A High Throughput Screening Platform for Skin Tuning Properties from Natural Products: Identification of Skin Tanning Compounds

Skin lightening and tanning are two major areas dominating the market of skincare and cosmetic products. Though the demands are originated from two different communities, the two areas share a same goal—skin colour tuning. The known safe compounds with skin colour tuning activities are limited. In contrary, Chinese medicinal herb provides a pool of natural bioactive compounds, which have been used in Asian countries for long time and have been tested for its toxicity. Here, we demonstrate a high throughput screening platform for potential compounds usable for skin colour tuning. From 147 natural compounds, 26 of them showed potential in skin tanning functions by using the high throughput melanogenesis platform based on the melanogenesis assay on B16 melanocytes. Five of them promoted melanogenesis by over 50%. Moreover, apart from 1, 8-dihydroxyanthraquinone, the other four compounds showed enhancement effect on tyrosinase activity. From the result, the compounds increased the Vmax of tyrosinase without changing the Km in a dose-dependent manner. Thus, there should be no irreversible structural change of the enzyme. Definitely, this report contributes to the development of personalization in skincare and cosmetic products.

Edible Bird’s Nest, an Asian Health Food Supplement, Possesses Skin Lightening Activities: Identification of N-Acetylneuraminic Acid as Active Ingredient

Edible bird’s nest (EBN;Yan Wo), or cubilose, is originated from the salivary secretion of Aerodramus fuciphagus. In Asia, EBN is famous for its unproven skin lightening function. Here, we aim to reveal the active ingredients of EBN responsible for skin lightening function. Three major fractions were isolated from EBN water extract by chromatography using LC-MS/MS, bioactivities of these isolated fractions were analyzed by assays of tyrosinase, melanocytes and 3D human skin model, from which, N-acetylneuraminic acid (NANA), the second isolated fraction showed an inhibition effect on tyrosinase activity in a dose-dependent manner. The IC50 of tyrosinase originated from mushroom and human was 16.93 mM and 0.10 mM respectively. Furthermore, only EBN with higher content of NANA (e.g. White and Red EBN), but not EBN with less NANA (e.g. Grass EBN), showed promising skin lightening function. This is the first report to reveal NANA being an active ingredient of EBN on skin lightening function.

An UPLC-MS/MS method for simultaneous determination of multiple constituents in Guizhi Fuling capsule with ultrafast positive/negative ionization switching

Guizhi Fuling capsule(GFC), a traditional Chinese medicine(TCM) with effects of promoting blood circulation and dissipating blood stasis, has been widely used in the clinic. Because of the complex matrix and various chemical structure types, quality control of GFC remains great challenge. In the present study, an ultra performance liquid chromatography hybrid triple-quadrupole mass spectrometry(UPLC-QQQ MS) method with ultrafast positive/negative ionization switching was developed for simultaneous determination of 18 bioactive components in GFC, including methyl gallate, ethyl gallate, oxypaeoniflorin, benzoic acid, albiflorin, paeonolide, paeoniflorin, 1, 2, 3, 4, 6-pentagalloylglucose, mudanpioside C, benzoyloxypaeoniflorin, benzoylpaeoniflorin, pachymic acid, amygdalin, cinnamaldehyde, paeonol, cinnamic acid, 4-hydroxybenzoic acid, and gallic acid. Separation was performed on an Agilent Zorbax Extend–C18 column(2.1 mm × 50 mm, 1.8 μm), using a gradient elution with acetonitrile and water containing 0.1% formic acid. Cholic acid was selected as the internal standard. This newly developed method was fully validated for linearity, precision, accuracy, and stability, and then applied to quality assessment of GFC. Finally, the batch-to-batch reproducibility of GFC samples was evaluated by the cosine ration and Euclidean distance method, which showed high quality consistency. The results demonstrated that the developed method provided a reasonable and powerful manner for quality control of GFC.

Characterization of edible bird’s nest by peptide fingerprinting with principal component analysis

OBJECTIVES:Proteins are the major component and play a key role in nutritious and therapeutic functions of edible bird’s nest(EBN);however,limited studies have been conducted on the protein due to difficulties in extraction,isolation as well as identification.This study aimed to provide comprehensive information for the quality evaluation of EBN peptides,which would be a valuable reference for further study on EBN proteins.METHODS:Here,we developed a quality control method using high performance liquid chromatography(HPLC)peptide fingerprints deriving from EBN being digested with simulated gastric fluid.The characteristic peptide peaks were collected and identified by LC-MS/MS.RESULTS:The characteristic peptide peaks,corresponding to the protein fragments of acidic mammalian chitinase-like,lysyl oxidase,and Mucin-5AC-like,were identified and quantified.Interestingly,the principal component analysis indicated that the fingerprints were able to discriminate colour of EBN(white/red)and production sites(cave/house)of White EBN on the same weight basis.As proposed by the model developed in this study,Muc-5AC-like and AMCaselike proteins were the markers with the highest discriminative power.CONCLUSIONS:The overall findings suggest that HPLC peptide fingerprints were able to clearly demonstrate peptide profile differences between genuine and adulterated EBN samples;and classify EBN samples by its color and production site.In addition,the protein identification results suggested that Muc-5AC-like protein was the major protein in EBN.

An optimization of ultra-sonication-assisted extraction from flowers of Apocynum venetum in targeting to amount of free amino acids determined by UPLC-MS/MS

Amino acids are naturally occurring compounds in many edible or medicinal plants,which possess a variety of nutraceutical effects in human.Here,a method of ultrasound-assisted extraction was optimized using Box-Behnken design of response surface methodology in maximizing the yield of free amino acids deriving from flowers of Apocynum venetum L.Under the optimal condition of ultrasound-assisted extraction,i.e.187.5 W of ultrasonic power,31.93 min of extraction time,and 0.47 mg/ml of solid-liquid ratio,the experimental yield of extractive was 287.17±0.205 mg/g,which was in close agreement with the value,as predicted by the established model.In addition,a hydrophilic interaction ultra-high performance liquid chromatography coupled with QqQ-MS/MS method was developed and validated for simultaneous quantification of 20 types of amino acids without derivatization contained in A.venetum flowers.The analytical method was validated by matrix effect,linearity,limit of detection,limit of quantification,precision,repeatability,stability,and recovery.The analysis results showed that A.venetum flower was rich in free amino acids of~3%of total dried weight,and which contained leucine(13.7 g/mg),isoleucine(7.9 g/mg),and lysine(2.2 g/mg)as the most abundant amino acids.Thus,A.venetum flower could provide beneficial nutrient values for human health,e.g.adult weight maintenance or glucose homeostasis.