Study On The Plant Extracts For Cosmetics Preservatives

In recent years,the safety concern of parabens,which are the most frequently used chemical preservatives in cosmetics,have been questioned by more and more scholars and consumers.At the same time,chemical preservatives will be gradually restricted in cosmetics in the near furture.Therefore,the development of natural,safe and efficient anti-microbial system from natural plants as a substitute for chemical preservatives is a hot topic in cosmetic preservative field.In this paper,four cheap plants,magnolia officinalis,phyllostachys pubescens,phryma leptostachya and cinnamon,with best antimicrobal activity were selected.Then the crude extraction process and purification by different organic solvents of these four plants were determined with the inhibition zone of S.aureus,E.coli,C.albicans and A.niger as well as extraction yields.The four extraction parts were compounded by L25(56)orthogonal table,when the ratio of magnolia officinalis,phyllostachys pubescens,phryma leptostachya and cinnamon was 2: 5: 1: 2,the antibacterial activity was strongest and the antimicrobial spectrum was wide,which was named nature preservative system(NPs).The antibacterial zone of NPs to S.aureus,E.coli,C.albicans and A.niger were 28.58±0.75 mm?28.98±0.63 mm?32.10±0.76 mm?33.02±0.78 mm,respectively.Both the MIC and MBC of NPs were 1.56 mg/mL?0.78 mg/mL?0.39 mg/mL?0.78 mg/mL,respectively.The antibacterial mechanism of NPs was further investigated.Firstly,flavonoids,lignans,organic acids and phenolic were the mianly active ingredients of these four plants by the initial identification.Then,the growth inhibition curve,cell membrane permeability test,DNA injury test in vitro,cell cycle analysis and bacterial morphology observation were used to research the mechanism of S.aureus and E.coli,it was found that NPs showed synergism antibacterial activity by destroy different growth cycle or different target sites,compared with single plant extraction.Multiple fence effect could be used to explain the antibacterial mechanism of NPs.Firstly,the cell wall was destroyed by speranskia officinalis and magnolia officinalis extractions,and magnolia officinalis extraction further destroyed the cell membrane structure.Thus,the pathway opened which can help phyllostachys pubescens extraction enter into the cell to inhibit or destruct the genetic material.Therefore,NPs showed significant synergistic effect with high efficiency and broad spectrum of antibacterial activity through the destruction of different target sites.This also provides a theoretical basis for the antimicrobial plant extractions compounding program.Finally,in order to apply NPs to different cosmetic systems,the stability of NPs was studied.NPs was suitable for cosmetic products with pH 4 to 6.With UV inradiation,the antibacterial activity of NPs was reduced.The antibacterial effect of NPs was better at the temperature below 60 ?.Besides,the effect of NPs was stable stored at 40 ? for 90 days.At the same time,red blood cell test showed that NPs was very mild,with no irritation.Besides,the microbial challenge test of mask liquid,mud mask,O/W moisturizing cream and W/O suncreen lotion were further tested.When the addition amount of NPs was 0.5%~1.2%,the antimicrobial ability was good.While using NPs with chemical preservatives or assistant microbial inhibitor,such as phenoxyethanol or octylalchol,could reduce the amount of chemical preservatives.Therefore,NPs can be used as a natural,mild,safe cosmetic preservatives,completely or partially replaced the use of chemical preservatives.