Anti-inflammatory effects of antimicrobial agents: an in vivo study

Immunologic effect and clinical impact of erythromycin in septic patients: A randomized clinical trial

To investigate the potential regulatory effect of erythromycin added to standard care in septic patients on sepsis biomarkers and clinical outcome. It was a single-blind randomized trial including critical septic patients. The primary endpoint was the change in the TNF/IL-10 ratio between days 0 and 6. Changes in other biomarkers, vasopressor use, and 28-day mortality were secondary endpoints. One hundred and ten patients were examined (erythromycin group, n = 55 versus placebo group, n = 55). Clinical features of the groups were well matched. Erythromycin addition had no beneficial effects on the TNF/IL-10 ratio or mortality (51% vs. 47%, p = 0.62). Both groups' serum TNF/IL-10 ratios did not significantly rise (from 0.48 [0.34-1.18] to 0.59 [0.21-1.10] vs. 0.65 [0.25-1.14] to 0.93 [0.24-1.88] in the erythromycin and placebo groups, respectively; p values = 0.86 and 0.12). Serum Procalcitonin (PCT) and CRP dropped considerably in the Erythromycin group, whereas only PCT showed a drop in the placebo group. On day 6, the non-survivors' serum TNF/IL-10 ratio was lower than that of the survivors (0.55 [0.17-1.04] vs 1.08 [0.4-2.28], p = 0.029). Neither the pro/anti-inflammatory imbalance nor the mortality were impacted by the addition of erythromycin to standard care in septic patients (ClinicalTrials.gov ID: NCT04665089 (11/12/2020)).

Saponins of Paris polyphylla for the Improvement of Acne: Anti-Inflammatory, Antibacterial, Antioxidant and Immunomodulatory Effects

Acne is a chronic inflammatory skin disease with a recurring nature that seriously impacts patients' quality of life. Currently, antibiotic resistance has made it less effective in treating acne. However, Paris polyphylla (P. polyphylla) is a valuable medicinal plant with a wide range of chemical components. Of these, P. polyphylla saponins modulate the effects in vivo and in vitro through antibacterial, anti-inflammatory, immunomodulatory, and antioxidant effects. Acne is primarily associated with inflammatory reactions, abnormal sebum function, micro-ecological disorders, hair follicle hyperkeratosis, and, in some patients, immune function. Therefore, the role of P. polyphylla saponins and their values in treating acne is worthy of investigation. Overall, this review first describes the distribution and characteristics of P. polyphylla and the pathogenesis of acne. Then, the potential mechanisms of P. polyphylla saponins in treating acne are listed in detail (reduction in the inflammatory response, antibacterial action, modulation of immune response and antioxidant effects, etc.). In addition, a brief description of the chemical composition of P. polyphylla saponins and its available extraction methods are described. We hope this review can serve as a quick and detailed reference for future studies on their potential acne treatment.

Immunomodulatory Effects of Macrolides Considering Evidence from Human and Veterinary Medicine

Macrolide antimicrobial agents have been in clinical use for more than 60 years in both human and veterinary medicine. The discovery of the non-antimicrobial properties of macrolides and the effect of immunomodulation of the inflammatory response has benefited patients with chronic airway diseases and impacted morbidity and mortality. This review examines the evidence of antimicrobial and non-antimicrobial properties of macrolides in human and veterinary medicine with a focus toward veterinary macrolides but including important and relevant evidence from the human literature. The complete story for these complex and important molecules is continuing to be written.

Pleiotropic effects of antibiotics on T cell metabolism and T cell-mediated immunity

T cells orchestrate adaptive and innate immune responses against pathogens and transformed cells. However, T cells are also the main adaptive effector cells that mediate allergic and autoimmune reactions. Within the last few years, it has become abundantly clear that activation, differentiation, effector function, and environmental adaptation of T cells is closely linked to their energy metabolism. Beyond the provision of energy equivalents, metabolic pathways in T cells generate building blocks required for clonal expansion. Furthermore, metabolic intermediates directly serve as a source for epigenetic gene regulation by histone and DNA modification mechanisms. To date, several antibiotics were demonstrated to modulate the metabolism of T cells especially by altering mitochondrial function. Here, we set out to systematically review current evidence about how beta-lactam antibiotics, macrolides, fluoroquinolones, tetracyclines, oxazolidinones, nitroimidazoles, and amphenicols alter the metabolism and effector functions of CD4+ T helper cell populations and CD8+ T cells in vitro and in vivo. Based on this evidence, we have developed an overview on how the use of these antibiotics may be beneficial or detrimental in T cell-mediated physiological and pathogenic immune responses, such as allergic and autoimmune diseases, by altering the metabolism of different T cell populations.

Could Azithromycin Be Part of Pseudomonas aeruginosa Acute Pneumonia Treatment?

Azithromycin (AZM) is a 15-membered-ring macrolide that presents a broad-spectrum antimicrobial activity against Gram-positive bacteria and atypical microorganisms but suffers from a poor diffusion across the outer-membrane of Gram-negative bacilli, including Pseudomonas aeruginosa (PA). However, AZM has demonstrated clinical benefits in patients suffering from chronic PA respiratory infections, especially cystic fibrosis patients. Since the rise of multidrug-resistant PA has led to a growing need for new therapeutic options, this macrolide has been proposed as an adjunctive therapy. Clinical trials assessing AZM in PA acute pneumonia are scarce. However, a careful examination of the available literature provides good rationales for its use in that context. In fact, 14- and 15-membered-ring macrolides have demonstrated immunomodulatory and immunosuppressive effects that could be of major interest in the management of acute illness. Furthermore, growing evidence supports a downregulation of PA virulence dependent on direct interaction with the ribosomes, and based on the modulation of several key regulators from the Quorum Sensing network. First highlighted in vitro, these interesting properties of AZM have subsequently been confirmed in the animal models. In this review, we systematically analyzed the literature regarding AZM immunomodulatory and anti-PA effects. In vitro and in vivo studies, as well as clinical trials were reviewed, looking for rationales for AZM use in PA acute pneumonia.

High-Throughput Identification of Antibacterials Against Pseudomonas aeruginosa

Antibiotic resistance is a growing public health concern, though the constant development of new antibiotics. The combination of high-throughput screening and drug repurposing is an effective way to develop new therapeutic uses of drugs. In this study, we screened a drug library consisting of 1,573 drugs already approved by the Food and Drug Administration and 903 drugs from the natural product library, to identify antimicrobials against Pseudomonas aeruginosa. A high-throughput screening assay based on microtiter plate was used to screen 39 drugs that inhibit the planktonic or biofilm formation of P. aeruginosa while most of them are antibiotics. The antimicrobial activities of these drugs were evaluated by phenotypic analysis. Further studies showed the combined therapy of tetracycline antibiotics demeclocycline hydrochloride (DMCT) and the novel antimicrobial peptide SAAP-148 has an effective synergistic antibacterial effect on P. aeruginosa PAO1 and P. aeruginosa ATCC27853. Moreover, the time-kill curve assay and murine model of cutaneous abscesses further confirmed the synergistic effect. In addition, the combination of DMCT and SAAP-148 has the potential to combat clinically isolated multidrug-resistant (MDR) P. aeruginosa strains. Our results clearly indicate that DMCT and SAAP-148 combined therapy could be an effective method to combat MDR P. aeruginosa-related infections.

Azithromycin: The First Broad-spectrum Therapeutic

The Strategic Plan for Biodefense Research by the U.S. Department of Health and Human Services demarcates the need for drugs which target multiple types of pathogens to prepare for infectious threats. Azithromycin is one such broad-spectrum therapeutic that is both included in the University of Oxford's RECOVERY and excluded from the World Health Organization's SOLIDARITY trials. Here we review azithromycin's broad antibiotic, antimalarial, antiviral pharmacology and contextualise it against a broader history as the most repositioned therapeutic of the macrolide class; we further evaluate azithromycin's clinical and socio-economic propriety for respiratory pandemics and delineate a model for its combinatorial mechanism of action against COVID-19 pneumonia.

Azithromycin: The First Broad-spectrum Therapeutic

The Strategic Plan for Biodefense Research by the U.S. Department of Health and Human Services demarcates the need for drugs which target multiple types of pathogens to prepare for infectious threats. Azithromycin is one such broad-spectrum therapeutic that is both included in the University of Oxford's RECOVERY and excluded from the World Health Organization's SOLIDARITY trials. Here we review azithromycin's broad antibiotic, antimalarial, antiviral pharmacology and contextualise it against a broader history as the most disease-repositioned therapeutic of the macrolide class; we further evaluate azithromycin's clinical and socio-economic propriety for respiratory pandemics and delineate a model for its combinatorial mechanism of action against COVID-19 pneumonia.

Erythromycin inhibits neutrophilic inflammation and mucosal disease by upregulating DEL-1

Macrolide antibiotics exert antiinflammatory effects; however, little is known regarding their immunomodulatory mechanisms. In this study, using 2 distinct mouse models of mucosal inflammatory disease (LPS-induced acute lung injury and ligature-induced periodontitis), we demonstrated that the antiinflammatory action of erythromycin (ERM) is mediated through upregulation of the secreted homeostatic protein developmental endothelial locus-1 (DEL-1). Consistent with the anti-neutrophil recruitment action of endothelial cell-derived DEL-1, ERM inhibited neutrophil infiltration in the lungs and the periodontium in a DEL-1-dependent manner. Whereas ERM (but not other antibiotics, such as josamycin and penicillin) protected against lethal pulmonary inflammation and inflammatory periodontal bone loss, these protective effects of ERM were abolished in Del1-deficient mice. By interacting with the growth hormone secretagogue receptor and activating JAK2 in human lung microvascular endothelial cells, ERM induced DEL-1 transcription that was mediated by MAPK p38 and was CCAAT/enhancer binding protein-β dependent. Moreover, ERM reversed IL-17-induced inhibition of DEL-1 transcription, in a manner that was dependent not only on JAK2 but also on PI3K/AKT signaling. Because DEL-1 levels are severely reduced in inflammatory conditions and with aging, the ability of ERM to upregulate DEL-1 may lead to a novel approach for the treatment of inflammatory and aging-related diseases.

Antibiotic resistance in acne: changes, consequences and concerns

Antibiotic resistance in acne was first observed in the 1970s and has been a major concern in dermatology since the 1980s. The resistance rates and types of antimicrobials have subsequently shown great variations in regions and countries. Illustrative of this is the resistance to topical erythromycin and clindamycin which continues to be a problem worldwide, while resistance to systemic treatment with tetracyclines has remained low during the past decade. The resistance for the newer macrolides like azithromycin and clarithromycin has been increasing. The results of antibiotic resistance may include treatment failure of acne, disturbance of skin microbiota, induction of opportunistic pathogens locally and systemically, and dissemination of resistant strains to both healthcare personnel and the general population. The ensuing complications, such as aggravated opportunistic infections caused by Propionibacterium acnes and the emergence of multiresistant superbugs, have not yet been confirmed.

The Immunomodulatory Effects of Macrolides-A Systematic Review of the Underlying Mechanisms

Background

The mechanisms underlying the non-antimicrobial immunomodulatory properties of macrolides are not well understood.

Objectives

To systematically review the evidence for the immunomodulatory properties of macrolides in humans and to describe the underlying mechanism and extent of their influence on the innate and adaptive immune system.

Methods

A systematic literature search was done in MEDLINE using the OVID interface from 1946 to December 2016 according to the preferred reporting items for systematic reviews and meta-analysis (PRISMA). Original articles investigating the influence of four macrolides (azithromycin, clarithromycin, erythromycin, and roxithromycin) on immunological markers in humans were included.

Results

We identified 22 randomized, controlled trials, 16 prospective cohort studies, and 8 case–control studies investigating 47 different immunological markers (186 measurements) in 1,834 participants. The most frequently reported outcomes were a decrease in the number of neutrophils, and the concentrations of neutrophil elastase, interleukin (IL)-8, IL-6, IL-1beta, tumor necrosis factor (TNF)-alpha, eosinophilic cationic protein, and matrix metalloproteinase 9. Inhibition of neutrophil function was reported more frequently than eosinophil function. A decrease in T helper (Th) 2 cells cytokines (IL-4, IL-5, IL-6) was reported more frequently than a decrease in Th1 cytokines (IL-2, INF-gamma).

Conclusion

Macrolides influence a broad range of immunological mechanisms resulting in immunomodulatory effects. To optimize the treatment of chronic inflammatory diseases by macrolides, further studies are necessary, particularly comparing different macrolides and dose effect relationships.

Clinical impact of minocycline on afatinib-related rash in patients with non-small cell lung cancer harboring epidermal growth factor receptor mutations

BACKGROUND

The management of skin toxicity is crucial for efficient afatinib treatment, but the role of tetracycline class antibiotics (TCs) in managing these rashes is relatively unknown.

METHODS

We reviewed the clinical records of patients who were administered afatinib for the treatment of non-small cell lung cancer harboring epidermal growth factor receptor mutations between October 2014 and November 2016. Twenty-five patients, who received TCs for the management of afatinib-related skin disorders, were enrolled.

RESULTS

Minocycline was administered orally to participants. Afatinib-related toxic effects, such as rash, diarrhea, and paronychia, were observed in 92%, 92%, and 40% of cases, respectively. Although 24% of diarrhea and 4% of paronychia cases were rated grade 3 or higher, no severe cases of rash were observed during afatinib treatment. Of the 18 afatinib dose reductions, 14 (78%), three (17%), and one (6%) resulted from diarrhea, paronychia, and stomatitis, respectively; no patients required a dose reduction because of rash. When minocycline treatment started, 21 patients (84%) had a rash of grade 1 or less, and three patients had a grade 2 rash. A response to afatinib was observed in 18 patients (72%) and the median duration of afatinib administration was 501 days. An adverse event related to minocycline (grade 1 nausea) was observed in one patient.

CONCLUSIONS

A large proportion of the study patients started minocycline before grade 2 rash development and the severity of afatinib-related rash was lower than that previously reported. Oral TCs may be beneficial, especially if started early.

Study of pharmacokinetic interaction of paroxetine and roxithromycin on bencycloquidium bromide in healthy subjects

PURPOSE

The aim of this study was to investigate the potential drug-drug interaction between Bencycloquidium bromide (BCQB) and paroxetine, and between BCQB and roxithromycin.

METHODS

Two studies were conducted on healthy male Chinese volunteers. Study A was an open-label, two-period, one-sequence crossover study (n=21). Each participant received a single nasal spray dose of BCQB 180μg on day 1. After a 7-day wash-out period, subjects received 20mg of paroxetine from day 8 to 17, and were co-administered 20mg of paroxetine and BCQB 180μg on day 18. In study B, participants (n=12) were randomly assigned to two groups. In period I, group A received BCQB 180μg on day 1, followed by the same dose four times daily from day 4 to 10, then, on day 11 a single dose of 150mg roxithromycin with BCQB 180μg were co-administered. In parallel, group B received a single dose of roxithromycin 150mg on day 1, followed by 300mg of roxithromycin from day 4 to 10, then, on day 11 a single dose of BCQB 180μg with roxithromycin 300mg were co-administered. After a wash-out time of 7days the respective treatments of each group (A and B) were swapped in period II. Blood samples were collected for pharmacokinetic analysis. Statistical comparison of pharmacokinetic parameters was performed to identify a possible drug interaction between treatments. Tolerability was evaluated by recording adverse events.

RESULTS

Study A: Geometric mean AUC0-36 for BCQB alone and co-administered with paroxetine were 474.3 and 631.3pgh/ml, respectively. The geometric mean ratio (GMR) of AUC0-36 was 1.33 (1.13-1.46), 90% C.Is, and was out the predefined bioequivalence interval (90% C.Is, 0.80-1.25). Geometric mean Cmax were 187.0 and 181.2pg/ml. Study B: The GMR of AUC0-36 was 0.98 (0.90-1.07), 90% C.Is for BCQB, and the GMR of AUC0-72 was 0.98 (0.87-1.11), 90% C.Is for roxithromycin. Both GMRs were within the predefined bioequivalence interval (90% C.Is, 0.80-1.25). Other pharmacokinetic parameters were within the predefined interval. No serious adverse events were reported and no significant clinical changes were observed in laboratory test results, vital signs and ECGs in any of the studies. All treatments were well tolerated.

CONCLUSION

The co-administration of BCQB with paroxetine showed a moderate increase in BCQB exposure, but was not clinically relevant. Also, no drug interaction was found between BCQB and roxithromycin.

Febrile ulceronecrotic mucha habermann disease: case report of a dark-skinned patient

A male dark-skinned patient, 33 years old, complaining of a 1-month history of skin lesions in the abdominal region and high fever was admitted to the clinical ward. There were ulcerated and coalescent skin lesions all over the body but sparing the palmar region. The culture of material obtained from the penile lesions was positive for Staphylococcus aureus. He was treated with oxacillin and prednisone. The patient persisted with high fever and skin lesions. After histopathological diagnosis of Mucha Habermann's disease, treatment was started with tetracycline with rapid improvement of the lesions. He was reexamined by the dermatologic service with no recurrences during the 12 months of follow-up. At this time, there was a great number of keloid scars from the skin lesions.

[How acne vulgaris develops]

For the initiation of acne multiple factors are required from endogenous to exogenous sources. The morphogenesis of acne is well studied, and the principle steps are discussed in the paper. Acne is a disease of humans, developing in sebaceous follicles. The first step is a proliferation-retention hyperkeratosis in the infundibulum, thus forming a follicular filament, from which a microcomedo arises. Finally open and closed comedones appear. This sequence is not strictly followed, but quite typical. Androgen stimulation activates sebaceous lipogenesis. At this point propionibacteria colonize the follicle and comedones. At earlier or later stages of the comedo development inflammatory phenomena appear, ranging from subtle to severe. Depending on the amount of inflammation, scars may develop. There is an undisputable genetic component for the initiation of acne, as twin studies have shown. The or these genetic factors have not been determined yet. The inflammatory cascade is up-regulated by immunological factors. Exogenous factors, underestimated in the past, seem to play an important role as well, as epidemiological studies and recent publications from different investigators have shown. Nutrition, particularly hyperglycemic food and milk products, are directly involved in the pathogenesis of acne.

Rokitamycin induces a mitochondrial defect and caspase-dependent apoptosis in human T-cell leukemia Jurkat cells

Macrolides are a well-known family of oral antibiotics whose antibacterial spectrum of activity covers most relevant bacterial species responsible for respiratory infectious disease. In recent years, it has been reported that macrolides have not only bactericidal activity but also direct immunomodulating activity in mammals. In this study, we observed new physiological activity of macrolides and examined whether various macrolides induce apoptosis in human leukemia cell lines. We investigated the effects of 13 different macrolides on the viability of Jurkat and HL-60 cells. Among all the macrolides used in this study, rokitamycin, a semisynthetic macrolide with a 16-member ring, effectively induced cell death. Rokitamycin induced DNA fragmentation and caspase activation, resembling the progression of apoptosis. Moreover, rokitamycin reduced the mitochondrial transmembrane potential and released cytochrome c from mitochondria to the cytosol, suggesting that mitochondrial perturbation is involved in rokitamycin-induced apoptosis. These results suggest that rokitamycin possesses not only bactericidal activity but also pro-apoptotic activity in human leukemia cells.

Survey of antibiotic prescription use for inflamed epidermal inclusion cysts

BACKGROUND

Symptomatic epidermal inclusion cysts (EICs) are variously called "inflamed" or "infected," and the mechanism of inflammation or suppuration is controversial. Whether physicians routinely prescribe antibiotics for inflamed EICs is of concern owing to cost and bacterial resistance.

OBJECTIVES

To determine whether there is any difference in the diagnosis and treatment of EICs between primary care physicians and dermatologists and to estimate the rate and cost of antibiotic prescriptions for EICs.

METHODS

One hundred twenty-five primary care physicians and 52 dermatologists were surveyed using a standard case study and a photograph.

RESULTS

Sixty-seven percent of the primary care physicians used the term "infected," whereas 69% of the dermatologists used the term "inflamed" or "ruptured." Eighty-four percent of the general practitioners and 94% of the dermatologists chose antibiotics for treatment.

CONCLUSION

This study shows that despite the differences between general practitioners and dermatologists in diagnosis, the majority of physicians use antibiotics for the treatment of inflamed EICs.

Synthesis of ring-contracted erythromycin A derivatives via microwave-assisted intramolecular transesterification

The synthesis of ring-contracted derivatives of erythromycin A via intramolecular transesterification under microwave irradiation of 8,9-anhydroerythromycin A 6,9-hemiketal and its derivatives is described. It was found that microwave irradiation could significantly improve the yields and shorten the reaction times under either solvent-containing (method A) or solvent-free (method B) conditions.

Proportion of antibiotic resistance in subgingival plaque samples from Mexican subjects

AIM

To determine the proportion of bacteria resistant to amoxicillin and doxycycline in subgingival plaque samples from Mexican subjects.

MATERIALS AND METHODS

Two subgingival plaque samples were taken from 20 Mexican subjects. Samples were dispersed, diluted and plated on non-antibiotic agar plates and on plates containing 0.5, 1, 2, 4, 8 and 16 microg/ml of either amoxicillin or doxycycline. The proportion of resistant bacteria was calculated based on the total number of colony-forming units present in the non-antibiotic containing plates.

RESULTS

On average, 0.4-13.4% and 0.9-20.4% of the total cultivable subgingival microbiota was resistant to the concentrations tested of amoxicillin and doxycycline, respectively. The differences between antibiotics were statistically significant for the 0.5, 2 and 4 mug/ml concentrations (p < 0.05, Wilcoxon's test).

CONCLUSIONS

Our findings revealed that a relatively small proportion of the total cultivable subgingival microbiota from Mexican subjects was resistant to amoxicillin and doxycycline.

Tetracyclines: nonantibiotic properties and their clinical implications

Tetracyclines are broad-spectrum antibiotics that act as such at the ribosomal level where they interfere with protein synthesis. They were first widely prescribed by dermatologists in the early 1950s when it was discovered that they were effective as a treatment for acne. More recently, biologic actions affecting inflammation, proteolysis, angiogenesis, apoptosis, metal chelation, ionophoresis, and bone metabolism have been researched. The therapeutic effects of tetracycline and its analogues in various diseases have also been investigated. These include rosacea, bullous dermatoses, neutrophilic diseases, pyoderma gangrenosum, sarcoidosis, aortic aneurysms, cancer metastasis, periodontitis, and autoimmune disorders such as rheumatoid arthritis and scleroderma. We review the nonantibiotic properties of tetracycline and its analogues and their potential for clinical application.

Comparison of five antimicrobial regimens for treatment of mild to moderate inflammatory facial acne vulgaris in the community: randomised controlled trial

BACKGROUND

We investigated the efficacy and cost-effectiveness of five antimicrobial regimens for mild to moderate facial acne and whether propionibacterial antibiotic resistance affects treatment response.

METHODS

In this randomised, observer-masked trial, 649 community participants were allocated one of five antibacterial regimens. Primary outcomes were patients' self-assessed improvement and reduction in inflamed lesions at 18 weeks. Analyses were by intention to treat.

FINDINGS

Moderate or greater improvement at 18 weeks was reported in 72 (55%) of 131 participants assigned oral oxytetracycline plus topical placebo, 70 (54%) of 130 assigned oral minocycline plus topical placebo, 78 (60%) of 130 assigned topical benzoyl peroxide plus oral placebo, 84 (66%) of 127 assigned topical erythromycin and benzoyl peroxide in a combined formulation plus oral placebo, and 82 (63%) of 131 assigned topical erythromycin and benzoyl peroxide separately plus oral placebo. Most improvement occurred in the first 6 weeks. Treatment differences for the proportion of people with at least moderate improvement were: minocycline versus oxytetracycline -1.2% (unadjusted 95% CI -13.3 to 10.9); combined erythromycin and benzoyl peroxide versus oxytetracycline 11.1% (-0.7 to 22.9) and versus minocycline 12.3% (0.4 to 24.2); erythromycin and benzoyl peroxide separately versus combined formulation -3.5% (-15.2 to 8.2); benzoyl peroxide versus oxytetracycline 5.0% (-7.0 to 17.0), versus minocycline 6.2% (-5.8 to 18.2), and versus combined formulation -6.1% (-17.9 to 5.7). Benzoyl peroxide was the most cost-effective treatment. Efficacy of both tetracyclines was reduced by pre-existing tetracycline resistance.

INTERPRETATION

Topical benzoyl peroxide and benzoyl peroxide/erythromycin combinations are similar in efficacy to oral oxytetracycline and minocycline and are not affected by propionibacterial antibiotic resistance.

Antibiotics in cutaneous medicine: an update

Antibiotics play a vital role in contemporary cutaneous medicine and surgery. They are prescribed more commonly than perhaps any other group of medications with the exception of the corticosteroids. This review discusses the major oral antibacterial agents used in dermatology today, including the beta-lactams, macrolides, tetracyclines, quinolones, sulfonamides, clindamycin, and rifampin.

Inhibitory action of a macrolide antibiotic, roxithromycin, on co-stimulatory molecule expressions in vitro and in vivo

OBJECTIVE

The influence of a macrolide antibiotic, roxithromycin (RXM), on co-stimulatory molecule expression was examined in vitro and in vivo.

MATERIALS AND METHODS

Spleen cells obtained from BALB/c mice 10 days after immunization with 8.0 microg of hemocyanin absorbed to 4.0 mg of aluminum hydroxide were cultured in the presence of 100.0 microg/ml of hemocyanin and various concentrations of RXM. We first examined the influence of RXM on cell activation by examining the proliferative response of cells and cytokine production. We also examined the influence of RXM on co-stimulatory molecule (CD40, CD80 and CD86) expressions on cultured splenic B-lymphocytes induced by in vitro antigenic stimulation using flow cytometry. In the second part of experiments, non-immunized and immunized mice were treated orally with 2.5 mg/kg of RXM once a day for 4 or 8 weeks. Splenic B lymphocytes were obtained from these mice 24 h after antigenic challenge, and co-stimulatory molecule expressions were examined by flow cytometer.

RESULTS

Cell activation induced by in vitro antigenic stimulation was suppressed by RXM when cells were cultured in the presence of more than 5.0 microg/ml of the agent. Addition of RXM at a concentration of 5.0 microg/ml into cell cultures also suppressed co-stimulatory molecule (CD40, CD80 and CD86) expressions on splenic B lymphocytes, which was enhanced by antigenic stimulation in vitro. Oral RXM administration for 4 weeks clearly suppressed the enhancement of CD40 and CD86 (but not CD80) expressions on splenic B lymphocytes induced by antigenic stimulation in vivo. This suppressive activity of RXM on co-stimulatory molecule (CD40 and CD86) expressions was further strengthened by the treatment of mice for 8 weeks. Long-term treatment with oral RXM also suppressed CD80 expressions, which was not suppressed by 4-week treatment.

CONCLUSION

The present results suggest that RXM exerts its immunomodulating effects through suppression of both cell activation and co-stimulatory molecule expressions induced by antigenic stimulation. These suppressive activities of RXM might contribute, in part, to the therapeutic mode of action of RXM on inflammatory diseases.

Anti-inflammatory capabilities of macrolides

Macrolide antibiotics play a significant role in clinical practise due not only to their antibacterial activity, but also to their accompanying anti-inflammatory effect that is independent of their antibiotic action. Several studies reported in literature show that macrolides affect several inflammatory processes, such as migration of neutrophils, the oxidative burst in phagocytes and production of pro-inflammatory cytokines, although the precise mechanisms are not clear. They also inhibit eosinophilic inflammation and may be useful in the treatment of patients with steroid-dependent asthma. Macrolides are also effective in diffuse panbronchiolitis, chronic sinusitis and inflammatory skin diseases.

Modulation of Th2 type cytokine production from human peripheral blood leukocytes by a macrolide antibiotic, roxithromycin, in vitro

The influence of a macrolide antibiotic, roxithromycin (RXM), on Th1 and Th2 cytokine productions from human peripheral blood T cells was examined under stimulation with co-stimulatory molecules. Peripheral blood T cells prepared from both healthy and allergic rhinitis donors were cultured in the presence of RXM on anti-CD3 mAb and anti-CD26 mAb-coated wells, anti-CD3 mAb and anti-CD28 mAb-coated wells, and anti-CD3 and PMA. T-cell proliferation, along with the concentration of interleukin (IL)-2, interferon (IFN)-gamma, IL-4 and IL-5 were measured. RXM did not affect T-cell proliferation induced by several ways of co-stimulatory activation as assessed by 3H-thymidine incorporation into DNA. RXM also had no effect on IL-2 and IFN-gamma secretion by T cells prepared from both healthy and allergic rhinitis donors. On the other hand, RXM markedly inhibited both IL-4 and IL-5 secretions under each of the co-stimulatory conditions in a dose-dependent manner. These results indicate that RXM inhibits specifically Th2 cytokine secretion from T cells induced by co-stimulatory molecule stimulations. This inhibitory action of RXM may be partially responsible for attenuating effect of the agent on the inflammatory diseases.

Suppression of co-stimulatory molecule expressions on splenic B lymphocytes by a macrolide antibiotic, roxithromycin in vitro

The influence of a macrolide antibiotic, roxithromycin (RXM), on co-stimulatory molecule expression was examined using in vitro cell culture technique. Spleen cells obtained from BALB/c mice 10 days after immunization with 8.0 micrograms of haemocyanin absorbed to 4.0 mg aluminum hydroxide were cultured in the presence of 100.0 micrograms/ml haemocyanin and various concentrations of RXM for 72 h. Low concentrations (1.0 and 2.5 micrograms/ml) of RXM did not influence cell activation induced by antigenic stimulation, whereas RXM showed a suppressive effect on blastic activity of the cells when the agent was added to the cultures at more than 5.0 micrograms/ml. RXM did not affect blastic activity of splenic T cells by anti-CD3 monoclonal antibody stimulation even when the cells were cultured in the presence of 10.0 micrograms/ml RXM. Addition of anti-CD80 and anti-CD86 monoclonal antibody to cell cultures caused significant suppression of cell activation by antigenic stimulation. We next examined the influence of RXM on co-stimulatory molecule expressions on splenic B cells in response to antigenic stimulation. Addition of RXM at a concentration of 5.0 micrograms/ml into cell cultures remarkably suppressed co-stimulatory molecule, CD40, CD80 and CD86, expressions, which enhanced by antigenic stimulation in vitro.

Anti-inflammatory and tissue-protectant drug effects: results from a randomized placebo-controlled trial of gastritis patients at high risk for gastric cancer

BACKGROUND

The inflammatory process involving Helicobacter pylori-associated gastritis is thought to lead to epithelial damage and contribute to the development of gastric cancer. Evidence exists from animal and in vitro studies suggesting that tetracyclines have both anti-inflammatory and tissue-protectant effects unrelated to their antimicrobial activity. We attempted to modulate components of H. pylori's inflammatory process by: (i) eliminating the infection; (ii) using tetracycline to alter the host's reaction to the infection without reducing the bacterial load; and (iii) using calcium to counteract the effect of excessive dietary salt.

METHODS

We conducted a 16-week placebo-controlled clinical trial with 374 H. pylori-associated gastritis patients randomly assigned to one of five groups: (1) triple therapy consisting of metronidazole, amoxicillin and bismuth subsalicylate for 2 weeks, followed by bismuth alone for 14 weeks; (2) calcium carbonate; (3) triple therapy and calcium carbonate; (4) tetracycline; or (5) placebo.

RESULTS

Subjects in the tetracycline and triple therapy groups, but not the calcium carbonate only group, showed a reduction in inflammation and epithelial damage vs. those in the placebo group, independent of a change in H. pylori density and other factors. Our results also indicate that epithelial damage may be affected by mechanisms independent of H. pylori density or inflammation.

CONCLUSION

The results are consistent with the hypothesis that tetracycline can decrease inflammation independent of a reduction in the bacterial load. More research is needed to investigate mechanisms leading to epithelial damage which are independent of H. pylori density and inflammation.

The efficacy and safety of a combination benzoyl peroxide/clindamycin topical gel compared with benzoyl peroxide alone and a benzoyl peroxide/erythromycin combination product

BACKGROUND

Topical clindamycin and benzoyl peroxide have each demonstrated clinical efficacy in the treatment of acne vulgaris. When used in tandem, they promise greater efficacy than either individual agent through their antibacterial and anti-inflammatory effects.

OBJECTIVE

To determine the efficacy and safety of combination benzoyl peroxide/ clindamycin compared with benzoyl peroxide or benzoyl peroxide/erythromycin in the treatment of acne.

METHODS

In this randomized, 10-week, multicenter, single-blind trial, 492 patients with moderate to moderately severe acne were treated twice daily with 5% benzoyl peroxide/1% clindamycin, 5% benzoyl peroxide, or 5% benzoyl peroxide/3% erythromycin and assessed every 2 weeks.

RESULTS

Compared with benzoyl peroxide, benzoyl peroxide/clindamycin demonstrated significantly greater reductions in inflammatory lesions (p = 0.04) and significantly greater overall improvement as assessed by physicians (p < or = 0.04) and patients (p < 0.001). Benzoyl peroxide/clindamycin demonstrated a nonsignificant trend for greater efficacy compared to benzoyl peroxide/erythromycin. Dry skin was the most frequent (< or = 7.3%) adverse event with all three therapies.

CONCLUSION

Benzoyl peroxide/clindamycin demonstrated improved efficacy and similar tolerability; to benzoyl peroxide used alone and was similar to benzoyl peroxide/ erythromycin, making this combination product an effective alternative antimicrobial therapy for acne.

Is acne an infection of blocked pilosebaceous follicles? Implications for antimicrobial treatment

A model is proposed which is based on the assumption that acne is due to infection of functionally blocked pilosebaceous follicles by propionibacteria. Noninflamed lesions, which are first visible during the adrenarche in acne-prone individuals, do not contain propionibacteria. Comedogenesis appears to be independent of bacterial infection and may be driven by high levels of bioactive interleukin-1 alpha derived from ductal hyperkeratinocytes. The stimulus which triggers interleukin-1 alpha production is unknown. Formalin killed Propionibacterium acnes failed to stimulate production of the cytokine by cultured human keratinocytes in vitro. Inflamed lesions are thought to arise from microcomedones, but the initiating events are unknown. Evidence that propionibacteria are involved in the generation of inflammatory lesions is inconclusive. The cellular infiltrate is consistent with a type IV hypersensitivity response to one or more persistent lesional antigens, not necessarily bacterial. The potent adjuvant activity of P. acnes would up-regulate the immune response to any antigen which came into contact with the mononuclear cell infiltrate. Antibiotics are widely used in the treatment of acne, and their effects in selecting a predominantly resistant commensal population are well recognized. Although they reduce numbers of propionibacteria on the skin, other modes of action may contribute to or explain their therapeutic efficacy. At a time when there is global concern that antibiotic resistance rates in common bacterial pathogens may threaten our future ability to control bacterial infections, practices which promote the spread of antibiotic-resistant bacteria must be fully justified. A thorough reappraisal of the role of propionibacteria in acne is overdue. It is likely that further experimental work is needed to confirm or refute that P. acnes is aptly named.

[Macrolides and Pseudomonas aeruginosa infection]

Several unique effects of subinhibitory concentrations of C14 and C15 macrolides on Pseudomonas aeruginosa infection are described in vitro: P. aeruginosa virulence factors inhibition, bacterial biofilm disruption, P. glycoprotein expression upregulation, anti-inflammatory and immunoregulatory effects. Clinical trials in vivo are warranted to assess the potential usefulness of macrolides for treatment of chronic infections caused by P. aeruginosa.

Disfiguring draining sinus tracts in a female acne patient

A 17-year-old girl with a 9-month history of papulopustular acne developed disfiguring, highly inflammatory, fluctuant nodules in both nasolabial folds within 2 months. Periodically she experienced discharge of pus and blood from these lesions. A diagnosis of disfiguring draining sinus tracts associated with acne vulgaris was made. The therapeutic regimen included intralesional corticosteroid injection, systemic corticosteroids along with a macrolide antibiotic, and systemic isotretinoin to reduce the inflammatory process. Outcome was favorable, with no recurrences during the following 10 months. Draining sinus is a malevolent lesion usually seen in severe forms of acne such as acne conglobata, acne fulminans, and acne inversa. Treatment is difficult and often unsatisfactory. In many cases, excision of the lesion is necessary to provide a permanent cure.

Suppressive activity of a macrolide antibiotic, roxithromycin on co-stimulatory molecule expression on mouse splenocytes in vivo

The influence of roxithromycin (RXM) on the expression of co-stimulatory molecules, CD40, CD80 and CD86, was examined in vivo. When BALB/c mice were immunized intraperitoneally with two doses of dinitrophenylated ovalbumin (DNP-OVA) at 1 week intervals, intraperitoneal administration of RXM at 250 microg/kg once a day for 14 days strongly suppressed IgE contents in sera obtained from mice 22 days after the first immunization. In addition, RXM treatment of mice suppressed endogenous IL-4 contents in aqueous spleen extracts, which were enhanced by DNP-OVA immunization. We next examined the influence of RXM on co-stimulatory molecule expression on splenic lymphocytes. RXM treatment of the immunized mice caused suppression of CD40 expression, but this treatment did not affect CD80 and CD86 expression.

Minocycline and autoimmunity

Minocycline is the most widely prescribed systemic antibiotic for the management of acne. In the past several years, increasing attention has been paid to the drug, both for its potential use as a disease-modifying antirheumatic agent and for its propensity to engender untoward autoimmune reactions, including serum sickness-like disease, drug-induced lupus, and autoimmune hepatitis. This paper reviews the evidence for minocycline as an anti-inflammatory and immunomodulatory agent, its utility in the treatment of rheumatoid arthritis, and the spectrum of adverse reactions that have been ascribed to the drug in the past 5 years.

Minocycline for the treatment of rheumatoid arthritis

The scientific basis for the use of antibiotics (with special emphasis on tetracycline and its derivatives) in the treatment of RA is discussed. The data on efficacy and toxicity are presented. The possible place of tetracycline derivatives within the overall strategy of RA treatment is also presented.

Azithromycin impact on neutrophil oxidative metabolism depends on exposure time

Several antimicrobial agents have already been investigated relating to their influence on neutrophil ROS generation. Azithromycin provides, a dose-related anti-oxidant effect, after 15 min incubation, with the stimulating agent FMLP, as well with PMA or S. aureus. This finding was however obtained with concentrations not considered in therapeutics. Since short incubation times are not representative of the physiological situation, and since azithromycin is characterized by prolonged high concentrations within phagocytes, the same experiments were performed over 2 and 4 h exposures. A time-dependent anti-oxidant effect was then reported. The maximum effect was obtained with PMA (IC50 were 856 and 30 micrograms/ml for 15 min and 4 h incubation times respectively). Time-dependent modifications of neutrophil oxidative metabolism seem to be correlated with intracellular concentrations. Depressed oxidative metabolism might be related neither to azithromycin cellular toxicity, nor to superoxide scavenging properties. By increasing exposure periods, therapeutic concentrations could therefore lead to an anti-inflammatory effect, potentially of clinical interest since associated with bacteriostatic activity.

Effect of macrolide antibiotics on macrophage functions

Macrolide antibiotics have a variety of actions other than antimicrobial activities. Recently, it has been suggested that macrolide antibiotics act as immunomodulators. In this study, we evaluated the effects of macrolide antibiotics on macrophage functions. For the macrophage, we used the mouse macrophage cell line J774.1. The following effects of macrolide antibiotics on macrophage functions were evaluated: the effect of macrolide antibiotics on macrophage growth; the phagocytosis of beads; cytocidal activity against Candida albicans; and chemotaxis to lipopolysaccharide (LPS). Macrolide antibiotics except for azithromycin significantly stimulated the growth of the macrophage. In addition, pretreatment with macrolide antibiotics except for roxithromycin significantly stimulated the macrophage phagocytosis of beads, macrophage chemotaxis to LPS, and macrophage cytocidal activity against Candida albicans. These results suggest that macrolide antibiotics stimulate macrophage functions.

Treatment of pyoderma gangrenosum

Critical to the proper management of pyoderma gangrenosum are correct diagnosis, identification and treatment of any underlying disorder, and the proper choice of topical and systemic therapy. Many agents are available for the treatment of pyoderma gangrenosum. We review the current therapeutic options, their efficacy and side effects, and we offer some guidelines for their proper selection.

Erythromycin shortens neutrophil survival by accelerating apoptosis

Erythromycin is reported to have an anti-inflammatory action, which may account for its clinical effectiveness in the treatment of chronic inflammatory diseases such as diffuse panbronchiolitis. To evaluate the anti-inflammatory action of erythromycin, we examined the survival of isolated neutrophils with and without erythromycin. Erythromycin shortened neutrophil survival in a dose-dependent fashion, with a maximum effect at 10 micrograms/ml [corrected] and above. Survival at 24 h was 63.4% in medium with 10 micrograms of erythromycin per ml compared with 82.7% in control medium (P < 0.01). This shortening of survival was brought about by acceleration of apoptosis, as evidenced by transmission electron microscopy. In a manner similar to that of erythromycin, other macrolide antibiotics, i.e., clarithromycin, roxithromycin, and midecamycin, also shortened neutrophil survival, but neither the beta-lactams ampicillin and cefazolin nor the aminoglycoside gentamicin affected their survival. Erythromycin increased intracellular levels of cyclic AMP (cAMP) to 150% of control levels in neutrophils. Forskolin, rolipram, and dibutyryl-cAMP, which are known to increase intracellular cAMP levels, also shortened neutrophil survival. H-89, an inhibitor of cAMP-dependent protein kinase A, partially blocked the survival-shortening effect of erythromycin. Our findings suggest that erythromycin shortens neutrophil survival at least in part through elevation of intracellular cAMP levels.

Variation in comedonal antibiotic concentrations following application of topical tetracycline for acne vulgaris

A miniaturized sensitive bioassay was used to detect tetracycline in open comedones following topical twice daily application of 0.22% tetracycline hydrochloride for a minimum of 4 weeks to the facial skin of patients with mild to moderate acne. The lower limit of detection was 4.8 +/- 0.8 ng per comedone or per 10 microliters. Using this method, 111 of 155 open comedones from 15 patients were found to contain a detectable amount of tetracycline, ranging from 1.8 to 156.9 ng per comedone, and between 4.5 and 1140.1 ng per mg comedonal material. There was a significant effect of comedone weight on tetracycline content, with smaller comedones containing proportionately more tetracycline. The Spearman rank correlation coefficient was -0.5619 (P < 0.001). All 111 comedones in which tetracycline was detected contained sufficient drug to inhibit fully antibiotic-sensitive propionibacteria. However, conditions favourable to the selection and overgrowth of highly tetracycline-resistant strains (MIC > or = 32 micrograms/ml) prevailed in at least 18.7% (29 of 155) of the comedones tested.