=24) and normal controls (n=25). An analysis of patients' sera by western blot assay recognized a number of antigenic components of P. acnes, ranging from 29 to 205 kDa. The major reactive component was an approximately 96 kDa polypeptide, which was recognised in 92% (24 of 26) of the patients sera. Further, the P. acnes culture supernatant, crude cell lysate and heat killed P. acnes whole cells, obtained from 72-h incubation culture, were observed to be able to induce significant amounts of IL-8 and tumor necrosis factor alpha (TNF-alpha) by the PBMCs in both the healthy subjects and patients, as analysed by cytokine-ELISA. The levels of cytokines were significantly higher in the patients than the healthy subjects. A major 96 kDa polypeptide reactant was eluted from the gel and was found to cause dose dependent stimulation of the productions of IL-8 and TNF-alpha. Thus, the above results suggest that both humoral and pro-inflammatory responses play major roles in the pathogenesis of acne.     

Biological activities of Curcuma longa L

There are several data in the literature indicating a great variety of pharmacological activities of Curcuma longa L. (Zingiberaceae), which exhibit anti-inflammatory, anti-human immunodeficiency virus, anti-bacteria, antioxidant effects and nematocidal activities. Curcumin is a major component in Curcuma longa L., being responsible for its biological actions. Other extracts of this plant has been showing potency too. In vitro, curcumin exhibits anti-parasitic, antispasmodic, anti-inflammatory and gastrointestinal effects; and also inhibits carcinogenesis and cancer growth. In vivo, there are experiments showing the anti-parasitic, anti-inflammatory potency of curcumin and extracts of C. longa L. by parenteral and oral application in animal models. In this present work we make an overview of the pharmacological activities of C. longa L., showing its importance.     

Neutrophils as firemen, production of anti-inflammatory mediators by neutrophils in a mixed cell environment

Neutrophils represent critical components of the innate immune system that bear primary responsibility for phagocytosis and killing of invading pathogens. Following stimulation of human whole blood, robust production of multiple cytokines and cytokine inhibitors occurs. We attempted to define the cell population responsible for the synthesis of different mediators by first stimulating whole blood and then isolating pure populations of granulocytes and monocytes. Monocytes produced mRNA coding for the classic pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and IL-6, while mRNA for these cytokines was not detectable in the isolated neutrophils. In contrast, neutrophils produce significant quantities of cytokine inhibitors such as the type 2 TNF soluble receptor and the IL-1 receptor antagonist. Both neutrophils and monocytes produced mRNA coding for IL-8. These data indicate that following stimulation of a mixed cell population the monocytes primarily produce pro-inflammatory mediators while the neutrophils synthesize a significant portion of the anti-inflammatory mediators. The neutrophils may be compared to firemen who bring the resources necessary to put out the flame of acute inflammation.     

Anti-inflammatory activity of cationic peptides: application to the treatment of acne vulgaris

Cationic antimicrobial peptides exhibit potent antimicrobial activity against clinically relevant microorganisms including Propionibacterium acnes. Recent studies showed that, in addition to the antimicrobial activity, these peptides can exhibit an anti-inflammatory effect. These properties make cationic peptides attractive drug candidates for the treatment of acne vulgaris, a disease with both bacterial and inflammatory components. This review focuses on the anti-inflammatory activity of cationic antimicrobial peptides and its application for the treatment of acne vulgaris. The anti-inflammatory activity of cationic peptides in acne vulgaris can be explained by their ability to both bind proinflammatory bacterial factors (e.g. lipoteichoic acid), sequestering them from the site of inflammation, and to inhibit the secretion of proinflammatory cytokines (e.g. tumor necrosis factor-alpha, IL-1) by host cells. These anti-inflammatory effects combined with potent antimicrobial activity may translate into a novel therapeutic option for acne vulgaris.     

Anti-hypertensive effects of Rosuvastatin are associated with decreased inflammation and oxidative stress markers in hypertensive rats

Among their pleiotropic effects, statins exert antioxidant and anti-inflammatory properties. The aim of this study was to evaluate in normotensive (WKY) and in spontaneously hypertensive rats (SHR) the effect of rosuvastatin (ROSU) treatment on (1) plasma inflammation markers and endogenous NO synthase inhibitor (ADMA) levels, (2) reactive oxygen species (ROS) generated by circulating leukocytes and (3) vascular oxidative stress and tissue inflammation markers. Plasma cytokines were higher in SHR than in WKY, except for IL-4, which was lower in SHR than in WKY. SHR monocytes exhibited higher production of ROS than did WKY monocytes. In the experimental conditions, ROSU did not modify plasma cholesterol levels in SHR but attenuated the increase in systolic blood pressure. In SHR only, ROSU lessened pro-inflammatory cytokines and ADMA levels, increased IL-4 and reduced ROS production in circulating monocytes. These results demonstrate the beneficial effects of ROSU in SHR, independently of any lowering of cholesterol levels.     

Anti-hypertensive effects of Rosuvastatin are associated with decreased inflammation and oxidative stress markers in hypertensive rats

Among their pleiotropic effects, statins exert antioxidant and anti-inflammatory properties. The aim of this study was to evaluate in normotensive (WKY) and in spontaneously hypertensive rats (SHR) the effect of rosuvastatin (ROSU) treatment on (1) plasma inflammation markers and endogenous NO synthase inhibitor (ADMA) levels, (2) reactive oxygen species (ROS) generated by circulating leukocytes and (3) vascular oxidative stress and tissue inflammation markers. Plasma cytokines were higher in SHR than in WKY, except for IL-4, which was lower in SHR than in WKY. SHR monocytes exhibited higher production of ROS than did WKY monocytes. In the experimental conditions, ROSU did not modify plasma cholesterol levels in SHR but attenuated the increase in systolic blood pressure. In SHR only, ROSU lessened pro-inflammatory cytokines and ADMA levels, increased IL-4 and reduced ROS production in circulating monocytes. These results demonstrate the beneficial effects of ROSU in SHR, independently of any lowering of cholesterol levels.     

The inner gel component of Aloe vera suppresses bacterial-induced pro-inflammatory cytokines from human immune cells

The present study was carried out to examine the anti-inflammatory activity of the inner leaf gel component of Aloe barbadensis Miller. A simple in vitro assay was designed to determine the effect of the inner gel on bacterial-induced pro-inflammatory cytokine production, namely TNF-alpha and IL-1 beta, from peripheral blood leukocytes stimulated with Shigella flexneri or LPS. This report describes the suppression of both cytokines with a freeze-dried inner gel powder and a commercial health drink from the same source. Comparison was made with a human monocytic cell-line (THP-1 cells) and a similar trend in responses was demonstrated.     

Propionibacterium acnes and lipopolysaccharide induce the expression of antimicrobial peptides and proinflammatory cytokines/chemokines in human sebocytes

Acne is a common skin disorder of the pilosebaceous unit. In addition to genetic, hormonal and environmental factors, abnormal colonization by Propionibacterium acnes has been implicated in the occurrence of acne via the induction of inflammatory mediators. To gain more insight into the role that sebocytes play in the innate immune response of the skin, particularly in acne, we compared the antimicrobial peptide and proinflammatory cytokine/chemokine expression at mRNA and protein levels, as well as the viability and differentiation of SZ95 sebocytes in response to co-culture with representative isolates of P. acnes type IA and type IB as well as Escherichia coli-derived lipopolysaccharide (LPS). We found that, in vitro, P. acnes type IA and IB isolates and LPS induced human beta-defensin-2 and proinflammatory cytokine/chemokine expression, and influenced sebocyte viability and differentiation. Our results provide evidence that sebocytes are capable of producing proinflammatory cytokines/chemokines and antimicrobial peptides, which may have a role in acne pathogenesis. Furthermore, since P. acnes types IA and IB differentially affect both the differentiation and viability of sebocytes, our data demonstrate that different strains of P. acnes vary in their capacity to stimulate an inflammatory response within the pilosebaceous follicle.     

Anti-inflammatory mechanisms of suppressors of cytokine signaling target ROS via NRF-2/thioredoxin induction and inflammasome activation in macrophages

Suppressors of cytokine signaling (SOCS) exhibit diverse anti-inflammatory effects. Since ROS acts as a critical mediator of inflammation, we have investigated the anti-inflammatory mechanisms of SOCS via ROS regulation in monocytic/macrophagic cells. Using PMA-differentiated monocytic cell lines and primary BMDMs transduced with SOCS1 or shSOCS1, the LPS/TLR4-induced inflammatory signaling was investigated by analyzing the levels of intracellular ROS, antioxidant factors, inflammasome activation, and pro-inflammatory cytokines. The levels of LPS-induced ROS and the production of pro-inflammatory cytokines were notably down-regulated by SOCS1 and up-regulated by shSOCS1 in an NAC-sensitive manner. SOCS1 up-regulated an ROS-scavenging protein, thioredoxin, via enhanced expression and binding of NRF-2 to the thioredoxin promoter. SOCS3 exhibited similar effects on NRF-2/thioredoxin induction, and ROS downregulation, resulting in the suppression of inflammatory cytokines. Notably thioredoxin ablation promoted NLRP3 inflammasome activation and restored the SOCS1-mediated inhibition of ROS and cytokine synthesis induced by LPS. The results demonstrate that the anti-inflammatory mechanisms of SOCS1 and SOCS3 in macrophages are mediated via NRF-2-mediated thioredoxin upregulation resulting in the downregulation of ROS sig-nal. Thus, our study supports the anti-oxidant role of SOCS1 and SOCS3 in the exquisite regulation of macrophage activation under oxidative stress.     

Cutting edge: all-trans retinoic acid down-regulates TLR2 expression and function

A major consequence of microbial infection is the tissue injury that results from the host inflammatory response. In acne, inflammation is due in part to the ability of Propionibacterium acnes to activate TLR2. Because all-trans retinoic acid (ATRA) decreases inflammation in acne, we investigated whether it regulates TLR2 expression and function. Treatment of primary human monocytes with ATRA led to the down-regulation of TLR2 as well as its coreceptor CD14, but not TLR1 or TLR4. The ability of a TLR2/1 ligand to trigger monocyte cytokine release was inhibited by pre- and cotreatment with ATRA; however, TLR4 activation was affected by cotreatment only. ATRA also down-regulated monocyte cytokine induction by P. acnes. These data indicate that ATRA exerts an anti-inflammatory effect on monocytes via two pathways, one specifically affecting TLR2/1 and CD14 expression and one independent of TLR expression. Agents that target TLR expression and function represent a novel strategy to treat inflammation in humans.     

Effect of maternal fluoride exposure on developing CNS of rats: protective role of Aloe vera, Curcuma longa and Ocimum sanctum

Fluoride is toxic to neuronal development and its excessive intake during pregnancy cause adverse effects on neonatal development. The present study examined the presence of oxidative stress during maternal exposure of fluoride and the therapeutic strategy of Aloe vera, Curcuma longa and Ocimum sanctum extracts in functional prevention of fluoride led oxidative stress. The pregnant Wistar rats were exposed to 100 ppm fluoride in drinking water and pups born to them were supplemented with phytoextracts daily. On 21st postpartum day, the pups were sacrificed to analyse fluoride and oxidative stress markers. Fluoride exposure significantly increased its accumulation, lipid peroxidation and decreased the activities of catalase, superoxide dismutase, glutathione peroxidase, glutathione-S-transferase and glutathione levels in discrete regions of the central nervous system (CNS) of pups indicating oxidative stress and inhibited antioxidant defense. The results implied the vulnerability of developing CNS to fluoride toxicity. On phytoextract supplementation, the oxidant devastation was suppressed by regaining antioxidant homeostasis near normal level proving efficacy and therapeutic strategy. Among the phytoextracts supplemented the Ocimum sanctum is found to be more effective.     

Effects of moxifloxacin in zymogen A or S. aureus stimulated human THP-1 monocytes on the inflammatory process and the spread of infection

Antimicrobial agents have been reported to exhibit immunomodulatory and anti-inflammatory activities, both in vivo and in vitro (e.g., in human lymphocytes, macrophages and monocytes). The effects of moxifloxacin on cytokine immunomodulatory mediators, free radical generation and hydrolytic enzyme activities in zymogen A-stimulated human THP-1 monocytes were evaluated. An increase in c-AMP levels, protein kinase C activity, and the release of nitric oxide and hydrogen peroxide with a decrease in pH occurred within the first hour. Further, the effects of moxifloxacin were reduced by agents which blocked the oxygen burst, lysosome-phagosome fusion, and the energy generation within the cell. After 4 h, there was a decrease in NAG and cathepsin D activities, lipid peroxidation and the release of pro-inflammatory cytokines. These data indicate that moxifloxacin may modify the acute-phase inflammatory responses through inhibition of cytokine release in monocytes. Moxifloxacin inhibited the release of TNFalpha, IL-1, IL-6, and IL-8 in a concentration-dependent manner across a range of 0.004 to 4 microg/mL. After 4 h, there was a decrease in the release of these cytokines, thus interfering with the inflammation process to reduce infection and its spread. The effects of moxifloxacin appear initially to activate monocytes to kill bacteria through the innate immune process by releasing ROS and lysosomal hydrolytic enzymes as well as phagocytosis of the organism. At a later time the bacteria are killed through a Bacterialstatic mechanism of protein synthesis inhibition and there is a reversal of the effects of moxifloxacin on cytokine release, free radical generation and hydrolytic enzymes so that lipid peroxidation and tissue destruction by the infection process is suppressed.     

姜黄素与消化系统肿瘤的研究进展

姜黄素是一种疏水多酚,从姜黄中提取的姜黄磺胺类草药。半个世纪以来大量的研究表明姜黄素在体外及体内显示了各种诸如抗炎、细胞活素的释放、抗氧化、免疫调节、促进凋亡以及抗血管生成的特性。姜黄素同样也被证明是耐药性和放疗不敏感性的调解者。同样,在各种临床试验研究中证明了姜黄素抗肿瘤的作用,本文就姜黄素在消化系统肿瘤中的抗肿瘤机制做一综述。     

Isolation and characterization of novel protein with anti-fungal and anti-inflammatory properties from Aloe vera leaf gel

The Aloe protein of 14 kDa from the Aloe vera leaf gel was isolated by an ion exchange chromatography using DEAE-cellulose and CM-cellulose column. The purified Aloe protein exhibited a potent anti-fungal activity against Candida paraprilosis, Candida krusei and Candida albicans. In addition, the purified Aloe protein also showed an anti-inflammatory property against pure lipoxygenase and cyclooxygenase-2 with 84% and 73% inhibition, respectively, and was verified by binding with these proteins by real time method by the phenomenon of surface plasmon resonance. This Aloe protein is a novel protein possessing antifungal and anti-inflammatory properties and thus sets a platform to be used as a medicinal plant product.     

Cathelicidin-BF, a snake cathelicidin-derived antimicrobial peptide, could be an excellent therapeutic agent for acne vulgaris

Cathelicidins are a family of antimicrobial peptides acting as multifunctional effector molecules in innate immunity. Cathelicidin-BF has been purified from the snake venoms of Bungarus fasciatus and it is the first identified cathelicidin antimicrobial peptide in reptiles. In this study, cathelicidin-BF was found exerting strong antibacterial activities against Propionibacterium acnes. Its minimal inhibitory concentration against two strains of P. acnes was 4.7 μg/ml. Cathelicidin-BF also effectively killed other microorganisms including Staphylococcus epidermidis, which was possible pathogen for acne vulgaris. Cathelicidin-BF significantly inhibited pro-inflammatory factors secretion in human monocytic cells and P. acnes-induced O2.- production of human HaCaT keratinocyte cells. Observed by scanning electron microscopy, the surfaces of the treated pathogens underwent obvious morphological changes compared with the untreated controls, suggesting that this antimicrobial peptide exerts its action by disrupting membranes of microorganisms. The efficacy of cathelicidin-BF gel topical administering was evaluated in experimental mice skin colonization model. In vivo anti-inflammatory effects of cathelicidin-BF were confirmed by relieving P. acnes-induced mice ear swelling and granulomatous inflammation. The anti-inflammatory effects combined with potent antimicrobial activities and O2.- production inhibition activities of cathelicidin-BF indicate its potential as a novel therapeutic option for acne vulgaris.     

Activation of toll-like receptor 2 in acne triggers inflammatory cytokine responses

One of the factors that contributes to the pathogenesis of acne is Propionibacterium acnes; yet, the molecular mechanism by which P. acnes induces inflammation is not known. Recent studies have demonstrated that microbial agents trigger cytokine responses via Toll-like receptors (TLRs). We investigated whether TLR2 mediates P. acnes-induced cytokine production in acne. Transfection of TLR2 into a nonresponsive cell line was sufficient for NF-kappa B activation in response to P. acnes. In addition, peritoneal macrophages from wild-type, TLR6 knockout, and TLR1 knockout mice, but not TLR2 knockout mice, produced IL-6 in response to P. acnes. P. acnes also induced activation of IL-12 p40 promoter activity via TLR2. Furthermore, P. acnes induced IL-12 and IL-8 protein production by primary human monocytes and this cytokine production was inhibited by anti-TLR2 blocking Ab. Finally, in acne lesions, TLR2 was expressed on the cell surface of macrophages surrounding pilosebaceous follicles. These data suggest that P. acnes triggers inflammatory cytokine responses in acne by activation of TLR2. As such, TLR2 may provide a novel target for treatment of this common skin disease.     

茜草叶绿体全基因组序列及其系统发育分析

以茜草科(Rubiaceae)植物茜草(Rubia cordifolia L.)为研究对象,采用Illumination高通量测序技术对其叶绿体全基因组进行测序,并运用MAGA11等生信学工具进行全基因组解析及系统发育分析。结果表明,(1)茜草叶绿体基因组呈典型的四分环状结构,总GC含量37.2%,长153 959 bp,其中包含大单拷贝(LSC)区83 844 bp、小单拷贝(SSC)区17 083 bp和2个反向重复(IR)区26 516 bp;共注释得到124个基因,包括79个蛋白质编码基因、37个tRNA和8个rRNA。(2)序列共鉴定到169个SSR位点,以A、T组成为主,包括129个单核苷酸、18个双核苷酸、11个三核苷酸、9个四核苷酸和2个五核苷酸,六核苷酸SSR未检测到;边界分析显示,茜草叶绿体基因组LSC区差异性最大,变异程度最高,而IRa区则差异性最小,最为保守。(3)最大似然法(ML)构建系统发育树显示,样品茜草与同属植物Rubia horrida以100%支持率聚为一类,茜草亚科、仙丹花亚科与金鸡纳亚科聚为姐妹类群,证明茜草科植物在进化过程中保守发育。     

Intratumoral injection of Propionibacterium acnes suppresses malignant melanoma by enhancing Th1 immune responses

Malignant melanoma (MM) is an aggressive cutaneous malignancy associated with poor prognosis; many putatively therapeutic agents have been administered, but with mostly unsuccessful results. Propionibacterium acnes (P. acnes) is an aerotolerant anaerobic gram-positive bacteria that causes acne and inflammation. After being engulfed and processed by phagocytes, P. acnes induces a strong Th1-type cytokine immune response by producing cytokines such as IL-12, IFN-γ and TNF-α. The characteristic Th2-mediated allergic response can be counteracted by Th1 cytokines induced by P. acnes injection. This inflammatory response induced by P. acnes has been suggested to have antitumor activity, but its effect on MM has not been fully evaluated.We analyzed the anti-tumor activity of P. acnes vaccination in a mouse model of MM. Intratumoral administration of P. acnes successfully protected the host against melanoma progression in vivo by inducing both cutaneous and systemic Th1 type cytokine expression, including TNF-α and IFN-γ, which are associated with subcutaneous granuloma formation. P. acnes-treated tumor lesions were infiltrated with TNF-α and IFN-γ positive T cells. In the spleen, TNF-α as well as IFN-γ producing CD8(+)T cells were increased, and interestingly, the number of monocytes was also increased following P. acnes administration. These observations suggest that P. acnes vaccination induces both systemic and local antitumor responses. In conclusion, this study shows that P. acnes vaccination may be a potent therapeutic alternative in MM.