Nano-Elicitation as an Effective and Emerging Strategy for In Vitro Production of Industrially Important Flavonoids

Abstract

Flavonoids represent a popular class of industrially important bioactive compounds. They possess valuable health-benefiting and disease preventing properties, and therefore they are an important component of the pharmaceutical, nutraceutical, cosmetical and medicinal industries. Moreover, flavonoids possess significant antiallergic, antihepatotoxic, anti-inflammatory, antioxidant, antitumor, antiviral, and antibacterial as well as cardio-protective activities. Due to these properties, there is a rise in global demand for flavonoids, forming a significant part of the world market. However, obtaining flavonoids directly from plants has some limitations, such as low quantity, poor extraction, over-exploitation, time consuming process and loss of flora. Henceforth, there is a shift towards the in vitro production of flavonoids using the plant tissue culture technique to achieve better yields in less time. In order to achieve the productivity of flavonoids at an industrially competitive level, elicitation is a useful tool. The elicitation of in vitro cultures induces stressful conditions to plants, activates the plant defense system and enhances the accumulation of secondary metabolites in higher quantities. In this regard, nanoparticles (NPs) have emerged as novel and effective elicitors for enhancing the in vitro production of industrially important flavonoids. Different classes of NPs, including metallic NPs (silver and copper), metallic oxide NPs (copper oxide, iron oxide, zinc oxide, silicon dioxide) and carbon nanotubes, are widely reported as nano-elicitors of flavonoids discussed herein. Lastly, the mechanisms of NPs as well as knowledge gaps in the area of the nano-elicitation of flavonoids have been highlighted in this review.

Effect of UV Irradiation (A and C) on Casuarina equisetifolia-Mediated Biosynthesis and Characterization of Antimicrobial and Anticancer Activity of Biocompatible Zinc Oxide Nanoparticles

“…Flavonoids belong to a group of phenolic compounds with industrial significance [38]. They act as chelating agents of metal oxide as they possess a functional hydroxyl group which mediates antioxidant activity [39].…”

Nanotechnology in Plant Metabolite Improvement and in Animal Welfare

“…Callus which is derived from plant organs cultured in vitro can be defined as unorganized or undifferentiated cell mass that can serve as a potential plant biotechnological platform to manufacture significant bioactive compounds of pharmaceutical interests [10]. In addition, callus culture coupled with nano-elicitation has been reported as a promising strategy for enhancing alkaloid [49], flavonoid, and phenolic compounds [50]. For instance, AgNPs have been reported to boost the concentration of different flavonoids including flavonols, hydroxybenzoic and hydroxycinnamic acids in the CSC of bitter gourd [21].…”

Designer nanoparticles for plant cell culture systems: Mechanisms of elicitation and harnessing of specialized metabolites

“…Metal and metal oxide NPs of silver, cobalt, and zinc oxide, copper oxide, titanium oxide, respectively, are the most widely studied group of nanoscale materials and are extensively reviewed elsewhere. [5][6][7][8][9][10] Synthesis and manipulation of the physicochemical characteristics of these are relatively simple, and therefore many studies have focused on this class as compared to the other types of NPs (Box 1). Table S1 provides further insights into the genetic, enzymatic, and reactive oxygen species (ROS) responses of plant cell culture system to these NPs.…”

“…In recent years, scientific literature has increasingly documented the use of "elicitor like" microbes, microbial extracts, phytohormones, and nanoparticles (NPs) for enhancing the yield of specialized metabolites in plant cell culture systems. [5][6][7][8][9][10] Among them, the NPs are emerging as more effective alternatives to conventional biotic elicitors due to their customizable physicochemical properties and the responses they generate. Numerous studies have been performed to evaluate the effect of NPs on plant growth, development, toxicity, primary and secondary (specialized) metabolism, photosynthesis, nutrient uptake, and translocation.…”