Minocycline protects against lipopolysaccharide-induced glial cells activation and oxidative stress damage in the medial prefrontal cortex (mPFC) of the rat

PURPOSE/AIM

Neuroinflammation and oxidative stress have been encountered in neurodegenerative diseases such as Alzheimer's disease (AD). However, the neuroprotective effects of minocycline against lipopolysaccharide (LPS)-induced glial cells activation and oxidative stress damage in the medial prefrontal cortex (mPFC) of rats are still elusive. The purpose of this study is to investigate the effects of minocycline and memantine, an N-methyl-D-aspartate (NMDA) receptor antagonist, on the microglia and astrocytes expression, as well as oxidative stress levels in the mPFC of LPS injected rats.

MATERIALS AND METHODS

Fifty adult Male Sprague Dawley rats were divided into five groups: control, LPS (5 mg/kg), LPS treated with minocycline (25 mg/kg), LPS treated with minocycline (50 mg/kg) and LPS treated with memantine (10 mg/kg). The immunohistochemistry and western blotting were used to analyse the expressions and densities of microglia marker (Iba-1) and astrocyte marker, (GFAP) while enzyme-linked immunosorbent assay (ELISA) was used to measure the protein carbonyl (PCO), malondialdehyde (MDA), catalase (CAT), and superoxide dismutase (SOD) levels.

RESULTS

In comparison to the control group, the expression and density of Iba-1 and GFAP were significantly enhanced in the LPS group (p < 0.05). LPS group also exhibited significantly higher levels of PCO and MDA (p < 0.05) and significantly lower levels of CAT and SOD (p < 0.05) when compared to the control group. Both minocycline and memantine-treated LPS rats were able to protect against these effects.

CONCLUSION

Minocycline, like memantine treatment, reduces oxidative stress in the mPFC of LPS rats via inhibition of glial cells activation.

Guidelines of care for the management of acne vulgaris

BACKGROUND

Acne vulgaris commonly affects adults, adolescents, and preadolescents aged 9 years or older.

OBJECTIVE

The objective of this study was to provide evidence-based recommendations for the management of acne.

METHODS

A work group conducted a systematic review and applied the Grading of Recommendations, Assessment, Development, and Evaluation approach for assessing the certainty of evidence and formulating and grading recommendations.

RESULTS

This guideline presents 18 evidence-based recommendations and 5 good practice statements. Strong recommendations are made for benzoyl peroxide, topical retinoids, topical antibiotics, and oral doxycycline. Oral isotretinoin is strongly recommended for acne that is severe, causing psychosocial burden or scarring, or failing standard oral or topical therapy. Conditional recommendations are made for topical clascoterone, salicylic acid, and azelaic acid, as well as for oral minocycline, sarecycline, combined oral contraceptive pills, and spironolactone. Combining topical therapies with multiple mechanisms of action, limiting systemic antibiotic use, combining systemic antibiotics with topical therapies, and adding intralesional corticosteroid injections for larger acne lesions are recommended as good practice statements.

LIMITATIONS

Analysis is based on the best available evidence at the time of the systematic review.

CONCLUSIONS

These guidelines provide evidence-based recommendations for the management of acne vulgaris.

Mimicking Rosacea? Jessner's Lymphocytic Infiltration of the Skin: A Case Report

We report a case of rash in a 35-year-old female presenting with erythematous papules and infiltrative plaques on the nose and upper jaw resembling rosacea. The patient had been experiencing these symptoms for one year. A pathological biopsy revealed an inflammatory infiltrate consisting of dense perivascular lymphocytes surrounding hair follicles and sweat glands in the dermis. Immunohistochemistry demonstrated a predominance of CD4+ T cells compared to CD8+ T cells. Based on the clinical manifestations, histopathology, and immunohistochemistry, the patient was diagnosed with Jessner's Lymphocytic infiltration of the skin (JLIS). The patient was treated with oral Minocycline, 100mg twice daily. After 4 weeks, the dosage was reduced by half and the treatment continued for 2 months, resulting in complete resolution of the rash. The clinical presentation resembled rosacea, and this particular manifestation of JLIS has not been previously reported. Treatment with minocycline yielded satisfactory efficacy, and no recurrence has been observed for 5 year.

Comparison of endoscopic ultrasound-guided drainage and percutaneous drainage combined with minocycline sclerotherapy for symptomatic hepatic cysts: A retrospective study

Simple hepatic cysts (SHC) are generally asymptomatic and incidentally diagnosed using imaging studies. Asymptomatic SHC does not require treatment, but symptomatic SHC warrants treatment using different modalities, including intravenous antibiotic therapy, ultrasound-guided percutaneous catheter drainage (PCD) with sclerotherapy, and surgery. The dissemination of endoscopic ultrasonography (EUS) intervention techniques has enabled the performance of puncture and drainage via the transgastrointestinal route for intra-abdominal abscesses. Despite the development of an EUS-guided drainage method for treating symptomatic SHC, only a few case reports using this method have been reported. This study retrospectively analyzed the safety and feasibility of EUS-guided drainage of symptomatic SHC as well as its clinical outcomes and compared it with combined therapy using PCD and minocycline sclerotherapy. The records of 10 consecutive patients with 11 symptomatic SHCs treated with either EUS-guided drainage or PCD combined with minocycline sclerotherapy at the Musashino Tokushukai Hospital from August 2019 to January 2024 were retrospectively examined. All cases in both groups achieved technical and clinical success, with no reported adverse events. The median reduction rates of the major cyst diameters in the EUS-guided drainage and PCD with sclerotherapy groups were 100% (interquartile range [IQR]: 94%-100%) and 67% (IQR: 48.5%-85%). The length of hospital stay was 7 and 22.5 days in the EUS-guided and PCD with sclerotherapy groups (P = .01). EUS-guided drainage of symptomatic SHC is a safe and effective therapeutic alternative to percutaneous drainage with sclerotherapy and surgery for treating symptomatic SHC.

Case Report: Minocycline-induced drug reaction with eosinophilia and systemic symptoms syndrome: a case report and literature review

Minocycline is a tetracycline commonly used for several dermatological diseases. Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a rare but severe adverse event which can be caused by minocycline. An 18-year-old male patient developed fever, acute rash, pharyngeal pain, lymphadenopathy, hematologic abnormalities, increased creatinine level, elevated liver enzyme levels, and splenomegaly 4 weeks after the oral treatment of minocycline, 100 mg daily, for acne. Once diagnosed with DRESS syndrome, intravenous methylprednisolone was applied and his clinical manifestations and laboratory results remarkably improved. Then, a total of 13 DRESS syndrome cases induced by minocycline were reviewed and their clinical characteristics were summarized. In these cases, only two patient (15.4%) was present with pharynx involved. In conclusion, we reported a rare minocycline-induced DRESS syndrome who developed fever, eosinophilia, acute rash, pharyngitis, lymphadenopathy, acute kidney injury, hepatitis, and splenomegaly. Our report provides detailed clinical features of minocycline-induced DRESS syndrome, which helps us further understand this severe adverse event.

Printing GelMA bioinks: a strategy for building in vitro model to study nanoparticle-based minocycline release and cellular protection under oxidative stress

Owing to its thermoresponsive and photocrosslinking properties, gelatin methacryloyl (GelMA) based biomaterials have been commonly used as a novel and promising bioink for 3D bioprinting and various biomedical applications. However, the time and temperature dependent flow behaviors of GelMA at sol-gel transition state pose great challenges when printing thick scaffolds that also sustain high cell viability. Additionally, the turnabilities and in situ photocrosslinking ability of GelMA hydrogel make it a promising candidate for local drug delivery applications. Previous studies have reported on the direct encapsulation of minocycline (MH) in GelMA scaffolds for therapeutic applications. However, achieving prolonged and sustained release of high concentration MH is challenging due to its small molecular size. The aim of this study is to explore an optimal extrusion printing strategy for GelMA bioink in extrusion bioprinting considering its time and temperature dependent flow behaviors and then investigate its applications as drug loading carriers for sustained MH release for cellular protection under oxidative stress. Material properties of GelMA were characterized followed by printing optimization considering both the printability and cell survivability. A metal ion-mediated interaction mechanism between MH, dextran sulfate (DS), and magnesium to form nanoparticle complexes (MH-DS) was adopted for sustained drug release in GelMA. Additionally, an in vitro model was printed with GelMA to study the cell protection effect of MH against oxidative stress. Our results showed that the printability and cell survival rate of GelMA are significantly influenced by printing time, nozzle temperature, and GelMA concentrations. Optimal printing zones were determined based on both printability and cell viability window. Scaffolds printed using the parameters derived from optimal zones exhibited excellent printability and cell viability. We observed that lower concentrations of GelMA resulted in reduced burst release of MH from MH-DS on the first day, leading to more sustained release profiles compared to direct mixing. Additionally, released MH significantly increased fibroblasts survival in an in vitro oxidative stress model. .

Minocycline mitigates tau pathology via modulating the TLR-4/NF-кβ signalling pathway in the hippocampus of neuroinflammation rat model

INTRODUCTION

The neuroinflammatory response was seen to impact the formation of phosphorylated tau protein in Alzheimer's disease (AD). This study aims to investigate the molecular mechanism of minocycline in reducing phosphorylated tau protein formation in the hippocampus of lipopolysaccharide (LPS)-induced rats.

METHODS

Fifty adult male Sprague Dawley (SD) rats were randomly allocated to 1 of 5 groups: control, LPS (5 mg/kg), LPS + minocycline (25 mg/kg), LPS + minocycline (50 mg/kg) and LPS + memantine (10 mg/kg). Minocycline and memantine were administered intraperitoneally (i.p) for two weeks, and LPS was injected i.p. once on day 5. ELISA was used to determine the level of phosphorylated tau protein in SD rats' hippocampal tissue. The density and expression of Toll-like receptor-4 (TLR-4), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-кβ), tumour necrosis factor-alpha (TNF-α), and cyclooxygenase (COX)-2 were determined using Western blot and immunohistochemistry.

RESULTS

Minocycline, like memantine, prevented LPS-induced increasein phosphorylated tau protein level suggested via reduced density and expression of TLR-4, NF-кβ, TNF-αand COX-2 proteins in rat hippocampal tissue. Interestingly, higher doses were shown to be more neuroprotective than lower doses.

CONCLUSION

This study suggests that minocycline suppresses the neuroinflammation signalling pathway and decreased phosphorylated tau protein formation induced by LPS in a dose-dependent manner. Minocycline can be used as a preventative and therapeutic drug for neuroinflammatory diseases such as AD.

Nodular vasculitis (erythema induratum) associated with systemic minocycline

A 29-year-old Caucasian woman presented with a 3-month history of bilateral lower limb swelling with painful erythematous nodules on shins without ulceration. She had been taking minocycline for acne vulgaris for 3 years. Biochemical investigations showed deranged liver function test with positive ANA and mixed antinuclear factor (ANF) pattern. A skin biopsy was in keeping with a diagnosis of nodular vasculitis. Her skin lesions and liver function test improved within 3 months of stopping the minocycline treatment. This case report raises the awareness that minocycline could be a potential cause of nodular vasculitis, patients on minocycline should be closely monitored and minocycline should ideally not be prescribed for more than 12 weeks, given the possible adverse effects.

A systematic review of case series and clinical trials investigating systemic oral or injectable therapies for the treatment of vitiligo

AIMS AND OBJECTIVES

The purpose of this study is to investigate the effectiveness and safety of oral and injectable systemic treatments, such as methotrexate, azathioprine, cyclosporine, tofacitinib, baricitinib, corticosteroids, statins, zinc, apremilast, etc., for treating vitiligo lesions.

METHOD

Databases including PubMed, Scopus, and Web of Science were meticulously searched for studies spanning from 2010 to August 2023, focusing on systemic oral and injectable therapies for vitiligo, using comprehensive keywords and search syntaxes tailored to each database. Key data extracted included study design, treatment efficacy, patient outcomes, patient satisfaction, and safety profiles.

RESULTS

In a total of 42 included studies, oral mini-pulse corticosteroid therapy (OMP) was the subject of six studies (14.2%). Minocycline was the focus of five studies (11.9%), while methotrexate, apremilast, and tofacitinib each were examined in four studies (9.5%). Antioxidants and Afamelanotide were the subjects of three studies each (7.1%). Cyclosporine, simvastatin, oral zinc, oral corticosteroids (excluding OMP) and injections, and baricitinib were each explored in two studies (4.8%). Azathioprine, mycophenolate mofetil, and Alefacept were the subjects of one study each (2.4%).

CONCLUSION

Systemic treatments for vitiligo have been successful in controlling lesions without notable side effects. OMP, Methotrexate, Azathioprine, Cyclosporine, Mycophenolate mofetil, Simvastatin, Apremilast, Minocycline, Afamelanotide, Tofacitinib, Baricitinib, Antioxidants, and oral/injectable corticosteroids are effective treatment methods. However, oral zinc and alefacept did not show effectiveness.

Comparative evaluation of antimicrobial efficacy of triple antibiotic paste and amoxicillin clavulanate paste as an intracanal medicament against Enterococcus faecalis: An in vitro study

Background

Triple antibiotic paste (TAP) is the commonly used intracanal medicament against Enterococcus faecalis. Amoxicillin clavulanate paste (ACP) is recommended as a "fall-back" antibiotic when traditional dental antibiotics fail. Literature comparing the antimicrobial efficacy of TAP and ACP in eradicating E. faecalis from the root canal system is sparse; hence, this in vitro study was conducted to evaluate and compare the antimicrobial efficacy of TAP and ACP as an intracanal medicament for endodontic treatment of single-rooted permanent teeth against E. faecalis.

Materials and Methods

This in vitro, experimental study evaluated 60 root samples obtained from extracted single-rooted human permanent teeth. The canal diameter was enlarged and subsequently infected with E. faecalis for 21 days. Four groups of the contaminated samples were treated with TAP, ACP, calcium hydroxide (positive control), and saline (negative control), respectively. Dentinal shavings were collected at the end of the 1st, 7th, and 10th day and inoculated in agar plates. The number of colony-forming units was determined, and the data were statistically analyzed using the Kolmogorov-Smirnov and Shapiro-Wilks test. P <0.05 was considered statistically significant.

Results

The mean number of E. faecalis colony counts across all 3 test days demonstrated that TAP exhibited the highest inhibition of bacterial growth, followed by ACP which is not statistically significant (P = 1.00).

Conclusion

Considering the limitations of this in vitro study, the findings suggest that ACP could be an effective alternative intracanal medicament to TAP for endodontic therapy.

Minocycline in Severe Cerebral Amyloid Angiopathy: A Single-Center Cohort Study

BACKGROUND

Evidence from animal studies suggests that minocycline may reduce lobar intracerebral hemorrhage (ICH) recurrence in cerebral amyloid angiopathy, possibly by inhibiting perivascular extracellular matrix degradation in cerebral small vessels. There is currently no evidence of its safety or efficacy in humans with cerebral amyloid angiopathy.

METHODS AND RESULTS

To provide preliminary data to support future studies of minocycline's efficacy, the authors performed a retrospective single-center cohort study to assess the incidence of recurrent ICH in patients with an aggressive clinical course of probable cerebral amyloid angiopathy who had been prescribed minocycline off-label via shared decision-making. Crude incidence rate ratios were calculated to compare incidence rates before versus after treatment. Sixteen patients (mean age at minocycline initiation, 66.3±3.5 years; women 62.5%; median of 3 lobar ICHs [range, 1-6]) were initiated on minocycline and followed for a median of 12.4 months (range, 1.8-61.4 months). Adverse events were reported in 4 of 16 patients (gastroenteric, n=3; dizziness, n=1) and were considered mild. ICH incidence sharply increased the year before minocycline initiation compared with the preceding years (2.18 [95% CI, 1.50-3.07] versus 0.40 [95% CI, 0.25-0.60] events per patient-year) and fell to 0.46 (95% CI, 0.23-0.83) events per patient-year afterwards. Incidence rate ratios of recurrent ICH after minocycline was lower (0.21 [95% CI, 0.11-0.42], P<0.0001) compared with the year before initiation.

CONCLUSIONS

Minocycline appeared safe and generally tolerated in a small group of patients with clinically aggressive cerebral amyloid angiopathy and was associated with reduced ICH recurrence. Determining whether this reduction represents a biological response to minocycline rather than a regression to the mean, however, will require a future controlled treatment trial.

Minocycline alleviates LPS-induced cognitive dysfunction in mice by inhibiting the NLRP3/caspase-1 pathway

BACKGROUND

Growing experimental evidence indicates that cognitive impairment is linked to neuroinflammation. Minocycline (MINO), an antibiotic known for its anti-inflammatory, has shown promise in alleviating cognitive impairment. Nonetheless, the exact mechanism through which MINO improves cognitive impairment is not yet understood.

METHODS

A neuroinflammatory model was establish by utilizing lipopolysaccharide. The assessment of mice's cognitive and learning abilities was conducted through the MWM and Y-maze tests. The evaluation of hippocampal neuronal injury and microglial activation were achieved by performing HE staining and IHC, respectively. To evaluate BV2 cell viability and apoptosis, the CCK-8 and Hoechst 33342/PI staining assays were employed. In order to assess the protein and RNA expression levels of NLRP3, caspase-1, IL-1β, IL-18, Iba-1, and Bcl2/Bax, WB and RT-qPCR were utilized. Additionally, the inhibitory effect of MINO on apoptosis by targeting the NLRP3/caspase-1 pathway was investigated using Nigericin.

RESULTS

MINO was effective in reducing the time it took for mice to escape from the test, increasing the number of platforms they crossed, and mitigating damage to the hippocampus while also suppressing microglial activation and the expression of Iba-1 in a neuroinflammatory model caused by LPS. Furthermore, MINO improved the viability of BV2 cell and reduced apoptosis. It also had the effect of reducing the expression levels of NLRP3/Caspase-1, IL-1β, IL-18, and BAX, while upregulating the expression of Bcl2. Additionally, MINO was found to downregulate the NLRP3 expression, which is specifically activated by nigericin.

CONCLUSION

The protective effect of MINO relies on the crucial involvement of the NLRP3/caspase-1 pathway.

Effects of minocycline on dendrites, dendritic spines, and microglia in immature mouse brains after kainic acid-induced status epilepticus

PURPOSE

This study aimed to investigate whether minocycline could influence alterations of microglial subtypes, the morphology of dendrites and dendritic spines, the microstructures of synapses and synaptic proteins, or even cognition outcomes in immature male mice following status epilepticus (SE) induced by kainic acid.

METHODS

Golgi staining was performed to visualize the dendrites and dendritic spines of neurons of the hippocampus. The microstructures of synapses and synaptic proteins were observed using transmission electron microscopy and western blotting analysis, respectively. Microglial reactivation and their markers were evaluated using flow cytometry. The Morris water maze (MWM) test was used to analyze spatial learning and memory ability.

RESULTS

Significant partial spines increase (predominate in thin spines) was observed in the dendrites of neurons after acute SE and partial loss (mainly in thin spines) was presented by days 14 and 28 post-SE. The postsynaptic ultrastructure was impaired on the 7th and 14th days after SE. The proportion of M1 microglia increased significantly only after acute SE Similarly, the proportion of M2 microglia increased in the acute stage with high expression levels of all surface markers. In contrast, a decrease in M2 microglia and their markers was noted by day 14 post-SE. Minocycline could reverse the changes in dendrites and synaptic proteins caused by SE, and increase the levels of synaptic proteins. Meanwhile, minocycline could inhibit the reactivation of M1 microglia and the expression of their markers, except for promoting CD200R. In addition, treatment with minocycline could regulate the expression of M2 microglia and their surface markers, as well as ameliorating the impaired spatial learning and memory on the 28th day after SE.

CONCLUSIONS

Dendritic spines and microglia are dynamically changed after SE. Minocycline could ameliorate the impaired cognition in the kainic acid-induced mouse model by decreasing the damage to dendrites and altering microglial reactivation.

Effectiveness of Conventional Periodontal Treatment With Tetracycline Fiber Versus Minocycline Gel Application Subgingivally in Periodontitis Patients

BACKGROUND

Locally delivered antibiotics are adjunctive therapies for the selective removal or inhibition of pathogenic microbes in combination with scaling and root planing (SRP) for the management of periodontitis.

OBJECTIVE

The primary objective of this study was to evaluate the effectiveness of tetracycline fibers against minocycline gel when used as local drug delivery in conjunction with SRP for treating periodontitis.

METHODS AND MATERIALS

This is a pilot randomized open single, blinded trial study comparing three treatment modalities: SRP with topical tetracycline fibers (SRP+T), SRP with topical minocycline HCL 2% gel (SRP+M), and SRP only as a control group. Probing pocket depth (PPD), clinical attachment loss (CAL), and bleeding on probing (BOP) percentages were recorded at baseline, one month, and at the end of three months. The data were subjected to analysis using IBM Corp. Released 2019. IBM SPSS Statistics for Windows, Version 26.0. Armonk, NY: IBM Corp. Repeated measures ANOVA was used to compare the clinical outcomes between the three treatment groups, accounting for the repeated measurements at baseline, one month, and three months. A p-value less than 0.05 at a 95% confidence interval was deemed statistically significant.

RESULTS

There were statistically significant changes within the groups in all the clinical parameters, including pocket depth, clinical attachment loss, and bleeding on probing score, at different time intervals, with the greatest mean pocket depth changes seen in the tetracycline group after one month (mean changes = 1.4 mm, P < 0.001) and over three months (mean changes = 1.79 mm, p < 0.001). For clinical attachment loss, after one month, the highest improvement in clinical level was seen in the minocycline group (mean changes = 0.7mm, p < 0.05), and the overall improvement was seen in the control group (mean changes = 1.1mm, p < 0.05). The minocycline group showed greater mean changes in bleeding on probing percentage, with the greatest changes after one month (mean changes = 19.34%, p < 0.001) and over three months (mean changes = 26.42%, p <0.001). However, there was no significant difference between the groups.

CONCLUSION

Locally delivered tetracycline and minocycline gel are effective as adjuncts to SRP and may improve the healing outcome in the management of periodontitis.

Minocycline declines interleukin-1ß-induced apoptosis and matrix metalloproteinase expression in C28/I2 chondrocyte cells: an in vitro study on osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease that occurs with aging. In its late phases, it is determined by the loss of chondrocytes and the breakdown of the extracellular matrix, resulting in pain and functional impairment. Interleukin-1 beta (IL-1β) is increased in the injured joints and contributes to the OA pathobiology by inducing chondrocyte apoptosis and up-regulation of matrix metalloproteinases (MMPs). Here, we aimed to understand whether minocycline could protect chondrocytes against the IL-1β-induced effects. The human C28/I2 chondrocyte cell line was treated with IL-1β or IL-1β plus minocycline. Cell viability/toxicity, cell cycle progression, and apoptosis were assessed with MMT assay and flow cytometry. Expression of apoptotic genes and MMPs were evaluated with qRT-PCR and western blotting. IL-1β showed a significant cytotoxic effect on the C28/I2 chondrocyte cells. The minocycline effective concentration (EC50) significantly protected the C28/I2 cells against the IL-1β-induced cytotoxic effect. Besides, minocycline effectively lowered IL-1β-induced sub-G1 cell population increase, indicating the minocycline anti-apoptotic effect. When assessed by real-time PCR and western blotting, the minocycline treatment group showed an elevated level of Bcl-2 and a significant decrease in the mRNA and protein expression of the apoptotic markers Bax and Caspase-3 and Matrix metalloproteinases (MMPs) such as MMP-3 and MMP-13. In conclusion, IL-1β promotes OA by inducing chondrocyte death and MMPs overexpression. Treatment with minocycline reduces these effects and decreases the production of apoptotic factors as well as the MMP-3 and MMP-13. Minocycline might be considered as an anti-IL-1β therapeutic supplement in the treatment of osteoarthritis. See also the graphical abstract(Fig. 1).

Assessment of carvacrol-antibiotic combinations' antimicrobial activity against methicillin-resistant Staphylococcus aureus

Introduction

This study aimed to assess the antimicrobial activity of carvacrol in combination with approved antibiotics against methicillin-resistant Staphylococcus aureus (MRSA). Carvacrol, a phenolic monoterpenoid component of essential oils, has demonstrated antimicrobial properties against gram positive and gram negative bacteria. The study evaluated the antimicrobial effects of carvacrol combined with sulfamethoxazole, linezolid, minocycline, and trimethoprim.

Methods

The MRSA strain (ATCC-33591) was used, and various assays, including MIC determination, checkerboard assay, and microdilution assay were conducted.

Results

The results showed that the combination of carvacrol with antibiotics yielded better outcomes compared to monotherapy, leading to reduced bacterial colonization. Carvacrol, sulfamethoxazole, and trimethoprim exhibited weak anti-staphylococcal effects, while linezolid and minocycline demonstrated stronger effects. This suggests that conventional antibiotic therapy may not be sufficient to effectively treat MRSA infections, potentially causing delays in healing or an exacerbation of the condition. Carvacrol combinations with two antibiotics displayed superior results compared to other pairs, indicating synergistic or additive effects of carvacrol with linezolid, minocycline, and sulfamethoxazole.

Conclusion

These findings propose a new approach for developing drug molecules for MRSA treatment which combine volatile oils with available regimens. Further studies are recommended to evaluate the efficacy and biosafety of these combinations using in vivo or ex vivo models, aiming to minimize side effects and facilitate human trials. This study provides valuable insights into the potential use of carvacrol-antibiotic combinations as a novel therapeutic approach against MRSA.

Comparison of Doxycycline or Minocycline to Sulfamethoxazole-Trimethoprim for Treatment of Stenotrophomonas maltophilia Pneumonia

BACKGROUND

Stenotrophomonas maltophilia is a multidrug-resistant organism with limited antibiotic treatment options. Minocycline and doxycycline may be appropriate, but clinical data are limited.

OBJECTIVE

To compare tetracyclines (minocycline and doxycycline [TCN]) with standard of care, sulfamethoxazole-trimethoprim (TMP-SMZ), in S. maltophilia pneumonia treatment.

METHODS

This retrospective, 2-center study evaluated patients treated for S. maltophilia pneumonia with TCN or TMP-SMZ for clinical success, defined as resolution of leukocytosis, fever, and tachypnea. Patients were classified as treatment with TCN or TMP-SMZ based on definitive agent used for ≥50% of the treatment course and ≥4 days. Inclusion criteria were age ≥18 years, S. maltophilia confirmed on respiratory culture from January 2013 to November 2020, and appropriate definitive antibiotic dosing. Pregnancy, incarceration, S. maltophilia-resistant or intermediate to definitive therapy, and combination therapy for treatment of S. maltophilia pneumonia were exclusion criteria. Secondary outcomes were microbiologic success and recurrence or reinfection within 30 days requiring treatment.

RESULTS

A total of 80 patients were included (21 TCN [15 minocycline, 6 doxycycline], 59 TMP-SMZ). There was no difference in clinical success (28.6% vs 25.4%; P = 0.994), microbiologic success (n = 28, 55.6% vs 66.4%; P = 0.677), or recurrence or reinfection (n = 24, 66.7% vs 26.7%; P = 0.092) between TCN and TMP-SMZ, respectively.

CONCLUSION AND RELEVANCE

Clinical and microbiologic success rates were similar in patients treated with TCN compared with TMP-SMZ for S. maltophilia pneumonia. These data suggest minocycline and doxycycline may be options to treat S. maltophilia pneumonia, but conclusive clinical data continue to be lacking.

Increased expression of chondroitin sulfate proteoglycans in dentate gyrus and amygdala causes postinfectious seizures

Alterations in the extracellular matrix (ECM) are common in patients with epilepsy and in animal models of epilepsy, yet whether they are cause or consequence of seizures and epilepsy development is unknown. Using Theiler's murine encephalomyelitis virus (TMEV) infection-induced model of acquired epilepsy, we find de novo expression of chondroitin sulfate proteoglycans (CSPGs), a major ECM component, in dentate gyrus (DG) and amygdala exclusively in mice with acute seizures. Preventing synthesis of CSPGs specifically in DG and amygdala by deletion of the major CSPG aggrecan reduced seizure burden. Patch-clamp recordings from dentate granule cells (DGCs) revealed enhanced intrinsic and synaptic excitability in seizing mice that was significantly ameliorated by aggrecan deletion. In situ experiments suggest that DGCs hyperexcitability results from negatively charged CSPGs increasing stationary cations on the membrane thereby depolarizing neurons, increasing their intrinsic and synaptic excitability. These results show increased expression of CSPGs in the DG and amygdala as one of the causal factors for TMEV-induced acute seizures. We also show identical changes in CSPGs in pilocarpine-induced epilepsy suggesting that enhanced CSPGs in the DG and amygdala may be a common ictogenic factor and potential therapeutic target.

Acinetobacter baumannii-calcoaceticus species complex and Stenotrophomonas maltophilia isolates to minocycline, 2014-2021

IMPORTANCE

Acinetobacter baumannii-calcoaceticus species complex and Stenotrophomonas maltophilia are opportunistic, non-fermentative Gram-negative organisms that can cause serious hospital-acquired infections in immunocompromised patients. These pathogens are inherently resistant to several common drug classes and often acquire other resistance mechanisms, making them difficult to treat. In this study, we analyzed the trends of susceptibility of over 2,500 U.S. bacterial isolates collected from hospitalized patients over an 8-year period to minocycline, which is used to treat infections caused by these pathogens. These in vitro data suggest that minocycline is a useful treatment option for infections caused by Acinetobacter baumannii-calcoaceticus species complex or Stenotrophomonas maltophilia.

Minocycline and Diacetyl Minocycline Eye Drops Reduce Ocular Neovascularization in Mice

Purpose

To evaluate the efficacy of minocycline and a novel, modified minocycline analogue that lacks antimicrobial action, diacetyl minocycline (DAM), on choroidal neovascularization (CNV) in mice of both sexes.

Methods

CNV was induced via laser injury in female and male C57BL/6J mice. Minocycline, DAM, or saline was administered via topical eye drops twice a day for 2 weeks starting the day after laser injury. CNV volume was measured using immunohistochemistry labeling and confocal microscopy.

Results

Minocycline reduced lesion volume by 79% (P ≤ 0.0004) in female and male mice. DAM reduced lesion volume by 73% (P ≤ 0.001) in female and male mice. There was no significant difference in lesion volume between minocycline and DAM treatment groups or between female and male mice.

Conclusions

Both minocycline and DAM eye drops significantly reduced laser-induced CNV lesion volume in female and male mice. While oral tetracyclines have been shown to mitigate pathologic neovascularization in both preclinical studies and clinical trials, the present data are the first to suggest that tetracycline derivatives may be effective to reduce pathologic CNV when administered via topical eye drops. However, the action is unrelated to antimicrobial action. Targeted delivery of these medications via eye drops may reduce the potential for systemic side effects.

Translational Relevance

Topical administration of minocycline and/or DAM via eye drops may represent a novel therapeutic strategy for disorders involving pathologic CNV.

Prophylactic Minocycline for Delirium in Critically Ill Patients: A Randomized Controlled Trial

BACKGROUND

Delirium is a potentially severe form of acute encephalopathy. Minocycline has neuroprotective effects in animal models of neurologic diseases; however, data from human studies remain scarce.

RESEARCH QUESTION

Does the neuroprotective effect of minocycline prevent delirium occurrence in critical ill patients?

STUDY DESIGN AND METHODS

This study was a randomized, placebo-controlled, double-blind trial conducted in four ICUs. Patients aged 18 years or older were eligible and randomized to receive minocycline (100 mg, twice daily) or placebo. The primary outcome was delirium incidence within 28 days or before ICU discharge. Secondary outcomes included days in delirium during ICU stay, delirium/coma-free days, length of mechanical ventilation, ICU length of stay, ICU mortality, and hospital mortality. The kinetics of various inflammatory (IL-1β, IL-6, IL-10, and C-reactive protein) and brain-related biomarkers (brain-derived neurotrophic factor and S100B) were used as exploratory outcomes.

RESULTS

A total of 160 patients were randomized, but one patient in the placebo group died before treatment; thus the data from 159 patients were analyzed (minocycline, n = 84; placebo, n = 75). After the COVID-19 pandemic it was decided to stop patient inclusion early. There was a small but significant decrease in delirium incidence: 17 patients (20%) in the minocycline arm compared with 26 patients (35%) in the placebo arm (P = .043). No other delirium-related outcomes were modified by minocycline treatment. Unexpectedly, there was a significant decrease in hospital mortality (39% vs. 23%; P = .029). Among all analyzed biomarkers, only plasma levels of C-reactive protein decreased significantly after minocycline treatment (F = 0.75, P = .78, within time; F = 4.09, P = .045, group × time).

INTERPRETATION

Our findings in this rather small study signal a possible positive effect of minocycline on delirium incidence. Further studies are needed to confirm the benefits of this drug as a preventive measure in critically ill patients.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT04219735; URL: www.

CLINICALTRIALS

gov.

Efficacy and safety of minocycline quadruple therapy for Helicobacter pylori eradication: A meta-analysis of RCTs

BACKGROUND

The effective regimen is lacking in areas with high antibiotic resistance and tetracycline unavailable. Whether minocycline can replace tetracycline for Helicobacter pylori eradication is unknown. This meta-analysis compared and summarized the efficacy and safety profiles of H. pylori quadruple regimens with and without minocycline.

MATERIALS AND METHODS

We conducted a literature search for regimens including minocycline quadruple therapy for H. pylori eradication and adverse events (AEs). Controls were patients undergoing any other treatment without minocycline. Searches were performed up to July 20, 2023, using PubMed and the Cochrane library.

RESULTS

A total of five randomized controlled clinical trials with 2004 patients were included in this meta-analysis. The H. pylori eradication rate of minocycline quadruple therapy was similar with that of control therapy (83.8% vs. 80.6%, OR 1.25, 95% CI [0.99-1.57], I2  = 0%, p = 0.06) in ITT analysis. When treatment regimens with minocycline were compared only with treatment regimens with tetracycline, no significant difference was found in eradication rate:85.5% vs. 85.5%, OR 1.00, 95% CI 0.67-1.47, p = 1.00. But when treatment regimens with minocycline were compared with treatment regimens without tetracycline, the former was significantly superiority to the latter (82.7% vs. 77.2%; OR, 1.40, 95% CI 1.06-1.87, p = 0.02). The incidence of AEs in the quadruple therapy with minocycline group was similar with the control group (35.9% vs. 38.8%, OR 0.88, 95% CI [0.73-1.06], I2  = 13%, p = 0.17).

CONCLUSIONS

We demonstrated the H. pylori eradication effect of minocycline quadruple therapy, and it might be an optional therapy. The safety of regimens containing minocycline was relatively satisfactory.

The ratio of M1 to M2 microglia in the striatum determines the severity of L-Dopa-induced dyskinesias

L-Dopa, while treating motor symptoms of Parkinson's disease, can lead to debilitating L-Dopa-induced dyskinesias, limiting its use. To investigate the causative relationship between neuro-inflammation and dyskinesias, we assessed if striatal M1 and M2 microglia numbers correlated with dyskinesia severity and whether the anti-inflammatories, minocycline and indomethacin, reverse these numbers and mitigate against dyskinesia. In 6-OHDA lesioned mice, we used stereology to assess numbers of striatal M1 and M2 microglia populations in non-lesioned (naïve) and lesioned mice that either received no L-Dopa (PD), remained non-dyskinetic even after L-Dopa (non-LID) or became dyskinetic after L-Dopa treatment (LID). We also assessed the effect of minocycline/indomethacin treatment on striatal M1 and M2 microglia and its anti-dyskinetic potential via AIMs scoring. We report that L-Dopa treatment leading to LIDs exacerbates activated microglia numbers beyond that associated with the PD state; the severity of LIDs is strongly correlated to the ratio of the striatal M1 to M2 microglial numbers; in non-dyskinetic mice, there is no M1/M2 microglia ratio increase above that seen in PD mice; and reducing M1/M2 microglia ratio using anti-inflammatories is anti-dyskinetic. Parkinson's disease is associated with increased inflammation, but this is insufficient to underpin dyskinesia. Given that L-Dopa-treated non-LID mice show the same ratio of M1/M2 microglia as PD mice that received no L-Dopa, and, given minocycline/indomethacin reduces both the ratio of M1/M2 microglia and dyskinesia severity, our data suggest the increased microglial M1/M2 ratio that occurs following L-Dopa treatment is a contributing cause of dyskinesias.

Advances in Neuropathic Pain Research: Selected Intracellular Factors as Potential Targets for Multidirectional Analgesics

Neuropathic pain is a complex and debilitating condition that affects millions of people worldwide. Unlike acute pain, which is short-term and starts suddenly in response to an injury, neuropathic pain arises from somatosensory nervous system damage or disease, is usually chronic, and makes every day functioning difficult, substantially reducing quality of life. The main reason for the lack of effective pharmacotherapies for neuropathic pain is its diverse etiology and the complex, still poorly understood, pathophysiological mechanism of its progression. Numerous experimental studies, including ours, conducted over the last several decades have shown that the development of neuropathic pain is based on disturbances in cell activity, imbalances in the production of pronociceptive factors, and changes in signaling pathways such as p38MAPK, ERK, JNK, NF-κB, PI3K, and NRF2, which could become important targets for pharmacotherapy in the future. Despite the availability of many different analgesics, relieving neuropathic pain is still extremely difficult and requires a multidirectional, individual approach. We would like to point out that an increasing amount of data indicates that nonselective compounds directed at more than one molecular target exert promising analgesic effects. In our review, we characterize four substances (minocycline, astaxanthin, fisetin, and peimine) with analgesic properties that result from a wide spectrum of actions, including the modulation of MAPKs and other factors. We would like to draw attention to these selected substances since, in preclinical studies, they show suitable analgesic properties in models of neuropathy of various etiologies, and, importantly, some are already used as dietary supplements; for example, astaxanthin and fisetin protect against oxidative stress and have anti-inflammatory properties. It is worth emphasizing that the results of behavioral tests also indicate their usefulness when combined with opioids, the effectiveness of which decreases when neuropathy develops. Moreover, these substances appear to have additional, beneficial properties for the treatment of diseases that frequently co-occur with neuropathic pain. Therefore, these substances provide hope for the development of modern pharmacological tools to not only treat symptoms but also restore the proper functioning of the human body.

Minocycline synergizes with corticosteroids in reducing colitis severity in mice via the modulation of pro-inflammatory molecules

Background: A few studies have highlighted the anti-inflammatory properties of minocycline in reducing colitis severity in mice, but its molecular mechanism is not fully understood. The aim of this study was to determine the anti-inflammatory properties of minocycline and the expression/activity profiles of molecules involved in pro-inflammatory signaling cascades, cytokines, and molecules involved in the apoptotic machinery. The synergistic effect between minocycline and corticosteroids was also evaluated. Methods: The effects of various treatment approaches were determined in mice using the dextran sulfate sodium (DSS) colitis model at gross and microscopic levels. The expression/activity profiles of various pro- or anti-inflammatory molecules were determined using Western blotting and polymerase chain reaction (PCR). Results: Minocycline treatment significantly reduced colitis severity using prophylactic and treatment approaches and produced a synergistic effect with budesonide and methylprednisolone in reducing the active state of colitis. This was mediated in part through reduced colonic expression/activity of pro-inflammatory molecules, cytokines, proteins involved in the apoptotic machinery, and increased expression of the anti-inflammatory cytokine IL-10. Conclusion: Minocycline synergizes with corticosteroids to reduce colitis severity, which could reduce their dose-dependent side effects and treatment cost. The reduction in colitis severity was achieved by modulating the expression/activity profiles of various pro- and anti-inflammatory signaling molecules, cytokines, and molecules involved in the apoptotic machinery.

The application of electrosprayed minocycline-loaded PLGA microparticles for the treatment of glioblastoma

The survival of patients with glioblastoma multiforme (GBM), the most common and invasive form of malignant brain tumors, remains poor despite advances in current treatment methods including surgery, radiotherapy, and chemotherapy. Minocycline is a semi-synthetic tetracycline derivative that has been widely used as an antibiotic and more recently, it has been utilized as an antiangiogenic factor to inhibit tumorigenesis. The objective of this study was to investigate the utilization of electrospraying process to fabricate minocycline-loaded poly(lactic-co-glycolic acid) (PLGA) microparticles with high drug loading and loading efficiency and to evaluate their ability to induce cell toxicity in human glioblastoma (i.e., U87-MG) cells. The results from this study demonstrated that solvent mixture of dicholoromethane (DCM) and methanol is the optimal solvent combination for minocycline and larger amount of methanol (i.e., 70:30) resulted in a higher drug loading. All three solvent ratios of DCM:methanol tested produced microparticles that were both spherical and smooth, all in the micron size range. The electrosprayed microparticles were able to elicit a cytotoxic response in U87-MG glioblastoma cells at a lower concentration of drug compared to the free drug. This work provides proof of concept to the hypothesis that electrosprayed minocycline-loaded PLGA microparticles can be a promising agent for the treatment of GBM and could have potential application for cancer therapies.

Novel Treatments for PXE: Targeting the Systemic and Local Drivers of Ectopic Calcification

Pseudoxanthoma elasticum (PXE) is a heritable multisystem ectopic calcification disorder. The gene responsible for PXE, ABCC6, encodes ABCC6, a hepatic efflux transporter regulating extracellular inorganic pyrophosphate (PPi), a potent endogenous calcification inhibitor. Recent studies demonstrated that in addition to the deficiency of plasma PPi, the activated DDR/PARP signaling in calcified tissues provides an additional possible mechanism of ectopic calcification in PXE. This study examined the effects of etidronate (ETD), a stable PPi analog, and its combination with minocycline (Mino), a potent inhibitor of DDR/PARP, on ectopic calcification in an Abcc6-/- mouse model of PXE. Abcc6-/- mice, at 4 weeks of age, before the development of ectopic calcification, were treated with ETD, Mino, or both for 18 weeks. Micro-computed tomography, histopathologic examination, and quantification of the calcium content in Abcc6-/- mice treated with both ETD and Mino revealed further reduced calcification than either treatment alone. The effects were associated with reduced serum alkaline phosphatase activity without changes in plasma PPi concentrations. These results suggest that ETD and Mino combination therapy might provide an effective therapeutic approach for PXE, a currently intractable disease.

resistant to fluconazole

Species of the genus Candida, characterized as commensals of the human microbiota, are opportunistic pathogens capable of generating various types of infections with high associated costs. Considering the limited pharmacological arsenal and the emergence of antifungal-resistant strains, the repositioning of drugs is a strategy used to search for new therapeutic alternatives, in which minocycline and doxycycline have been evaluated as potential candidates. Thus, the objective was to evaluate the in vitro antifungal activity of two tetracyclines, minocycline and doxycycline, and their possible mechanism of action against fluconazole-resistant strains of Candida spp. The sensitivity test for antimicrobials was performed using the broth microdilution technique, and the pharmacological interaction with fluconazole was also analysed using the checkerboard method. To analyse the possible mechanisms of action, flow cytometry assays were performed. The minimum inhibitory concentration obtained was 4-427 µg ml-1 for minocycline and 128-512 µg ml-1 for doxycycline, and mostly indifferent and additive interactions with fluconazole were observed. These tetracyclines were found to promote cellular alterations that generated death by apoptosis, with concentration-dependent reactive oxygen species production and reduced cell viability. Therefore, minocycline and doxycycline present themselves as promising study molecules against Candida spp.

5-Aminolevulinic acid photodynamic therapy versus minocycline for moderate-to-severe rosacea: A single-center, randomized, evaluator-blind controlled study

BACKGROUND

5-Aminolevulinic acid photodynamic therapy (ALA-PDT) showed potential to treat rosacea according to recent studies; however, a lack of clinical evidence and unclear adverse effects limit its use.

OBJECTIVE

To compare the effect of ALA-PDT vs minocycline on rosacea.

METHODS

In this single-center, randomized, evaluator-blind, controlled study, patients with moderate-to-severe rosacea were allocated to receive 3 to 5 sessions of ALA-PDT or 8 weeks of 100 mg daily minocycline treatment, followed by a 24-week follow-up.

RESULTS

Of all the 44 randomized patients, 41 received complete treatment (ALA-PDT: 20 and minocycline: 21 patients). At the end of treatment, ALA-PDT showed noninferior improvement of papulopustular lesions and Rosacea-specific Quality of Life compared with minocycline (median reduction of lesion count: 19 vs 22, median change of Rosacea-specific Quality of Life score: 0.48 vs 0.53). The Clinician's Erythema Assessment success of ALA-PDT was lower than that of minocycline's (35% vs 67%). Demodex density and relapse rate were comparable in both groups. Erythema, mild pain, and exudation were the most common adverse reactions of ALA-PDT.

LIMITATIONS

Limited sample size restricted us from drawing further conclusions.

CONCLUSION

As minocycline does, ALA-PDT can improve rosacea mainly in papulopustular lesions and patients' quality of life, indicating a new option for rosacea.

Comparison of Prophylactic Effects between Localized Biomimetic Minocycline and Systematic Amoxicillin on Implants Placed Immediately in Infected Sockets

This study evaluated the prophylactic effect of localized biomimetic minocycline and systemic amoxicillin on immediate implant placement at infected extraction sites. Twelve mongrels with six implants each were randomly assigned to five groups: uninfected negative control (Group N); infected with oral complex bacteria (Group P); infected and treated with amoxicillin one hour before implant placement (Group A); infected and treated with minocycline during implant placement (Group B); and infected and treated with amoxicillin one hour before implant placement and with minocycline during implant placement (Group C). Radiographic bone level, gingival index (GI), probing depth (PD), papillary bleeding index (PBI), and removal torque (RT) were recorded. There was no significant difference between Groups A, B, and C for bone loss. Group A showed the highest RT, the lowest PBI, and significantly lower GI and PD values than Group P. Group B exhibited significantly higher RT value than Group N and significantly smaller PD value than Group P at 6 w postoperatively. Localized minocycline could improve implant success by reducing bone loss and increasing RT and systemic amoxicillin could maintain the stability of the peri-implant soft tissue. However, combined use of these two antibiotics did not augment the prophylactic effect.

Polymorphous Cutaneous Sarcoidosis With Excellent Response to Minocycline

Sarcoidosis is notorious for producing a wide variety of skin lesions, which are categorized as either specific or nonspecific. The specific lesions include primary morphologies ranging from micropapules to subcutaneous nodules. Nonspecific skin lesions include associated conditions like erythema nodosum, calcinosis cutis, and prurigo. It is not uncommon for a patient to have a combination of specific and nonspecific lesions. In contrast, it is exceedingly rare for one patient to have multiple specific sarcoidal lesions. When present, the term "polymorphous cutaneous sarcoidosis" has been used. We present the case of a patient who presented with three specific cutaneous morphologies of sarcoidosis: papular sarcoid, Darier-Roussy subcutaneous sarcoidosis, and lupus pernio. After only two months of oral minocycline, our patient demonstrated remarkable improvement with near-complete resolution of the cutaneous lesions. In addition to describing the rare polymorphous presentation, this case also highlights the challenge of relating lesion type to overall prognosis when multiple morphologies are present.

Trimethoprim/Sulfamethoxazole vs Minocycline for the Treatment of Nonurinary Monomicrobial Stenotrophomonas maltophilia Infections in Hospitalized Patients

BACKGROUND

Stenotrophomonas maltophilia is an opportunistic, gram-negative bacillus with few therapeutic options due to a high level of intrinsic resistance. Trimethoprim/sulfamethoxazole (SXT) is recommended as the first-line treatment; however, minocycline (MIN) has been shown to have similar clinical outcomes in treating S. maltophilia and addresses concern for increasing resistance to SXT.

OBJECTIVE

The objective of this study is to evaluate the efficacy and safety outcomes of nonurinary, monomicrobial infections due to S. maltophilia in hospitalized patients treated with MIN or SXT.

METHODS

This was a retrospective study of hospitalized adult patients receiving MIN or SXT for nonurinary monomicrobial S. maltophilia infection from April 1, 2018 to March 31, 2020. The primary outcome was clinical disposition classified as rates of clinical failure, clinical improvement, or clinical success.

RESULTS

Eighty-two patients (88.2%) received MIN and 11 patients (11.8%) received SXT initially. Clinical failure occurred in 16 (19.5%) patients in the MIN group and in 4 (36.4%) patients in the SXT group (P = 0.242). Clinical improvement occurred in 11 (13.4%) patients in the MIN group and in 1 (9.1%) patient in the SXT group (P = 1.0). Clinical success occurred in 55 (67.1%) patients in the MIN group and in 6 (54.5%) patients in the SXT group (P = 0.503). Total duration of antimicrobial therapy (P = 0.3198), in-hospital mortality (P = 1.0), hospital length of stay (P = 0.9668), intensive care unit (ICU) length of stay (P = 0.1384), and 30-day readmission (P = 0.686) were similar between groups.

CONCLUSIONS AND RELEVANCE

Rates of clinical failure, clinical improvement, or clinical success were similar between MIN and SXT for nonurinary monomicrobial S. maltophilia infections.

A Prospective, Randomized, Comparative Study of Topical Minocycline Gel 4% with Topical Clindamycin Phosphate Gel 1% in Indian Patients with Acne Vulgaris

Acne vulgaris is characterized by inflammatory and non-inflammatory skin lesions with a high prevalence among adolescents in India. Not enough studies are reported on the use of topical antibiotics for the management of acne in the Indian population. The proposed study aims to compare the efficacy and safety of topical minocycline gel 4% with topical clindamycin gel 1% in the Indian population. A randomized, open-label, double-arm study was planned at two centers in India. One hundred patients were enrolled and randomized equally to two treatment arms. The drugs were applied once daily, preferably at the same time each day. The number of inflammatory and non-inflammatory lesions, as well as the investigator's global assessment (IGA), were obtained at the baseline and on weeks 3, 6, 9, and 12. The change in these parameters from baseline to week 12 was compared between the two treatment arms. A tolerability assessment was also performed on selected parameters. The age of patients ranged between 14 and 31 years, with female preponderance in each arm. On week 12, the percent change in inflammatory and non-inflammatory lesions in the minocycline 4% arm was significantly higher than in the clindamycin 1% arm (p < 0.0001). The IGA treatment success was significantly higher in the minocycline arm compared to the clindamycin arm on weeks 9 and 12, with p-values of 0.001 and 0.015, respectively. Tolerability assessment revealed significantly improved parameter performance in the minocycline arm compared to the clindamycin arm. On subgroup analysis, in adolescents, minocycline was found to be more efficacious than clindamycin. The comparative assessment resulted in a significantly improved performance of minocycline gel 4% compared to clindamycin gel 1% in the Indian population, thus making it a preferred choice for the treatment of moderate-to-severe acne in India.

A Case of Granuloma Faciale Successfully Treated with Minocycline

Granuloma faciale (GF) is a rare chronic inflammatory dermatosis in clinical practice. The etiology is not yet clear, and it often occurs on the face. The progression of skin lesions is slow and persistent, with almost no self regression and a risk of recurrence, which may lead to disfigurement. We reported a 61-year-old male with GF who had poor reaction with topical corticosteroids and calcineurin inhibitors, but the lesions were significantly improved after systematic application of minocycline. This report describes the good clinical effect of minocycline on GF.

The Role of Reflectance Confocal Microscopy in the Diagnosis and Therapeutic Evaluation of Rare Disease Eosinophilic Pustular Folliculitis

Eosinophilic pustular folliculitis (EPF) is a rare skin disease for which the gold standard of diagnosis relies on the invasive examination of pathological tissue sections. However, due to its invasive nature, many patients tend to refuse this diagnostic test. In such situations, reflectance confocal microscopy (RCM) can be a valuable diagnosis tool. Reflectance confocal microscopy (RCM) can accurately identify the specific structures for biopsy and provide objective imaging data to evaluate clinical symptoms following treatment. Therefore, we present a case report demonstrating the utility of RCM in diagnosing and assessing the treatment of the rare disease EPF for reference.

Microglia and p38 MAPK Inhibitors Suppress Development of Mechanical Allodynia in Both Sexes in a Mouse Model of Antiretroviral-Induced Neuropathic Pain

Microglia activation in the spinal cord play a major role in the pathogenesis of neuropathic pain. The p38 mitogen-activated protein kinase (MAPK) regulates microglia activation. Previously, 2',3'-dideoxycytidine (ddC), a nucleoside reverse transcriptase inhibitor (NRTI), was found to induce mechanical allodynia and microglia activation in the spinal cords of male and female mice. In this study, we investigated the role of spinal microglia and p38 MAPK signaling in the development of mechanical allodynia using immunofluorescence staining and treatment with microglia and p38 MAPK inhibitors in both sexes. Male and female mice (BALB/c strain) treated intraperitoneally once daily with ddC 25 mg/kg for five consecutive days developed mechanical allodynia, assessed using the dynamic plantar aesthesiometer. Treatment with ddC increased microglia markers CD11b and ionized calcium-binding adapter molecule 1 (Iba1) staining intensity in male mice, while only CD11b was increased in female mice. Both sexes had increased phosphorylated p38 MAPK staining intensity. The administration of minocycline, an inhibitor of microglia activation, and adezmapimod, a selective p38 MAPK inhibitor, suppressed mechanical allodynia in both sexes at day 7 after ddC treatment. Therefore, microglia activation and p38 MAPK signaling are important for the development of antiretroviral drug-induced mechanical allodynia.

Efficacy of Minocycline for the Treatment of Mycoplasma genitalium

Background

High levels of macrolide resistance and increasing fluoroquinolone resistance are making Mycoplasma genitalium increasingly difficult to treat. Minocycline is an alternative treatment for patients with macrolide-resistant M genitalium infections that have failed moxifloxacin, or for those with fluoroquinolone contraindications or resistance. Published efficacy data for minocycline for M genitalium are limited.

Methods

We evaluated minocycline 100 mg twice daily for 14 days at Melbourne Sexual Health Centre (MSHC). Microbial cure was defined as a negative test of cure within 14-90 days after completing minocycline. The proportion cured and 95% confidence intervals (CIs) were calculated, and logistic regression was used to explore factors associated with treatment failure. We pooled data from the current study with a prior adjacent case series of patients with M genitalium who had received minocycline 100 mg twice daily for 14 days at MSHC.

Results

Minocycline cured 60 of 90 (67% [95% CI, 56%-76%]) infections. Adherence was high (96%) and side effects were mild and self-limiting. No demographic or clinical characteristics were associated with minocycline failure in regression analyses. In the pooled analyses of 123 patients, 83 (68% [95% CI, 58%-76%]) were cured following minocycline.

Conclusions

Minocycline cured 68% of macrolide-resistant M genitalium infections. These data provide tighter precision around the efficacy of minocycline for macrolide-resistant M genitalium and show that it is a well-tolerated regimen. With high levels of macrolide resistance, increasing fluoroquinolone resistance, and the high cost of moxifloxacin, access to nonquinolone options such as minocycline is increasingly important for the clinical management of M genitalium.

Symptomatic dermographism induced by oral minocycline: A report of four cases

Symptomatic dermographism (SD) is the most common form of chronic inducible urticarias. The etiology of this disease has rarely been reported in the literature. Minocycline is widely used in the treatment of acne, rosacea, and other inflammatory skin diseases. Herein we report four cases of SD onset during minocycline administration. These were young women in their 20s to 30s who were taking minocycline orally for acne vulgaris or rosacea. They all experienced the onset of SD 2-3 weeks after taking the drug, and then the complete disappearance of SD 1 month after stopping the drug. Minocycline was thought to be the culprit drug in these cases as other drugs were ruled out on clinical grounds. Our small series suggests that oral minocycline may induce SD, thus raising the awareness of this association in clinical practice. More research is needed to further confirm this association and reveal the underlying mechanism(s).

Minocycline-Induced Ocular Ochronosis

We report a case of minocycline-induced ocular ochronosis with scleral, retinal, and cutaneous manifestations. A 65-year-old male who had taken minocycline for four years to treat hidradenitis suppurativa, an inflammatory skin condition affecting the apocrine sweat glands and hair follicles, presented for evaluation of discoloration of bilateral sclera, nail beds, and gingiva. Ophthalmic evaluation revealed intact visual acuity, diffuse blue-gray hyperpigmentation of the sclera, more pronounced overlying insertions of the horizontal muscles, without any scleral thinning. Macular optical coherence tomography and fundus exam revealed a blue hue to the underlying choroid with dark deposits in the retinal pigment epithelium. Despite drug discontinuation, after six years the discoloration persisted. Management was directed towards patient tolerability.

Steno-sphere: Navigating the enigmatic world of emerging multidrug-resistant Stenotrophomonas maltophilia

Stenotrophomonas maltophilia is an opportunistic pathogen and frequent cause of serious nosocomial infections. Patient populations at greatest risk for these infections include the immunocompromised and those with chronic respiratory illnesses and prior antibiotic exposure, notably to carbapenems. Its complex virulence and resistance profile drastically limit available antibiotics, and incomplete breakpoint and pharmacokinetic/pharmacodynamic (PK/PD) data to inform dose optimization further complicates therapeutic approaches. Clinical comparison data of first-line agents, including trimethoprim-sulfamethoxazole (TMP-SMX), quinolones, and minocycline, are limited to conflicting observational data with no clear benefit of a single agent or combination therapy. Newer antibiotic approaches, including cefiderocol and aztreonam- avibactam, are promising alternatives for extensively drug-resistant isolates; however, clinical outcomes data are needed. The potential clinical utility of bacteriophage for compassionate use in treating S. maltophilia infections remains to be determined since data is limited to in-vitro and sparse in-vivo work. This article provides a review of available literature for S. maltophilia infection management focused on related epidemiology, resistance mechanisms, identification, susceptibility testing, antimicrobial PK/PD, and emerging therapeutic strategies.

Oral Tetracycline-Class Drugs in Dermatology: Impact of Food Intake on Absorption and Efficacy

Tetracycline-class drugs are frequently used in dermatology for their anti-inflammatory properties to treat skin diseases such as acne, rosacea, and hidradenitis suppurativa (HS). The American Academy of Dermatology (AAD) clinical guidelines do not offer guidance regarding the co-administration of food with tetracycline-class drugs. The objectives of this study were to review the available evidence regarding whether taking tetracycline-class drugs with food decreases systemic absorption and is associated with an impact on clinical efficacy. A literature search was conducted using the PubMed database between February to May 2023 using the keywords "tetracycline-class drugs", "pharmacokinetics", "absorption", and "dermatology". Inclusion criteria included articles written in English and relevant to the absorption and efficacy of tetracycline-class drugs. This search yielded 131 articles written between 1977 to 2022, of which 29 met the criteria for review. United States Food and Drug Administration (FDA)-approved prescribing information for oral formulations of tetracycline, doxycycline, minocycline, and sarecycline were reviewed. Systemic absorption of tetracycline decreased when co-administered with food. Systemic absorption of oral doxycycline and minocycline was variable with food co-administration. The impact on bioavailability varied with the drug formulation and dosage. The absorption of oral sarecycline decreased when administered with food. Sarecycline is the only oral antibiotic where population pharmacokinetic studies demonstrated limited or no impact of food intake on clinical efficacy. There are no available data for other tetracycline-class drugs in dermatology. If patients find it more tolerable to take doxycycline, minocycline, and sarecycline with food to avoid gastrointestinal distress, this may merit consideration to encourage patient adherence. Since the impact of food intake on absorption varied with the dosage form of doxycycline and minocycline, consulting the appropriate package insert may give clinicians additional insight into differences in the various formulations.

Efficacy and tolerability of minocycline in depressive patients with or without treatment-resistant: a meta-analysis of randomized controlled trials

Background

Minocycline, an antibiotic with anti-inflammatory, antioxidant, and neuroprotective properties, has been used for treating psychiatric disorders in research. This systematic review aimed to evaluate the efficacy and tolerability of minocycline in patients having depression with or without treatment-resistance.

Methods

Electronic databases including Embase, PubMed, and the Cochrane library were searched for relevant studies published up to October 17, 2022. The primary efficacy outcome was the change in depression severity scores and the secondary efficacy outcomes included the changes in Clinical Global Impression (CGI) and Beck Depression Inventory (BDI) scores and the incidence of response and partial response. Safety outcomes were evaluated based on the incidence of classified adverse events and all-cause discontinuation.

Results

Five studies with 374 patients were selected for analysis. The minocycline group demonstrated a significant reduction in depression severity scale (standardized mean difference [SMD]: -0.59, 95% confidence interval [CI]: -0.98 to -0.20, P = 0.003) and CGI (SMD: -0.28, 95% CI: -0.56 to -0.01, P = 0.042) scores; however, no statistical difference was found in terms of the BDI score, response, and partial response. No significant differences were found between the groups in terms of adverse events (other than dizziness) and discontinuation rates. Subgroup analysis showed that minocycline was also effective in reducing depression severity scores in treatment-resistant depression (SMD: -0.36, 95% CI: -0.64 to -0.09, P = 0.010). Subgroup analysis of Hamilton Depression Rating Scale (17-item) scores showed a statistical difference in response in patients with depression (relative risk: 2.51, 95% CI: 1.13 to 5.57, P = 0.024).

Conclusions

Minocycline may improve depressive symptoms and augment response to treatment in patients with depression irrespective of treatment-resistance. However, clinical trials with large sample sizes are warranted for evaluating long-term outcomes with minocycline.

Systematic review registration

https://inplasy.com/inplasy-2022-12-0051/.

After Ischemic Stroke, Minocycline Promotes a Protective Response in Neurons via the RNA-Binding Protein HuR, with a Positive Impact on Motor Performance

Ischemic stroke is the most common cause of adult disability and one of the leading causes of death worldwide, with a serious socio-economic impact. In the present work, we used a new thromboembolic model, recently developed in our lab, to induce focal cerebral ischemic (FCI) stroke in rats without reperfusion. We analyzed selected proteins implicated in the inflammatory response (such as the RNA-binding protein HuR, TNFα, and HSP70) via immunohistochemistry and western blotting techniques. The main goal of the study was to evaluate the beneficial effects of a single administration of minocycline at a low dose (1 mg/kg intravenously administered 10 min after FCI) on the neurons localized in the penumbra area after an ischemic stroke. Furthermore, given the importance of understanding the crosstalk between molecular parameters and motor functions following FCI, motor tests were also performed, such as the Horizontal Runway Elevated test, CatWalk™ XT, and Grip Strength test. Our results indicate that a single administration of a low dose of minocycline increased the viability of neurons and reduced the neurodegeneration caused by ischemia, resulting in a significant reduction in the infarct volume. At the molecular level, minocycline resulted in a reduction in TNFα content coupled with an increase in the levels of both HSP70 and HuR proteins in the penumbra area. Considering that both HSP70 and TNF-α transcripts are targeted by HuR, the obtained results suggest that, following FCI, this RNA-binding protein promotes a protective response by shifting its binding towards HSP70 instead of TNF-α. Most importantly, motor tests showed that reduced inflammation in the brain damaged area after minocycline treatment directly translated into a better motor performance, which is a fundamental outcome when searching for new therapeutic options for clinical practice.

Chronic Suppressive Antibiotic Treatment for Staphylococcal Bone and Joint Implant-Related Infections

Prosthetic joint infection (PJI) and fracture-related infection (FRI) are difficult-to-treat conditions in patients with severe comorbidity or significant surgical risk. In cases not eligible for standard strategy, debridement procedures with the retention of prosthesis or internal fixation device, combined with long-term antibiotic treatment and subsequent indefinite chronic oral antimicrobial suppression (COAS), can be the only reasonable choice. The aim of this study was to investigate the role of COAS and its follow-up in the management of these cases. We retrospectively analyzed a cohort of 16 patients with a follow-up of at least 6 months (mean age 75 yo, 9F, 7M, 11 PJI, 5 FRI). All microbiological isolates were tetracycline-susceptible staphylococci and for this reason a minocycline-based COAS was adopted after debridement and 3 months of antibiogram-guided antibiotic treatment. Patient monitoring was carried out on a clinical basis, with bimonthly execution of the inflammation indices and serial radiolabeled leukocyte scintigraphy (LS). The overall median time of COAS follow-up was 15 months (min 6-max 30). Moreover, 62.5% of patients were still taking COAS with no relapse after cure at the last evaluation available. Clinical failure with a relapse of the infection was observed in 37.5% of patients; interestingly, 50% of them had previously stopped COAS due to side effects of the antibiotic used. In the COAS follow-up, a combination of clinical, laboratory and LS evaluation seems to monitor the infection properly. COAS can be considered as an interesting approach in patients not suitable for standard treatments of PJI or FRI but it requires careful monitoring.

The interaction between kynurenine pathway, suicidal ideation and augmentation therapy with minocycline in patients with treatment-resistant depression

BACKGROUND AND AIMS

We investigated kynurenine pathway (KP) metabolites levels and their association with suicidal ideation in patients with treatment-resistant depression (TRD) and elevated peripheral inflammation. The effect of antidepressant augmentation with minocycline on KP metabolites was tested.

METHODS

We analysed data from MINocycline in DEPression, a 4-week, randomized, placebo controlled (1:1) trial of minocycline added to antidepressant treatment in 39 TRD patients (n = 18 minocycline; n = 21 placebo) with C-reactive protein (CRP) ⩾1 mg/L. At baseline and at week 4, we collected data on suicidality (Beck Depression Inventory) and blood samples to measure inflammatory markers and KP metabolites. We tested (1) the association of KP metabolites ratios with inflammatory markers and suicidal ideation at baseline and (2) the role of suicidality and treatment (minocycline vs placebo) in affecting KP changes over time.

RESULTS

At baseline, kynurenine/tryptophan (KYN/TRP) ratio positively correlated with high-sensitivity CRP (Spearman's ρ = 0.35, p = 0.02) and IL-10, (ρ = 0.41, p = 0.009); and tumour necrosis factor was positively correlated with quinolinic acid/3-hydroxykynurenine ratio (ρ = 0.55, p < 0.001). Moreover, participants with suicidal ideation showed higher levels of KYN/TRP (U = 143.000, p = 0.02) than those without suicidal ideation. There was no significant effect of minocycline on KP metabolites changes from baseline to week 4. However, in the minocycline group, the number of participants with suicidal thoughts decreased from 44.4% (8/18) to 22.2% (4/18).

CONCLUSION

Increased KP neurotoxic metabolites are associated with elevated peripheral inflammation in depressed individuals, particularly in those with suicidal ideation. Targeting KP in this population could be a potential effective personalized approach. Whether this includes minocycline should be investigated in future larger trials.