Bioactivity of Basil

Traditional Medicine

Basil has traditionally been used for head colds and as a cure for warts and worms, as an appetite stimulant, carminative, and diuretic. In addition, it has been used as a mouth wash and adstringent to cure inflammations in the mouth and throat. Alcoholic extracts of basil have been used in creams to treat slowly healing wounds. Basil is more widely used as a medicinal herb in the Far East, especially in China and India. It was first described in a major Chinese herbal around A.D. 1060 and has since been used in China for spasms of the stomach and kidney ailments, among others. It is especially recommended for use before and after parturition to promote blood circulation. The whole herb is also used to treat snakebite and insect bites.

In Nigeria, a decoction of the leaves of Ocimum gratissimum is used in the treatment of fever, as a diaphoretic and also as a stomachic and laxative. In Franchophone West Africa, the plant is used in treating coughs and fevers and as an anthelmintic. In areas around Ibadan (Western State of Nigeria), Ocimum gratissimum is most often taken as a decoction of the whole herb (Agbo) and is particularly used in treating diarrhoea. It is known to the Yorubas as “Efirin-nla” and to the Ibos as “Nehanwu”, in Nigeria.

In Kenya most members of Ocimum are used as expectorants. The people in rural areas are the principle utilizers of the herbal remedies.

Ocimum basilicum is known under the following local names in the Rift Valley in central Kenya (area in brackets): Chemishwa (Tugen), Chenekom/Sipko (Pokot), Embuke/ Emboa (Bukusu), Lemurran (Samburu), Mwenye (Luhya), Mutaa (Kamba) and Rigorio (Marakwet). The vapour of boiling leaves is inhaled for nasal or bronchial catarrh and colds. The leaves may be rubbed between the palms and sniffed for colds. It cures stomachache and constipation. The leaves are crushed and the juice is used as vermifuge. It is further used to repel mosquitoes and as a broom to sweep chicken house in order to get rid of fleas.

Ocimum gratissimum is known under the name Mutaa (Kamba). The leaves are eaten for stomach-ache. Pounded leaves are soaked in water and concoction is used as insecticide on maize cobs. Ocimum kilimandscharicum is known under the names Gethereti/Makori (Meru), lisuranza/Mwonyi (Luhya), Mbirirwa (Marakwet) and Mutei (Kikuyu). The leaves treat congested chest, cough and cold, by sniffing crushed leaves or inhaling vapour of boiling leaves. Infusion is a cure for measles. It is also used to repel insects.

Ocimum pseudokilimandscharicum is known by the name Mukandu munini in the Kamba area. The leaves are ground to powder, mixed with water and drunk to cure stomach-ache.

Ocimum suave is known under the names Chemwoken (Pokot), Mukandu (Kamba), Makanda kandu (Meru), Yoiyoiya/Chesimia (Marakwet), Mkandu (Kikuyu), Sivai (Kipsigis) and Sunoni (Masai). The leaves are rubbed between palms and sniffed to treat a blocked nose and cough. The Meru prepare an infusion of the leaves for flu. Chewed leaves treat toothache, the juice is an anthelmintic in small children and roots boiled in soup treats chestache. It may be burnt at night to drive away insects. In Tanzania Ocimum suave have been claimed to have various medicinal activities, and extracts of the plant are used for treating coughs, eye and ear complaints, and abdominal pains.

Ocimum canum, Ocimum gratissimum, Ocimum trichodon and Ocimum urticifolium (Ocimum suave) are used in Rwanda as infusions and for inhalation of their aromatic vapours, as sneezing powders for curing headache and madness.

In Congo Ocimum gratissimum aerial parts are taken as febrifuge, against cough and angin.

Ocimum sanctum is a great sacred medicinal plant in India. It is called Thulasi (or Vishnupriya) in Sanskrit, Thulasi in Tamil and Kala-Thulasi in Hindi. It is used for the prevention of pregnancy among the Irulars, the tribal of Anaikkatty Hills, Coimbatore, Tamil Nadu. Roots of Piper betle and half the quantity of fruits of Piper nigrum are made into a paste in leaf juice of Ocimum sanctum. It is administered internally, 5 g/day, for both male and female for 96 days to get complete sterility.

Ocimum basilicum (Albahaca) is one of many plants used in Guatemala to treat gastrointestinal disorders such as colic, stomach pains, intestinal parasites, flatulence, and loss of appetite. It is also used as an anti-emetic agent. Among the Caribs, a small ethnic group of Afro-Caribbean origin, in Guatemala a decoction of Ocimum micranthum (Albahaca) leaves is used orally for coughs and phlegm, stomach pains, intestinal parasites and skin diseases (locally). The juice is used directly for ear pain.

Modern Use

Basil is used as a fragrance ingredient in perfumes, soaps, hair dressings, dental creams, and mouth washes. The most extensive use is as a spice in all major food products, usually in rather low levels (mostly below 0.005%). The use in foodstuffs is discussed in another chapter in this book. The fresh herb is considered by some a source of vitamin C. Basil is subject of a German therapeutic monograph as stomachicum.

Antimicrobial Activity

Bioactivity of Basil: Antibacterial Activity

Bioactivity of Basil: Antifungal Activity

Insecticidal Activity

In warm countries all kinds of insects are a nuisance as well as the cause of diseases in plants, animals and humans. Stored products has to be protected against different insects. Therefore much effort has been put into the development of different insect repellants. Since synthetic agents often have severe toxic effects and may be too expensive for people in developing countries much hope has been placed on insect repellants of plant origin, preferably plants growing locally. Ocimum species have been studied along with many others in this respect and the results of these studies are reported below.

The essential oil (2% in acetone) of Ocimum gratissimum showed 100% repellency against the housefly, Musca domestica ().

The essential oil of Ocimum basilicum showed repellent activity of class IV against red flour beetle, Tribolium castaneum ().

Protection of Growing Plants

The aphidicidal effect of an ethanol extract of Ocimum sanctum was tested against the following aphid species: Myzus persicae, Metopolophium dirhodum, Aphis fabae, Sitobion avenae and Acyrthosiphon pisum. The best effect, with a mortality rate of 79%, was observed for M.dirhodum ().

Methanol extracts of leaves of Ocimum sanctum at a concentration 1.0% resulted in 90% mortality of the grub of Henosepilachna vigintioctopunctata, a pest of brinjal, at 12 to 24h after treatment.

Acetonic solutions with different concentrations of Ocimum basilicum essential oil were sprayed on bean leaf discs and were found to induce repellency in adult females of the carmine spider mite, Tetranychus dnnabarinus. Also egglaying was reduced. The EC50-value was 1.4%.

Fruit flies (Dacus spp.) cause heavy damage to ripe and semi-ripe fruits and vegetables. Ocimum sanctum extracts can be used to lure and trap fruit flies and so prevent damage to crops. Leaf extract in ethyl acetate (0.25 ml on a cotton pad) effectively attracted fruit flies from a distance of 0.8 km. Methyl eugenol gave the same result.

Protection of Stored Products

The dried ground leaves and essential oil of Ocimum kilimandscharicum in doses of 25.0 g leaves and 0.3 g essential oil per 250 g grain (maize or sorghum) killed 100% of Sitophilus zeamais, Rhyzppertha dominica and Sitotroga cereaklla in 48 h. The best repellent activity was seen by 0.3 g essential oil/250 g grains against Sitophilus %eamais (Jembere et al., 1995).

Powdered leaves of Ocimum canum at a concentration of 2% w/w completely inhibited the oviposition of adult Zabrotes subfasciatus in dried Pinto beans. 1% w/w powdered leaves in Pinto beans caused 100% mortality of adult subfasdatus in 48 h. The EC50 was determined as 0.45% w/w. Linalool is the major compound in Ocimum canum leaves and the fumigant toxicity can be explained by the gradual release of linalool from the powdered material. The contact toxicity evidently involves other components. Dose-response curves for linalool were completed with adult Zabrotes subfasdatus, Acanthoscelides obtectus, Rhyzopertha dominica and Sitophilus oryzae using a filter paper bioassay. The LC50-values were: 428 μg/cm2 (Z.subfasdatus), 405 μg/cm2 (A.obtectus), 428 μg/cm2 (R.dominica) and 427 μg/cm2 (S.oryzae) (). In another study the essential oil of Ocimum basilicum was found to kill adult Acanthoscelides obtectus insects on kidney beans in the field and during storage, as well as inhibit reproduction through ovicidal and larvicidal effects.

Powdered leaves of Ocimum gratissimum reduced the egglaying of Callosobruchus maculatus in stored cowpea seeds.

Protection of Animals

Ocimum suave essential oil was found to repel and kill all stages of the tick Rhipicephalus appendiculatus. In an in vitro assay for the larvae the LC of the oil in liquid paraffin was 0.024%. A 10% solution was found to kill all immatur50es and more than 70% of the adults feeding on rabbits. The rabbits were protected for 5 days using the 10% solution. The same protection may be useful for field kept cattle.

Protection of Humans Against Diseases

An extract of Ocimum sanctum showed pupicidal effects against fleas, which are vectors of bubonic plaque, murine typhus and other rodent borne diseases. A crude extract of Ocimum sanctum showed pupicidal effect on newly emerged pupae of the vector Aedes aegypti (). The essential oils of Ocimum basilicum and Ocimum sanctum and their major constituents showed insecticidal properties against the vectors Anopheles stephensi, Aedes aegypti and Culex quinquejasdatus in laboratory tests. Ocimum basilicum and its major constituent, methyl chavicol, were more effective than Ocimum sanctum. The essential oils and their major constituents were more toxic to A. stephensi, followed by A aegypti and C.quinquefasdatus ().

Bioactivity of Basil: Other Activities

Yvonne Holm, Department of Pharmacy, P.O Box 56, FIN-00014, University of Helsinki, Finland

Selections from the book: “Basil: The Genus Ocimum”.

Edited by Raimo Hiltunen and Yvonne Holm, Department of Pharmacy, University of Helsinki, Finland, 1999