Essential Oils in Pharmacognosy
Introduction
An essential oil is a concentrated hydrophobic liquid containing volatile aroma compounds from plants. Essential oils are also known as volatile oils, ethereal oils or aetherolea, or simply as the "oil of" the plant from which they were extracted, such as oil of clove. Volatile oils are the odorous and volatile products of various plant and animal species. As they have a tendency to undergo evaporation on being exposed to the air even at an ambient temperature, they are invariably termed as volatile oils, essential oils or ethereal oils. They mostly contribute to the odoriferous constituents or “essences” of the aromatic plants that are used abundantly in enhancing the aroma by seasoning of eatables. Oil is "essential" in the sense that it carries a distinctive scent, or essence, of the plant. Essential oils do not form a distinctive category for any medical, pharmacological, or culinary purpose.
Essential oils are generally extracted by distillation. Steam distillation is often used. Other processes include expression or solvent extraction. They are used in perfumes, cosmetics, soaps and other products, for flavouring food and drink, and for adding scents to incense and household cleaning products. In general, it has been observed that a single volatile oil invariably comprises even more than 200 different chemical components, and mostly the trace constituents are solely responsible for attributing its characteristics flavour and odour.
Essential oils have been used medicinally in history. Medical applications proposed by those who sell medicinal oils range from skin treatments to remedies for cancer and often are based solely on historical accounts of use of essential oils for these purposes. Claims for the efficacy of medical treatments, and treatment of cancers in particular, are now subject to regulation in most countries.
Interest in essential oils has revived in recent decades with the popularity of aromatherapy, a branch of alternative
An essential oil is a concentrated hydrophobic liquid containing volatile aroma compounds from plants. Essential oils are also known as volatile oils, ethereal oils or aetherolea, or simply as the "oil of" the plant from which they were extracted, such as oil of clove. Volatile oils are the odorous and volatile products of various plant and animal species. As they have a tendency to undergo evaporation on being exposed to the air even at an ambient temperature, they are invariably termed as volatile oils, essential oils or ethereal oils. They mostly contribute to the odoriferous constituents or “essences” of the aromatic plants that are used abundantly in enhancing the aroma by seasoning of eatables. Oil is "essential" in the sense that it carries a distinctive scent, or essence, of the plant. Essential oils do not form a distinctive category for any medical, pharmacological, or culinary purpose.
Essential oils are generally extracted by distillation. Steam distillation is often used. Other processes include expression or solvent extraction. They are used in perfumes, cosmetics, soaps and other products, for flavouring food and drink, and for adding scents to incense and household cleaning products. In general, it has been observed that a single volatile oil invariably comprises even more than 200 different chemical components, and mostly the trace constituents are solely responsible for attributing its characteristics flavour and odour.
Essential oils have been used medicinally in history. Medical applications proposed by those who sell medicinal oils range from skin treatments to remedies for cancer and often are based solely on historical accounts of use of essential oils for these purposes. Claims for the efficacy of medical treatments, and treatment of cancers in particular, are now subject to regulation in most countries.
Interest in essential oils has revived in recent decades with the popularity of aromatherapy, a branch of alternative