Botanical Name: Ocimum gratissimum
Preferred Common Name: African basil
International Common Names
Local Common Names
The Scent leaf, botanically known as Ocimum gratissimum, is an aromatic herb that has been introduced extensively across tropical and subtropical regions of the world. It is native to Nigeria, Ghana, Cameroun, Madagascar, Southern Asia, and the Bismarck Archipelago. It has been naturalized in countries such as Polynesia, Hawaii, Brazil, Panama, the West Indies, and Mexico. The plant is normally a perennial homegrown shrub, although it can be found in the wild, and is used mainly as a spice for cooking delicacies due to its aromatic taste.
Now, it is easy to dismiss this plant as just another sweet-smelling plant but it is more than just that. The plant boasts a lot of antibacterial, antifungal, larvicidal, and antipyretic activities that give it a prominent role in the treatment and prevention of diseases and infections. Scent Leaves contain vital bioactive substances which confer it with the above-mentioned activities including; tannins, phenols, calcium, phosphorus, iron, vitamin A, and more, all of which are essential for human health.
For a better appreciation of the uniqueness of this plant, its amazing benefits are here outlined;
Scent leaf is rich in Vitamin A, which promotes good eyesight. Vitamin A is needed by the retina of the eyes in the form of retinal which combines with protein opsin to form rhodopsin, the light-absorbing molecule which is ultimately necessary for both scotopic vision (low-light) and color vision.
The deficiency of vitamin A can be terrible for the eyes leading to xerophthalmia (a medical condition in which the eye fails to produce tears) and night blindness both of which are preventable when adequate amounts of scent leaves are consumed.
Excess intake of vitamin A and by extension, the scent leaves, by pregnant women can lead to birth defects and is not recommended. Also, Information regarding safety and efficacy in lactation is lacking.
Scent leaves contain calcium and magnesium, both of which help to reduce bad cholesterol (low-density lipoprotein cholesterol) and increase blood circulation. Low-density lipoprotein (LDL) cholesterols increase the risk of Coronary Artery Disease in adults and so the intake of scent leaves can reduce this ever-present risk.
Heart and artery problems resulting from the clogging of arteries are nearly preventable if adequate amounts of scent leaves are consumed.
Scent leaves can help relieve bloating and also help digest meals on time. Brewed scent leaves can have a calming effect on the stomach and help with bowel evacuation. Drinking scent leaves tea also relieves heartburn.
Scent leaves have an unprecedented ability to lower blood sugar and protect the pancreatic islets that produce insulin from damage. A research study conducted on mice showed that scent leaves were efficacious in lowering blood sugar levels.
Another randomized study equally showed a decrease in blood sugar levels in Non-Insulin Dependent (NID) Diabetes Mellitus patients after eating significant amounts of scent leaves.
Scent leaves contain compounds like camphor, cineole, and limonene which are larvicidal and so are harmful to mosquitoes or insects. The leaves can be potted and left in residential quarters to serve as a repellent for houseflies, mosquitoes, and other insects.
This has a double role given that by reducing the population of mosquitoes and houseflies in residences, the incidences of malaria and enteric diseases (caused by houseflies) are both reduced.
Studies have shown scent leaves to have antifungal activity against Penicillium chrysogenum (also known as Penicillium notatum), Candida albicans, and Microsporeum gyseum. Chloroform extracts from the leaves showed great antifungal activity against the fungal species mentioned. Thus, scent leaves when crushed and smeared on skin infections, help in its treatment.
Ethanol and hot water (100oC) extracts of scent leaves have been extensively demonstrated to be effective against some pathogenic bacteria known to cause diarrhea including Staphylococcus aureus, Escherichia coli, Shigella sp. and Salmonella sp. It is thus conceivable that scent leaves can be brewed as tea to treat cases of diarrhea caused by the above organisms.
Also, the use of scent leaves in the control of diarrhea can be attributed to the relaxant action of the essential oil of O. gratissimum which is likely to be due to a direct effect on the smooth muscle of the ileum rather than an indirect action on neurotransmitter release.
Scent leaves have been shown to possess anti-inflammatory properties akin to drugs such as aspirin and ibuprofen but are kinder to the inner linings of the stomach. Decoction made from leaves of O. gratissimum is useful for healing menstrual pain, stomach ache, earache, and fever.
Aqueous extracts of scent leaves have demonstrated effects on markers of inflammation, including interleukins, protein kinases, and leukocytes/eosinophils in models of respiratory allergy (in vitro experiments evaluating effects on airway epithelial cells, in vivo studies in rodents) and thus can be used in managing respiratory problems.
The leaves are rubbed between the palms and sniffed as a treatment for blocked nostrils.
The stem of scent leaf when used as chewing stick kills bacteria in the mouth and help fight off bad breath. It is also able to prevent tooth decay. Tea made from the leaves of scent leaf can be taken as a tonic or used as a gargle to treat sore throat.
Edible plants with antimutagenic activity and chemopreventive potential have been documented from several plant groups. Investigations have shown that organic solvent extracts of scent leaves have antimutagenic effects against reverse mutation induced by ethyl methanesulfonate (EMS), 4-nitrophenylenediamine, and 2-aminofluorine.
Scent leaf is widely used in the dressing of neonatal umbilical cord and wounds as it is believed to keep the baby’s umbilical cord and wound surfaces sterile. The wound healing effects of scent leaf may be attributed to its ability to increase vascular permeability.
Formulations of the leaf essential oil of O. gratissimum (Ocimum oil) have been incorporated in a variety of bases as topical antiseptics and for use in the treatment of boils and pimples.
Hair loss is one of the most feared side effects of cancer chemotherapy. Investigations by Orafidiya et al., showed the efficacy of the leaf essential oil of scent leaves (Ocimum oil) in promoting hair growth and follicular proliferation in cyclophosphamide-induced hair loss.
Scent leaf is a good source of arginine, an amino acid that helps in the maintenance of optimum penile health and sperm vitality. It also contains compounds such as epigenin fenkhona and eugenol which can facilitate erection.
In addition, the anetol and boron in the leaves are capable of inducing estrogen in women while the same eugenol effective in men helps to kill fungus that has been implicated in vaginal discharge.
Scent leaves have been reported to have antimicrobial properties. The fact that its extracts are plant-based implies that the ethanol extract can be used as a potent food preservative to keep away bacteria and fungi that may otherwise cause food spoilage. This presents a cheaper and possibly healthier alternative to the more popular preservatives.
The oil extracts obtainable from scent leaves have a wide spectrum of usage. The essential oils can be used for aromatherapy massage as the oils can relieve and refresh the body. The oils can equally be used in the manufacture of soaps, perfumes, ointments, and aromatherapy oils.
There are so many other unconfirmed uses of this powerful plant including; reduction of nicotine levels, ceremonial washing of corpses (in Indonesia) etc. One thing that is clear is that the plant is more than meets the nose and must be better researched and utilized before its beauty in its entirety can be duly appreciated.