**3. Economic importance of essential oils of** *Cymbopogon*

*C. citratus* Stapf. (lemongrass) is a spice commonly used in tropical regions, particularly in Southeast Asia. The primary compounds identified in *C. citratus* essential oil include *α*-citral, *β*-citral, geraniol, nerol, citronellal, myrcene, terpinolene, geranyl acetate, and terpinol methylheptenone. Terpenes, alcohols, ketones, and certain flavonoids and phenolics have also found in the plant [29]. Scientific research has described the antibacterial, anticarcinogenic, anti-inflammatory, antifungal, antioxidant, antiprotozoal, antirheumatic and cardioprotective effects of *C*. *citratus* [30–32]. It has shown a marked suppression of fungal infections including athlete's foot, itching, ringworm, and yeast infections and has a synergistic effect by suppressing the growth of filamentous fungi by inactivating yeast cells [6, 33]. Citral, myrcene, and citronellal are secondary metabolites that have been isolated from lemongrass and characterized as antimalarials. They showed remarkable activity against *Plasmodium* sp. [34]. In HIV/ AIDS patients, oral candidiasis brought on by *Candida albicans* has been demonstrated to be successfully treated with lemongrass essential oil in 1 to 5 days [35].

LGEO's pharmaceutical potential has been reported in rodents in a well-designed trial involving oral administration of EO's key ingredient, citral, in combination with the nonsteroidal anti-inflammatory drug naproxen to experimental rats. The combination of naproxen and citral showed comparable anti-inflammatory effects compared with naproxen alone, but with much less stomach adverse effects [36]. Citral from *C*. *citratus* is used as an additive in creams and ointments to treat local inflammation as it significantly inhibits inflammatory mediators. It has also been shown to inhibit neutrophil attachment generated by tumor necrosis factor (TNF)-α at a dose of 0.1% and lipopolysaccharide (LPS)-induced nitric oxide synthase (iNOS) and monooxidation-induced signaling pathways co-bind to receptors, thereby blocking the nuclear factor Kappa B (NFƙB) pathway, COX2 and peroxisome proliferators. It suppresses activated receptor alpha (PPARα) by 60–70% and inhibits oral and tissue inflammation [6].

It has been reported to inhibit platelet composition and treat anxiety, gastrointestinal infections, diabetes, malaria, and pneumonia [25]. Tea made from lemongrass essential oil has been proven to have sedative, analgesic, anti-inflammatory, antipyretic, and antispasmodic properties. It has also been used as massage oil for relief of joint and muscle pain [37]. Diarrhea, stomach aches, and digestive issues can all be treated with lemongrass tea [38]. Lipid-lowering and hypoglycemic drugs may also contain lemongrass. In folk remedies and Ayurvedic medicines, it is used to control serum glucose, fat, and lipid levels and prevent obesity and high blood pressure. This plant has been used to keep blood sugar levels stable by secreting insulin (hyperinsulinemia). It lowers blood pressure that may result in hypertension [5]. It has been reported that citral (geranial and neral), the main constituent of *C*. *citratus* essential oil, is cytotoxic to a number of human leukemia cell lines. This occurs by the activation of procaspase 3. It has also been proven to inhibit the proliferation of pathogenic food-borne bacteria including *Listeria monocytogenes* and *Salmonella* Typhimurium [4].

Essential oils from *C*. *citratus* have been used to control infections and insects. It is efficient against *Aedes aegypti*, *Phenacoccus solenopsis*, *Dermatophagoides* sp., and *Musca domestica*. *C*. *citratus* is used in herbal soaps to cure swelling, itching skin, and rashes [6]. It has also been demonstrated that lemongrass essential oil inhibits *Microsporum canis*. Shampoos containing citral were efficient against *Malassezia furfur*, a fungus found in dandruff [39]. Lemongrass essential oil has been noted to exhibit considerable resistance to pathogenic fungi that interfere with the release of *Phytochemical Contents of Essential Oils from* Cymbopogon *Species: A Tropical Medicinal Plant DOI: http://dx.doi.org/10.5772/intechopen.105396*

mycotoxins during preservation of grains and other food products [40]. *Cymbopogon* is a common herb in tropical regions [30]. It is frequently used as a food ingredient for human consumption. Lemongrass is frequently used in Asian cuisine for its aroma. Industrially, they are important as part of beverages, baked goods, fragrances, pesticides, and preservatives [6, 41]. They can serve as deodorants for perfumes, local samples, candle repellents, and other insect repellents. It has been used as a repellent against snakes and other reptiles in some Asian and African countries [42, 43]. The potential of lemongrass as an effective substitute to antibiotic growth promoters was evaluated [44].
