The potential effects of Ocimum basilicum on health: a review of pharmacological and toxicological studies

ABSTRACT

Introduction: Basil (Ocimum basilicum L., OB) is a plant world widely used as a spice and a typical ingredient of the healthy Mediterranean diet. In traditional medicine, OB is indicated for many maladies and conditions; OB-containing nutritional supplements are increasingly sold. Conversely, safety concerns have been raised about the promutagens and procarcinogens alkenylbenzenes contained in OB.

Areas covered: A critical review of the current status of OB as a nutraceutical, the pharmacology of its bioactive components, the rationale for its indications, and its safety.

Expert opinion: Due to the polyphenolic and flavonoidic content, OB can be considered as an important ingredient in healthy diets; OB preparations may be effective as chemopreventive agents or adjunctive therapy in the treatment of different clinical conditions.

From a toxicological perspective, since the tumorigenic potential of alkenylbenzenes is counteracted by other OB constituents such as nevadensin, it can be concluded that OB consumption in food and preparations is safe. The only concern relates to OB essential oils: in this case, a concentration limit for alkenylbenzenes should be precautionary defined, and the use of plant chemotypes with no or low levels of these alkylbenzenes for the preparation of essential oils should be made compulsory.

KEYWORDS:

• Alkenylbenzenes
• estragole
• genotoxicity
• health-promoting effects
• Ocimum basilicum

Article highlights

• Adherence to the traditional Mediterranean diet is associated with a decrease in all-cause mortality. This evidence may be related to several components of the Mediterranean diet, which provides a high intake of fiber, vitamins, and natural antioxidants together with a high ratio of monounsaturated fatty acid to saturated fatty acid. There may be, however, herbs and spices used in this dietary pattern that play a role in the observed health benefits of the Mediterranean diet.

• Basil (Ocimum basilicum) has been used for culinary purposes for hundreds of years all over the world in salads, tomato-based dishes, and in pasta sauces. Moreover, basil is a component of several food supplements, which are easily accessible as products able to maintain and promote health.

• Basil exhibits many pharmacological activities making it useful for protecting against or treating several diseases, but it contains different alkenylbenzenes, characterized by a genotoxic and/or carcinogenic profile.

• Due to the protective effect of plant matrix and its flavonoid content, Ocimum basilicum as it is does not represent a risk for human health.

The daily consumption of its essential oil, which may contain and deliver high amounts of alkenylbenzenes in a quasi-purified form without the matrix-associated protection, may pose risks for human health.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer declaration of interest

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.