Effect of Wide-Spectrum Monochromatic Lights on Growth, Phytochemistry, Nutraceuticals, and Antioxidant Potential of In Vitro Callus Cultures of Moringa oleifera.

Moringa oleifera, also called miracle tree, is a pharmaceutically important plant with a multitude of nutritional, medicinal, and therapeutic attributes. In the current study, an in-vitro-based elicitation approach was used to enhance the commercially viable bioactive compounds in an in vitro callus culture of M. oleifera. The callus culture was established and exposed to different monochromatic lights to assess the potentially interactive effects on biomass productions, biosynthesis of pharmaceutically valuable secondary metabolites, and antioxidant activity. Optimum biomass production (16.7 g/L dry weight), total phenolic contents (TPC: 18.03 mg/g), and flavonoid contents (TFC: 15.02 mg/g) were recorded in callus cultures placed under continuous white light (24 h), and of other light treatments. The highest antioxidant activity, i.e., ABTS (550.69 TEAC µM) and FRAP (365.37 TEAC µM), were also noted under white light (24 h). The analysis of phytochemicals confirmed the significant impact of white light exposures on the enhanced biosynthesis of plant secondary metabolites. The enhanced levels of secondary metabolites, i.e., kaempferol (1016.04 µg/g DW), neochlorogenic acid (998.38 µg/g DW), quercetin (959.92 µg/g DW), and minor compounds including luteolin, apigenin, and p-coumaric acid were observed as being highest in continuous white light (24 h with respect to the control (photoperiod). Similarly, blue light enhanced the chlorogenic acid accumulation. This study shows that differential spectral lights demonstrate a good approach for the enhancement of nutraceuticals along with novel pharmacologically important metabolites and antioxidants in the in vitro callus culture of M. oleifera.

Differential induction of antioxidant and anti-inflammatory phytochemicals in agitated micro-shoot cultures of Ajuga integrifolia Buch. Ham. ex D.Don with biotic elicitors.

Ajuga integrifolia Buch. Ham. ex D.Don, a member of Lamiaceae family is pharmaceutically an active perennial herb widely spread in China, Afghanistan and Pakistan Himalayan region. The application of biotic elicitors is a promising approach to cover limitations of in vitro cell technology and challenges faced by pharmaceuticals industry for bulk up production. The current study involved the induction of agitated micro-shoot cultures with the aim to investigate the growth-promoting as well as phytochemicals enhancement role of yeast extract (YE) and pectin (PE). The results showed that both elicitors induced a considerable physiological response. Biomass accumulation was observed maximum (DW: 18.3 g/L) against PE (10 mg/L) compared to YE and control. Eleven secondary phytocompounds were quantified using high-performance liquid chromatography. PE (50 mg/L) was found to be effective in elicitation of rosmarinic acid (680.20 µg/g), chlorogenic acid (294.12 µg/g), apigenin (579.61 µg/g) and quercetin (596.89 µg/g). However, maximum caffeic acid (359.52 µg/g) and luteolin (546.12 µg/g accumulation was noted in PE (1 mg/L) treatment. Harpagide, aucubin, harpagoside and 8-O-acetyl-harpagoside production was suppressed by both elicitors except for YE (100 mg/L). Catalpol accumulation in micro-shoot cultures was also downregulated except in response to YE (50 and 100 mg/L). Antioxidant activity and anti-inflammatory activity remained higher under PE (50 mg/L) and YE (100 mg/L) respectively. Therefore, results suggested that Ajuga integrifolia micro-shoot cultures treated with yeast extract and pectin might be an efficient bio-factory to produce commercially potent specific secondary metabolites.