A comprehensive review on tissue culture studies and secondary metabolite production in Bacopa monnieri L. Pennell: a nootropic plant

Bacopa monnieri L. Pennell, commonly known as Brahmi, is an important medicinal plant that belongs to the family Plantaginaceae. Brahmi is rich in innumerable bioactive secondary metabolites, especially bacosides that can be employed to reduce many health issues. This plant is used as a neuro-tonic and treatment for mental health, depression, and cognitive performance. Brahmi is also known for its antioxidant, anti-inflammatory, and anti-hepatotoxic activities. There is a huge demand for its raw materials, particularly for the extraction of bioactive molecules. The conventional mode of propagation could not meet the required commercial demand. To overcome this, biotechnological approaches, such as plant tissue culture techniques have been established for the production of important secondary metabolites through various culture techniques, such as callus and cell suspension cultures and organ cultures, to allow for rapid propagation and conservation of medicinally important plants with increased production of bioactive compounds. It has been found that a bioreactor-based technology can also enhance the multiplication rate of cell and organ cultures for commercial propagation of medicinally important bioactive molecules. The present review focuses on the propagation and production of bacoside A by cell and organ cultures of Bacopa monnieri, a nootropic plant. The review also focuses on the biosynthesis of bacoside A, different elicitation strategies, and the over-expression of genes for the production of bacoside-A. It also identifies research gaps that need to be addressed in future studies for the sustainable production of bioactive molecules from B. monnieri.