No abstract

Various skin hyperpigmentation disorders consist in accumulation and overproduction of melanin. In this report, we investigated the melanogenesis inhibitory and antioxidant effects of Bifidobacterium bifidum culture filtrate. The results revealed that B. bifidum culture filtrate effectively suppresses murine tyrosinase activity and decreases the amount of intracellular melanin in a dose-dependent manner. Additionally, the bacterial culture filtrate-scavenged DPPH and ABTS radicals, and shows potent-reducing power in a dose-dependent pattern. Our results expand the application of B. bifidum culture filtrate in the development and research of skin-whitening ingredients.

The toxicity of nitrofuran drugs has attracted great attention, and the reported electroanalytical methods suffered limited sensitivity. In this work, a sensitive electrochemical assay in the cathodic region is developed to determine four nitrofuran derivatives, including nitrofurantoin (NFT), nitrofurazone (NFZ), furaltadone (FTD), and furazolidone (FZD). The screen-printed carbon electrode (SPCE) was used as the electrode substrate, and the sensing surface was composed of multi-walled carbon nanotube (MWCNT) and conducting poly(melamine) (PME). The overoxidation-pretreated MWCNTs affect the surface morphology of the electrodeposited PME and, thus, the interaction with nitrofuran drugs. The characteristics of the nanocomposite-modified electrode surfaces were well characterized by field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), and surface water contact angle experiments. The nanocomposite-modified electrodes exhibited excellent adsorption and electrochemical reduction of nitrofurans by cyclic voltammetry. The proposed assay exhibited a linear range of sub-micro to micro molar concentrations for the four drugs under the optimized differential pulse voltammetric (DPV) technique. The detection limits were found to be in the nanomolar ranges. The developed assay was applied to detect NFT in two real samples, and the results showed good recoveries that ranged from 99.0 to 104.8% and 98.0 to 103.2% for milk and lake water samples, respectively. Graphical abstract ᅟ.

The study was aimed at investigating the antimelanogenic and antioxidative effects of Bifidobacterium infantis culture filtrate. The efficacy of the bacterial culture filtrate was evaluated spectrophotometrically. The results revealed that B. infantis culture filtrate effectively scavenge 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) ABTS radicals, and show potent reducing power in a dose-dependent pattern. Additionally, the bacterial culture filtrate suppresses murine B16F10 tyrosinase activity and the amount of melanin in a dosedependent manner. We conclude that the B. infantis culture filtrate may be applied in the formulations of skin care cosmetics.