In vitro inhibitory potential of avocado fruits, Persea americana (Lauraceae) against oxidation, inflammation and key enzymes linked to skin diseases / Inhibidor potencial in vitro de frutos de aguacate, Persea americana (Lauraceae) contra la oxidación, inflamación y enzimas clave vinculadas a enfermedades de la piel

Abstract Introduction: Avocado (Persea americana Mill.) is a member of Lauraceae with one-seeded berry fruit and cultivated in all tropical, subtropical regions in the world and in the Southern coast region of Turkey. Oxidative damage caused by UV can trigger inflammation, resulting in serious inflammatory skin diseases including eczema, seborrheic dermatitis, hyperpigmentation and ageing. Enzyme inhibitors involved in melanogenesis, such as tyrosinase, have been used recently for hyperpigmentation and skin diseases in cosmetic products. Objective: This study aimed to evaluate the antioxidant, anti-inflammatory, anti-tyrosinase activities and total polyphenolic contents of the different parts of P. americana fruit. Methods: The fruit was divided into exocarp, mesocarp, seed, and then methanol and n-hexane extracts were prepared. DPPH and ABTS free radical scavenging capacities and inhibitory potentials on lipid peroxidation were determined to investigate the antioxidant potentials of the extracts. Anti-inflammatory activities of the extracts were evaluated by measuring the stabilization level of the human red blood cell membrane. The tyrosinase inhibitory activities of the samples were determined using mushroom tyrosinase. Results: In general methanol extracts possessed remarkable higher DPPH free radical scavenging activities than n-hexane extracts. The highest activity was determined in methanol extracts of seed (4.17 ± 0.04 mg/mL) followed by exocarp (5.25 ± 0.05 mg/mL). Overall methanol extracts possessed higher ABTS free radical scavenging activities than n-hexane extracts. The greatest ABTS free radical scavenging activity was obtained in methanol extracts of seed (0.03 ± 0.01 mg/mL). In the anti-lipid peroxidation assay, the greatest activity was noticed in methanol extracts of seed (7.71 ± 0.36 µg/mL) followed by exocarp (12.12 ± 0.34 µg/mL), while all n-hexane extracts were inactive. Overall methanol extracts exhibited higher anti-inflammatory and antioxidant properties than n-hexane extracts. However, the maximum anti-tyrosinase activity was determined in n-hexane extracts of exocarp (0.40 ± 0.01 mg/mL) followed by seed (0.46 ± 0.01 mg/mL). Conclusions: These extracts are promising candidates for use as natural products-based antioxidant and anti-inflammatory properties in inflammation-related disease, and also anti-tyrosinase properties in dermatological applications.

Resumen Introducción: El aguacate (Persea americana Mill.) es un miembro de Lauraceae, es una baya de una semilla que se cultiva en todas las regiones tropicales y subtropicales del mundo y la región costera sur de Turquía. El daño oxidativo causado por los rayos ultravioleta puede desencadenar inflamación, lo que posteriormente da como resultado enfermedades inflamatorias graves de la piel como eccema, dermatitis seborreica, hiperpigmentación y envejecimiento. Los inhibidores de enzimas implicados en la melanogénesis, como la tirosinasa, se han utilizado recientemente para la hiperpigmentación y enfermedades de la piel en productos cosméticos. Objetivo: Evaluar las actividades antioxidantes, antiinflamatorias, antitirosinasas y los contenidos polifenólicos totales de las partes del fruto de P. americana. Métodos: El fruto se dividió en tres partes: exocarpio, mesocarpio y semilla, y se prepararon extractos de metanol y n-hexano. Se determinaron las capacidades de eliminación de radicales libres de DPPH y ABTS y los potenciales inhibidores sobre la peroxidación de lípidos para investigar los potenciales antioxidantes de los extractos. Las actividades antiinflamatorias de los extractos se evaluaron midiendo el nivel de estabilización de la membrana de los glóbulos rojos humanos. Las actividades inhibidoras de tirosinasa de las muestras se determinaron utilizando tirosinasa de hongos. Resultados: En general, los extractos de metanol poseían actividades de eliminación de radicales libres de DPPH notablemente más altas que los extractos de n-hexano. La actividad más alta se presentó en extractos metanólicos de semilla (4.17±0.04 mg/mL) seguido del exocarpio (5.25±0.05 mg/mL). En general, los extractos de metanol poseían una mayor actividad de eliminación de radicales libres ABTS que los extractos de n-hexano. La mayor actividad captadora de radicales libres de ABTS se obtuvo en extractos metanólicos de semilla (0.03±0.01 mg/mL). En el ensayo de anti-peroxidación lipídica, la mayor actividad se observó en los extractos metanólicos de semillas (7.71±0.36 µg/mL) seguidos del exocarpio (12.12±0.34 µg/mL), mientras que todos los extractos de n-hexano estaban inactivos. En general, los extractos de metanol exhibieron mayores propiedades anti-inflamatorias y antioxidantes que los extractos de n-hexano. Sin embargo, la actividad anti-tirosinasa máxima se determinó en extractos de exocarpio de n-hexano (0.40±0.01 mg/mL) seguido de semillas (0.46±0.01 mg/mL). Conclusiones: Estos extractos son candidatos prometedores como productos naturales debido a sus propiedades antioxidantes y antiinflamatorias para tratar enfermedades relacionadas con la inflamación, y también propiedades antitirosinasas en aplicaciones dermatológicas.

An overview of dermatological and cosmeceutical benefits of Diospyros kaki and its phytoconstituents

Abstract Diospyros kaki L.f. belonging to family Ebenaceae, commonly known as persimmon is used as a medicinal plant in Chinese traditional medicine since many years for different ailments including cosmetics and dermatologic applications. Traditionally this plant is used to treat different skin conditions including pimples, skin eruptions and eczema. Present interest has been focused toward use of natural bioactive compounds in various curative and beautifying applications in dermatological and cosmeceutical disciplines. The objective of this article is to present cumulative data on potential use of D. kaki for its possible role in dermatologic and cosmetic applications. Scientific data has revealed an excellent position of D. kaki in both dermatology and cosmetic discipline making it a valuable choice in respective field. Active principles from different plant parts have shown to possess anti-inflammatory, antiallergic, photo-protective, and anti-wrinkle effects with appreciable activities against tyrosinase, elastase, and collagenase enzymes. Promising antioxidant activity and skin whitening potential, augmented by reduction in sebum contents, and reduction in size and number of skin pores make it a suitable choice as cosmetic ingredient. Data has been summarized and presented on available molecular mechanism that can contribute toward phytoconstituents usage in cosmetics and dermatology mediated by different cellular pathways. Crude extracts and some of phytochemical obtained from this plant such as isoquercitrin and hyperin have better reported activities than well-known cosmetic ingredients viz., arbutin, kojic acid and hydroquinone with possibility of having no side effects. Photo protection against degenerative effects of UVA, UVB and gamma radiation can help skin to fight well against oxidative stress and reactive oxygen species. Further investigation need to be directed toward human subjects for evaluation of these reported activities for obtaining optimum commercial and industrial benefits from this valuable plant.

Detection of anti-tyrosinase IgG antibody and anti-tyrosinase-related protein-1 IgG antibody in sera of patients with vitiligo / 中华皮肤科杂志

Objective To investigate relationships between serum levels of anti?tyrosinase IgG antibody(TYR IgG)as well as anti?tyrosinase?related protein?1 IgG antibody(TRP?1 IgG)and vitiligo. Methods Enzyme linked immunosorbent assay(ELISA)was performed to detect serum levels of TYR IgG and TRP?1 IgG in 260 patients with vitiligo and 50 health controls. The threshold for defining a positive test result was set at 3 standard deviations above the mean serum level of TYR IgG or TRP?1 IgG in the healthy controls. Results The positive rate of TYR IgG and/or TRP?1 IgG in the vitiligo group was 57.31%(149/260). The positive rates of TYR IgG and TRP?1 IgG were both significantly higher in the vitiligo group than in the control group(TYR IgG:37.3%[97/260]vs. 0,χ2=25.441, P0.05). Among patients with vitiligo, the positive rate of TRP?1 IgG was significantly higher in females than in males(χ2=5.811, P20 years(χ2=6.498, P 20 years (both P >0.05). Conclusion Detection of TYR IgG and TRP?1 IgG may provide some evidence for the diagnosis and treatment of vitiligo.

Activities of different types of Thai honey on pathogenic bacteria causing skin diseases, tyrosinase enzyme and generating free radicals

BACKGROUND: Honey is a natural product obtained from the nectar that is collected from flowers by bees. It has several properties, including those of being food and supplementary diet, and it can be used in cosmetic products. Honey imparts pharmaceutical properties since it has antibacterial and antioxidant activities. The antibacterial and antioxidant activities of Thai honey were investigated in this study. RESULTS: The honey from longan flower (source No. 1) gave the highest activity on MRSA when compared to the other types of honey, with a minimum inhibitory concentration of 12.5% (v/v) and minimum bactericidal concentration of 25% (v/v). Moreover, it was found that MRSA isolate 49 and S. aureus were completely inhibited by the 50% (v/v) longan honey (source No. 1) at 8 and 20 hours of treatment, respectively. Furthermore, it was observed that the honey from coffee pollen (source No. 4) showed the highest phenolic and flavonoid compounds by 734.76 mg gallic/kg of honey and 178.31 mg quercetin/kg of honey, respectively. The antioxidant activity of the honey obtained from coffee pollen was also found to be the highest, when investigated using FRAP and DPPH assay, with 1781.77 mg FeSO4•7H2O/kg of honey and 86.20 mg gallic/kg of honey, respectively. Additionally, inhibition of tyrosinase enzyme was found that honey from coffee flower showed highest inhibition by 63.46%. CONCLUSIONS: Honey demonstrates tremendous potential as a useful source that provides anti-free radicals, anti-tyrosinase and anti-bacterial activity against pathogenic bacteria causing skin diseases.

Antioxidant and Anti-tyrosinase Activities from Piper officinarum C.DC (Piperaceae).

The present study was carried out to evaluate antioxidant and anti-tyrosinase activities from Piper officinarum stems, as well as investigation of its chemical constituents. In a series of in vitro assays, antioxidant (DPPH radical scavenging and total phenolic content) and anti-tyrosinase (mushroom tyrosinase) activities of various extracts of stem were evaluated. The isolation and purification of the constituents were carried out on the extracts using various chromatographic methods and identified by direct comparison of their spectroscopic data with respective published data. The results showed that the methanol extracts showed the highest DPPH (80.0%) at 1 mg/ml, as well as total phenolic content (50.5%). Phytochemical analysis of the stem extracts have isolated five compounds identified as 4-allyl resorcinol (1), aristolactam AII (2) aristolactam BII (3), stigmast-4-en-3-one (4) and 6-hydroxystigmast-4-en-3-one (5). Compound (1), (2) and (3) showed significant activity towards DPPH radical scavenging (I%=17.3-28.1%), while (2), (3) and (4) demonstrated potent inhibitory effects against tyrosinase mushroom (I%=11.1-24.4%). The results showed that the stem extracts has significant antioxidant activity that may help to discover new chemical classes of natural antioxidant substances.

Detection of Serum Anti-tyrosinase Antibodies and sICAM-1 in Vitiligo Patients / 中华皮肤科杂志

Objective To investigate the relationship between the activity of vitiligo and the serum levels of IgG and IgM anti-tyrosinase antibodies and sICAM-1. Methods Anli-tyrosinase, anti-melanocyte antibodies and sICAM-1 were detected by enzyme-linked immunosorbent assay. Results The average titres of IgG and IgM antibodies in the sera of patients with vitiligo were 0.316 and 0.238 respectively, which were significantly higher than those of the healthy control (both P 0.05) in the serum level of sICAM-1 between the healthy control and patients with stable vitiligo or localized vitiligo. Conclusions Both the serum levels of IgG and IgM anti-tyrosinase antibodies and sICAM-1 have a stong correlation with the activity and severity of vitiligo.