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Pachyrhizus erosus is a plant that is traditionally used in Asia as a food and herbal medicine. This study examined the impact of light-emitting diodes (LEDs), light-emitting plasma (LEP), and fluorescent lamps (FLs) on the growth, antioxidant properties, and phenolic metabolites of P. erosus. Phenolic compound concentration and composition were determined by high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) system. Radical scavenging activity was measured using stable radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. P. erosus antioxidant activity and phenolic compound composition were improved by the application of LEDs and LEP. Blue LED light also produced significantly higher DPPH radical scavenging activity and ABTS values than the other LED and fluorescent light treatments. In P. erosus seedlings, dry weight, fresh weight, plant height, leaf area, and chlorophyll content were greater under blue LED than under FL light. Furthermore, growth under the blue LED enhanced the epidermal cell length, epidermal cell width, and number of stomata. Antioxidant activity and total phenolic and total flavonoid contents positively correlated in the P. erosus grown under blue LED light condition. Among LED treatments, blue LED produced higher total phenolic compounds, dominated by malonyl daidzin and l-phenylalanine. DPPH assay was highly and significantly correlated with vitexin, salicylic acid, p-coumaric acid, p-hydroxybenzoic acid, l-phenylalanine, daidzein, and daidzin. The present study demonstrated that changes in the growth pattern, antioxidant activity, composition, and metabolite concentration occurred in response to light of different wavelengths in P. erosus seedlings. Thus, LED exposure has the potential to enhance the growth characteristics, metabolite accumulation, and antioxidant properties of P. erosus. [ABSTRACT FROM AUTHOR]

Rhodomyrtus tomentosa (Aiton) Hassk. is a flowering plant belonging to the family Myrtaceae, native to southern and southeastern Asia. It has been used in traditional Vietnamese, Chinese, and Malaysian medicine for a long time for the treatment of diarrhea, dysentery, gynecopathy, stomachache, and wound healing. Moreover, R. tomentosa is used to make various food products such as wine, tea, and jam. Notably, R. tomentosa has been known to contain structurally diverse and biologically active metabolites, thus serving as a potential resource for exploring novel functional agents. Up to now, numerous phenolic and terpenoid compounds from the leaves, root, or fruits of R. tomentosa have been identified, and their biological activities such as antioxidant, antibacterial, anti-inflammatory, and anticancer have been evidenced. In this contribution, an overview of R. tomentosa and its health beneficial properties was focused on and emphasized. [ABSTRACT FROM AUTHOR]