الفهرس 
A pharmaceutical Study on Herbal Drug in Vesicular Systems
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Abstract
Quercetin is a plant pigment (flavonoid) that gives many fruits, flowers, and vegetables their colors. It’s found in many plants and foods, such as red wine, onions, green tea, apples, and berries. Quercetin has antioxidant and anti-inflammatory effects that might help reduce swelling, kill cancer cells, control blood sugar. Flavonoids, such as quercetin, are antioxidants. They scavenge particles in the body known as free radicals which damage cell membranes, tamper with DNA, and even cause cell death. Antioxidants can neutralize free radicals. They may reduce or even help prevent some of the damage free radicals cause. Quercetin may help protect against heart disease and cancer. Quercetin can also help stabilize the cells that release histamine in the body and thereby have an anti-inflammatory and antihistamine effect. Quercetin supplements are available as pills or capsules. They are often packaged with bromelain (an enzyme found in pineapple) because both are anti-inflammatories. Other flavonoid-rich extracts include those from grapeseed, bilberry, Ginkgo biloba, and green tea. There are also water-soluble forms of quercetin available, such as hesperidn-methyl-chalcone (HMC) or quercetin-chalcone.
The antioxidant and anti-inflammatory features of the quercetin were also reported to provide a scar free wound healing. The effects of quercetin in wound healing were manifested with stimulation of extracellular matrix formation, up-regulation of vascular endothelial growth factor (VEGF), and transforming growth factor (TGF)-β synthesis. Quercetin was also found to be effective in disrupted wound healing process in persistent wounds associated with diabetes after topical quercetin implementation.
Skin is a multifunctional organ with activities in protection, metabolism and regulation. Skin is in a continuous exposure to oxidizing agents and inflammogens from the sun and from the contact with the environment. These agents may overload the skin auto-defense capacity. To strengthen skin defense mechanisms against oxidation and inflammation, supplementation of exogenous antioxidants is a promising strategy.
Quercetin is a flavonoid with very pronounced effective antioxidant and anti-inflammatory activities, and thus a candidate of first choice for such skin supplementation. Quercetin showed interesting actions in cellular and animal based models, ranging from protecting cells from UV irradiation to support skin regeneration in wound healing. However, due to its poor solubility, quercetin has limited skin penetration ability, and various formulation approaches were taken to increase its dermal penetration. To overcome these barriers and improve efficacy, research in the field of nanotechnology is a tool that has been extensively investigated. So incorporation in nanovesicles is urgently needed to enhance its topical and transdermal effect. Nanotechnology is defined as the development, characterization and application of systems on the nanoscale. Therefore, several types of nanostructures have been developed, including mesoporous silica nanoparticles, liposomes, cyclodextrin, chitosan nanoparticles, PLGA polymer nanoparticles, biogenic nanomaterials and other technologies.
The aim of this work was to design topical quercetin loaded niosomes and quercetin loaded transfersomes for wound treatment. The work was divided into three chapters.