Insights into Metabolic Engineering of Bioactive Molecules in Tetrastigma hemsleyanum Diels & Gilg: A Traditional Medicinal Herb

Abstract

Plants are a vital source of bioactive molecules for various drug development processes. Tetrastigma hemsleyanum is one of the endangered medicinal plant species well known to the world due to its wide range of therapeutic effects. Many bioactive molecules have been identified from this plant, including many classes of secondary metabolites such as flavonoids, phenols, terpenoids, steroids, alkaloids, etc. Due to its slow growth, it usually takes 3-5 years to meet commercial medicinal materials for this plant. Also, T. hemsleyanum contains low amounts of specific bioactive compounds, which are challenging to isolate easily. Currently, scientists are attempting to increase bioactive molecules' production from medicinal plants in different ways or to synthesize them chemically. The genomic tools helped to understand medicinal plants' genome organization and led to manipulating genes responsible for various biosynthesis pathways. Metabolic engineering has made it possible to enhance the production of secondary metabolites by introducing manipulated biosynthetic pathways to attain high levels of desirable bioactive molecules. Metabolic engineering is a promising approach for improving the production of secondary metabolites over a short time period. In this review, we have highlighted the scope of various biotechnological approaches for metabolic engineering to enhance the production of secondary metabolites for pharmaceutical applications in T. hemsleyanum. Also, we summarized the progress made in metabolic engineering for bioactive molecule enhancement in T. hemsleyanum. It may lead to reducing the destruction of the natural habitat of T. hemsleyanum and conserving them through the cost-effective production of bioactive molecules in the future.

Keywords: Drug discovery; Tetrastigma hemsleyanum; bioactive molecules; flavanoids; genome editing; metabolic engineering.

Fig. (1)

Selected flavonoids and glycosylated flavonoids from T. hemsleyanum. These molecules have a wide range of biological activities. (Created with BioRender.com)

Fig. (2)

Plant cell, tissue, and organ culture (PCTOC) approach for producing secondary metabolites. The optimum culture media helps to accumulate desirable secondary metabolites within a short period. The desirable secondary metabolites have high therapeutic values it helps human health care.

Fig. (3)

Transgenic approaches for metabolic engineering in plant cell culture. The Agrobacterium-mediate transformation is the most common way to introduce heterologous DNA (desirable genes) in plants. It is one of the efficient methods for metabolic engineering approaches widely used by plant biotechnologists. It needs efficient tissue culture and transformation protocols.

Fig. (4)

Metabolic engineering through CRISPR/Cas9 genome editing system. Metabolomics and transcriptomics analysis help to identify the candidate genes related to metabolic pathways. The CRISPR/Cas9 genome-editing system allows to alteration of metabolic production through the knock-in or knock-out of desirable genes.