**Abstract**

Essential oils are the volatile compounds having the oily fragrance. Essential oils are obtained from the different plant parts, and they are extracted from the different techniques and the most preferable method of extraction is the hydrodistillation which is cheap and easy to use. Plant parts including the flowers, leaves, stem, bark and roots are used for the isolation of essential oils. Essential oils are used in almost every field of life and because of these characteristics, the market of essential oils is growing rapidly. Essential oils are used in the aromatherapy and act as antioxidant, antimicrobial, antifungal, pain relievers, anxiety, depression. In the field of cosmetics and industries, the essential oils are used rapidly and mostly used in the perfume industries which are growing increasingly. Essential oils are used in the food preservations and many food items. Essential oils are used as the folk herbal medicines and their fragrance is used for the improvement of the mood and as the depression release.

**Keywords:** acts as the antioxidant, antimicrobial, antifungal, pain reliever, anxiety and depression

### **1. Introduction**

Essential oils have been used in the folk medicines throughout the history. Essential oils are called the ethereal or volatile oils, which are fragrant oily liquid that are extracted from the various parts of the plants and mostly used as the food flavors. An essential oil is "essential" in sense that it contains the essence of the different fragrance, and the properties of the plants from which they are derived. These volatile oils showed the different kinds of biological activities including the antibacterial, antioxidant, antiviral, insecticidal, etc. [1]. These oils are also used for cancer treatment, while some other has been used for the food preservations, aromatherapy, and in the perfumery industries [2]. The antimicrobial and antioxidant screening of essential oil acts as the root of numerous applications including the processed and fresh food preservations, natural therapies, pharmaceuticals, and alternative medicines [3]. Essential oils are used in aromatherapy as an alternative source of wound healing because of the aromatic compounds that are present in the essential oils. It is also used as a relaxation process, but this evidence is not under consideration [4].

Numerous efforts are made to explore the essential oils usage as the treatment of various infectious diseases that supernumerary to the pharmaceutical's remedies. Medicinal and aromatic plants are extensively used as natural organic compounds

and as medicines [5]. Previously, essential oils have been used for the treatment of various sorts of infectious diseases in the whole world. Now, in this era, the importance of essential oils is increasing day by day, because they are mostly used in the beverage and food industries, cosmetics and fragrance industries for making valuable perfumes, and with lot of biological activities [6].

Various essential oils have been used for the insecticidal activities against the different pests, but in detail, studies showed that they do not show the repellence, avicidal, phytochemistry, antifungal, and oviposition. The essential oils do not show the abovementioned characteristics, but there is still urgent need to work on this side of research and study the in vivo and in vitro studies to control the pests, and most of the oils have shown good antioxidant activities [7]. Essential oils that showed good antioxidant activates and acts as the defensive role for the unsaturation of lipids in the tissue of the animal and they also act as hepatoprotective negotiators in mammals. The antioxidant substances are most important for human being because of the oxygen which is a toxic element and has the ability to change the metabolic activities into the most reactive form of oxygen just like the super oxide, hydrogen peroxide, hydroxyl free radicals, and the singlet oxygen which are collectively called as active oxygen [8]. Essential oils are best known for their action as the antispasmodic, antiviral negotiators, antimicrobial, and carminative, and the essential oil composition is variable; they also show different sorts of activities and mostly depend upon the chemo types [9].
