Antiinflammatory effects of Tacrolimus in a mouse model of pleurisy

Cardiac transplant recipient with COVID-19 induced acute hypoxic respiratory failure: a case report

BACKGROUND

Heart transplant recipients represent a particularly vulnerable patient population to the novel coronavirus disease 2019 (COVID-19) due to chronic immunosuppression and high rates of comorbidities. Currently, data are limited and evidence to guide management of heart transplant recipients with COVID-19 is sparse. In this case report, we provide a summary of the current literature as well as an in-depth analysis of our clinical decision-making.

CASE SUMMARY

A 67-year-old female who underwent cardiac transplantation 1 year prior was found to have acute hypoxic respiratory failure due to COVID-19. Her immunosuppressant medications were modulated with discontinuation of mycophenolate and titration of tacrolimus troughs with a goal of 6-10 ng/dL. She was administered supportive treatment including convalescent plasma, remdesivir, and dexamethasone, in addition to antibiotic treatment that resulted in resolution of her symptoms within a matter of days despite her precarious disposition.

DISCUSSION

This case demonstrates that it can be safe and efficacious to modulate immunosuppressant medications in cardiac transplant recipients in accordance with recommendations made by the International Society of Heart and Lung Transplantation. This case additionally demonstrates that aspects of the current literature regarding the management of COVID-19 can be safely extrapolated to cardiac transplant recipients. Providing supportive care with dexamethasone, remdesivir, and convalescent plasma as indicated can be beneficial in cardiac transplant recipients; although, the current literature regarding convalescent plasma and remdesivir is conflicting.

Pulmonary surfactant and drug delivery: Vehiculization, release and targeting of surfactant/tacrolimus formulations

This work explores the potential for strategizing pulmonary surfactant (PS) for drug delivery over the respiratory air-liquid interface: the interfacial delivery. The efficacy of PS- and interface-assisted drug vehiculization was determined both in vitro and in vivo using a native purified porcine PS combined with the hydrophobic anti-inflammatory drug Tacrolimus (TAC), a calcineurin inhibitor. In vitro assays were conducted in a novel double surface balance setup designed to emulate compression-expansion dynamics applied to interfacially connected drug donor and recipient compartments. In this setup, PS transported TAC efficiently over air-liquid interfaces, with compression/expansion breathing-like dynamics enhancing rapid interface-assisted diffusion and drug release. The efficacy of PS-assisted TAC vehiculization was also evaluated in vivo in a mouse model of lipopolysaccharide (LPS)-induced acute lung injury (ALI). In anesthetized mice, TAC combined with PS was intra-nasally (i.n) instilled prior administering i.n. LPS. PS/TAC pre-treatment caused greater TAC internalization into a higher number of lung cells obtained from bronchoalveolar lavages (BAL) than TAC pre-treatment alone. Additionally, the PS/TAC combination but not TAC or PS alone attenuated the LPS-induced pro-inflammatory effects reducing cells and proteins in BAL fluid. These findings indicated that PS-mediated increase in TAC uptake blunted the pro-injurious effects of LPS, suggesting a synergistic anti-inflammatory effect of PS/drug formulations. These in vitro and in vivo results establish the potential utility of PS to open novel effective delivery strategies for inhaled drugs.

Acupuncture reduces peripheral and brainstem cytokines in rats subjected to lipopolysaccharide-induced inflammation

BACKGROUND

Lipopolysaccharide (LPS) endotoxins are activators of innate immunity inducing infection and inflammatory responses. Anti-inflammatory drugs can have undesirable side effects. Acupuncture may be an alternative for the treatment of inflammatory processes.

OBJECTIVE

We investigated the potential anti-inflammatory effect of manual acupuncture (MA) at SP6 upon LPS-induced peritonitis in rats.

METHODS

Peritonitis was induced in rats with an intraperitoneal injection of LPS (0.002, 0.02, 0.2 or 2 µg/kg) in four experimental groups (n = 6 each). A fifth group was injected with sterile saline solution (saline group, n = 6). Four hours after the procedure, peritoneal fluid was collected to determine total cell counts for inflammatory cells, differential leukocyte counts and peritoneal capillary permeability. The LPS dose of 0.02 µg/kg was used in the subsequent experiments as it most successfully induced peritoneal inflammation. Subsequently, five experimental groups (n = 12 rats each) were used: (1) saline, (2) control (untreated LPS group), (3) indomethacin (LPS group treated with indomethacin), (4) NA (LPS group treated with MA at a location not corresponding to any traditional acupuncture point), and (5) SP6 (LPS group treated with verum MA at SP6). Ten minutes after MA or 30 min after indomethacin treatment, the rats received an intraperitoneal injection of LPS. After 4 h, total leukocyte and differential cell counts, myeloperoxidase (MPO) activity, vascular permeability and cytokine levels were evaluated in the peritoneal fluid. Cytokine levels were additionally evaluated in the brainstem.

RESULTS

SP6 MA and indomethacin treatments reduced inflammatory cell infiltration, vascular permeability and MPO activity in the LPS-exposed rats. Pre-treatment with indomethacin and SP6 MA decreased tumor necrosis factor (TNF)-α levels and preserved interleukin (IL)-10 in the peritoneal fluid. Indomethacin also reduced IL-6 in the peritoneal fluid. In the brainstem, indomethacin reduced IL-1β, IL-6, TNFα and IL-10, whereas SP6 MA reduced only TNFα and IL-6 levels.

CONCLUSIONS

This study clearly demonstrates the anti-inflammatory effect of acupuncture, which we believe may involve the activation of anti-inflammatory neural reflexes in the regulation of peritonitis.

Streptomyces-Derived Metabolites with Potential Photoprotective Properties-A Systematic Literature Review and Meta-Analysis on the Reported Chemodiversity

Sun overexposure is associated with the development of diseases that primarily affect the skin, which can lead to skin cancer. Among the main measures of photoprotection is the use of sunscreens. However, there is currently concern about the reported harmful effects to both humans and the environment due to several of the sunscreen ingredients available on the market. For this reason, the search for and development of new agents with photoprotective properties is required. In searching for these metabolites, researchers have turned their attention to microbial sources, especially the microbiota in unusual hostile environments. Among the diverse microorganisms available in nature, Actinobacteria and specifically Streptomyces, have been shown to be a source of metabolites with various biological activities of interest, such as antimicrobial, antitumor and immunomodulator activities. Herein, we present the results of a systematic review of the literature in which Streptomyces isolates were studied as a source of compounds with photoprotective properties. A meta-analysis of the structure-property and structure-activity relationships of those metabolites identified in the qualitative analysis phase was also carried out. These findings indicate that Streptomyces are a source of metabolites with potential applications in the development of new, safe and more eco-friendly sunscreens.

Withdrawing mycophenolate mofetil in treating a young kidney transplant recipient with COVID-19: A case report

RATIONALE

Coronavirus disease 2019 (COVID-19) is a novel infectious disease and became a global issue. Treatment of COVID-19 especially in solid organ transplant recipients is empirical and controversial, especially the adjustment of the immunosuppressants.

PATIENT CONCERNS

A 29-year-old kidney transplant recipient with the symptoms of COVID-19 pneumonia.

DIAGNOSES

COVID-19 pneumonia after kidney transplantation.

INTERVENTIONS

He was treated with modified immunosuppressants (unchanged dose of tacrolimus and oral corticosteroids while discontinuing mycophenolate mofetil (MMF)), antibiotics, interferon α-2b inhalation and traditional Chinese medicine.

OUTCOMES

He recovered from COVID-19 pneumonia after 29 days of hospitalization. And the renal function (measured as blood urea nitrogen, serum creatinine, and urine protein) returned to normal.

LESSONS

In certain group of COVID-19 (e.g., mild to moderate cases, young patients without comorbidities), a reduction instead of an overall withdrawal of immunosuppressant in kidney transplant recipients is feasible.

Evaluation of the Roflumilast Effect Supplemented with Linezolid in Pleural Empyema in Rats Caused by Intrapleural Staphylococcus aureus Inoculation

In addition to tube drains, pleural empyema is treated with antibiotics and anti-inflammatory drugs. We aimed to evaluate the anti-inflammatory activity of roflumilast combined with linezolid in a rat model of pleural empyema induced by Staphylococcus aureus. A total of 40 rats were divided into 7 groups: sham (n = 4), S. aureus inoculation (n = 6), S. aureus + 10 mg/kg linezolid (n = 6), S. aureus + 5 mg/kg roflumilast (n = 6), S. aureus + 10 mg/kg linezolid + 5 mg/kg roflumilast (n = 6), S. aureus + 10 mg/kg roflumilast (n = 6), and S. aureus + 10 mg/kg linezolid + 10 mg/kg roflumilast (n = 6). Animals were administered linezolid 1 h before and 12 h after inoculation with S. aureus. Roflumilast was administered orally as a single dose 30 min before inoculation with S. aureus. Compared to linezolid treatment alone, linezolid combined with 5 mg/kg roflumilast significantly improved TNF-α, IL-1β, vasodilation/congestion, and tissue/pleural polynuclear leukocyte (PNL) infiltration (p < 0.05). Linezolid combined with 10 mg/kg roflumilast also provided a significant improvement in TNF-α, IL-1β, IL-6, endothelin-1, vasodilation/congestion, mesothelial cell damage, lung tissue PNL, and pleural PNL compared to linezolid alone (p < 0.05). Due to its anti-inflammatory effects and significant impact on recovery, roflumilast can be used in conjunction with antibiotherapy for the treatment of pleural empyema.

Beneficial effect of Ageratum conyzoides Linn (Asteraceae) upon inflammatory response induced by carrageenan into the mice pleural cavity

ETHNOPHARMACOLOGICAL RELEVANCE

Ageratum conyzoides Linn (Asteraceae), a tropical plant that is very common in West Africa and some parts of Asia and South America, has been used to treat inflammatory disorders. In Brazil, teas made from A. conyzoides L. are used as anti-inflammatory, analgesic and anti-diarrheic agents. Therefore, it is necessary to study the mechanism of anti-inflammatory action of A. conyzoides L. to support its medicinal use for treating inflammatory conditions. These studies will also support the development of effective pharmacological agents with potent anti-inflammatory properties.

AIM OF THE STUDY

To evaluate the anti-inflammatory effects of the crude extract (CE), its derived fractions: ethanol (EtOH-F), hexane (HEX-F), ethyl acetate (EtOAc-F) and dichloromethane (DCM-F) and isolated compounds, such as 5'-methoxy nobiletin (MeONOB), 1,2-benzopyrone and eupalestin, which are obtained from the aerial parts of A. conyzoides L.

MATERIALS AND METHODS

These evaluations were performed using an animal model of inflammation induced by carrageenan. The following inflammatory parameters were analysed: leukocyte influx, protein concentration of the exudate, myeloperoxidase (MPO), adenosine deaminase (ADA) and nitric oxide metabolites (NOx) concentrations, interleukin 10 (IL-10), interleukin 17A (IL-17A), interleukin 6 (IL-6), tumor necrosis factor (TNF), interferon gamma (IFN-γ) and phosphorylation of p65 subunit of NF-κB (p-p65 NF-κB), p38 mitogen-activated protein kinases (p-p38 MAPK) were also analysed.

RESULTS

CE, its EtOH-F, HEX-F, EtOAc-F and DCM-F and the isolated compounds, including MeONOB, 1,2-benzopyrone and eupalestin, significantly reduced leukocyte influx, protein concentration of the exudate, MPO, ADA, and NOx concentrations (p<0.05). CE, EtOH-F and isolated compounds significantly reduced IL-17A, IL-6, TNF and IFN-γ levels (p<0.05). CE, EtOH-F and isolated compound 1,2-benzopyrone also increased IL-10 levels (p<0.05). Isolated compounds, MeONOB, 1,2-benzopyrone and eupalestin, reduced p-p65 NF-κB and p-p38 MAPK (p<0.01).

CONCLUSIONS

This study demonstrates that A. conyzoides L. exerts its important anti-inflammatory properties by inhibiting leukocyte influx and protein concentration of the exudate, as well as reducing the levels of several pro-inflammatory mediators. The anti-inflammatory action of A. conyzoides L. may be because of the inhibition of p65 NF-κB and MAPK activation by the isolated compounds.

Tacrolimus (FK506) suppresses TREM-1 expression at an early but not at a late stage in a murine model of fungal keratitis

PURPOSE

To investigate the efficacy and mechanism of tacrolimus(FK506), which is a novel macrolide immunosuppressant, in inhibiting triggering receptor expressed on myeloid cells-1 (TREM-1) expression in a murine keratitis model induced by Aspergillus fumigatus.

METHOD

TREM-1 was detected in 11 fungus-infected human corneas by quantitative real-time PCR (qRT-PCR). RAW264.7 macrophages were divided into four groups, which received treatment with zymosan (100 µg/ml), zymosan (100 µg/ml) + mTREM-1/Fc protein (1 µg/ml), or zymosan (100 µg/ml) + FK506 (20 µM) or negative-control treatment. After this treatment, the expression of TREM-1, interleukin-1β (IL-1β) and tumor necrosis factor α (TNFα) was assayed using qRT-PCR and ELISA. The mouse model of fungal keratitis was created by intrastromal injection with Aspergillus fumigatus, and the mice were divided into 2 groups: group A received vehicle eye drops 4 times each day, and group B received 4 doses of FK506 eye drops each day. Corneal damage was evaluated by clinical scoring and histologic examination,and myeloperoxidase (MPO) protein levels were also detected by ELISA. The expression of TREM-1, IL-1β and TNFα was then determined at different time points using qRT-PCR and ELISA.

RESULTS

TREM-1 expression dramatically increased in the human corneas with fungal keratitis. In contrast, FK506 reduced the expression of TREM-1, IL-1β and TNFα in RAW264.7 macrophages stimulated with zymosan. In the mouse model, at day 1 post-infection, the corneal score of the FK506-treated group was lower than that of the control, and polymorphonuclear neutrophil (PMN) infiltration was diminished. TREM-1, IL-1β and TNFα expression was significantly reduced at the same time point. However, the statistically significant differences in cytokine expression, clinical scores and infiltration disappeared at 5 days post-infection.

CONCLUSIONS

FK506 may inhibit the inflammation induced by fungi and alleviate the severity of corneal damage at an early stage of fungal keratitis by downregulating TREM-1 expression.

Anti-inflammatory effect of (E)-4-(3,7-dimethylocta-2,6-dienylamino)phenol, a new derivative of 4-nerolidylcatechol

Objectives

We have investigated the anti-inflammatory and antinociceptive effects of (E)-4-(3,7-dimethylocta-2,6-dienylamino)phenol (LQFM-015), which was designed through molecular simplification strategy from 4-nerolidylcatechol.

Methods

The possible anti-inflammatory and antinociceptive effects were assayed on carrageenan-induced paw oedema and pleurisy, acetic acid-induced abdominal writhing and formalin tests in mice.

Key findings

LQFM-015 reduced the activity of PLA2 enzyme in vitro by 18%. Docking studies into the catalytic site of PLA2 were used to identify the binding mode of the LQFM-015. LQFM-015 showed a moderate antinociceptive effect, since this compound reduced the number of writhings by approximately up to 40% in the acetic acid-induced pain model; this antinociceptive activity also emerged in the second phase of the formalin-induced pain model (58% of inhibition). The anti-inflammatory action of LQFM-015 was confirmed in acute inflammation models, in which it reduced the formation of oedema to 52.78 ± 8.6 and 46.64 ± 5.2 at the second and third hour of carrageenan-induced paw oedema, respectively. Also in the carrageenan-induced pleurisy model, LQFM-015 reduced the migration of leucocytes by 26.0% and decrease myeloperoxidase activity by 50%. LQFM-015 showed different concentrations to inhibit 50% of isoenzyme cyclooxygenase activity (IC50); COX-1 IC50 = 36 μm) and COX-2 IC50 = 28 μm.

Conclusions

LQFM-015 demonstrated inhibition of both PLA2 and COX enzymes; thus, the moderate antinociceptive effect of this compound could be attributed to its anti-inflammatory activity.

Anti-inflammatory effect of triterpene 3β, 6β, 16β-trihydroxylup-20(29)-ene obtained from Combretum leprosum Mart & Eich in mice

ETHNOPHARMACOLOGICAL RELEVANCE

The 3β, 6β, 16β-trihydroxylup-20(29)-ene (TTHL) is a pentacyclic triterpene obtained from a medicinal plant named Combretum leprosum. In folk medicine, this plant is used to treat several diseases associated with inflammation and pain. We previously demonstrated that TTHL presents a significant antinociceptive effect, suggesting the involvement of the glutamatergic system.

AIM OF THE STUDY

This study was designed to investigate the effect of TTHL on nociception and vascular permeability induced by acetic acid. We also evaluated the effect of TTHL on carrageenan-induced peritonitis and the levels of cytokines (interleukin 1-β [IL-1β], tumor necrosis factor α [TNF-α] and interleukin 10 [IL-10]) on peritoneal fluid.

MATERIALS AND METHODS

TTHL was administered orally by intra-gastric gavage (i.g.) 60 min prior to experimentation. Abdominal contractions and vascular permeability were induced by an intraperitoneal (i.p.) injection of acetic acid (0.6%). We also investigated whether TTHL decreases carrageenan-induced peritonitis (750 μg/cavity) by measuring leukocyte migration and vascular permeability. In addition, we evaluated the effects of TTHL on TNF-α, IL-1β and IL-10 release induced by carrageenan on peritoneal fluid. The levels of these cytokines were measured by ELISA.

RESULTS

TTHL (0.01-10 mg/kg) administered by intra-gastric (i.g.) gavage inhibited (69±3%) acetic acid-induced abdominal constrictions, with an ID₅₀ of 0.15 (0.03-0.8) mg/kg. TTHL (10mg/kg) also reduced the leukocyte infiltration induced by acetic acid, with an inhibition of 59±9 but had no effect on abdominal vascular permeability. In addition, indomethacin (10 mg/kg, i.p.) reduced the nociceptive behavior (92±1%), total leukocyte migration (29±3%) and capillary permeability (71±3%) induced by acetic acid. While the glucocorticoid dexamethasone (2 mg/kg, s.c.) reduced partially but significantly the nociception (31±1%), besides to promote a marked reduction on total leukocyte migration (60±2%) to the peritoneal cavity caused by acetic acid. In a model of peritonitis induced by carrageenan, TTHL also reduced total leukocyte migration, mainly neutrophils (inhibition of 84±3% and 85±2% at 30 mg/kg and 100 mg/kg, respectively). Likewise, dexamethasone (0.5 mg/kg, i.p.) resulted in an inhibition of 93±3%. Nevertheless, carrageenan-induced abdominal vascular permeability was reduced by dexamethasone but was not altered by TTHL. Furthermore, dexamethasone and TTHL significantly reduced the TNF-α and IL-1β levels in peritoneal fluid, whereas the IL-10 levels were unchanged.

CONCLUSIONS

Altogether, our data confirm the antinociceptive effect of TTHL and demonstrate its effect in inflammatory animal models, providing novel data about this compound, which could be useful as an anti-inflammatory drug.

Evidence of an anti-inflammatory effect of mycophenolate mofetil in a murine model of pleurisy

A promising therapeutic approach to reducing inflammation is to inhibit the production of proinflammatory cytokines (e.g., tumor necrosis factor alpha [TNF-α], interleukin 1 beta [IL-1β], vascular endothelial growth factor alpha (VEGF-α), and, as shown more recently, interleukin-17 [IL-17]). In the present study, the authors have demonstrated the anti-inflammatory effects of mycophenolate mofetil (MMF) in in vivo experiments and have investigated the mechanism of action underlying those effects. Oral administration of MMF significantly inhibited leukocyte influx during the first (4 hours) and second (48 hours) phases of inflammation in a mouse model of pleurisy caused by carrageenan (P < .01). As expected, MMF suppressed protein levels of TNF-α, IL-1β, VEGF-α, and IL-17A (P < .01). This inhibitory effect was due to down-regulation of mRNA expression for these proinflammatory cytokines (P < .01). These results provide evidence of MMF-mediated inhibition of proinflammatory cytokines, and these anti-inflammatory effects are assumed to result mainly from the inhibition of the synthesis and release of TNF-α, IL-1β, VEGF-α, and IL-17A from activated leukocytes. These findings suggest that MMF might be an applicable therapeutic in the regulation of the inflammatory response-a response in which the humoral system plays a pivotal role.

Involvement of Interleukin-10 in the Anti-Inflammatory Effect of Sanyinjiao (SP6) Acupuncture in a Mouse Model of Peritonitis

In this study, we determined the anti-inflammatory effect of manual acupuncture at the Sanyinjiao or Spleen 6 (SP6) point on carrageenan-induced peritonitis in mice and investigated mechanisms that may underlie this effect. In the first set of experiments, male Swiss mice were allocated into five groups: the control (sterile saline), dexamethasone (DEXA), invasive sham-acupuncture (non-acupoint), SP6 acupuncture and carrageenan-treated groups. Ten minutes after needle retention or 30 min after DEXA treatment, mice received an intraperitoneal injection of carrageenan (750 μg/mouse). After 4 h, total leukocyte and differential cell counts (neutrophils and mononuclear), myeloperoxidase (MPO) activity, vascular permeability and cytokine levels were evaluated. In another set of experiments, adrenalectomized (ADX) mice were used to study the involvement of the adrenal gland on the therapeutic effects of acupuncture. Mice were allocated into two groups: the ADX and sham-operated animals (Sham ADX) that were subdivided into four subgroups each: the control (sterile saline), DEXA, SP6 acupuncture and carrageenan-treated groups. The SP6 and DEXA treatments inhibited the inflammatory cell infiltration, vascular permeability and MPO activity in carrageenan-injected mice. In addition, the SP6 treatment also increased interleukin (IL)-10 levels. In contrast, when the animals were adrenalectomized, the SP6 treatment failed to reduce total leukocyte and the plasma extravasation. In conclusion, this study clearly demonstrates the anti-inflammatory effect of SP6 acupuncture in a model of carrageenan-induced peritonitis. Our results demonstrated that SP6 acupuncture depends of the adrenal glands and increased IL-10 levels to produce its anti-inflammatory action.

[Cytoprotective effect of low-dose tacrolimus on islets of Langerhans in cultures subjected to stimulation by acute rejection cytokines]

INTRODUCTION

The improvement in pancreatic islet transplantation results is due to immunosuppression protocols that include, among others, low-dose tacrolimus. Both anti-inflammatory and anti-oxidant effects of tacrolimus could be useful in preventing primary rejection.

AIM

To evaluate in vitro islet low-dose tacrolimus response after pro-inflammatory stimulation.

MATERIAL AND METHODS

Isolated rat islets were cultured in RPMI medium in the presence of IL-1 (50 UI/mL) plus IF-gamma (1000 UI/mL) and tacrolimus (5 ng/mL). The 24 h production of lipoperoxide (LPO) and nitric oxide (NO) were measured as oxidative stress markers. Determination of apoptosis markers (nucleosome content and Bcl-2) was also performed.

RESULTS

Oxidative stress (LPO 10.1+/-1.16 pmol/islet x 24; NO 19.1+/-3.28 pmol/isletx24 h) and apoptosis (nucleosome 0.24+/-0.04 UI/islet; Bcl-2 0.69+/-0.212 UI/islet) markers showed a very significant increase after cytokine stimulation (p<0.01). Both effects improved by adding tacrolimus to the medium. Protective effect was complete when lipoperoxide (1.58 pmol/isletx24 h), nitric oxide (9.81 pmol/isletx24 h) and Bcl-2 (1.37+/-0.23 UI/islet) were determined.

CONCLUSION

In vitro cytoprotective effect of low-dose tacrolimus on isolated rat islets decreases both oxidative stress and apoptosis markers after stimulation of pro-inflammatory mediators.

Anti-inflammatory evaluation of Coronopus didymus in the pleurisy and paw oedema models in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Mastrunço (Coronopus didymus--CD) is currently considered as a medicinal specie often used in Brazil, especially in southeast region, for the treatment of several diseases in which pain and inflammation are common. Treatment with the plant can be done by infusion, decoction, or through food. The aim of this study was: to investigate the anti-inflammatory effect of hydroalcoholic extract obtained from the leaves of CD following the traditional procedure.

MATERIALS AND METHODS

The anti-inflammatory activity was determined using mouse of pleurisy and paw oedema models, both process being induced by different flogistic agents such as: carrageenan (Cg), bradykinin (BK), histamine (HIS), substance P (SP), dextran (DEX) or prostaglandin E(2) (PGE(2)). We evaluated the effect of CD (200-600 mg/kg) administered by oral route (p.o.) upon leukocytes migration, myeloperoxidase (MPO), and adenosine-deaminase (ADA) activities and nitric oxide (NO) levels.

RESULTS

CD (200-600 mg/kg) inhibited the leukocytes by 60.0+/-1.42%, neutrophils by 82.75+/-1.29%, MPO by 42.30+/-4.23%, and ADA activities by 57.89+/-1.94%, as well as NO levels by 64.28+/-2.15% in Cg induced pleurisy. CD also inhibited total and differential leukocytes in the pleurisy induced by BK (1.30+/-0.11/0.29+/-0.02), HIS (1.20+/-0.09/0.42+/-0.05) and SP (0.74+/-0.06/0.14+/-0.01). In addition, CD was effective in reducing paw oedema induced by Cg by 72.79+/-1.13%, SP by 68.26.+/-0.78%, BK by 66.66.+/-0.77%, PGE(2) by 53.346.+/-1.18 and DEX by 65.14+/-2.35%.

CONCLUSION

Several mechanisms, including the inhibition of enzymes (MPO and ADA) and mediators (BK, HIS, SP, NO and PGE(2)) release and/or action, appear to account for the anti-inflammatory effect of Coronopus didymus.

Tacrolimus ameliorates metabolic disturbance and oxidative stress caused by hepatitis C virus core protein: analysis using mouse model and cultured cells

Hepatic steatosis and insulin resistance are factors that aggravate the progression of liver disease caused by hepatitis C virus (HCV) infection. In the pathogenesis of liver disease and metabolic disorders in HCV infection, oxidative stress due to mitochondrial respiratory chain dysfunction plays a pivotal role. Tacrolimus (FK506) is supposed to protect mitochondrial respiratory function. We studied whether tacrolimus affects the development of HCV-associated liver disease using HCV core gene transgenic mice, which develop hepatic steatosis, insulin resistance, and hepatocellular carcinoma. Administration of tacrolimus to HCV core gene transgenic mice three times per week for 3 months led to a significant reduction in the amounts of lipid in the liver as well as in serum insulin. Tacrolimus treatment also ameliorated oxidative stress and DNA damage in the liver of the core gene transgenic mice. Tacrolimus administration reproduced these effects in a dose-dependent manner in HepG2 cells expressing the core protein. The intrahepatic level of tumor necrosis factor-alpha, which may be a key molecule for the pathogenesis in HCV infection, was significantly decreased in tacrolimus-treated core gene transgenic mice. Tacrolimus thus reversed the effect of the core protein in the pathogenesis of HCV-associated liver disease. These results may provide new therapeutic tools for chronic hepatitis C, in which oxidative stress and abnormalities in lipid and glucose metabolism contribute to liver pathogenesis.

Tacrolimus causes a blockage of protein secretion which reinforces its immunosuppressive activity and also explains some of its toxic side-effects

BACKGROUND

Tacrolimus (FK506) is a macrolide immunosuppressant drug from the calcineurin inhibitor family, widely used in solid organ and islet cell transplantation, but produces significant side-effects.

OBJECTIVE

This study examined the effect of FK506 on interleukin-2 (IL-2) and insulin secretion, establishing a novel characteristic of this drug that could explain its diverse adverse effects, and developed an experimental model for the simultaneous analysis of mRNA expression and protein secretion affected by this drug.

METHODS

The IL-2 levels when tacrolimus was administered were analysed by Western blot, immunocytochemistry and RT-PCR in a T lymphocyte cellular line (Jurkat) 24 h post-stimulation. The insulin levels when tacrolimus was administered were analysed 4 h after stimulation of glucose-induced insulin secretion in a pancreatic cellular line (MIN6).

RESULTS

The previously published information describes tacrolimus as only capable of partially blocking IL-2 mRNA expression. In our hands, the cellular content of IL-2 is almost undetectable in stimulated Jurkat cells and can be detected in cellular extracts only when the secretory pathway is blocked by brefeldin A (BFA). BFA added 2 h after the beginning of stimulation was able to inhibit IL-2 secretion, without affecting IL-2 mRNA expression. Therefore BFA utilization allowed us to establish a model to analyze the effect on IL-2 secretion, separately from its expression. Tacrolimus added before stimulation inhibits only IL-2 synthesis, but blocks IL-2 protein secretion when added 2 h after stimulation. Similarly, tacrolimus is also capable of blocking the glucose-stimulated secretion of insulin by MIN6 cells. An increase of the intracellular content can be detected concomitantly with a decrease of the hormone measured in the culture medium.

CONCLUSIONS

Results of this study indicate that tacrolimus possesses another important effect in addition to the inhibition of IL-2 gene transcription, namely the ability to act as a general inhibitor of the protein secretory pathway. These results strongly suggest that the diabetogenic effect of the immune suppressant FK506 could be caused by the blockade of insulin secretion. This novel effect also provides an explanation for other side-effects observed in immunosuppressive treatment.

Tacrolimus hydrate ointment inhibits skin plasma extravasation in rats induced by topical m-xylene but not capsaicin

Tacrolimus ointment is used to treat various chronic inflammatory skin diseases. However, the effect of this ointment on acute neurogenic inflammation in the skin remains to be fully elucidated. Topical capsaicin and m-xylene produce tachykinin release from sensory nerves in the skin, resulting in skin plasma leakage. We investigated the effect of tacrolimus ointment (0.1%) on skin microvascular leakage induced by topical capsaicin (10 mM) and m-xylene (neat), and intracutaneous compound 48/80 (c48/80) (10 microg/ml, 50 microl/site) in two groups of rats pretreated with excessive capsaicin or its vehicle. The amount of leaked Evans blue dye reflected skin plasma leakage. Capsaicin, m-xylene or c48/80 was applied to the shaved abdomens of rats 8 h after topical application of tacrolimus ointment or its base. Desensitization with capsaicin reduced the skin response to capsaicin and m-xylene by 100% and 65%, respectively, but not to c48/80. Tacrolimus ointment significantly inhibited the skin response induced by m-xylene and c48/80, regardless of pretreatment with capsaicin. However, topical tacrolimus did not influence the skin response induced by capsaicin. We also evaluated whether topical capsaicin and m-xylene, and intracutaneous c48/80 cause mast cell degranulation in skin treated with tacrolimus. Mast cell degranulation was microscopically assessed. Topical tacrolimus only significantly suppressed degranulation induced by m-xylene and c48/80. Our data shows that tacrolimus ointment partially inhibits plasma leakage and mast cell degranulation in rat skin induced by m-xylene and c48/80 but not capsaicin, suggesting that the inhibitory effect is not associated with a reduction in neurogenic-mediated mechanisms.

Efficacy of tacrolimus in inhibiting inflammation caused by carrageenan in a murine model of air pouch

BACKGROUND

Tacrolimus (Tac) is a macrolide immunosuppressant drug isolated from Streptomyces tsukubaensis, widely used in organ transplantation.

OBJECTIVE

This study examined the effect of tacrolimus administered by oral route (p.o.) on inflammation in mouse subcutaneous air pouch triggered by carrageenan (Cg 1%).

METHODS

The air pouch was induced as described by Benincá et al. [Benincá JP, Montanher AB, Zucolotto SM, Schenkel EP, FrödeTS. Anti-inflammatory effects of the Passiflora edulis: forma flavicarpa Degener inhibition of leukocytes, enzymes and pro-inflammatory cytokine levels in the air pouch model, in mice. Food Chem 2007; 104(3); 1097-1105.]. The inflammatory parameters (leukocytes, exudation, myeloperoxidase (MPO) and adenosine-deaminase (ADA) activities, as well as nitrate/nitrate concentrations (NO(x)), interleukin-1 beta (IL-1beta), chemokine to neutrophil (KC) and tumor necrosis factor-alpha (TNF-alpha) levels were analysed 24 h after injection of carrageenan.

RESULTS

Tacrolimus, indomethacin and dexamethasone significantly inhibited leukocytes, neutrophils and exudation (P<0.05) when they were administered 0.5 h before inflammation. These drugs, under the same conditions, decreased MPO and ADA activities (P<0.05), NO(x) and IL-1beta levels (P<0.01). Tacrolimus and indomethacin, but not dexamethasone, inhibited KC levels (P<0.01). On the other hand, tacrolimus and dexamethasone, but not indomethacin, decreased TNF-alpha levels (P<0.01).

CONCLUSIONS

Results of this study indicate that tacrolimus has an important anti-inflammatory property, showing not only inhibition of pro-inflammatory mediators release, but also inhibition of activated leukocyte infiltration into the site of inflammation. Furthermore, these results showed that most of the anti-inflammatory actions of tacrolimus were similar to those observed in animals treated with either indomethacin or dexamethasone.