The effect of a sulfonated shale oil extract (Ichthyol) on the migration of human neutrophilic granulocytes in vitro

Sodium Bituminosulfonate Used to Treat Rosacea Modulates Generation of Inflammatory Mediators by Primary Human Neutrophils

Background

Sodium bituminosulfonate is derived from naturally occurring sulphur-rich oil shale and is used for the treatment of the inflammatory skin disease rosacea. Major molecular players in the development of rosacea include the release of enzymes that process antimicrobial peptides which, together with reactive oxygen species (ROS) and vascular endothelial growth factor (VEGF), promote pro-inflammatory processes and angiogenesis. The aim of this study was to address the molecular mechanism(s) underlying the therapeutic benefit of the formulation sodium bituminosulfonate dry substance (SBDS), which is indicated for the treatment of skin inflammation, including rosacea.

Methods

We investigated whether SBDS regulates the expression of cytokines, the release of the antimicrobial peptide LL-37, calcium mobilization, proteases (matrix metalloproteinase, elastase, kallikrein (KLK)5), VEGF or ROS in primary human neutrophils. In addition, activity assays with 5-lipoxygenase (5-LO) and recombinant human MMP9 and KLK5 were performed.

Results

We observed that SBDS reduces the release of the antimicrobial peptide LL-37, calcium, elastase, ROS and VEGF from neutrophils. Moreover, KLK5, the enzyme that converts cathelicidin to LL-37, and 5-LO that produces leukotriene (LT)A₄, the precursor of LTB₄, were both inhibited by SBDS with an IC₅₀ of 7.6 µg/mL and 33 µg/mL, respectively.

Conclusion

Since LTB₄ induces LL-37 which, in turn, promotes increased intracellular calcium levels and thereby, ROS/VEGF/elastase release, SBDS possibly regulates the LTB₄/LL-37/calcium – ROS/VEGF/elastase axis by inhibiting 5-LO and KLK5. Additional direct effects on other pro-inflammatory pathways such as ROS generation cannot be ruled out. In summary, SBDS reduces the generation of inflammatory mediators from human neutrophils possibly accounting for its anti-inflammatory effects in rosacea.

Efficacy and tolerability of pale sulfonated shale oil cream 4% in the treatment of mild to moderate atopic eczema in children: a multicentre, randomized vehicle-controlled trial

BACKGROUND

Reports on controlled trials on the efficacy and tolerability of sulfonated shale oils in atopic eczema are not available so far. The aim of this study was to investigate whether topically applied, specially prepared pale sulfonated shale oil (PSSO) cream is capable of improving symptoms/signs of mild to moderate atopic eczema in children more efficaciously than a corresponding vehicle cream.

PATIENTS AND METHODS

A total of 99 children suffering from mild to moderate atopic eczema were enrolled in this multicentre, randomized, vehicle-controlled study. Verum or vehicle cream was applied to the affected skin area three times a day over 4 weeks. As the primary outcome parameter served the reduction of the total score after 4 weeks of treatment, compared with the initial examination. Secondary outcome parameters were addressed as well. Tolerability was judged by investigators and patients/parents, and adverse events were documented.

RESULTS

After 4 weeks of treatment, the total score declined from 13.4 ± 3.7 to 4.5 ± 7.4 score points in the verum group and from 13.0 ± 3.1 to 11.7 ± 8.6 score points in the vehicle group (P < 0.0001). The superiority of verum regarding total score was already apparent after a treatment period of 1 week (reduction by 5.6 ± 4.3 vs. 1.3 ± 5.9 score points; P < 0.0001). Tolerability was found superior at the end of the treatment in the verum when compared with the control group--both by investigators (P < 0.0001) and patients/parents (P = 0.0051).

CONCLUSION

Pale sulfonated shale oil cream 4% is capable to treat mild to moderate atopic eczema in children more efficaciously than vehicle and is well tolerated. PSSO thus represents a valuable addition to our therapeutic armamentarium. PSSO should be considered in particular when valid alternatives for topical glucocorticoids are sought for.

Efficacy of topical pale sulfonated shale oil in the treatment of venous leg ulcers: A randomized, controlled, multicenter study

BACKGROUND

Venous leg ulcers are a growing socioeconomic burden. Pale sulfonated shale oils (PSSO) are used for therapy of inflammatory skin diseases and have been shown to enhance wound healing in vitro and in vivo. The aim of this study was to investigate whether PSSO is capable of enhancing venous ulcer healing beyond compression therapy alone.

METHODS

One hundred nineteen patients were enrolled in this randomized, multicenter, observer-blind study. In the treatment group, PSSO 10% was applied daily for 20 weeks, and the control group received the vehicle only. Wounds were covered by a nonadherent gauze dressing, and compression therapy with short-stretch elastic bandages was performed in an outpatient setting. The primary study end point was defined as cumulative reduction in wound area; the secondary study end point was treatment success as assessed by both physicians and patients. Additionally, adverse events, including changes with respect to physical examination and vital signs, were documented.

RESULTS

At the end of the study period, ulcer size was significantly more reduced in the PSSO group compared with the vehicle group (15 +/- 15.9 to 6.2 +/- 12.9 cm(2) vs 11.4 +/- 14.5 to 10.8 +/- 15.7 cm(2); P = .0005). The cumulative relative reduction in ulcer area was significantly higher in the PSSO group (-4391 +/- 4748.7 vs -231.9 +/- 6283.6 % x days; P < .0001). Relative reduction in wound area was significantly greater in the PSSO group as early as 6 weeks after the beginning of treatment (-47.4 +/- 28.4 vs -23.8 +/- 42.2%; P < .001). PSSO was judged successful both by physicians and patients. There were no significant differences in adverse events (PSSO, 9 [12.2%]; vehicle, 7 [11.1%]. Similarly, tolerability of PSSO was equal to the tolerability of the vehicle.

CONCLUSION

Pale sulfonated shale oils were capable of favoring venous ulcer healing in addition to compression therapy. PSSO should be considered for future wound care protocols for treatment of venous leg ulcers.

Glycerol and ichthammol: medicinal solution or mythical potion?

Glycerol and ichthammol (G & I) has been used for generations by otologists. However, there is a paucity of information on both its mode of action and its anti-bacterial properties. The aim of this paper was to ascertain firstly, what the most common organisms found in discharging ears were and secondly, what antibacterial activity G & I had against these organisms. All ear swabs from 1992-1994 in our unit were reviewed to ascertain the prevalence of the commonly isolated organisms. Fresh isolates of these organisms were collected and plated onto agar with wells of glycerol, ichthammol and a combination of both as used in clinical practice. The diameters of the zones of inhibition observed after incubation were measured in millimetres. Common isolates were: Pseudomonas aeruginosa, Staphylococcus aureus, Proteus mirabalis, Streptococcus pyogenes in descending order of frequency. Pure glycerol showed no significant zones of inhibition against any of the organisms tested. The average zones of inhibition for G & I and ichthammol alone were for Staphylococcus aureus 15 mm and 18 mm and for Streptococcus pyogenes: 16 mm and 23 mm. Ichthammol alone was significantly more effective than G & I (p < 0.001). There was no significant activity against Proteus mirabalis and Pseudomonas aeruginosa. The therapeutic benefit of G & I is due in part to the inherent anti-bacterial activity of ichthammol against the Gram positive organisms as well as its anti-inflammatory action and the dehydrating effect of the glycerol.

Adherence-induced enhancement of the oxidative burst of human neutrophilic granulocytes: effects of the surface coat and of divalent cations

Neutrophilic granulocytes are capable of adhering to biological or artificial surfaces. In addition to specific interactions between adherence molecules on the cell surface and corresponding structures on other cells or matrix proteins like fibronection or collagen there appeared to be non-specific attachment as well. Adherence augmentation induced by stimulation with chemotactic factors or cytokines was an active process which did not proceed at 4 degrees C and after removal of divalent cations from the medium. Adherence acted as a priming stimulus increasing the amount of superoxide anion and hydrogen peroxide produced in response to stimulation by certain chemotactic factors and cytokines. Adherence priming like priming by GM-CSF was strongly suppressed by chelation of intracellular Ca2+ ions. The two priming mechanisms differed, however, in their requirement for divalent cations in the external medium: whereas Mg2+ suppressed GM-CSF priming, it synergised with Ca2+ in the adherence-augmented oxidative burst.

Inhibitory effects of shale oils (Ichthyols) on the secretion of chemotactic leukotrienes from human leukocytes and on leukocyte migration

Ichthyols are sulfated shale oils with well-known anti-inflammatory effects in dermatologic diseases. Their possible mechanisms of action were studied by measuring chemotactic factor release from peripheral human leukocytes in vitro. Ichthyols caused no release of such factors by themselves but inhibited ionophore-induced release. After elution of the cell supernatants on reverse-phase high-pressure liquid chromatography, followed by analysis of the fractions in the chemotaxis assay and the radioimmunoassay, Ichthyols caused a reduction of lipids at marker positions for leukotriene B4 (LTB4) and 20-COOH-LTB4. The inhibition was also evident in the LTB4 radioimmunoassay, was dose- and time-dependent, and occurred in noncytotoxic concentrations of the agents. Ichthyols also inhibit the chemotactic response of neutrophils toward LTB4 and the unstimulated migration of cells. These inhibitory effects of Ichthyols on secretion of chemotactic arachidonate metabolites from leukocytes and on cell migration provide a plausible explanation for their anti-inflammatory activity.

Inhibitory effect of sulfonated shale oils (ammonium bituminosulfonate) on the stimulation of neutrophilic granulocytes by the chemotactic tripeptide f-Met-Leu-Phe

Sulfonated shale oils (ammonium bituminosulfonate, ichthammol, Ichthyol), shown previously to induce the directed migration of human neutrophils in Boyden chambers and to inhibit the directed migration towards the chemotactic factors C5a, LTB4, and f-Met-Leu-Phe, were studied for their effect on other neutrophil functions, which are stimulated by chemotactic factors. Like other chemotactic factors ammonium bituminosulfonate increased the adherence of neutrophils to nylon fibers, but it did not induce the release of the primary granule enzyme glucosaminidase from cytochalasin B-treated cells and it did not stimulate the production of oxygen radicals as measured by lucigenin-dependent chemiluminescence if studied under nontoxic conditions. When added together with the chemotactic tripeptide f-Met-Leu-Phe, ammonium bituminosulfonate inhibited adherence augmentation, enzyme release, and oxygen-radical production induced by the chemotactic factor. The results indicate that ammonium bituminosulfonate not only inhibited chemotactic migration but the whole spectrum of neutrophil functions induced by a chemotactic factor.