Basil is a culinary herb prominently featured in Italian cuisine, and also plays a major role in the Southeast Asian cuisines of Thailand, Vietnam and Laos. The plant tastes somewhat like anise, with a strong, pungent, sweet smell. It is originally native to Iran, India and other tropical regions of Asia, having been cultivated there for more than 5,000 years.

There are many varieties of basil. That which is used in Italian food is typically called sweet basil, as opposed to Thai basil, lemon basil and holy basil, which are used in Asia. While most common varieties of basil are treated as annuals, some are perennial in warm, tropical climates, including African Blue and Holy Thai basil.

Basil is commonly used fresh in cooked recipes. It is generally added at the last moment, as cooking quickly destroys the flavour. The fresh herb can be kept for a short time in plastic bags in the refrigerator, or for a longer period in the freezer, after being blanched quickly in boiling water. The dried herb also loses most of its flavour, and what little flavour remains tastes very different, with a weak coumarin flavour, like hay.

When soaked in water the seeds of several basil varieties become gelatinous, and are used in Asian drinks and desserts such as falooda or sherbet. Such seeds are known variously as subza, takmaria, falooda or selasih. They are used for their medicinal properties in Ayurveda, the traditional medicinal system of India.They are also used as popular drinks in Southeast Asia.

The various basils have such different scents because the herb has a number of different essential oils which come together in different proportions for various breeds. The strong clove scent of sweet basil is derived from eugenol, the same chemical as actual cloves. The citrus scent of lemon basil and lime basil is because they have a higher portion of citral which causes this effect in several plants. African blue basil has a strong camphor smell because it has camphor in higher proportions. Licorice Basil contains anethole, the same chemical that makes anise smell like licorice.

Basil contains large amounts of (E)-beta-caryophyllene (BCP), which might have a use in treating inflammatory bowel diseases and arthritis. BCP is the only product identified in nature that activates CB2 selectively. It interacts with one of two cannabinoid receptors, blocking chemical signals that lead to inflammation, without triggering cannabis’s mood-altering effects.

Recently, there has been much research into the health benefits conferred by the essential oils found in basil. Scientific studies have established that compounds in basil oil have potent antioxidant, anti-cancer, anti-viral, and anti-microbial properties. In addition, basil has been shown to decrease the occurrence of platelet aggregation and experimental thrombus in mice. It is traditionally used for supplementary treatment of stress, asthma and diabetes in India.