A Citrus Polymethoxy Flavonoid, Nobiletin Inhibits Sebum Production and Sebocyte Proliferation, and Augments Sebum Excretion in Hamsters

The Antioxidant Power of a Diet May Improve the Quality of Life of Young Women with Acne Vulgaris

Acne vulgaris (AV) significantly reduces the quality of life (QoL) of young people, so it is important to look for factors that can improve their QoL. The aim of this study was to assess the relationship between dietary antioxidants measured using the new DAQI index and QoL measured using standardized tests. The DAQI included the following elements: antioxidant vitamins, minerals, carotenoids, polyphenols, phytosterols, lignans, and the total antioxidant capacity of the diet. The study involved 165 young women with AV, mainly students. A self-report survey was used to collect basic data on their sociodemographic status, anthropometric information, and lifestyle. The energy value of the diet and the content of vitamins, minerals, and carotenoids with antioxidant activity in the diet were estimated using 3-day food diaries and the Diet 6.0 program. The antioxidant potential of the diet and the content of polyphenols, phytosterols, lignans, and selenium were calculated based on the consumption of individual food products and available databases. The results of this study showed that the QoL of the young women with AV was impaired. However, greater adherence to an antioxidant diet reduces the risk of AV impact on the QoL by approximately 30-32% and the risk of depression by 33%. The DAQI may be used as a new indicator of diet quality in acne vulgaris.

A novel deformable liposomal hydrogel loaded with a SREBP-1-inhibiting polypeptide for reducing sebum synthesis in golden hamster model

Excessive sebum is the major factor involved in the pathophysiology of seborrheic diseases. Chemical medicines can result in mild to severe side effects. Polypeptides with much less side effects make them ideal for reducing sebum synthesis. Sterol regulatory element-binding proteins-1 (SREBP-1) is necessary for the biosynthesis of sterols. A SREBP-1-inhibiting polypeptide (SREi), which competitively inhibits the ubiquitination of Insig-1 so as to suppress the activation of SREBP-1 was selected as an active ingredient and formulated into skin topical preparations. The SREi anionic deformable liposomes contained sodium deoxycholate (SDCh) at the concentration of 4.4 mg/mL (SREi-ADL3) and SREi-ADL3 in 0.3% (w/v) carbomer hydrogel (SREi-ADL3-GEL) were prepared and characterized. The SREi-ADL3 presented a high entrapment efficiency of 92.62 ± 6.32%, a particle size of 99.54 ± 7.56 nm and a surface charge of -19.18 ± 0.45 mV. SREi-ADL3-GEL exhibited a sustained release behavior, a higher stability, a much more cellular uptake ability and transdermal absorption. In vivo golden hamster model confirmed that SREi-ADL3-GEL presented the strongest inhibitory effect on sebaceous gland growth and sebum synthesis by down-regulating the mRNA and protein expression of SREBP-1, fatty acid synthase (FAS) and acetyl-coenzyme A carboxylase 1 (ACC1). As confirmed by histological analysis, only a small amount of sebaceous gland lobes with the lightest staining intensity and the smallest dyeing area could be observed in the SREi-ADL3-GEL group. Taken together, SREi-ADL3-GEL displayed potential applications in sebum excessive production related diseases.

Flavonoids as Promising Natural Compounds in the Prevention and Treatment of Selected Skin Diseases

Phytochemicals represent a large and diverse group of naturally occurring compounds, bioactive nutrients, or phytonutrients produced by plants, widely found in fruits, vegetables, whole grains products, legumes, beans, herbs, seeds, nuts, tea, and dark chocolate. They are classified according to their chemical structures and functional properties. Flavonoids belong to the phenolic class of phytochemicals with potential solid pharmacological effects as modulators of multiple signal transduction pathways. Their beneficial effect on the human body is associated with their antioxidant, anti-inflammatory, antimutagenic, and anticarcinogenic properties. Flavonoids are also widely used in various nutritional, pharmaceutical, medical, and cosmetic applications. In our review, we discuss the positive effect of flavonoids on chronic skin diseases such as vitiligo, psoriasis, acne, and atopic dermatitis.

Non-conventional therapeutical approaches to acne vulgaris related to its association with metabolic disorders

The ever-increasing frequency of metabolic syndrome (MetS) is still a major challenge of the public health care system, worldwide. In recent years, researchers have been drawn to the uncommon (at first look) link between skin illnesses and MetS. Because of the pro-inflammatory mechanisms and insulin resistance (IR) that are upregulated in metabolic syndrome, many skin disorders are correlated to metabolic dysfunctions, including acne vulgaris. A comprehensive understanding of the link between MetS and acne vulgaris may contribute to the development of new treatment strategies. The current review focuses on dietary and therapeutic interventions and assesses the effect of various approaches such as improving diet by avoiding certain food products (i.e., milk and chocolate) or increasing the intake of others (i.e., food products rich in omega-3 fatty acids), metformin administration, therapy with plant extracts, plant essential oils, and probiotic supplementation on the improvement of certain acne vulgaris severity parameters. These therapeutic approaches, when combined with allopathic treatment, can improve the patients' quality of life.

Nobiletin-loaded composite penetration enhancer vesicles restore the normal miRNA expression and the chief defence antioxidant levels in skin cancer

Skin cancer is one of the most dangerous diseases, leading to massive losses and high death rates worldwide. Topical delivery of nutraceuticals is considered a suitable approach for efficient and safe treatment of skin cancer. Nobiletin; a flavone occurring in citrus fruits has been reported to inhibit proliferation of carcinogenesis since 1990s, is a promising candidate in this regard. Nobiletin was loaded in various vesicular systems to improve its cytotoxicity against skin cancer. Vesicles were prepared using the thin film hydration method, and characterized for particle size, zeta potential, entrapment efficiency, TEM, ex-vivo skin deposition and physical stability. Nobiletin-loaded composite penetration enhancer vesicles (PEVs) and composite transfersomes exhibited particle size 126.70 ± 11.80 nm, 110.10 ± 0.90 nm, zeta potential + 6.10 ± 0.40 mV, + 9.80 ± 2.60 mV, entrapment efficiency 93.50% ± 3.60, 95.60% ± 1.50 and total skin deposition 95.30% ± 3.40, 100.00% ± 2.80, respectively. These formulations were selected for cytotoxicity study on epidermoid carcinoma cell line (A431). Nobiletin-loaded composite PEVs displayed the lowest IC50 value, thus was selected for the in vivo study, where it restored skin condition in DMBA induced skin carcinogenesis mice, as delineated by histological and immuno-histochemical analysis, biochemical assessment of skin oxidative stress biomarkers, in addition to miRNA21 and miRNA29A. The outcomes confirmed that nobiletin- loaded composite PEVs is an efficient delivery system combating skin cancer.

Effect of Genetic Polymorphisms of Human SLC22A3 in the 5'-flanking Region on OCT3 Expression and Sebum Levels in Human Skin

BACKGROUND

Human organic cation transporter 3 (OCT3,SLC22A3) mediates the uptake of many important endogenous substances and basic drugs, and has been identified as one of the transporters that are highly expressed in human skin. However, the mechanisms responsible for variability in mRNA expression, and the role of SLC22A3 in human skin is not clear.

OBJECTIVE

We examined the effects of the single nucleotide polymorphisms ofSLC22A3 on the variability in SLC22A3 expression and sebum levels in humans.

METHODS

Immunostaining of OCT3 in human skin was performed. We analyzed the association of promoter variants with the SLC22A3 mRNA expression levels in human skins. Luciferase, knockdown, chromatin immunoprecipitation (ChIP), electrophoretic mobility shift assay were employed to investigate transcriptional regulation of SLC22A3 expression. Effects of the identified variant on sebum levels were evaluated in healthy volunteers.

RESULTS

Immunohistochemistry revealed marked expressions of OCT3 in the basal epidermis, sebaceous glands, hair follicles, and sweat glands of human skin. SLC22A3 mRNA levels were significantly lower in skin samples with homozygotes for -1603A/A than in those for -1603 G/G. The analysis of p53 binding to -1603 G > A in the promoter ofSLC22A3 suggested that -1603 G > A down-regulates SLC22A3 gene expression by decreased p53 binding in the vicinity of the -1603 site. In humans, squalene levels in samples from the back at the baseline were significantly lower in homozygotes for -1603A/A than in those for -1603 G/G.

CONCLUSION

These results suggest that the genetic variant contributes to the variability of expression and activities of OCT3 in human skin.

Triptolide suppresses ultraviolet B-enhanced sebum production by inhibiting the biosynthesis of triacylglycerol in hamster sebaceous glands in vivo and in vitro

Ultraviolet B (UVB) irradiation causes alterations in cutaneous barrier function, including excessive production of sebum in sebaceous glands, which is associated with the aggravation of acne. This study aimed to evaluate the inhibitory effects of triptolide, a diterpenoid triepoxide from Tripterygium wilfordii Hook F, on sebocytic lipogenesis in UVB-irradiated hamster skin in vivo and in vitro. Topical application of triptolide decreased the UVB-enhanced sebum accumulation in the sebaceous glands of hamster skin. The level of triacylglycerol (TG), a major sebum component, on the skin surface was reduced by triptolide treatment in UVB-irradiated hamsters, whereas there was no change in that of free-fatty acids and cholesterol, which are minor sebum components. UVB irradiation significantly enhanced TG production (P<0.01 in extracellular lipids, P<0.05 in intracellular lipids), and the activity of acyl coenzyme A/diacylglycerol acyltransferase (DGAT), a rate-limiting enzyme of TG synthesis, in differentiated hamster sebocytes (P<0.05 at 6 h and UVB of 0.62 kJ/m², P<0.001 at 24 h and UVB 0.37 or 0.62 kJ/m²). Furthermore, triptolide significantly inhibited UVB-enhanced TG production (P<0.05 at 28 nM and P<0.01 at 56 and 112 nM triptolide) and DGAT activity (P<0.01 at 28 nM and P<0.001 at 56 and 112 nM triptolide) in differentiated hamster sebocytes. These results provide novel evidence that triptolide decreases UVB-enhanced sebum production by inhibiting DGAT-dependent TG biosynthesis in differentiated hamster sebocytes. These findings may be applicable to the prevention of acne aggravation.

Significance of diet in treated and untreated acne vulgaris

The relationship between diet and acne is highly controversial. Several studies during the last decade have led dermatologists to reflect on a potential link between diet and acne. This article presents the latest findings on a potential impact that diet can have on pathogenesis of acne vulgaris. The association between diet and acne can no longer be dismissed. Compelling evidence shows that high glycemic load diets may exacerbate acne. Dairy ingestion appears to be weakly associated with acne and the roles of omega-3 fatty acids, dietary fiber, antioxidants, vitamin A, zinc and iodine remain to be elucidated. The question of what the impact of diet is on the course of acne vulgaris still remains unclear.

Microfluidic Isolation of CD34-Positive Skin Cells Enables Regeneration of Hair and Sebaceous Glands In Vivo

Skin stem cells resident in the bulge area of hair follicles and at the basal layer of the epidermis are multipotent and able to self-renew when transplanted into full-thickness defects in nude mice. Based on cell surface markers such as CD34 and the α6-integrin, skin stem cells can be extracted from tissue-derived cell suspensions for engraftment using the gold standard cell separation technique of fluorescence-activated cell sorting (FACS). This paper describes an alternative separation method using microfluidic devices coated with degradable antibody-functionalized hydrogels. The microfluidic method allows direct injection of tissue digestate (no preprocessing tagging of cells is needed), is fast (45 minutes from injected sample to purified cells), and scalable. This method is used in this study to isolate CD34-positive (CD34+) cells from murine skin tissue digestate, and the functional capability of these cells is demonstrated by transplantation into nude mice using protocols developed by other groups for FACS-sorted cells. Specifically, the transplantation of microfluidic isolated CD34+ cells along with dermal and epidermal cells was observed to generate significant levels of hair follicles and sebaceous glands consistent with those observed previously with FACS-sorted cells.

Antimetastatic effect of nobiletin through the down-regulation of CXC chemokine receptor type 4 and matrix metallopeptidase-9

CONTEXT

Nobiletin is one of the citrus bioflavonoids and can be found in citrus fruits such as lemons, oranges, tangerines, and grapefruits. The most studied properties of nobiletin are its anti-inflammatory and anticancer activities.

OBJECTIVE

The exact mechanisms of how nobiletin inhibits tumor metastasis and invasion are still not fully understood. In this study, we screened various natural compounds to down-modulate the CXC chemokine receptor-4 (CXCR4) and matrix metallopeptidase-9 (MMP-9).

MATERIALS AND METHODS

The effect of nobiletin on the constitutive expressions of CXCR4 and MMP-9, MMP-9 enzymatic activity, associated nuclear factor κB (NF-κB) and mitogen-activated protein kinases (MAPKs) activation, and tumor cell invasion in human breast cancer cells was investigated. CXCR4 and MMP-9 expression were evaluated via reverse transcription polymerase chain reaction (RT-PCR) and western blotting. NF-κB activation was also evaluated by electrophoretic mobility shift assay (EMSA). In addition, the antimetastatic effects of nobiletin were determined by gelatin zymography and invasion assay.

RESULTS

Nobiletin down-regulated both the constitutive expressions of CXCR4 and MMP-9 in human breast cancer cells with IC(50) values of 32 and 24 µM, respectively. Nobiletin also suppressed MMP-9 enzymatic activity and tumor cell invasion under noncytotoxic concentrations. Neither proteasome inhibition nor lysosomal stabilization had any effect on the nobiletin-induced decrease in CXCR4 expression. A detailed study of the underlying molecular mechanisms revealed that the regulation of the down-regulation of CXCR4 and MMP-9 were at the transcriptional level, as indicated by the down-regulation of mRNA expression and the suppression of the constitutive NF-κB and MAPKs activation.

DISCUSSION AND CONCLUSION

Our results indicate, for the first time, that nobiletin is a novel blocker of CXCR4 and MMP-9 expressions and thus has the potential to suppress metastasis of breast cancer.

Epigallocatechin-3-gallate suppresses IGF-I-induced lipogenesis and cytokine expression in SZ95 sebocytes

Acne vulgaris is the most common disease of the pilosebaceous unit. The pathogenesis of this inflammatory disease is complex, involving increased sebum production and perifollicular inflammation. To identify effective agents for factors that induce acne vulgaris, we explored the pharmacological potential of epigallocatechin-3-gallate (EGCG), which has been widely investigated as an anti-proliferative and anti-inflammatory agent. In this study, we demonstrated that topical application of EGCG to rabbit auricles reduced the size of the sebaceous glands. When applied to cultured human SZ95 sebocytes, EGCG strongly suppressed cell proliferation and lipogenesis. These actions of EGCG were reproduced in IGF-I-differentiated SZ95 sebocytes. To investigate the anti-inflammatory potential of EGCG, we evaluated pro-inflammatory cytokine synthesis in IGF-I-differentiated SZ95 sebocytes and found that expression of IL-1, IL-6, and IL-8 was decreased. These results provide early evidence that EGCG is an effective candidate for acne therapy whose mechanisms of action in IGF-I-differentiated SZ95 sebocytes include the inhibition of lipogenesis and inflammation.

Effect of Duabanga grandiflora for Human Skin Cells

The purpose of this investigation was to evaluate the effects of Duabanga grandiflora (Sonneratiaceae), which has been used as a traditional Thai medicine on human skin cells. The leaf extract of D. grandiflora actively affected several human skin cells such as skin whitening, anti-aging and anti-inflammation. It became evident that the extract stimulated the production of type III collagen. The crude extract was fractionated and analyzed for stimulation of type III collagen production, and finally by HPLC to isolate an active compound which was determined to be eugeniin by EI-mass, 13C NMR, 1H NMR and acidic hydrolysis. Eugeniin has strong dose dependent activity for type III collagen production, with this being the first example of stimulation activity for type III collagen production.

Identification and characterization of ABCB1-mediated and non-apoptotic sebum secretion in differentiated hamster sebocytes

Sebaceous glands secrete sebum onto the skin surface in a holocrine manner and as such a thin lipid layer is formed as a physiological barrier. In the present study, extracellular level of triacylglycerols (TG), a major sebum component, as well as intracellular TG accumulation was augmented in insulin-differentiated hamster sebocytes (DHS). The DHS exhibited phosphatidylserine exposure in an apoptosis-independent manner. In addition, intracellular ATP level and membrane-transporter activity using a substrate, Rhodamine 123, were highly detectable in the DHS rather than in the undifferentiated hamster sebocytes. A membrane-transporter activating reagent, 2'(3')-O-(4-benzoylbenzoyl) adenosine 5'-triphosphate (BzATP), enhanced transporter activity, extracellular TG level, and phosphatidylserine exposure in the DHS. Both transporter activity and TG secretion were suppressed by R-verapamil, a potent membrane-transporter inhibitor, in the BzATP-treated and untreated DHS. Furthermore, the gene expression and production of ATP-binding cassette subfamily B member 1 (ABCB1) were augmented in the DHS. ABCB1 was also detectable in sebaceous glands in the skin of hamsters. Moreover, the cell-differentiation- and BzATP-augmented transporter activity and TG secretion were dose-dependently inhibited by adding not only an ABCB1 antibody but also a selective inhibitor of ABCB1, PSC833. Thus, these results provide novel evidence that ABCB1 is involved in sebum secretion in the DHS, which is associated with non-apoptotic phosphatidylserine exposure and the increased level of intracellular ATP. These findings should accelerate the understanding of sebum secretion occurring in a holocrine-independent manner in sebaceous glands, and may contribute to the development of therapies for sebaceous gland disorders such as acne, seborrhea, and xerosis.

Diet and acne

Historically, the relationship between diet and acne has been highly controversial. Before the 1960s, certain foods were thought to exacerbate acne. However, subsequent studies dispelled these alleged associations as myth for almost half a century. Several studies during the last decade have prompted dermatologists to revisit the potential link between diet and acne. This article critically reviews the literature and discusses how dermatologists might address diet when counseling patients with acne. Dermatologists can no longer dismiss the association between diet and acne. Compelling evidence exists that high glycemic load diets may exacerbate acne. Dairy ingestion appears to be weakly associated with acne, and the roles of omega-3 fatty acids, antioxidants, zinc, vitamin A, and dietary fiber remain to be elucidated. This study was limited by the lack of randomized controlled trials in the literature. We hope that this review will encourage others to explore the effects of diet on acne.