Nerium oleander L.: A review of diversity, toxicity, chemical compositions and biological activities

The Apocynaceae family includes the evergreen ornamental shrub known as oleander (Nerium oleander). Numerous cultivars were listed in this species, and these differ essentially by the color of the flower. The level of diversity within this species is linked to several factors, such as the geographical region where it grows naturally, environmental conditions, and genetic diversity. Numerous studies of this plant have highlighted bioactive ingredients and several pharmacological effects. Nerium oleander is an extremely toxic and even fatal plant because cardiac glycosides such as oleandrin and neriin are constituents present in different parts of the plant. However, a few common oleander pests occasionally feed on the bush. Despite the danger, oleander is of great medicinal importance. Compounds such as terpenes, steroids, polyphenols, and flavonoids have been identified in extracts of different plant parts. The essential oil also includes compounds such as digitoxigenin. Its compounds are involved in several biological activities such as anti-inflammatory, antioxidant, anticancer, hepatoprotective, antimicrobial, larvicidal, and antidiabetic activities which can be used to produce natural drugs.