Effects of doxycycline on serum and endometrial levels of MMP-2, MMP-9 and TIMP-1 in women using a levonorgestrel-releasing subcutaneous implant

Doxycycline as an anti-inflammatory agent: updates in dermatology

Doxycycline, a tetracycline antibiotic, is widely used in the field of dermatology for its antibiotic properties, anti-inflammatory properties and good safety profile. Over the past decades, numerous studies have clarified some of the anti-inflammatory mechanisms of doxycycline. In this review article, we aimed to provide an update on recent data on the anti-inflammatory properties of doxycycline and its potential role in cutaneous inflammatory diseases. Better understanding of these mechanisms might offer the practicing clinicians a better use of this therapeutic tool. In addition, research in this field could help clarify pathogenic aspects of inflammatory dermatologic diseases responsive to this medication. Further research is needed to fully elucidate the potential of doxycycline as an anti-inflammatory agent, and the development of new topical vehicles could open ways to new therapeutic possibilities for dermatologists.

Effect of oral contraceptives and doxycycline on endometrial MMP-2 and MMP-9 activity

OBJECTIVES

To describe the effect of combined oral contraceptives (COCs) on matrix metalloproteinases MMP-2 and MMP-9 activity and compare MMP activity in women taking a COC with or without doxycycline.

STUDY DESIGN

Subjects (n=20) underwent endometrial biopsies (1) in the late luteal phase of a baseline cycle prior to initiating COCs, (2) on days 19-21 while taking COCs in a standard 28-day cycle (7-day hormone-free interval) and (3) on days 26-28 while taking active COCs continuously for a 28-day cycle. During the continuous COC cycle, they were randomized to receive daily subantimicrobial dose doxycycline 40mg or placebo.

RESULTS

Compared to baseline, COC treatment increased MMP-2 (p<.001) and MMP-9 (p<.001). MMP activity was lower in subjects taking a COC with doxycycline compared to those receiving placebo although only significantly lower for MMP-2 latent form (p=.002).

CONCLUSIONS

Unscheduled bleeding with COCs may be the result of increased endometrial MMPs. Sample size limitations prevent us from determining how doxycycline affects MMP activity in COC users.

Effects of levonorgestrel-releasing intrauterine system on lymphangiogenesis of adenomyosis

OBJECTIVES

Lymphangiogenesis may be involved in the pathogenesis of adenomyosis. We investigated the lymphatic vessels of patients with adenomyosis, including those treated with levonorgestrel-releasing intrauterine system (LNG-IUS).

METHODS

Full-thickness uterine samples were obtained from patients who received hysterectomies. Twenty-one patients with adenomyosis and 17 patients with adenomyosis who were treated with LNG-IUS were included. Eighteen patients with cervical intraepithelial neoplasia served as controls. Immunohistochemical staining was performed with antibodies against podoplanin and lymphatic vessel endothelial hyaluronan receptor 1. The lymphovascular density (LVD) was analyzed in each sample by the "hot spot" method.

RESULTS

The LVDs were significantly higher in the endometrial and myometrial tissues of patients with adenomyosis compared with those of patients treated with the LNG-IUS or controls. No significant differences were noted between the LNG-IUS-treated group and controls. Evaluation of the LVDs according to the menstrual cycle showed that the differences in the endometrial tissues of the adenomyosis group and those of the LNG-IUS-treated group or the controls were more prominent during the secretory phase.

CONCLUSIONS

Treatment with the LNG-IUS resulted in reduced lymphangiogenesis and LVD in the endometrial and myometrial tissues of patients with adenomyosis. Reduced lymphangiogenesis may be one mechanism by which the LNG-IUS reduces adenomyosis-related symptoms.

Effect of the non-specific matrix metalloproteinase inhibitor Doxycycline on endometriotic implants in an experimental rat model

The aim of this study was to investigate the possible therapeutic effects of Doxycycline (Dox) on endometriotic lesions in an experimental rat model. Thirty-seven female Wistar albino rats with surgically induced endometriosis were randomized and divided into four groups. The rats were administered 5 mg/kg/day oral Dox in Group 1 (low-dose Dox group, n=9), 20 mg/kg/day oral Dox in Group 2 (high-dose Dox group, n=10) and 1 mg/kg single dose, subcutaneous leuprolide acetate in Group 3 (leuprolide acetate group, n=9). The rats in Group 4 (control group, n=9) were given no medication. The rats received medication for three weeks and were then sacrificed to evaluate the morphological and histological features of the implants. Matrix metalloproteinase (MMP)-9 immunoreactivity of the implants was also evaluated. The size of the endometriotic implants decreased in Groups 1-3 but statistically significant differences were not observed among the groups. The mean surface area of the endometriotic implants decreased from 69.3±30.8 to 52.1±27.0 mm² in Group 1 (P>0.05), from 60.2±18.9 to 38.6±28.7 mm² in Group 2 (P>0.05) and from 58.1±33.1 to 26±9.0 mm² in Group 3 (P=0.03). The epithelial MMP-9 immunohistochemical score was significantly higher in Group 1 and lower in Group 3 when compared with the control group (Group 4) (P=0.042 and P=0.014, respectively). When the stromal MMP-9 immunohistochemical and histopathological scores of the endometriotic implants were compared, no statistically significant differences were found among the groups. Although there was no statistically significant difference, Dox reduced the endometriotic implant area in the rat endometriosis model. Further studies are required to investigate the potential efficacy of Dox in endometriosis due to its widespread use and tolerability.

Synergistic protection of MLC 1 against cardiac ischemia/reperfusion-induced degradation: a novel therapeutic concept for the future

Cardiovascular diseases are a major burden to society and a leading cause of morbidity and mortality in the developed world. Despite clinical and scientific advances in understanding the molecular mechanisms and treatment of heart injury, novel therapeutic strategies are needed to prevent morbidity and mortality due to cardiac events. Growing evidence reported over the last decade has focused on the intracellular targets for proteolytic degradation by MMP-2. Of particular interest is the establishment of MMP-2-dependent degradation of cardiac contractile proteins in response to increased oxidative stress conditions, such as ischemia/reperfusion. The authors' laboratory has identified a promising preventive therapeutic target using the classical pharmacological concept of synergy to target MMP-2 activity and its proteolytic action on a cardiac contractile protein. This manuscript provides an overview of the body of evidence that supports the importance of cardiac contractile protein degradation in ischemia/reperfusion injury and the use of synergy to protect against it.

Effect of doxycycline in patients of moderate to severe chronic obstructive pulmonary disease with stable symptoms

BACKGROUND:

The protease-antiprotease hypothesis proposes that inflammatory cells and oxidative stress in chronic obstructive pulmonary disease (COPD) produce increased levels of proteolytic enzymes (neutrophil elastase, matrix metalloproteinases [MMP]) which contribute to destruction of parenchyma resulting in progressive decline in forced expiratory volume in one second. Doxycycline, a tetracycline analogue, possesses anti-inflammatory properties and inhibits MMP enzymes.

OBJECTIVES:

To assess the effect of 4 weeks doxycycline in a dose of 100 mg once a day in patients of moderate to severe COPD with stable symptoms.

METHODS:

In an interventional, randomized, observer-masked, parallel study design, the effect of doxycycline (100 mg once a day for 4 weeks) was assessed in patients of COPD having stable symptoms after a run-in period of 4 weeks. The study participants in reference group did not receive doxycycline. The parameters were pulmonary functions, systemic inflammation marker C-reactive protein (CRP), and medical research council (MRC) dyspnea scale. Use of systemic corticosteroids or antimicrobial agents was not allowed during the study period.

RESULTS:

A total of 61 patients completed the study (31 patients in doxycycline group and 30 patients in reference group). At 4 weeks, the pulmonary functions significantly improved in doxycycline group and the mean reduction in baseline serum CRP was significantly greater in doxycycline group as compared with reference group. There was no significant improvement in MRC dyspnea scale in both groups at 4 weeks.

CONCLUSION:

The anti-inflammatory and MMP-inhibiting property of doxycycline might have contributed to the improvement of parameters in this study.

A randomized controlled trial of subantimicrobial-dose doxycycline to prevent unscheduled bleeding with continuous oral contraceptive pill use

BACKGROUND

Unscheduled bleeding is the main side effect of continuous oral contraceptive pills (OCPs) and has been correlated with the up-regulation of matrix metalloprotineases (MMPs). The study objective was to determine if prophylactic administration of doxycycline (an MMP inhibitor at low subantimicrobial doses) would prevent unscheduled bleeding during the initiation of a continuous OCP.

STUDY DESIGN

Subjects using cyclic hormonal contraceptives (combined OCPs, patch or ring) without unscheduled bleeding were switched to continuous OCPs (20 mcg ethinyl estradiol/100 mcg levonorgestrel). They were randomized to receive daily doxycycline [sustained-release subantimicrobial dose (40 mg daily)] or placebo for the first 84 days and then observed for an additional 28 days on the continuous OCP alone. The number of bleeding/spotting days and the time in days it took to achieve amenorrhea were compared using a t test.

RESULTS

Sixty-five subjects were randomized. Although the use of doxycycline did not significantly decrease the number of mean bleeding/spotting days in the first 84 days of the study [doxycycline 14.75 (SE 2.30), placebo 17.78 (2.31), p=.36], women who received doxycycline had a significantly earlier onset of amenorrhea [mean last day of bleeding/spotting doxycycline 61.7 (7.7), placebo 85.2 (6.7), p=.03].

CONCLUSION

The coadministration of subantimicrobial-dose doxycycline during initiation of continuous OCPs results in a significant reduction in the length of time needed to achieve amenorrhea.

Treatment of unscheduled bleeding in continuous oral contraceptive users with doxycycline: a randomized controlled trial

OBJECTIVE

To estimate whether doxycycline, a matrix metalloproteinase inhibitor, would decrease unscheduled bleeding associated with initiation of a continuous oral contraceptive pill.

METHODS

Participants initiating a continuous oral contraceptive pill (20 micrograms of ethinyl estradiol/90 micrograms of levonorgestrel) were randomly assigned to receive either doxycycline (100 mg orally twice daily) or placebo taken for 5 days at the onset of each bleeding or spotting episode during the first 84 days of the study period. For the final 28 days of the study, participants were observed on the oral contraceptive pill alone. The primary outcome was the number of bleeding and spotting days. A sample size of 66 (33 in each arm) was calculated to detect a 50% reduction in bleeding (beta=0.80, alpha=0.05) and accounted for a 30% dropout rate.

RESULTS

Sixty-six women were randomly assinged (33 in each study group). There were no significant differences during the 84-day treatment in bleeding or spotting days (doxycycline [mean {standard error}, placebo, P=.32) or the length of the longest bleeding or spotting episode (doxycycline, placebo, P=.70) between study groups. Similarly, no significant differences in bleeding patterns existed between groups during the final 28 days.

CONCLUSION

Doxycycline, administered once bleeding has started, does not decrease unscheduled bleeding or shorten episodes of unscheduled bleeding in continuous oral contraceptive pill users.

LEVEL OF EVIDENCE

I.