Polyploidy plays an important role in plant diversification and speciation. The ploidy level of plants is associated with morphological and biochemical characteristics, and its modification has been used as a strategy to alter the quantitative and qualitative patterns of secondary metabolite production in different medicinal plants. Polyploidization can be induced by many anti-mitotic agents, among which colchicine, oryzalin, and trifluralin are the most common. Other variables involved in the induction process include the culture media, explant types, and exposure times. Due to the effects of polyploidization on plant growth and development, chromosome doubling has been applied in plant breeding to increase the levels of target compounds and improve morphological characteristics. Prompted by the importance of herbal medicines and the increasing demand for drugs based on plant secondary metabolites, this review presents an overview of how polyploidy can be used to enhance metabolite production in medicinal plants.

Modern lifestyle factors, such as physical inactivity, obesity, smoking, and exposure to environmental pollution, induce excessive generation of free radicals and reactive oxygen species (ROS) in the body. These by-products of oxygen metabolism play a key role in the development of various human diseases such as cancer, diabetes, heart failure, brain damage, muscle problems, premature aging, eye injuries, and a weakened immune system. Synthetic and natural antioxidants, which act as free radical scavengers, are widely used in the food and beverage industries. The toxicity and carcinogenic effects of some synthetic antioxidants have generated interest in natural alternatives, especially plant-derived polyphenols (e.g., phenolic acids, flavonoids, stilbenes, tannins, coumarins, lignins, lignans, quinines, curcuminoids, chalcones, and essential oil terpenoids). This review focuses on the well-known phenolic antioxidant rosmarinic acid (RA), an ester of caffeic acid and (R)-(+)-3-(3,4-dihydroxyphenyl) lactic acid, describing its wide distribution in thirty-nine plant families and the potential productivity of plant sources. A botanical and phytochemical description is provided of a new rich source of RA, Satureja khuzistanica Jamzad (Lamiaceae). Recently reported approaches to the biotechnological production of RA are summarized, highlighting the establishment of cell suspension cultures of S. khuzistanica as an RA chemical biofactory.

Highly methoxylated flavones, which have known potential as cancer chemopreventive agents, accumulate on the leaf surfaces of some plant species and their physiological role is to protect the plant against harmful UV radiation. Xanthomicrol is one of the methoxylated flavones currently attracting most attention from researchers worldwide because of its promising pharmacological activities, including anti-spasmodic, anti-platelet and anti-cancer effects, among others. This review covers the chemistry and biological origin, distribution and pharmacological activity of xanthomicrol. Knowledge of the botanical distribution of this compound will not only encourage the use of plant sources for pharmacological purposes, but will also serve as a reference in the search for this valuable flavonoid in another genus or family. New approaches to xanthomicrol production are also described, including biotechnological attempts to develop xanthomicrol-producing plant cell factories.

The growing interest in rosmarinic acid (RA), an ester of caffeic acid and 3,4‐dihydroxyphenyl lactic acid, is due to its biological activities, which include cognitive‐enhancing effects, slowing the development of Alzheimer's disease, cancer chemoprotection, and anti‐inflammatory activity. Inspired by the challenge of meeting the growing demand for this plant secondary metabolite, we developed a biotechnological platform based on cell suspension cultures of Satureja khuzistanica. The high amounts of RA produced by this system accumulated mainly inside the cells. To further improve production, two elicitors, 100 μM methyl jasmonate (MeJA) and 40 mM cyclodextrin (CD), were tested, separately and together. MeJA increased RA productivity more than 3‐fold, the elicited cultures achieving an RA production of 3.9 g L−1 without affecting biomass productivity. CD did not have a clear effect on RA production, and under the combined treatment of MeJA + CD only a small amount of RA was released to the medium. When the cell culture was transferred from a shake flask to a wave‐mixed bioreactor, a maximum RA production of 3.1 g L−1 and biomass productivity of 18.7 g L−1 d−1 was achieved under MeJA elicitation, demonstrating the suitability of S. khuzistanica cell suspensions for the biotechnological production of this bioactive plant secondary metabolite.