Innovative uses for zinc in dermatology

Oxidative stress and metabolic syndrome in acne vulgaris: Pathogenetic connections and potential role of dietary supplements and phytochemicals

Acne vulgaris is a highly prevalent skin condition caused by androgen-induced elevated sebum secretion, abnormal keratinization, bacterial colonization, and inflammation. Current research indicates a link between acne vulgaris and the metabolic syndrome, a group of disorders that includes obesity, insulin resistance, hypertension, and dyslipidemia. This link is thought to be modulated by excessive concentrations of oxidative stress markers and chronic inflammation, which are included in the pathophysiological mechanisms shared by both conditions. Excessive generation of reactive oxygen species damages cellular components and initiates an inflammatory response, hence promoting the development of both disorders. The current narrative review focuses on the molecular implications of inflammatory, hormonal, and environmental factors in the acne-metabolic syndrome correlation. Furthermore, it outlines the current state of knowledge related to the phyto-therapeutic approach to these conditions as an adjuvant strategy to allopathic treatment, but future multicenter and larger-scale research studies are needed establish new algorithms to be included in the future management of patients with these conditions.

Topical Non-Steroidal Immunomodulators in Dermatology

Immunological abnormality is the pathological basis of many dermatological disorders. Although steroids are the backbone of topical therapy in dermatology, the side effects are encountered quite frequently. Thorough knowledge of non-steroidal immunomodulators will broaden our treatment options. A summary of important non-steroidal immunomodulators has been given to help the residents understand the mechanism of action, indications, application, and adverse effects of these drugs.

The impact of clinical nutrition on inflammatory skin diseases

The influence of nutrition on the pathophysiology and clinical severity of inflammatory facial dermatoses such as acne, rosacea, seborrheic dermatitis, and perioral dermatitis has been controversially discussed for years. As part of a modern treatment approach, clinicians should provide patients with information on how their choice of diet might impact their dermatologic diagnosis and could potentially enhance therapeutic outcome. Recently, the concept of a gut-skin axis has gained momentum in the understanding of inflammatory dermatoses, with nutrition considered a contributing factor in this context. For example, gastrointestinal symptoms in rosacea patients may indicate a dysbiosis of the gut microbiome, treatment of which may also improve severity of the skin disease. New research efforts were recently made for acne patients addressing the clinical effects of omega-3 fatty acids and probiotics. In contrast, due to the limited data available, no comparable specific dietary recommendations can yet be made for seborrheic or perioral dermatitis. However, there are promising signs that clinical nutrition and dermatology will be more extensively interlinked in the future, both clinically and scientifically.

Zinc Chloride: Time-Dependent Cytotoxicity, Proliferation and Promotion of Glycoprotein Synthesis and Antioxidant Gene Expression in Human Keratinocytes

Simple Summary

Zinc ions are involved in the biology of cell growth, proliferation, differentiation or apoptosis by regulating many biological molecules, such as transcription factors, enzymes and growth factors. In this study, the time-dependent cytotoxicity, cell proliferation and gene expression in human keratinocytes HaCaT cells were evaluated when exposed to ZnCl₂. The results of this study showed non-cytotoxic effects up to 10 µg/mL after 24 h, no significant effect on cell proliferation when exposed to 5 or 1 µg/mL ZnCl₂ at 72 h and upregulation of eight genes, with great potential in the biomedical field, particularly for regenerative-medicine applications and wound healing.

Abstract

The use of ionic metals such as zinc (Zn²⁺) is providing promising results in regenerative medicine. In this study, human keratinocytes (HaCaT cells) were treated with different concentrations of zinc chloride (ZnCl₂), ranging from 1 to 800 µg/mL, for 3, 12 and 24 h. The results showed a time–concentration dependence with three non-cytotoxic concentrations (10, 5 and 1 µg/mL) and a median effective concentration value of 13.5 µg/mL at a cell exposure to ZnCl₂ of 24 h. However, the zinc treatment with 5 or 1 µg/mL had no effect on cell proliferation in HaCaT cells in relation to the control sample at 72 h. The effects of the Zn²⁺ treatment on the expression of several genes related to glycoprotein synthesis, oxidative stress, proliferation and differentiation were assessed at the two lowest non-cytotoxic concentrations after 24 h of treatment. Out of 13 analyzed genes (superoxide dismutase 1 (SOD1), catalase (CAT), matrix metallopeptidase 1 (MMP1), transforming growth factor beta 1 (TGFB1), glutathione peroxidase 1 (GPX1), fibronectin 1 (FN1), hyaluronan synthase 2 (HAS2), laminin subunit beta 1 (LAMB1), lumican (LUM), cadherin 1 (CDH1), collagen type IV alpha (COL4A1), fibrillin (FBN) and versican (VCAN)), Zn²⁺ was able to upregulate SOD1, CAT, TGFB1, GPX1, LUM, CDH1, FBN and VCAN, with relative expression levels of at least 1.9-fold with respect to controls. We found that ZnCl₂ promoted glycoprotein synthesis and antioxidant gene expression, thus confirming its great potential in biomedicine.

A Review of the Health Implications of Heavy Metals in Food Chain in Nigeria

Heavy metals such as Zn, Pb, Fe, and Cu are abundant in the environment and contribute largely to the sustainability and equilibrium of ecosystem processes. However, because of their bioaccumulation, nondegradability, and the excessive amounts in which they exist, these metals contaminate the food chain and subsequently become a source of toxicity to human beings and the entire ecological function. This is a major issue of concern within the study of environmental science and geochemistry. Although there is a global significance to the issue, it seems more immediate for the developing countries (DCs) such as Nigeria, where the pressure of the teeming population escalates the exigency for human sustainability, food security, and total eradication of hunger. Within the Nigerian context, many studies have examined this all-important issue, but most of these studies are fragmented and limited within the purview of mostly individual states and localities within the country. Taken on a wider geographical scale, the discussions and perspectives of these studies on heavy metal contamination of the food chain offer insufficient insight and expose merely a snapshot of the actual situation. As a result of this, a country-wide knowledge base of the implications of heavy metals on the food chain is lacking. Thus, the present study synthesises existing literature and their findings to create a knowledge base on the vulnerability of the food chain in Nigeria. Aquatic foods, fruits, vegetables, and major staple food such as tubers are the major host of carcinogenic and mutagenic components of heavy metals in Nigeria. This study motivates the Standard Organisation of Nigeria (SON), along with other food and agricultural agencies, to intensify their efforts in monitoring and analysing food components, and we advise consumers to eat with certain degrees of caveat.

Serum zinc levels in seborrheic dermatitis: a case-control study

Background/aim

Malassezia colonization, sebaceous gland activity, hormones, immune system defects, environmental factors, and the interactions between these factors are thought to contribute to the pathogenesis of seborrheic dermatitis (SD). Zinc, an essential element, is involved in many biological processes including the ones that contribute to the development of SD. The aim of this study is to evaluate serum zinc levels in patients with SD.

Materials and methods

Forty-three patients with SD and 41 healthy controls were enrolled in the study. Disease activity was assessed by the Seborrheic Dermatitis Area and Severity Index by a single dermatologist. Serum zinc levels of all subjects were evaluated.

Results

Statistically significantly lower serum zinc levels were noted in SD patients than in the control group (79.16 ± 12.17 vs. 84.88 ± 13.59, respectively; P = 0.045).

Conclusion

The results of the study demonstrated that patients who had SD had lower levels of serum zinc levels than healthy subjects.

A revisit to the effects of zinc salt on skin burn wound healing to reflect the risks in current pharmaceutical care

The lower limit of soluble zinc content that can possibly be applied onto a wounded skin as a healing promoter was not known. This study examined skin wound healing process of rats inflicted by partial thickness thermal burn wound as a function of applied soluble zinc contents (0.1 ml of zinc chloride solution 0.01% (w/w) or 5.0% (w/w)). The size, surface morphology and histological profiles of wound beds of untreated rats and those treated with zinc chloride solutions were characterized. A soluble zinc content as low as 10.5 μg/cm² of skin negated skin wound healing when compared to the untreated rats. This was alarming as the commercial products currently in the market are formulated with a high level of zinc content. Albeit the zinc salt employed was water-insoluble, a minute fraction of soluble zinc might be available to the treatment sites. This could be partially responsible for the late adverse effects such as pruritis and inflammation reported with calamine/diphenhydramine lotion, medicated shampoo, Olay Complete defense moisturizing lotion and Zineryt^® topical solution. The skin irritation was likely a resultant oxidative stress action of soluble zinc, where a small fraction could be adequate to negate the skin homeostasis.[Figure: see text]Key messagesZinc is essentially a cofactor for skin collagen formation.Soluble zinc content as low as 10.5 μg/cm² of skin irritates skin and negates burn wound healing.Skin irritation of commercial products relates to minute soluble zinc content availability.

Serum Zinc Levels in Hidradenitis Suppurativa: A Case-Control Study

BACKGROUND

Serum zinc levels in patients with hidradenitis suppurativa (HS) have not been previously studied.

OBJECTIVE

The aim was to investigate the association between HS and serum zinc levels.

METHODS

A multicenter, prospective clinical and analytical case-control study was designed to assess the possible association between HS and serum zinc levels. Consecutive patients with moderate or severe HS (Hurley II or III exclusively) were enrolled. A control population was recruited from primary care clinics. Fasting blood samples were extracted from each patient and serum zinc levels determined. Candidate predictors for low serum zinc levels were determined using logistic regression models.

RESULTS

In total, 122 patients with HS and 122 control subjects were studied. Of the 122 HS patients, 79 (64.8%) were Hurley II and 43 (35.2%) were Hurley III. Low serum zinc levels (≤ 83.3 µg/dL) were more prevalent in HS (adjusted odds ratio [ORa] 6.7, P < 0.001). After logistic regression analysis, low serum zinc levels were associated with Hurley III (ORa 4.4, P < 0.001), Dermatology Life Quality Index ≥ 9 (ORa 3.1, P = 0.005), number of affected sites ≥ 3 (ORa 2.4, P = 0.042), genital location (ORa 2.9, P = 0.009), and perineal location (ORa 2.5, P = 0.025).

CONCLUSION

Low serum zinc levels are more prevalent in HS than in a healthy population, an indicator that may also be associated with disease severity.

Synchronizing Pharmacotherapy in Acne with Review of Clinical Care

Acne is a chronic inflammatory skin disease that involves the pathogenesis of four major factors, such as androgen-induced increased sebum secretion, altered keratinization, colonization of Propionibacterium acnes, and inflammation. Several acne mono-treatment and combination treatment regimens are available and prescribed in the Indian market, ranging from retinoids, benzoyl peroxide (BPO), anti-infectives, and other miscellaneous agents. Although standard guidelines and recommendations overview the management of mild, moderate, and severe acne, relevance and positioning of each category of pharmacotherapy available in Indian market are still unexplained. The present article discusses the available topical and oral acne therapies and the challenges associated with the overall management of acne in India and suggestions and recommendations by the Indian dermatologists. The experts opined that among topical therapies, the combination therapies are preferred over monotherapy due to associated lower efficacy, poor tolerability, safety issues, adverse effects, and emerging bacterial resistance. Retinoids are preferred in comedonal acne and as maintenance therapy. In case of poor response, combination therapies BPO-retinoid or retinoid-antibacterials in papulopustular acne and retinoid-BPO or BPO-antibacterials in pustular-nodular acne are recommended. Oral agents are generally recommended for severe acne. Low-dose retinoids are economical and have better patient acceptance. Antibiotics should be prescribed till the inflammation is clinically visible. Antiandrogen therapy should be given to women with high androgen levels and are added to regimen to regularize the menstrual cycle. In late-onset hyperandrogenism, oral corticosteroids should be used. The experts recommended that an early initiation of therapy is directly proportional to effective therapeutic outcomes and prevent complications.

The Properties of the Ulcinj Peloid make it Unique Biochemical Laboratory Required for the Treatment of Problematic Skin and Health Care

The aim of this study was to investigate the physicochemical properties of peloid, its mineralogical composition and its antimicrobial activity, including the presence of algae, with the aim of considering its dermo-cosmetic application, such as anti-skin aging and treatment. Physicochemical analysis showed that peloid from Ulcinj coast, contains minerals, necessary for smooth performance of skin functions, as well as, the whole body. A studied peloid sample showed significant antimicrobial activity of Candida albicans strain, and the presence of algae of Bacillariophyta division, known to have a beneficial effect on skin health. Results of examination of peloid from Ulcinj locality, recommended it as a high quality natural substance applicative in dermo-cosmetic preparations for treatment of problematic skin.

Anti-inflammatory effects of zinc in PMA-treated human gingival fibroblast cells

OBJECTIVES

Abnormal cellular immune response has been considered to be responsible for oral lesions in recurrent aphthous stomatitis. Zinc has been known to be an essential nutrient metal that is necessary for a broad range of biological activities including antioxidant, immune mediator, and anti-inflammatory drugs in oral mucosal disease. The objective of this study was to investigate the effects of zinc in a phorbol-12-myristate-13-acetate (PMA)-treated inflammatory model on human gingival fibroblast cells (hGFs).

STUDY DESIGN

Cells were pre-treated with zinc chloride, followed by PMA in hGFs. The effects were assessed on cell viability, cyclooxygenease-1,2(COX-1,2) protein expression, PGE2 release, ROS production and cytokine release, Results: The effects were assessed on cell viability, COX1/2 protein expression, PGE2 release, ROS production, cytokine release. The results showed that, in the presence of PMA, zinc treatment leads to reduce the production of ROS, which results in decrease of COX-2 expression and PGE2 release.

CONCLUSIONS

Thus, we suggest that zinc treatment leads to the mitigation of oral inflammation and may prove to be an alternative treatment for recurrent aphthous stomatitis.

Zinc therapy in dermatology: a review

Zinc, both in elemental or in its salt forms, has been used as a therapeutic modality for centuries. Topical preparations like zinc oxide, calamine, or zinc pyrithione have been in use as photoprotecting, soothing agents or as active ingredient of antidandruff shampoos. Its use has expanded manifold over the years for a number of dermatological conditions including infections (leishmaniasis, warts), inflammatory dermatoses (acne vulgaris, rosacea), pigmentary disorders (melasma), and neoplasias (basal cell carcinoma). Although the role of oral zinc is well-established in human zinc deficiency syndromes including acrodermatitis enteropathica, it is only in recent years that importance of zinc as a micronutrient essential for infant growth and development has been recognized. The paper reviews various dermatological uses of zinc.

Is topical zinc effective in the treatment of melasma? A double-blind randomized comparative study

BACKGROUND AND OBJECTIVES

Zinc plays a role in skin health, and preliminary data have shown its beneficial effects for melasma. We compared the effect of topical zinc with that of hydroquinone as the standard treatment on severity of melasma.

PATIENTS AND METHODS

Ninety-three women with melasma were randomized to receive zinc sulfate 10% or hydroquinone 4% solutions once daily for 2 months. They were followed for an additional 3 months while using sunscreen. The severity of melasma was assessed at baseline and at 2 and 5 months using the Melasma Area and Severity Index (MASI).

RESULTS

Eighty-two patients completed the study. The MASI score fell significantly in both groups, but a greater decrease was seen in those who received hydroquinone (43.5 ± 15.5% vs 18.6 ± 20.8%, p < .001). Postinflammatory pigmentation occurred in 5.2% of the zinc group and irritation in 30.9% of the hydroquinone group.

CONCLUSION

Topical zinc therapy is not highly effective in reducing the severity of melasma, but further trials are needed to determine whether adding zinc to current topical treatments could improve treatment response.

Zinc pyrithione impairs zinc homeostasis and upregulates stress response gene expression in reconstructed human epidermis

Zinc ion homeostasis plays an important role in human cutaneous biology where it is involved in epidermal differentiation and barrier function, inflammatory and antimicrobial regulation, and wound healing. Zinc-based compounds designed for topical delivery therefore represent an important class of cutaneous therapeutics. Zinc pyrithione (ZnPT) is an FDA-approved microbicidal agent used worldwide in over-the-counter topical antimicrobials, and has also been examined as an investigational therapeutic targeting psoriasis and UVB-induced epidermal hyperplasia. Recently, we have demonstrated that cultured primary human skin keratinocytes display an exquisite sensitivity to nanomolar ZnPT concentrations causing induction of heat shock response gene expression and poly(ADP-ribose) polymerase (PARP)-dependent cell death (Cell Stress Chaperones 15:309-322, 2010). Here we demonstrate that ZnPT causes rapid accumulation of intracellular zinc in primary keratinocytes as observed by quantitative fluorescence microscopy and inductively coupled plasma mass spectrometry (ICP-MS), and that PARP activation, energy crisis, and genomic impairment are all antagonized by zinc chelation. In epidermal reconstructs (EpiDerm™) exposed to topical ZnPT (0.1-2% in Vanicream™), ICP-MS demonstrated rapid zinc accumulation, and expression array analysis demonstrated upregulation of stress response genes encoding metallothionein-2A (MT2A), heat shock proteins (HSPA6, HSPA1A, HSPB5, HSPA1L, DNAJA1, HSPH1, HSPD1, HSPE1), antioxidants (SOD2, GSTM3, HMOX1), and the cell cycle inhibitor p21 (CDKN1A). IHC analysis of ZnPT-treated EpiDerm™ confirmed upregulation of Hsp70 and TUNEL-positivity. Taken together our data demonstrate that ZnPT impairs zinc ion homeostasis and upregulates stress response gene expression in primary keratinocytes and reconstructed human epidermis, activities that may underlie therapeutic and toxicological effects of this topical drug.