Kenneth D. Marenus

Sulfated polysaccharides from red microalgae have antiinflammatory properties in vitro and in vivo.

The primary goal of the present research was to determine whether sulfated polysaccharides derived from red microalgae possess anti inflammatory properties when directed against specific parameters of human skin inflammation. These unique biopolymers were studied in both in vitro and in vivo models of skin inflammation. Human subjects were recruited to participatein a study in which the polysaccharide material was applied topically and shown to inhibit cutaneousery thema induced by a known irritant. Leukocyte migration from capillary blood intosites of inflammation is an essential component of the inflammatory process and occurs in a series of steps, two of which are adhesion and chemotaxis. In vitro, the polysaccharide material primarily inhibited the migration of polymorphonuclear leukocytes (PMNs) toward a standard chemoattractant molecule and also partially blocked adhesion of PMNs to endothelial cells. The data obtained strongly suggest that sulfated polysaccharides derived from red microalgae have significant beneficial potential for use in topical products. In addition, the data suggested that the anti inflammatory mechanism for the polysaccharide was, at least in part, due to inhibition of circulating immune cell recruitment toward inflammatory stimuli.

Factors defining sensitive skin and its treatment

BACKGROUNDnUsers of cosmetics and skin care products often report adverse reactions ranging from itching and dryness to intense inflammatory responses such as erythema or wheal and rash. Self-assessment is not always an accurate parameter for categorizing skin as sensitive or nonsensitive, although it can be valuable. For this reason, it is important to define sensitive skin by more objective factors.nnnOBJECTIVEnStudies were undertaken to determine if objective biophysical measurements could detect differences in barrier function between those individuals who identified themselves as having sensitive skin and those self-identified as having normal skin. In addition, the effects of treatment on barrier functions of individuals with sensitive skin were determined.nnnMETHODSnThree main factors that contribute to cutaneous reactivities were observed for the estimation of skin sensitivity: barrier functions, reactivity to irritants, and neuronal responses manifested as sensory reactions. Barrier functions of the skin was tested by gentle removal of the stratum corneum with simple cellophane tape stripping followed by measurement of transepidermal water loss (TEWL) as a marker of barrier loss. The onset and intensity of skin reaction against an irritant, balsam of Peru, was tested on the same individuals to observe the reactivity of their skin. Using the lactic acid sting test, additional information regarding skin sensitivities was obtained.nnnRESULTSnSensitive skin individuals exhibiting easy barrier damage possess delicate skin that is also highly reactive to irritants. When these individuals used a regimen of products that contained minimal preservatives and no surfactants for 8 weeks, the skin barrier and reactivity changed such that it was similar to nonsensitive skin.nnnCONCLUSIONSnSkin sensitivity is observed because of a combination of factors, including a disrupted barrier and a tendency to hyperreact to topical agents. Treatment with special topical skin care formulations can reduce overall skin sensitivity.

Antiangiogenic properties of a novel shark cartilage extract: potential role in the treatment of psoriasis.

Background: A number of inflammatory and immune diseases are associated with vascular changes. Psoriasis, as an example, is a common inflammatory skin disease with dilation of capillaries as an early histological change. In more developed psoriatic lesions there is proliferation of blood vessels and neovascularization. The use of agents that target these vascular changes represents a novel therapeutic strategy in the treatment of inflammatory diseases. Since cartilage is an avascular tissue, it has been hypothesized that there may be factors found in cartilage that inhibit blood vessel formation. Objective: The objectives of this study were 1) to determine whether extracts of cartilage could inhibit angiogenesis, and 2) since altered angiogenesis is associated with certain diseases, including psoriasis, to examine whether inhibition of angiogenesis could potentially contribute to the treatment of psoriasis. Methods: Extracts of shark cartilage were prepared by homogenization and ultrafiltration to derive the active agent termed Æ-941. This agent was tested for antiangiogenesis activity using the embryonic vascularization test, which is a modification of the ex vivo chick embryo culture (CAM). Since one of the first steps in angiogenesis is degradation by metalloproteinases of the basement membrane of capillaries, Æ-941 was tested for collagenase activity using a fluorogenic peptide substrate. Anti-inflammatory properties were tested using a cutaneous irritation model in humans. Results: A dose dependent inhibition in embryonic neovascularization as well as in collagenase activity by Æ-941 was demonstrated. When test compounds were applied on the forearms of test subjects, Æ-941 was shown to have anti-inflammatory properties. Anecdotal data suggested that topical Æ-941 had a beneficial effect in psoriasis. Conclusion: Our results show that Æ-941 has anti-angiogenic and anti-inflammatory properties. Antiangiogenesis agents such as Æ-941 provide an entirely new class of agents to treat cutaneous and systemic diseases associated with altered vascularity.

Impact of stress of marital dissolution on skin barrier recovery: tape stripping and measurement of trans-epidermal water loss (TEWL).

Background: Psychological stress of marital disruption is associated with significant increases in a variety of psychological and physical disorders. The effect of stress on the immune system is well documented and skin disorders have been reported to exacerbate during stressful situations. This study was designed to observe the effects of stress on skin barrier strength and recovery. Twenty‐eight healthy females age 21–45 who were in the process of marital separation were tested for skin barrier strength and recovery. The panel was chosen on the basis of the intensity of self perceived stress. The control group was an age‐matched group of self perceived ‘happy’ subjects. Servomed evaporimeter was used to measure trans‐epidermal water loss (TEWL) from cheek area of the face, before and after removing stratum corneum layers with tape strippings. Skin barrier strength was defined as the number of tape strippings required to disrupt skin barrier, which is a TEWL of 18u2003g/m2/h or more. Barrier recovery was denoted by the level of TEWL, 3u2003h and 24u2003h after barrier disruption.

Tonality of suntan vs sunless tanning with dihydroxyacetone.

Background/aims: Although there is an increasing awareness of the detrimental effects of solar irradiation on skin, a tanned look is still in fashion. To achieve the tanned look without sun exposure various sunless tanning formulations have become available. Most of these contain dihydroxyacetone (DHA) which binds to the proteins of the stratum cornium and imparts a brown color to skin. This color is similar to a suntan but can be somewhat more yellow, making it appear unnatural. The aim of this study was to determine a quantitative method to define a “natural” tan and to study methods to improve the tonality of sunless tanning on skin.

Effect of antioxidants and free radical scavengers on protection of human skin against UVB, UVA and IR irradiation

Background/aims: This study was designed to observe the effect of a mix of commercial antioxidants and free radical scavengers (AO) on protection of human skin against different wavelengths of the solar spectrum: 280‐320 nm (UVB), 320‐400 nm (UVA) and 400‐900 nm (IR).

Effect of topical application of antioxidants and free radical scavengers on protection of hairless mouse skin exposed to chronic doses of ultraviolet B

Background/aims: Within the past three decades, there has emerged a greater awareness of the molecular effects of solar rays especially ultraviolet radiation (UV‐R), to the extent that the harmful effects of solar radiation are recognized not only by molecular biologists and physicians, but also by the general public (1). Various sunscreen molecules that effectively block the UVB component of the sun are available; however, a large part of Western populations elicits adverse reactions against chemical sunscreens (2). This study was designed to observe the protective effect of antioxidants against the damaging effects of chronic UVB exposure of skin in an attempt to introduce antioxidants and free radical scavengers as topical sun protective agents.