152 results about "Pterostilbene" patented technology

The invention discloses a methyltransferase mutant, a recombinant vector, a recombinant bacterium and application of the methyltransferase mutant in production of pterostilbene, and relates to the technical field of bioengineering. According to the methyltransferase mutant provided by the invention, resveratrol generates pterostilbene under the catalytic action of methyltransferase, and compared with the unmutated methyltransferase, the mutated methyltransferase has the advantages that the affinity of enzyme and a substrate is improved, and the resveratrol is promoted to be converted into pterostilbene. The coding gene of the methyltransferase mutant is transferred into a chassis cell or a chassis strain and is fermented, so that the yield of the pterostilbene can be greatly increased, the efficient synthesis of the plant-derived antioxidant pterostilbene in the microbial chassis cell is realized, and the ever-increasing market demand of the pterostilbene can be met.

The invention belongs to the field of daily chemicals, and discloses a liposome with high coating rate and anti-aging efficacy, which comprises 0.01-3 wt% of oil soluble substance, 1-5 wt% of liquid-solid mixed grease, 1-10 wt% of phospholipid, 1-10 wt% of surfactant, 10-30 wt% of polyol and 45-70 wt% of deionized water, the oil soluble substances comprise tetrahydrocurcumin and pterostilbene; the weight ratio of the tetrahydrocurcumin to the pterostilbene is (0.5-10): 1; the liquid-solid mixed grease consists of liquid grease and solid grease; the weight ratio of the liquid grease to the solid grease is (0.5-3): 1. According to the liposome, the liquid-solid mixed grease is matched with the tetrahydrocurcumin and the pterostilbene for common use, the liquid-solid mixed grease, the tetrahydrocurcumin and the pterostilbene form an amorphous mixture, the crystallinity of oil-soluble substances is reduced, crystallization separation is effectively inhibited, and the tetrahydrocurcumin and the pterostilbene can stably exist in the liposome. Meanwhile, the invention further provides a preparation method, application and cosmetics of the liposome.

The invention discloses a triggering probiotic-drug conjugate and a preparation method and application thereof, and belongs to the technical field of oral drug delivery systems, the triggering probiotic-drug conjugate comprises probiotics, an adhesive inner layer formed by coordination of tannic acid and Fe < 3 + >, and an outer layer formed by pterostilbene-phospholipid bridged by ROS-responsive thioether bonds and cholesterol; the inner layer coats the surfaces of the probiotics through coordination, and the outer layer coats the outer part of the inner layer through self-assembly. An outer lipid layer is decomposed under high-concentration ROS in an inflammation colon area, and probiotics coated with pterostilbene and a tannic acid layer are released. Pterostilbene relieves inflammation and rebuilds a pathological microenvironment, and catechol groups in a tannic acid layer and the surface of the intestinal tract generate multiple interactions to promote planting of probiotics. In UC mouse models, the conjugates exhibit enhanced therapeutic effects by inhibiting inflammation, restoring intestinal barrier function, and improving intestinal microbiota homeostasis. The invention has important transformation potential in clinical application of gastrointestinal diseases.

The present invention provides an anti-wrinkle and firming composition containing collagen and its application in cosmetics, the composition comprises the following components in parts by weight: 20-40 parts by weight of posiin, 0.5-2.5 parts by weight of pterostilbene, 0.5-2.5 parts by weight of soluble collagen, 0.5-2.5 parts by weight of ergothioneine, 0.02-0.1 parts by weight of palmitoyl tripeptide-5 and an appropriate amount of solvent component. After posiin, pterostilbene, soluble collagen, ergothioneine and palmitoyl tripeptide-5 are matched and coordinated with each other, a very thin film layer can be formed on the surface of the skin, thereby making the skin plump and wrinkles stretched, achieving control of sebaceous gland secretion to reduce oil discharge, locking collagen, and keeping the skin fresh, and finally improving the elasticity of the skin and reducing skin wrinkles.

The invention relates to the technical field of fibers, and discloses a high-water-absorption fiber for paper diapers and a preparation method thereof.The high-water-absorption fiber is prepared by taking polyvinyl alcohol as a base material and assisting with modified illite and an aerogel modified material through electrostatic spinning, a natural antibacterial agent pterostilbene is grafted to the surface of the illite, and the high-water-absorption fiber is prepared through electrostatic spinning; on one hand, the compatibility between the illite and the polyvinyl alcohol can be improved through a surface modification mode, and the water absorption effect of the fiber can be enhanced to a certain extent by utilizing the pore structure of the illite, on the other hand, the problem that the illite is easy to oxidize and lose efficacy can be effectively improved after the pterostilbene is grafted on the surface of the illite, and the water absorption effect of the fiber can be enhanced to a certain extent. The aerogel modified material has a special pore structure, so that urine can be quickly absorbed and locked and prevented from back seepage, meanwhile, the pore structure can store the urine, the absorbed water is not easy to flow out, and the excellent water absorption can greatly enhance the water absorption capacity of the polyvinyl alcohol fiber.

The invention relates to a methyltransferase gene for catalyzing methylation of resveratrol and application of the methyltransferase gene, and belongs to the technical field of biology. The invention provides a gene of methyltransferase capable of catalyzing resveratrol to generate pinostilbene and pterostilbene. The gene of the methyltransferase is a gene YC26, a gene SS15 or a gene HS97-5. The methyltransferase gene provided by the invention has the advantages of high substrate conversion rate, rich products, high activity and the like, the conversion rate of resveratrol can be increased and synthesis of pterostilbene can be promoted when the methyltransferase gene is combined with other methyltransferase genes to express in different strains, additional addition of expensive methyl donors is avoided, and the production cost is reduced. Only a small amount of substrate resveratrol needs to be added or no substrate resveratrol is added.

The invention relates to the technical field of functional antioxidants, in particular to a stability-enhanced antioxidant based on pterostilbene and a preparation method and application thereof. The pterostilbene tablet comprises the following components in percentage by weight: 10-30% of pterostilbene, 8-20% of Arabic gum, 5-15% of tocopheryl succinate, 1-5% of disodium ethylene diamine tetraacetate, 30-60% of beta-cyclodextrin, 2-8% of rosmarinic acid, 1-6% of chitosan quaternary ammonium salt, 0.5-3% of nano silicon dioxide and 2-7% of polyglycerol fatty acid ester. In the preparation process, beta-cyclodextrin and pterostilbene form an inclusion compound, the dispersity of nano silicon dioxide and chitosan quaternary ammonium salt is improved through hydrogen bonds, and tea polyphenol or ascorbyl palmitate can be added to enhance the synergistic effect. The antioxidant is high in stability, high in pterostilbene retention rate, uniform in dispersion, free of agglomeration, excellent in antioxidant activity, suitable for the fields of foods, cosmetics and medicines, simple in preparation process, low in consumption and suitable for industrial production.

The invention relates to a pterostilbene compound, a pharmaceutical composition and application of the pterostilbene compound in preparation of anti-inflammatory drugs. The compound shown in the formula (I) or the pharmaceutically acceptable salt thereof provided by the invention has relatively high stability and high bioavailability, can effectively improve symptoms such as colon shortening, diarrhea, hematochezia and weight loss caused by DSS-induced mouse colitis, has a remarkable inhibition effect on intestinal inflammation, and can be used for preparing anti-inflammatory drugs. # imgabs0 #

The invention discloses a whitening anti-oxidation composition which comprises pterostilbene and phenylethyl resorcinol, and the weight ratio of the pterostilbene to the phenylethyl resorcinol is 1: (0.6-1.5). According to the whitening anti-oxidation composition, the anti-oxidation and whitening effects can be remarkably improved, the anti-oxidation and whitening effects are good, and meanwhile the stability is high. According to the invention, lipidosome is adopted for coating, so that the formed cosmetic raw material has better stability and is not easy to yellow in stability detection, and the content retention effect of pterostilbene and phenylethyl resorcinol is better. The composition is applied to whitening and anti-oxidation products and is small in irritation and high in use stability, the whitening and anti-oxidation effects are further improved, the active oxygen removal rate reaches 68% or above, and the melanin inhibition rate reaches 88% or above.

The invention relates to pterostilbene flexible liposome as well as a preparation method and application thereof. The pterostilbene flexible liposome is mainly prepared from the following components in percentage by mass: 0.5%-1.25% of pterostilbene, 2%-4% of phospholipid, 0.06%-0.2% of cholesterol, 1%-2.5% of an emulsifying agent, 0.1%-0.6% of a membrane softening agent, 5.08%-12.1% of an auxiliary agent and 79.35%-91.26% of water, the emulsifier is a single-chain surfactant; the membrane softener is dipotassium glycyrrhizinate. The pterostilbene flexible liposome has good solubility in water, is mild to a human body, has good skin physiological effects of oxidation resistance, whitening, aging resistance and inflammation resistance, has good stability and good transdermal property, can penetrate through a skin surface layer to reach a deep layer and slowly release pterostilbene to play a role, improves the dose-effect relationship and bioavailability of pterostilbene, and has a good application prospect. The composition can be well used in the field of cosmetics.

The present invention relates to compositions comprising pterostilbene or a pharmaceutically acceptable salt thereof in combination with silybin or a pharmaceutically acceptable salt thereof, and uses thereof for treating, preventing, ameliorating or reducing ionizing radiation-induced diseases in a subject. The compositions and uses can further comprise at least one or more radiation mitigant compounds, preferably NAD+ boosters and / or FSL-1.

The present application relates to a kind of pterostilbene piperidine amide derivatives, its preparation method and medical use, belong to the field of medicinal chemistry and pharmacotherapy.The present application uses pterostilbene as raw material, designs, synthesizes a series of pterostilbene piperidine amide compounds with new structure, and its structure is characterized.The method used in the present application to prepare these compounds has the characteristics of easy-to-get raw material, simple operation and high yield, and can quickly synthesize target compounds.Compared with pterostilbene, the pterostilbene piperidine amide derivatives provided in the present application have significant cell proliferation inhibitory effect on tumor cells.

The present application relates to a kind of bone repair compositions and its preparation method, belong to biological medicine technical field, pharmaceutical composition includes acid anhydride bovine beta-lactoglobulin peptide, casein phosphopeptide, yak bone peptide, loquat leaf extract, pterostilbene, honeysuckle chlorogenic acid and cyperus rotundus extract;Acid anhydride bovine beta-lactoglobulin peptide is prepared using special enzymolysis method.Acid anhydride bovine beta-lactoglobulin peptide, casein phosphopeptide and yak bone peptide are loaded using carboxymethyl chitosan-hydroxyapatite composite microspheres, then using sodium alginate-sodium carboxymethyl cellulose containing loquat leaf extract, pterostilbene, honeysuckle chlorogenic acid and cyperus rotundus extract one coating, then using sodium alginate-sodium carboxymethyl cellulose secondary coating.The present application develops high-efficiency pharmaceutical combination component, using polymer material to coat drug to form sustained-release system, improve bioavailability, using granular carrier to increase the stability and solubility of drug, promote intestinal absorption, improve bone repair process.

The invention discloses a plant whitening and sunscreen composition as well as a preparation method and application thereof, and relates to the technical field of cosmetics. The invention provides a plant whitening and sunscreen composition. The plant whitening and sunscreen composition is prepared from the following components in parts by weight: 0.5 to 5 parts of P / O / W composite coating body, 0.1 to 3 parts of bakuchiol and 0.1 to 3 parts of thyme extract. According to the invention, pterostilbene and verbascoside are stabilized in a P / O / W pickering multiple emulsion system to prepare a P / O / W composite inclusion body, and the P / O / W composite inclusion body is mixed with the bakuchiol and thyme extract in specific parts by weight, so that on one hand, safe and efficient whitening can be realized by repairing, inhibiting melanin generation, inhibiting melanin transport and promoting melanin autophagy multi-channel synergistic interaction; on the other hand, whitening and sunscreen can be safely and efficiently achieved, the effect of external protection and internal whitening is achieved, the defensive barrier of the skin can be synergistically reinforced, and the problems of dark skin of sensitive skin and the like are solved.

The invention provides a whitening composition as well as a preparation method and application thereof, and belongs to the technical field of cosmetics. According to the whitening composition provided by the invention, the isopropyl lauroyl sarcosinate, the diisopropyl sebacate, the PPG-14 polyglycerol-2 ether, the bis-diethoxy diglycol cyclohexane 1, 4-dicarboxylate and the poly C10-30 alkanol acrylate are used as oil phases to wrap the whitening components (magnolol, pterostilbene, ferulic acid and dimethyl methoxy benzodihydropyranol) so as to form oil sacs, so that the whitening composition can be used for whitening the skin; and then dispersing in a polyhydric alcohol and carbomer matrix to control the composition of the oil phase and the whitening component, so that the whitening effect and the transdermal absorption effect of the whitening composition are improved.

This invention relates to the field of agricultural biotechnology, specifically to a rumen methane inhibitory composition for ruminants containing *Asparagus yew* and *Pterostilbene*. The active components of the composition include *Asparagus yew* and its preparations, and *Pterostilbene*, which are used in a predetermined ratio to reduce rumen methane production and alleviate hydrogen accumulation in ruminants.

The invention discloses an ursodesoxycholic acid-pterostilbene conjugate, a preparation method thereof and application of the ursodesoxycholic acid-pterostilbene conjugate in preparation of drugs for treating non-alcoholic fatty liver diseases, and belongs to the technical field of biological medicines. According to the conjugate, ursodesoxycholic acid and pterostilbene are covalently connected through specific chemical bridging, and the structural general formula is shown in the specification. The preparation method comprises the following steps: respectively preparing the alkynyl-containing pterostilbene derivative and the azido-containing ursodesoxycholic acid derivative through esterification and amidation reactions, and then realizing efficient coupling through a click chemical reaction. The conjugate provided by the invention can realize hepatic targeting delivery by virtue of a bile acid transporter, synchronously releases two active components in hepatic cells, plays a therapeutic role through multiple mechanisms such as synergistic regulation of lipid metabolism, inhibition of oxidative stress and inflammation, anti-fibrosis and the like, and is obviously superior to a single component or a physical mixture; and a new strategy is provided for treatment of the non-alcoholic fatty liver disease.

The present invention discloses a pterostilbene chalcone compound represented by general formula (I) or a pharmaceutically acceptable salt thereof. The compound has a strong inhibitory effect on LPS-induced NO production in RAW264.7 cells, significantly superior to indomethacin, and can be developed into a new anti-inflammatory drug. The preparation method of the compound of the present invention is characterized by readily available raw materials, simple operation, and high yield.

The invention belongs to the technical field of biological medicines, and provides a pterostilbene derivative and application thereof in preparation of medicines for treating and / or preventing related diseases caused by oxidative stress. The chemical structures of the pterostilbene derivative are as shown in formulas (I)-(III). The scavenging effects of the obtained derivative on free radicals such as DPPH., O2. And ABTS +. And the total reducing capacity of the derivative are detected respectively. In the aspects of DPPH, total reducing capacity and the like, the scavenging capacity of some derivatives is equivalent to that of pterostilbene or vitamin C. The scavenging efficacy of the derivatives 2a, 4a, 4c, 4e, 4h, 4i and 4m-4p on O2-free radicals is equivalent to that of pterostilbene or vitamin C; the removal effect of the derivative 2b on ABTS < + > is equivalent to that of vitamin C and is superior to that of pterostilbene. The pterostilbene derivative has a potential application prospect in the aspect of preparing the antioxidant. # imgabs0 #

The invention discloses a nano composition of pterostilbene, a preparation method of the nano composition, and application of the pterostilbene in preparation of an anti-hair loss product. Comprising the following components in percentage by mass: 0.1-25% of pterostilbene, 0.1-30% of polyol ether, 0.1-8% of terpene essential oil, 0.5-30% of a flexible agent, 0.1-20% of phospholipid and / or phospholipid derivative, 0-2% of honokiol, 0-3% of cinnamic acid, 0-35% of an additive and the balance of water. The invention proves that the pterostilbene has an excellent anti-hair loss effect and has relatively strong 5 alpha-reductase inhibitory activity, and the nano composition containing the pterostilbene, honokiol and cinnamic acid can synergistically enhance the 5 alpha-reductase inhibitory and anti-hair loss effects of the pterostilbene, and meanwhile, the nano composition enhances the solubility and stability of the pterostilbene, so that the anti-hair loss effect of the pterostilbene is improved, and the anti-hair loss effect of the pterostilbene is improved. The application of the pterostilbene is expanded.

The application discloses a method for constructing a characteristic map of a traditional Chinese medicine and the characteristic map, wherein the method adopts an HPLC method to determine the content of an effective component, imperatorin, in Zhikang capsules, and constructs a high performance liquid chromatography characteristic map of the Zhikang capsules; 10 characteristic peaks are determined as the characteristic map, which are respectively from dragon's blood, rhubarb and Bai Zhi; the components from the dragon's blood are dracorhodin B (peak 2) and pterostilbene (peak 4); the components from the rhubarb are peak 1 (aloe-emodin), peak 3, peak 6 (emodin), peak 9 and peak 10; and the components from the Bai Zhi are imperatorin (peak 5), peak 7 and peak 8; the method covers polyphenols, anthraquinones and furanocoumarins and other main components, and constructs a quality evaluation system of the Zhikang capsules; the method has good specificity, precision, repeatability and solution stability, and can be used for standardizing the production of the Zhikang capsules and guaranteeing the uniformity and stability of the internal quality of products to provide comprehensive quality control.

The present invention relates to compositions and methods for treating aging-related diseases. The present invention provides a composition comprising at least three substances selected from the group consisting of alpha-ketoglutaric acid, malic acid, pterostilbene, micro-dose lithium, glycine, ginger, Rhodiola rosea, acetylglucosamine, vitamin C, glucosamine, fisetin, L-theanine, oxaloacetic acid, fumaric acid, succinic acid, hyaluronic acid, butyric acid, anthocyanins, piper longum amide, quercetin, curcumin, and a pharmaceutically acceptable salt thereof. And caffeine, trehalose and spermidine. The present invention also provides related pharmaceutical compositions, methods for improving senescence profiles, and articles of manufacture.

The application belongs to the technical field of biological medicine, and proposes a use of a pterostilbene derivative and a preparation of a medicine for treating and / or preventing diseases caused by oxidative stress. The chemical structure of the pterostilbene derivative is shown as formula (I)-(III). The scavenging effect of the obtained derivative on DPPH·, O2 ‑ · and ABTS + · free radicals and its total reducing capacity are detected respectively. In terms of DPPH· and total reducing capacity, it is found that the scavenging capacity of some derivatives is equivalent to that of pterostilbene or vitamin C. Derivatives 2a, 4a, 4c, 4e, 4h, 4i and 4m-4p have the same scavenging effect on O2 ‑ · free radicals as pterostilbene or vitamin C; the scavenging effect of derivative 2b on ABTS + · is equivalent to that of vitamin C and is superior to that of pterostilbene. The pterostilbene derivative has potential application prospects in the preparation of antioxidants.

The application belongs to the technical fields of synthesis of compounds and pharmaceutical applications, and discloses an anti-tumor pterostilbene piperazine conjugate as well as a preparation method and application thereof. The pterostilbene, piperazine and various substituents are spliced in one molecule by using a molecular hybridization method, a novel anti-tumor pterostilbene piperazine conjugate is synthesized, and it is found through anti-tumor activity research that the anti-tumor activity of the conjugate is obviously higher than that of the two pharmacophores alone, and the conjugate has the potential to become a novel anti-tumor drug. The pterostilbene piperazine conjugate is synthesized, and it is found for the first time that the compound has good anti-tumor activity, can significantly inhibit the proliferation of various tumor cells in vitro, including hepatocarcinoma, triple-negative breast cancer, colon cancer and ovarian cancer cells, has little toxicity to normal cells, and can inhibit the migration ability of tumor cells. Therefore, the compound synthesized by the application has good anti-tumor application prospect.

The invention discloses an anti-tumor N-acetyl-D-glucosamine compound medicinal liquor and a preparation method thereof, and relates to the technical field of biological medicines. The anti-tumor N-acetyl-D-glucosamine compound medicinal liquor is prepared from the following components: N-acetyl-D-glucosamine, taurine, flavone metal chelate, pterostilbene lipidosome, astragalus membranaceus slices, hawthorn slices, ganoderma lucidum slices, ginseng slices, quercetin, cordyceps sinensis and pure grain liquor. The N-acetyl-D-glucosamine and the taurine which are added in proportion have a synergistic effect and can enhance the anti-tumor effect of the medicinal liquor, the flavone metal chelate and the flavone compound are added for chelating with metal ions, tumor cell apoptosis can be induced through the multi-target effect, the tumor inhibition capacity is enhanced, and after the medicinal liquor is prepared, the anti-tumor effect of the medicinal liquor is improved. The flavone metal chelate is gradually released along with slow metabolism of alcohol, so that a slow release effect is realized, and the action time of effective components in a body is prolonged.

The invention relates to a construction method of a characteristic chromatogram of a Chinese patent medicine and the characteristic chromatogram of the Chinese patent medicine, and the method adopts an HPLC (High Performance Liquid Chromatography) method to measure the content of imperatorin serving as an effective component in Zhengkang capsules and constructs the high performance liquid chromatography characteristic chromatogram of the Zhengkang capsules. 10 characteristic peaks are determined as characteristic spectrums and are respectively derived from dragon's blood, rheum officinale and radix angelicae, wherein the components derived from the dragon's blood comprise loureirin B (peak 2) and pterostilbene (peak 4); components from rheum officinale comprise a peak 1 (aloe-emodin), a peak 3, a peak 6 (emodin), a peak 9 and a peak 10; the components from the radix angelicae comprise imperatorin (peak 5), peak 7 and peak 8; main components such as polyphenols, anthraquinones and furocoumarins are covered, and a quality evaluation system of the Chinese patent medicine Zhikang capsule is constructed; the method is good in specificity, precision, repeatability and solution stability, and can be used for standardizing production of Chinese patent medicine Zhikang capsules and ensuring uniformity and stability of internal quality of products to provide comprehensive quality control.

The application discloses a bifendate biomimetic oral nanodelivery system based on lactobacillus helveticus exosomes and a preparation method and application thereof. The preparation method comprises the following steps: extracting lactobacillus helveticus exosomes from a lactobacillus helveticus culture solution by adopting a method combining continuous differential centrifugation and microporous membrane filtration; and mixing the lactobacillus helveticus exosomes with bifendate, and performing ultrasonic treatment and incubation treatment to prepare the lactobacillus helveticus exosome-bifendate biomimetic oral nanodelivery system. The application successfully extracts a lactobacillus helveticus source exosome with high yield and expandable advantages for the first time, and improves the clinical limitations of high cost and low productivity of animal source and plant source exosomes as oral delivery carriers; meanwhile, the prepared lactobacillus helveticus exosome-bifendate biomimetic oral nanodelivery system combines the natural characteristics of exosomes and the high biological safety of probiotics, and can realize the balance between the oral delivery performance and the biological safety of the nanocarrier.

The invention relates to the technical field of traditional Chinese medicines, and particularly discloses a traditional Chinese medicine composition and application thereof in preparation of medicines for improving yin deficiency constitution. The traditional Chinese medicine composition comprises the following traditional Chinese medicine raw material components: lily, mulberry, momordica grosvenori, folium mori, scaphium scaphigerum, radix polygonati officinalis, fructus cannabis and honey-fried licorice root. In addition, the composition also contains semen armeniacae amarae and fructus mume. Researches show that the traditional Chinese medicine composition has the effect of improving the constitution with yin deficiency; therefore, the traditional Chinese medicine composition disclosed by the invention can be used as a medicine for improving the yin-deficiency constitution and has an important application value.

The object of the present invention is to provide a technology for biotransforming resveratrol into pterostilbene using Yarrowia lipolytica, including: constructing a vector: assembling a resveratrol O-methyltransferase gene fragment with an Escherichia coli expression vector, followed by digestion, transformation, and then large-scale culture to obtain the recombinant plasmid pACYCDuet-ROMT; transformation: transferring the recombinant plasmid pACYCDuet-ROMT into Yarrowia lipolytica, and screening through culture to obtain recombinant Yarrowia lipolytica; fermentation: biotransforming resveratrol into pterostilbene through the fermentation of recombinant Yarrowia lipolytica in a basal medium. The present invention uses Yarrowia lipolytica as a chassis cell, and expresses resveratrol O-methyltransferase (ROMT) by genetic engineering means, realizing the biotransformation of resveratrol into pterostilbene, which is more efficient and environmentally friendly than chemically synthesizing or directly extracting pterostilbene from natural plants.

The invention discloses azelaic acid-pterostilbene ester and application thereof, and belongs to the technical field of compound synthesis. According to the invention, pterostilbene and azelaic acid are combined to form a new compound. The azelaic acid compound prepared by the invention not only is helpful for overcoming the limitations of poor permeability, higher irritation and the like of azelaic acid, but also can improve the overall efficacy of the azelaic acid compound through a synergistic effect, and provides a better solution for skin care and treatment.