Plant resources have remained an integral part of human society throughout history. World Health Organization (WHO) estimated that about 80% of the developing world’s population use traditional herbal medicines. In developing countries, traditional medicines provide a cheap and alternative source for primary health care due to the lack of modern health facilities, their effectiveness, cultural priorities, and choices. In developed nations, the usage of traditional herbal medicines is also a fast-growing phenomenon. For instance, in China, traditional herbal preparations account for 30–50% of the total drug consumption. While at the same time, in countries such as Nigeria, Ghana, Zambia, and Mali, the first choice for 60% of children suffering from high malarial fever is herbal medicines. In Ethiopia, about 80% of the population use traditional medicines due to the cultural acceptability of healers and local pharmacopoeias, the comparatively low cost of traditional medicines and the lack of access to modern drugs.

Although medicinal plants are generally considered to be safe, they are not entirely free of side effects or toxicity. The toxicity of medicinal plants varies with chemical composition, the volatile oil of the plant, and sometimes due to heavy metal-induced toxicity. Despite the benefits derived from medicinal plants, some may be a threat to the health of the users, due to potentially harmful effects or side effects that may be related to overdoses or toxic principles. This may lead to acute toxicity and death of patients.

Therefore, this Special Issue aims to collate original research and review articles that cover all aspects of aromatic medicinal plants which link the gap between beneficial and harmful effects of plants.

Potential topics include but are not limited to the following:

• Bio-active phytochemicals and their toxicological evaluation
• Bio-active phyto-extracts and their toxicological evaluation
• Biomedical applications of aromatic medicinal plants
• Phytochemical delivery in aromatic medicinal plants
• Ethnobotanical uses of aromatic medicinal plants
• Pharmacological effects of medicinal aromatic and poisonous plants
• Heavy metal-induced toxicology in medicinal plants