Selective inactivation of human neutrophil elastase by synthetic tannin

Medical devices that look like medicines: safety and regulatory concerns for children in Europe

INTRODUCTION

Medical devices (MedDevs) and medicines are assessed (and monitored) differently before and after launch. There are products for repeated oral ingestion that are marketed in the European Union as MedDevs.

OBJECTIVES AND METHODS

To illustrate the consequences of these differences in assessment, we compared the leaflet information of three MedDevs with the standards for medicines and with published evidence at launch. As examples, gelatin tannate (GT), its combination with tyndalised probiotics (TP) (GTTP) for diarrhoea and a gel containing hyaluronic acid (HA)/chondroitin sulfate (CS)/poloxamer (Pol407) (HACSPol) for gastro-oesophageal reflux disease were examined.

RESULTS

Applying standards for medicines, product composition is insufficiently defined in the MedDev leaflet (eg, plant origin, polymerisation grade, dose and ratio of the relevant constituents). As no age limit is mentioned in the leaflets, all 3 products allow use in children from birth onwards, although published clinical documentation in children was poor (GT) or lacking (GTTP and HACSPol). MedDev leaflets do not mention adverse events (AEs), while literature search suggests safety concerns such as tannic acid (TA) cytotoxicity, potentially more diarrhoea/AEs with TP, use of doses higher than established safe (TA and HA) and lack of chronic toxicity studies for oral Pol407. None refers to interactions with medicines, although some ingredients may affect medicine absorption.

CONCLUSION

Although these MedDevs require repeated oral intake as do medicines, their assessment and monitoring differ significantly from the standards for medicines. Compared with medicines, MedDevs for repeated oral use are poorly labelled and rely on very limited clinical information at market release.

Eczema: tactics of choice external therapy

The therapeutic effects of synthetic tannins are based on their binding action, as well as on their anti-pruritic, antimicrobial and anti-inflammatory effects. Materials and methods. A clinical study of Neotanin spray, Neotanin lotion (suspension) and Neotanin cream was carried out in 8 clinical centres during the period from June, 2017 to January, 2018. The study had an open and non-comparative character. The study included 68 patients of both sex es aged from 1 month to 80 years suffering from eczema dermatosis in the acute weeping phase, including cases with complications after secondary infections (including eczema elements localized on the face). Before the study, information on the clinical history, demographic data, co-morbidities, physical examination data of the patients was collected. The treatment regimen included 2 stages: 1) Neotanin in the spray or lotion (suspension) form 3–4 times per day during 1–5 days, up to the full drying of eczema elements; 2) Neotanin in the cream form 3 times per day, up to the disappearance of the clinical manifestations of skin dermatosis. The duration of the study ranged from 5 to 14 days: the study was completed when a patient had achieved remission. The criteria for assessing the drug efficacy were as follows: dynamics of subjective complaints, objective assessment of the patient's condition (the presence and severity of clinical symptoms), dynamics of the Dermatology Life Quality Index (DLQI). Results. Neotanin preparations showed a high efficacy in the acute and subacute stages of the inflammatory process as an antipruritic agent. Itching stopped within 5 minutes after the drug application, with the antipruritic effect lasting for an average of 3–4 hours. In 85 % of the patients, marked excoriations were absent on the 3rd day of treatment. Neotanin demonstrated a pronounced anti-inflammatory effect. In 92 % of the patients, the symptoms of erythema and edema were significantly reduced one week after the beginning of treatment, with the manifestations of inflammatory exudation being conclusively decreased. One week following the beginning of treatment, 100 % of the patients demonstrated no oozing lesions. The absence of serious undesirable effects in the patients during the study evidences to the good tolerability and safety of this drug.

Bio-Guided Isolation of Methanol-Soluble Metabolites of Common Spruce (Picea abies) Bark by-Products and Investigation of Their Dermo-Cosmetic Properties

Common spruce (Picea abies L.) is a fast-growing coniferous tree, widely used in several countries for the production of sawn wood, timber and pulp. During this industrial exploitation, large quantities of barks are generated as waste materials. The aim of this study was the bio-guided investigation and the effective recovery of methanol-soluble metabolites of common spruce bark for the development of new dermo-cosmetic agents. The active methanol extract was initially fractionated by Centrifugal Partition Chromatography (CPC) using a triphasic solvent system in a step-gradient elution mode. All resulting fractions were evaluated for their antibacterial activity, antioxidant activity and their capability to inhibit tyrosinase, elastase and collagenase activity. In parallel, the chemical composition of each fraction was established by combining a ¹³C-NMR dereplication approach and 2D-NMR analyses. As a result, fourteen secondary metabolites corresponding to stilbene, flavonoid and phenolic acid derivatives were directly identified in the CPC fractions. A high amount (0.93 g) of E-astringin was recovered from 3 g of crude extract in a single 125 min run. E-Astringin significantly induced the tyrosinase activity while E-piceid, taxifolin, and taxifolin-3′-O-glucopyranoside exhibited significant anti-tyrosinase activity. The above compounds showed important anti-collagenase and antimicrobial activities, thus providing new perspectives for potential applications as cosmetic ingredients.

Elasto-regenerative properties of polyphenols

Abdominal aortic aneurysms (AAA) are progressive dilatations of infra-renal aorta causing structural weakening rendering the aorta prone to rupture. AAA can be potentially stabilized by inhibiting inflammatory enzymes such as matrix metalloproteinases (MMP); however, active regression of AAA is not possible without new elastic fiber regeneration. Here we report the elastogenic benefit of direct delivery of polyphenols such as pentagalloyl glucose (PGG), epigallocatechin gallate (EGCG), and catechin, to smooth muscle cells obtained either from healthy or from aneurysmal rat aorta. Addition of 10 μg/ml PGG and ECGC induce elastin synthesis, organization, and crosslinking while catechin does not. Our results indicate that polyphenols bind to monomeric tropoelastin and enhance coacervation, aid in crosslinking of elastin by increasing lysyl oxidase (LOX) synthesis, and by blocking MMP-2 activity. Thus, polyphenol treatments leads to increased mature elastin fibers synthesis without increasing the production of intracellular tropoelastin.

Synthetic tannins in dermatology--a therapeutic option in a variety of pediatric dermatoses

Synthetic tannins are established adjuvants in the therapy of itchy, inflamed, weeping, superficial skin diseases. The therapeutic effects of synthetic tannins are based on their tanning action as well as on their antimicrobial, anti-inflammatory, and antipruritic effects. In terms of pharmacology and clinical applicability, synthetic tannins are particularly versatile substances. They have also been used as steroid-free, anti-inflammatory treatment alternatives, especially in pediatric dermatoses. Systemic absorption is not to be expected. Because of their high safety profile and good tolerance, they are appropriate for the treatment of all age groups. Thus, synthetic tannins can be safely used for infants and children and also during pregnancy and lactation.

Ellagic and tannic acids protect newly synthesized elastic fibers from premature enzymatic degradation in dermal fibroblast cultures

Progressive proteolytic degradation of cutaneous elastic fibers, that cannot be adequately replaced or repaired by adult dermal fibroblasts, constitutes a major feature of aging skin. Our present investigations, employing monolayer cultures of human dermal fibroblasts and organ cultures of skin biopsies, were aimed at testing whether the hydrophilic tannic acid (TA) and lipophilic ellagic acid (EA) would protect dermal elastin from exogenous and endogenous enzymatic degradation. Results from both culture systems indicated that dermal fibroblasts, maintained with TA or EA, deposit significantly more elastic fibers than untreated control cultures despite the fact that neither polyphenol enhanced transcription of elastin mRNA or cellular proliferation. Results of a pulse and chase experiment showed that pretreatment with both polyphenols enhanced biostability of tropoelastin and newly deposited elastin. Results of in vitro assays indicated that both polyphenols bound to purified elastin and significantly decreased its proteolytic degradation by elastolytic enzymes belonging to the serine proteinase, cysteine proteinase, and metallo-proteinase families. Importantly, both polyphenols also synergistically enhanced elastogenesis induced by selected elastogenic compounds in cultures of dermal fibroblasts. We propose that EA and TA may be useful for preventing proteolytic degradation of existing dermal elastic fibers and for enhancing more efficient elastogenesis in aged skin.

Inhibitory effect of an extract of Sanguisorba officinalis L. on ultraviolet-B-induced photodamage of rat skin

We previously reported that chronic Ultraviolet-B (UVB) irradiation causes wrinkle formation, decreases skin elasticity, and damages/curls dermal elastic fibers. Those UVB-induced wrinkles can be improved by treatment with retinoic acid or with a CO2 laser which results in a recovery of skin elasticity and a repair of elastic fiber linearity. We showed further that topical application of N-phenetyl-leucyl-tryptophane, an agent that specifically inhibits fibroblast-derived elastase, immediately after UVB irradiation inhibited UVB-induced wrinkle formation, maintained skin elasticity, and inhibited changes in the three-dimensional structure of dermal elastic fibers in a dose-dependent manner. In this study, the effects of an extract of Sanguisorba officinalis L., which also inhibits fibroblast-derived elastase, was evaluated for possible inhibition of UVB induced wrinkle formation, maintenance of skin elasticity, and prevention of damage to the 3-dimensional structure of dermal elastic fibers. Hind limb skins of 3-week-old Sprague-Dawley rats were irradiated with UVB at a suberythemal dose 3 times a week for 6 weeks. Simultaneously, an extract of Sanguisorba officinalis L. (at 0.2% (v/v) or 1% (v/v)) was topically applied 5 times per week immediately following each UVB irradiation and 1 d later. The extract of Sanguisorba officinalis L. inhibited wrinkle formation, maintained skin elasticity, and inhibited the decrease of dermal elastic fiber linearity in the rat hind limb skin in a dose-dependent manner. We have confirmed that the inhibition of elastase activity in fibroblasts immediately after UVB irradiation using an extract of Sanguisorba officinalis L. prevents chronic photodamage following UVB irradiation.

Antileukoprotease in psoriatic scales

Antileukoprotease is known to be an antiproteolytic compound of mucous secretions in humans. While searching for peptide-like inhibitors of neutrophil-derived serine proteases in horny layers of human skin, we isolated a potent inhibitor of human leukocyte elastase (EC 3.4.21.37) and cathepsin G (EC 3.4.21.20) from psoriatic scales. This inhibitor showed inhibitory constants for human leukocyte elastase of approximately 0.5-2 x 10(-10) M and for cathepsin G of 2-4 x 10(-9) N. The N-terminal amino acid sequence of the purified peptide matched the sequence of antileukoprotease and both peptides showed the same M(r) on SDS-PAGE. Therefore, antileukoprotease may not only regulate serine protease activities in mucous secretions, but also in skin.