Elicitation of Medicinally Important Antioxidant Secondary Metabolites with Silver and Gold Nanoparticles in Callus Cultures of Prunella vulgaris L.

Abstract

Prunella vulgaris L. (P. vulgaris) is an important medicinal plant with a wide range of antiviral properties. Traditionally, it is known as self-heal because of its faster effects on wound healing. It is commonly known as a natural antiseptic due to the presence of various polyphenols. There is lack of research efforts on its propagation and production of bioactive compounds under field and in vitro conditions. In this study, the effects of different ratios (1:2, 1:3, 2:1, and 3:1) of silver (Ag) and gold (Au) nanoparticles (NPs) alone or in combination with naphthalene acetic acid (NAA) were investigated for callus culture development and production of secondary metabolites. The Ag (30 μg l), AgAu (1:2), and AgAu (2:1) NPs in combination with NAA (2.0 mg l) enhanced callus proliferation (100 %) as compared to the control (95 %). Among the different NPs tested, AuNPs with or without NAA produced higher biomass in log phases (35-42 days) of growth kinetics. Furthermore, AgAu (1:3) and AuNPs alone enhanced total protein content (855 μg-BSAE/mg-fresh weight (FW)), superoxide dismutase (0.54 nM/min/mg-FW), and peroxidase (0.39 nM/min/mg-FW) enzymes in callus cultures. The AgAuNPs (1:3) in combination with NAA induced maximum accumulation of phenolics (TPC 9.57 mg/g-dry weight (DW)) and flavonoid (6.71 mg/g-DW) content. Moreover, AgAuNPs (3:1) without NAA enhanced antioxidant activity (87.85 %). This study provides the first evidence of NP effect on callus culture development and production of natural antioxidants in P. vulgaris.

Comparative Proteomic Analysis of the Graft Unions in Hickory (Carya cathayensis) Provides Insights into Response Mechanisms to Grafting Process

“…Further investigation verified that a significant increase occurred in the total flavonoid content in the scions ( Figure 6A ), which suggested that graft union formation increases the content of a series of downstream antioxidant secondary metabolites by activating flavonoid biosynthesis. A number of studies have reported that a close relationship exists between the production of antioxidant secondary metabolites and callus formation (Fazal et al, 2016a,b). The accumulation of flavonoids may positively affect the grafting process by enhancing callus formation.…”

Salicylic acid‐enhanced biosynthesis of pharmacologically important lignans and neo lignans in cell suspension culture of Linum ussitatsimum L

“…Cell extraction was made with slight modifications in the protocol of . About 200 mg of dry sample was mixed with 0.5 mL HPLC grade methanol, each dilution was placed on a shaker, left overnight for 24 h at room temperature.…”

“…However, several strategies have been developed to enhance biosynthesis of these BAIs in plant cell cultures to make the production process cost efficient. Elicitation of BAIs with several biotic and abiotic compounds/products is a famous strategy to date .…”

Nanomaterials in plant tissue culture: the disclosed and undisclosed

“…However, the actual mechanism via which Au NPs enhance embryogenesis is still unclear and needs further investigation. Fazal et al 73 studied the effects of Au and Ag NPs individually or in combination on callus proliferation in Prunella vulgaris. The Ag (30 mg L À1 ), Ag-Au (1 : 2), and Ag-Au (2 : 1) NPs in combination with NAA (2.0 mg L À1 ) enhanced callus proliferation (100%) compared to the control (95%).…”