Hydroponics and elicitation, a combined approach to enhance the production of designer secondary medicinal metabolites in Silybum marianum

Abstract

Medicinal plants have been used to cure human diseases since decades. Silybum marianum, a medicinal plant, is regarded as a source of secondary metabolites with therapeutic value against liver diseases and diabetes. The present study was conducted to enrich the production of secondary metabolites in the vegetative parts of Silybum marianum using elicitation strategy in hydroponic system with different elicitors. The elicitors of fungus Aspergillus niger (0.2 g/L), methyl jasmonate (MeJA) (100 μM) and silver nanoparticles (AgNPs) (1 ppm) were added in hydroponic medium, individually and in combination form to the 15 days old plant. The elicitor-treated plants were harvested at different time points (24–144 h; increment 24 h) and their biochemical parameters like phenolics, flavonoids, nitric oxide (NO), and superoxide dismutase (SOD) were analyzed. The results showed hyper-accumulation of these biochemical contents, especially in response to MeJA (100 μM), followed by AgNPs (1 ppm) and co-treatment of AgNPs (1 ppm) with other elicitors. The results revealed that the treatment with MeJA (100 μM) exhibited the highest flavonoid (304 μg g–1), phenolic (372 μg g–1), and SOD (16.2 U g–1) contents. For NO levels, the maximum value of 198.6 nmole g–1 was achieved in response to the treatment with MeJA + Green synthesized AgNPs (100 μM + 1 ppm). Our findings depicted an enhanced production of medicinally important plant secondary metabolites and antioxidants; hence, the method applied in this study can play a significant role to improve therapeutic values of the plants.

Enhancing Bioactive Metabolite Production in Aerva sanguinolenta Callus Cultures through Silver Nanoparticle and Salicylic Acid Elicitation

“…This overall situation leads to a better internal homeostasis culminating into a better phytochemical profile. Similar results have been reported by previous researchers [15][16][17][18][19] in terms of better callus proliferation and callus growth parameters upon elicitation in in vitro culture systems.…”

“…This causes a reduction in oxidative stress and can redirect metabolic resources for the production of cell metabolites. Mubeen et al [16] reported similar results for a higher accumulation of flavonoids and phenolics in callus cultures of Silybum marianum by exposing them to silver nanoparticles. Similarly, Bhat and Bhat [15] reported the benefits of elicitation in phenolic accumulation in in vitro cultures of Capsicum sp.…”

“…Aervine is an alkaloid compound that has been shown to have a range of pharmacological properties, including antioxidant, anti-inflammatory, analgesic, and diuretic effects [54,55]. An enhanced production of alkaloids upon elicitation has been previously documented by several researchers [15][16][17][18][19]. Hadizadeh et al [17] reported enhanced alkaloid production upon elicitation in marine algae Arthrospira platensis.…”

“…AgNPs have reportedly enhanced the capsaicin contents in suspension cultures of Capsicum [15]. Additionally, the use of Ag_NPs in hydroponic cultures of Silybum marianum has reportedly enhanced the contents of flavonolignans [16]. Like AgNPs, salicylic acid has been used as an elicitor to increase the production of metabolic compounds in plants, such as Arthrospira platensis [17], Nigella sativa [18], and Catharanthus roseus [19].…”