Pharmacokinetics of intra-articular vitamin D analogue calcipotriol in sheep and metabolism in human synovial and mesenchymal stromal cells

Clinical pharmacokinetics and pharmacodynamics of topical non-biological therapies for psoriasis patients

INTRODUCTION

Psoriasis is a chronic inflammatory cutaneous disease that causes patients psychosocial distress. Topical therapies are utilized for mild-to-moderate disease and for more severe disease in conjunction with systemic therapies. Topical corticosteroids are a cornerstone of treatment for psoriasis, but long-term use can cause stria and cutaneous atrophy and as well as systemic side effects such as topical steroid withdrawal. Non-steroidal topical therapies tend to be safer than topical corticosteroids for long-term use.

AREAS COVERED

We conducted a literature review on the pharmacokinetic (PK) and pharmacodynamic (PD) properties of topical therapies for psoriasis. We discuss how the PK and PD characteristics of these therapies inform clinicians on efficacy and toxicity when prescribing for patients.

EXPERT OPINION

Topical corticosteroids, used intermittently, are very safe and effective. Long-term, continuous use of topical corticosteroids can cause systemic side effects. Several generic and newly approved non-steroidal options are available, but no head-to-head studies compare the effectiveness of the generics (vitamin D analogs, tacrolimus, pimecrolimus) against the newer therapies (roflumilast, tapinarof). Patients often do not respond to topical therapies due to poor adherence to treatment regimens. For patients resistant to topical treatment, phototherapy or systemic therapy may be an option.

No adverse effects on periarticular tissue by intra-articular vitamin D analogue calcipotriol in a reduced-dose zymosan-induced arthritis model in rats

Calcipotriol, a vitamin D analogue, is an antiproliferative and anti-inflammatory drug currently used in psoriasis. Here, our aim was to analyse the safety of calcipotriol for cartilage and bone in alleviated-dose (0.1 mg instead of usual ≥1mg dose) zymosan-induced arthritis in rats. Theoretically, high doses of vitamin D or analogues could have detrimental effects on bone or cartilage. The rats were divided into four groups: vehicle (n = 9), dexamethasone 0.1 mg/kg (n = 9), calcipotriol 0.1 mg/kg (n = 8) and negative control (n = 10) with no injections. Arthritic rats were given phosphate-buffered saline (PBS) injections to left knees as a control. After euthanasia on day 8, all knees were imaged with micro-computed tomography for surface lesions and decalcified for histological analyses. Contrary to our expectations, no significant changes could be observed in the tomography data and histological scores among the three treatment groups or between the vehicle-treated and non-arthritic group. Calcipotriol did not cause adverse effects on cartilage or subchondral bone within a week, suggesting that it could be safely used in local treatment of arthritis. The alleviated model caused synovitis with local and systemic inflammatory response without cartilage erosions, which might be useful in studying self-limiting synovitis where cartilage or bone effects are not of primary interest.

Prodrug nanoparticles rationally integrating stroma modification and chemotherapy to treat metastatic pancreatic cancer

Accumulating evidence suggests that stromal modifications improve chemotherapeutic outcomes in pancreatic ductal adenocarcinoma (PDAC). However, combination regimens of stroma-modifying agents and small-molecule cytotoxic drugs have achieved only limited improvements in the clinic, probably due to unsatisfactory pharmacokinetic profiles and restricted drug distribution in tumors. Here, we developed self-assembled prodrug nanoparticles integrating a stromal reprogramming inducer, calcipotriol (CAL), and a potent chemotherapeutic agent, 7-Ethyl-10-hydroxycamptothecin (SN38), to treat PDAC. While SN38 is conjugated to the block polymer backbone, CAL is loaded into the inner hydrophobic space during polymer self-assembly into nanoparticles. To achieve an efficient drug co-package, a planar and hydrophobic cholesterol domain was introduced to stabilize the hydrophobic CAL. Notably, the blood circulation time of CAL significantly improved as CAL|SN38 nanoparticle (CAL|SN38 NP). In addition, CAL|SN38 NP treatment significantly decreased the expression of N-cadherin, collagen, and fibronectin in tumors, which play critical roles in PDAC metastasis. Potent inhibition of primary tumor growth and vigorous anti-metastasis effects were observed after systemic administration of CAL|SN38 NP to stroma-rich PDAC orthotopic tumor-bearing mice. These findings provide a promising paradigm for developing tailor-made nanoparticles with potent stroma-modification capability to combat metastatic cancer.

A single intra-articular dose of vitamin D analog calcipotriol alleviates synovitis without adverse effects in rats

1,25-dihydroxyvitamin-D3 and its derivatives have shown anti-arthritic and chondroprotective effects in experimental animal models with prophylactic dosing. The purpose of this preliminary study was to test the efficacy and safety of calcipotriol, vitamin D analog, as a treatment for a fully-developed knee arthritis in Zymosan-induced arthritis (ZIA) model. Forty 5-month-old male Sprague-Dawley rats were randomized into three arthritis groups and a non-arthritic control group with no injections (10 rats/group). A day after Zymosan (0.1 mg) had been administrated into the right knee joints, the same knees were injected with calcipotriol (0.1 mg/kg), dexamethasone (0.1 mg/kg) or vehicle in a 100 μl volume. The left control knees were injected with saline (PBS) on two consecutive days. All injections, blood sampling and measurements were performed under general anesthesia on days 0, 1, 3 and 8. Internal organs and knees were harvested on day 8 and the histology of the whole knees was assessed blinded. Joints treated with calcipotriol showed a milder histological synovitis than those treated with vehicle (p = 0.041), but there was no statistically significant difference between the dexamethasone and vehicle groups. The clinical severity of arthritis did not differ between the arthritis groups measured by body temperature, swelling of the knee, thermal imaging, clinical scoring or cytokine levels on days 1, 3 and 8. Weight loss was bigger in rats treated with dexamethasone, propably due to loss of appetite,compared to other arthritis groups on days 2-3 (p<0.05). Study drugs did not influence serum calcium ion and glucose levels. Taken together, this preliminary study shows that a single intra-articular injection of calcipotriol reduces histological grade of synovitis a week after the local injection, but dexamethasone did not differ from the vehicle. Calcipotriol may have an early disease-modifying effect in the rat ZIA model without obvious side effects.

Dialogue between gastrointestinal tract and skin: New insights into the Helicobacter pylori and atopic dermatitis

BACKGROUND

Although many studies have focused on the protective function of H pylori in some allergic diseases, it remains unknown as whether H pylori infection exerts a similar protective effect on atopic dermatitis(AD). Thus, the aim of this study was to evaluate the association between H pylori infection and AD.

MATERIALS AND METHODS

An animal model of H pylori infection-AD was established by epicutaneous sensitization with calcipotriol after infection with H pylori by gavage. The Treg cells were analyzed by flow cytometry and immunohistochemistry. The expression of key inflammatory cytokines in dermal tissues was investigated at the mRNA level by real-time PCR.

RESULTS

Compared with that in the H pylori-negative AD group, the severity of skin lesions, such as hyperemia, erythema, and swelling, was lower in the H pylori-positive AD group, while the serum IgE level decreased significantly in the H pylori-positive AD group. The percentage of CD4⁺ CD25⁺ Foxp3⁺ Treg cells in the peripheral blood and the number of Foxp3⁺ cells in dermal tissues increased significantly in the H pylori-positive AD group. The expression of IL-10 and TGF-β was upregulated, while the expression of IL-4 mRNA was downregulated in dermal tissues in the H pylori-positive AD group. The adoptive transfer assay showed that the number of CFSE⁺ Treg cells in the cervical lymph nodes of AD mice was significantly higher than that in normal mice, indicating the Tregs in H pylori-positive mice had a tendency to migrate to the skin tissue. It was also found that H pylori infection induced CCR4⁺ Treg cells expansion synchronously in gastric lymph nodes, spleen, blood, mesenteric lymph node (MLN), and cervical lymph nodes by the time of H pylori infection.

CONCLUSIONS

H pylori infection alleviated calcipotriol-inducing AD manifestations by inducing the amplification of CD4⁺ CD25⁺ Foxp3⁺ Treg cells in the peripheral blood. H pylori showed possible protection against atopic dermatitis, suggesting an immune dialogue between gastrointestinal tract and skin.