Humans ; Male ; Melanins ; metabolism ; Metaplasia ; metabolism ; pathology ; Middle Aged ; Nasopharyngeal Diseases ; metabolism ; pathology ; Nasopharynx ; metabolism ; pathology

OBJECTIVETo confirm the inhibitory effect of Chinese herbs of acid taste on melanin synthesis.

METHODSActive ingredients of 22 kinds Chinese herbs of acid tastes were extracted by alkali extraction and acid precipitation, alcohol extraction, and water extraction, respectively, which was then dispensed into 25.00, 12.50, and 6.25 g/L suspension. Their effects on activities of tyrosinase were detected using mushroom-tyrosinase-DOPA speed oxidation. Their inhibition rates on activities of tyrosinase were respectively compared with inhibition rates of 1.0, 0.5, and 0.1 mmol/L arbutin.

RESULTSThe 22 kinds Chinese herbs of acid taste included Cornus Officinalis, Crataegus pinnatifida, dark plum fruit, Schisandra Chinensis, Chaenomeles sinensis Koehne, Reynoutria japonica Houtt, Achyranthes Bidentata, Sanguisorba officinalis L., Semen Ziziphi Spinosae, Herba Ecliptae, blueberry, immature bitter orange, submature bitter orange, Prunus mume Var, Hovenia acerba Lindl., Fructus Mori, Pomegranate Rind, white paeony root, Rosa laevigata Michx., Portulaca oleracea L, Terminalia chebula Retz, Rhus chinensis Mill. Their alkaline extractions showed inhibition to activities of tyrosinase to different degrees except Herba Ecliptae. Of them, the highest inhibition rate (88.49% ± 9.98%) was got by dark plum fruit at 25 g/L, while the lowest inhibition rate (11.22% ± 3.36%) was got by immature bitter orange at 6.25 g/L. Their alcohol extractions showed inhibition to activities of tyrosinase to different degrees except Herba Ecliptae. Of them, the highest inhibition rate (75.92% ± 5.57%) was got by Hovenia acerba Lindl. at 25 g/L, while the lowest inhibition rate (9.60% ± 1.15%) was got by submature bitter orange at 6.25 g/L. Their water extractions all had inhibition on activities of tyrosinase. Of them, the highest inhibition rate (54.23% ± 3.56%) was got by Fructus Mori at 25 g/L, while the lowest inhibition rate (10.25% ± 1.83%) was got by Semen Ziziphi Spinosae at 6.25 g/L. Compared with 1 mmol/L arbutin water solution, alkaline extractions of dark plum fruit, Schisandra Chinensis, Rhus chinensis Mill., Rosa laevigata Michx., blueberry, Chaenomeles sinensis Koehne, Portulaca oleracea L, Fructus Mori, Achyranthes Bidentata, Pomegranate Rind; alcohol extractions of dark plum fruit, Rhus chinensis Mill., Pomegranate Rind, Hovenia acerba Lindl., Crataegus pinnatifida, Achyranthes Bidentata; water extractions of Chaenomeles sinensis Koehne, blueberry, and Fructus Mori at 25 g/L got obviously higher inhibition rates (P < 0.05, P < 0.01). Compared with 0.5 mmol/L arbutin water solution, alcohol extraction of Chaenomeles sinensis Koehne and alcohol extraction of dark plum fruit at 12.5 g/L got obviously higher inhibition rates (P < 0.05, P < 0.01).

CONCLUSIONChinese herbs of acid taste could inhibit melanin synthesis, and its mechanism was related to inhibiting activities of tyrosinase.

Drugs, Chinese Herbal ; pharmacology ; Humans ; Melanins ; metabolism ; Monophenol Monooxygenase ; metabolism ; Oxidation-Reduction ; Schisandra ; Taste

Eumelanin is a heteropolymer that is generally composed of hydroxylated indole residues and plays diverse protective functions in various species. Melanin is derived from the amino acid tyrosine and production of melanin is a highly complex oxidative process with a number of steps that can either proceed enzymatically or non-enzymatically. Although melanin plays important protective roles in many species, during melanization, particularly in steps that can proceed non-enzymatically, many toxic intermediates are produced, including semiquinones, dopaquinone, indole-quinones and moreover, the production of many reactive oxygen species. To mitigate the production of reactive species, a number of proteins that regulate the biochemical process of melanization have evolved in various living species, which is closely related to adaptation and physiological requirements. In this communication, we discuss differences between non-enzymatic and enzymatic processes of melanization and the enzymatic regulation of melanization in difference species with an emphasis on differences between mammals and insects. Comparison between melanization and insect sclerotization is also emphasized which raises some interesting questions about the current models of these pathways.
Animals ; Biological Evolution ; Humans ; Insecta ; metabolism ; Mammals ; metabolism ; Melanins ; biosynthesis ; chemistry ; Models, Biological ; Species Specificity

Ocular albinism is a rare condition of abnormality in the cellular metabolism of the product of melanin in the ocular tissue. This disease is transmitted as an imtermediate sex linked recessive. This condition was first described by Nettleship in 1909. In addition, many authors described this condition. The fundamentalelinical symptoms and signs are lowered visual acuity, photophobia, nystagmus, the yellow-orange color of the fundus with the choroidal vessels perfectly visible, absence of the foveal reflex and iris that transilluminates well with scleral illumination. Recently, we experienced two cases of typical ocular albinism.
Albinism, Ocular* ; Choroid ; Iris ; Lighting ; Melanins ; Metabolism ; Photophobia ; Reflex ; Visual Acuity

Pigmented extraadrenal paraganglioma is an unusual neoplasm that has rarely been reported in the literature. Based on histochemical staining or electron microscopy, pigment has been classified as lipofuscin, neuromelanin or true melanin. We report a case of pigmented extraadrenal paraganglioma in the posterior mediastinum of a 70-year-old woman. Histologically, the tumor had a characteristic organoid architecture of "zellballen" pattern with rich delicate microvasculature. Tumor cells contained numerous coarse brown-black pigment granules. Ultrastructurally, the tumor showed abundant large electron-dense pigment granules that vary in size and shape and smaller membrane-bound neurosecretory granules. The larger granules were consistent with neuromelanin or lipofuscin. Histochemically, the pigment is most likely neuromelanin, which is a waste product of catecholamine metabolism.
Aged ; Female ; Humans ; Lipofuscin ; Mediastinum ; Melanins ; Metabolism ; Microscopy, Electron ; Microvessels ; Organoids ; Paraganglioma* ; Waste Products

Antigens, CD34 ; metabolism ; Biomarkers ; metabolism ; Cell Differentiation ; physiology ; Hair Follicle ; cytology ; Humans ; Intramolecular Oxidoreductases ; metabolism ; Keratinocytes ; metabolism ; Melanins ; metabolism ; Melanocytes ; metabolism ; PAX3 Transcription Factor ; metabolism ; Stem Cells ; metabolism

Keloids are a common type of pathological scar as a result of skin healing, which are extremely difficult to prevent and treat without recurrence. The pathological mechanism of keloids is the excessive proliferation of fibroblasts, which synthesize more extracellular matrices (ECMs), including type I/III collagen (COL-1/3), mucopolysaccharides, connective tissue growth factor (CTGF, also known as cellular communication network factor 2 (CCN2)), and fibronectin (FN) in scar tissue, mostly through the abnormal activation of transforming growth factor-‍β (TGF-‍β)/Smads pathway (Finnson et al., 2013; Song et al., 2018). Genetic factors, including race and skin tone, are considered to contribute to keloid formation. The reported incidence of keloids in black people is as high as 16%, whereas white people are less affected. The prevalence ratio of colored people to white people is 5:1‍‍-‍‍15:1 (Rockwell et al., 1989; LaRanger et al., 2019). In addition, keloids have not been reported in albinism patients of any race, and those with darker skin in the same race are more likely to develop this disease (LaRanger et al., 2019). Skin melanocyte activity is significantly different among people with different skin tones. The more active the melanocyte function, the more melanin is produced and the darker the skin. Similarly, in the same individual, the incidence of keloids increases during periods when melanocytes are active, such as adolescence and pregnancy. Keloids rarely appear in areas where melanocytes synthesize less melanin, such as in the palms and soles. Thus, the formation of keloids seems to be closely related to melanocyte activity.
Adolescent ; Cells, Cultured ; Exosomes/metabolism* ; Fibroblasts/metabolism* ; Humans ; Keloid/pathology* ; Melanins/metabolism* ; Melanocytes/pathology* ; Pilot Projects ; Skin/metabolism* ; Transforming Growth Factor beta/metabolism*

Tea contains polyphenols and is one of the most popular beverages consumed worldwide. Because most tyrosinase inhibitors that regulate melanogenesis are phenol/catechol derivatives, this study investigated the inhibitory effects of Camellia sinensis water extracts (CSWEs), including black tea, green tea, and white tea extracts, on melanogenesis using immortalized melanocytes. CSWEs inhibited melanin accumulation and melanin synthesis along with tyrosinase activity in a concentration-dependent manner. These inhibitory effects were superior to those of arbutin, a well-known depigmenting agent. The anti-melanogenic activity of black (fermented) tea was higher than that of a predominant tea catecholamine, epigallocatechin gallate. CSWEs, especially black tea extract, decreased tyrosinase protein levels in a concentration-dependent manner. These results suggest that the anti-melanogenic effect of CSWEs is mediated by a decrease in both tyrosinase activity and protein expression, and may be augmented by fermentation. Thus, CSWEs could be useful skin-whitening agents in the cosmetic industry.
Animals ; Catechin/analogs & derivatives/metabolism ; Cell Line ; Melanins/*metabolism ; Melanocytes/enzymology/*metabolism ; Mice ; Monophenol Monooxygenase/*metabolism ; Plant Extracts/*pharmacology ; Plant Leaves/chemistry ; Tea/*chemistry

OBJECTIVETo investigate the expression of alpha-melanocyte-stimulating hormone (alpha-MSH) in human split-thickness skin autograft and the role of alpha-MSH in hyperpigmented process of the grafted skin.

METHODSImmunohistochemical technique was used to detect the expression and distribution of alpha-MSH in the split-thickness grafted skin and normal skin separately.

RESULTSThe expression of alpha-MSH in most of the split-thickness grafted skin was much stronger than the control skin. The positive ratio of alpha-MSH expression was 61.1% in the split-thickness grafted skin, 11.1% in the normal skin of the donor area and 16.7% in the normal skin around the recipient area. The expression of alpha-MSH in the split-thickness grafted skin was significant high, compared with the normal skins (P < 0.01). The expression of alpha-MSH in the normal skin of the donor area was no statistic remarkably differences compared to the normal skin around the recipient area.

CONCLUSIONThe results indicate that the expression of alpha-MSH may markedly increase in the split-thickness grafted skin and correlate with its pigmentation after the skin graft. Overexpression of alpha-MSH may play an important role in hyperpigmented process of the skin graft.

Adolescent ; Adult ; Child ; Female ; Humans ; Hyperpigmentation ; metabolism ; Male ; Melanins ; metabolism ; Skin ; metabolism ; Skin Transplantation ; Transplantation, Autologous ; Young Adult ; alpha-MSH ; metabolism

OBJECTIVETo investigate the effects of Liuwei Dihuang (LWDH) decoction on serotonine (5-HTs), melatonin and the activity of the rate-limiting enzymes ANNAT and HIOMT in cultured human melanocytes and in melanocytes co-cultured with keratinocytes.

METHODSCCK-8 assay was used to assess the proliferation of melanocytes and melanocytes co-cultured with keratinocytes after treatment with the serum from rabbits fed with LWDH decoction. High-performance liquid chromatography was used to determine 5-HT and melatonin contents, and real-time fluorescent PCR was employed to evaluate the ANNAT and HIOMT activities in the cell cultures.

RESULTSThe serum from rabbits fed with LWDH Decoction at low doses did not affect the proliferation of melanocytes co-cultured with keratinocytes, but at the concentrations of 20%-40%, the serum significantly inhibited the proliferation of melanocytes, and the effect was optimal with a concentration of 40% (P<0.05). 5-HT and melatonin contents in the cell culture decreased as the serum concentration increased (P<0.05), which was the most obvious with a serum concentration of 40% (P<0.01). Exposure of the cells to low and moderate doses of the serum caused a dose-dependent decrease in AANAT activity (P<0.05), but the serum produced no significant changes in the level of HIOMT mRNA expression in the cells.

COUCLUSIONSThe serotoninergic/melatoninergic system mediate the regulation of melanin metabolism by LWDH Decoction, the mechanism of which may involve 5-HTs, melatonin and ANNAT.

Animals ; Cells, Cultured ; Coculture Techniques ; Drugs, Chinese Herbal ; pharmacology ; Humans ; Keratinocytes ; Melanins ; metabolism ; Melanocytes ; drug effects ; metabolism ; Melatonin ; metabolism ; Rabbits ; Serotonin ; metabolism ; Serum ; chemistry