Influence of preparation procedures on the phenolic content, antioxidant and antidiabetic activities of green and black teas

The influence of common tea preparation procedures (temperature, infusion time, consumption time interval and tea bag/loose-leaf) and the type of water used, on the total phenolic content (TPC), the radical scavenging activity and the α-glucosidase inhibitory activity were assessed. Higher TPC and antioxidant activity were obtained when using lower mineralized waters. Tea bags also evidenced higher antioxidant activity than loose-leaf samples. Under the same conditions (90 ºC and five minutes of infusion time) green tea contains almost twice the quantity of polyphenols and the free radical scavenging ability of black tea. In the α-glucosidase assay all infusions were active (97-100 %). Furthermore, HPLC allowed to identify some of the polyphenols present in both teas and to monitor their composition change with time. After twenty-four hours, the antioxidant activity was maintained without significant changes, but a small decrease in enzyme inhibition was observed, although this activity was still very high

Active ingredients, mechanisms of action and efficacy tests of antipollution cosmetic and personal care products

Urban population around the globe is direct exposed to the pollution caused by several sources (vehicles, industries, smokes etc.) and primary pollutants are divided in particulate matter and toxic gases. Current researches in populous countries indicated that exposure to pollution could affect sebum composition, stratum corneum quality and signs of skin aging. Hair and scalp are also affected by the excessive exposure to pollutants, resulting in a dull, dry and lifeless appearance. Cosmetics have been evolved conceptual and scientifically to achieve substantial effectiveness against pollution damaging on the cutaneous tissue, involving the development of innovative multipurpose active ingredients and efficacy tests, skilled to prove the protection and benefits of such personal care products. In this review, we highlighted the skin and hair/scalp damages provoked by the main environmental pollutants and the active substances used in antipollution cosmetics/personal care products with the respective mechanisms of action. Likewise, in vitro and in vivo efficacy tests were discussed concerning the antipollution claim substantiating

Hydrolyzed collagen interferes with in vitro photoprotective effectiveness of sunscreens

ABSTRACT The chronological skin aging is a progressive and natural process with genetic and physiological changes. However, ultraviolet (UV) radiation may accelerate the oxidative stress, generating carcinogenesis and photoaging. Natural compounds and their applications are considered a trend in the cosmetic market. The protein-based film-forming compounds play an important role, once it collaborates for the better distribution of sunscreens on the skin. Here we investigated the in vitro photoprotective effectiveness of sunscreens containing the hydrolyzed collagen associated with UVA, UVB and/or inorganic filters. Sunscreens were developed with octocrylene (7.5%), butyl methoxydibenzoylmethane (avobenzone) (3.0%) and/or titanium dioxide (5.0%), associated or not with the hydrolyzed collagen (3.0%). In vitro photoprotective effectiveness was determined in a Labsphere(r) UV2000S by the establishment of the sun protection factor (SPF) and critical wavelength (nm) values. Physicochemical and organoleptic characteristics were also assayed. The hydrolyzed collagen subjectively improved the formulation sensory characteristics. However, this bioactive compound led to a decrease of the SPF values of the photoprotective formulations containing octocrylene alone and octocrylene + butyl methoxydibenzoylmethane + TiO2. This inadequate interaction may be considered during the development of new sunscreens intended to contain protein-based components.