Antioxidant and Anti-Inflammatory Effects of White Mulberry (Morus alba L.) Fruits on Lipopolysaccharide-Stimulated RAW 264.7 Macrophages

Abstract

In this study, the protective effects of white mulberry (Morus alba) fruits on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages were investigated. The ethanol (EtOH) extract of white mulberry fruits and its derived fractions contained adequate total phenolic and flavonoid contents, with good in vitro antioxidant radical scavenging activity. The extract and fractions also markedly inhibited ROS generation and antioxidant activity. After treatment with the EtOH extract and its fractions, LPS stimulation-induced elevated nitric oxide (NO) production was restored, which was primarily mediated by downregulation of inducible NO synthase expression. A total of 20 chemical constituents including flavonoids, steroids, and phenolics were identified in the fractions using ultra-high-performance liquid chromatography (UHPLC)-quadrupole time-of-flight (QTOF) high-resolution mass spectrometry (HRMS). These findings provide experimental evidence of the protective effects of white mulberry fruit extract against oxidative stress and inflammatory responses, suggesting their nutraceutical and pharmaceutical potential as natural antioxidant and anti-inflammatory agents.

Bioactive Phytochemicals from Mulberry: Potential Anti-Inflammatory Effects in Lipopolysaccharide-Stimulated RAW 264.7 Macrophages

“…Many studies have been performed with respect to the anti-inflammatory activity of extract of the mulberry fruit ( Morus alba L.) [ 7 , 34 , 35 , 36 , 37 ]. In contrast, studies on which compounds in mulberry fruit have anti-inflammatory activity are still lacking.…”

“…In our previous study, the anti-inflammatory activity of the ethanol extract of the mulberry fruit was reported [ 7 ]. As an extension of previous research, our present study performed phytochemical analysis to isolate 22 chemical constituents from the ethanol extract and their non-toxic concentrations were investigated in RAW 264.7 macrophages.…”

“…In Korea and China, where this plant is harvested, the leaves of M. alba have been traditionally used as a fodder for silkworms, as well as a medicinal herb to treat diabetes and improve eyesight [ 4 ]. The pharmacological activities of M. alba have also been actively studied, with reports that the white mulberry has a number of beneficial effects such as antioxidant [ 5 , 6 , 7 ], anti-microbial [ 8 ], anti-obesity [ 9 , 10 ], and anti-inflammatory activities [ 7 ].…”

“…As part of a continuing research project to discover bioactive natural products, our group has investigated biologically active and structurally interesting compounds from the ethanol extract of fruits of M. alba [ 7 , 11 , 12 , 13 , 14 ]. In our previous study, we observed that butyl pyroglutamate identified from the fruits of M. alba exhibits protective effects against apoptosis, characteristic of cisplatin-induced kidney cell damage [ 11 ].…”

“…In addition, loliolide in M. alba was demonstrated by our group to protect INS-1 human pancreatic β-cells against apoptosis triggered by streptozotocin [ 14 ]. In particular, our recent research on ethanol extract from mulberry fruits reported its inhibitory effect on LPS-stimulated NO production and iNOS expression in a mouse macrophage cell line (RAW 264.7), suggesting its potential for anti-inflammatory effect [ 7 ]. In the present study, the ethanol extract of M. alba fruits was further investigated to identify potential anti-inflammatory compounds.…”