Anti-Inflammatory Activity of Mulberry Leaf Flavonoids In Vitro and In Vivo

Abstract

Mulberry (Morus alba L.) is a flowering tree traditionally used in Chinese herbal medicine. Mulberry leaf flavonoids (MLFs) have been reported to exert important anti-inflammatory and antioxidant properties. The purpose of this study was to select the MLF with the best anti-inflammatory and antioxidative activities from MLFs eluted by different ethanol concentrations (30%, 50%, and 75%) and explore its pharmacological properties. Three types of MLFs inhibited the production of nitric oxide (NO), prostaglandin E2 (PGE2), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and inflammatory cytokines in lipopolysaccharide (LPS)-induced RAW 264.7 cells. All MLFs boosted the antioxidative capacity by decreasing the reactive oxygen species (ROS) production and the scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals and improving the metal ion chelating activity and reducing power. The results revealed that the MLFs eluted by 30% ethanol exhibited the best anti-inflammatory and antioxidative activities. A nontargeted metabolomic analysis was used to analyze 24 types of differential flavonoids between the MLFs. Quercetin, kaempferol, and their derivatives in 30%MLF were more abundant than the other two MLFs. Furthermore, we evaluated the pharmacological activities of 30%MLF in dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) mice. The 30%MLF could alleviate the clinical symptoms, reduce the secretion of inflammatory cytokines, and inhibit the activation of the inflammatory pathway in DSS-induced colitis mice. This study will provide valuable information for the development of MLFs eluted by 30% ethanol as a functional food.

Flavonoids as Antidiabetic and Anti-Inflammatory Agents: A Review on Structural Activity Relationship-Based Studies and Meta-Analysis

“…Furthermore, 30% ethanol extract of mulberry leaf was also evaluated for the pharmacological activities in dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) mice. The same extract alleviated the clinical symptoms, reduced the secretion of inflammatory cytokines, and inhibited the activation of the inflammatory pathway in DSS-induced colitis mice [ 44 ].…”

Protective Effects of Atractylodis lancea Rhizoma on Lipopolysaccharide-Induced Acute Lung Injury via TLR4/NF-κB and Keap1/Nrf2 Signaling Pathways In Vitro and In Vivo

“…Primers were synthesized by the Tsingke Biotechnology Co., Ltd. RT-qPCR was performed using a ChamQ SYBR qPCR Master Mix (Vazyme Biotech Co., Ltd., Nanjing, China) in a Roche Light Cycler 96 system (Roche, Basel, Switzerland). The PCR reaction was conducted as follows: 95 • C for 30 s, then 40 cycles at 95 • C for 10 s, and 60 • C for 30 s. Melt curve analysis was conducted after exposure of the samples to 95 • C for 15 s, 60 • C for 60 s, and 95 • C for 15 s. All gene expression values were normalized to β-actin expression and calculated using the 2 −∆∆CT method [59]. The specific primer sequences for all genes quantified are listed in Table 1.…”

Identification of mulberry leaf flavonoids and evaluating their protective effects on H2O2-induced oxidative damage in equine skeletal muscle satellite cells

“…Mulberry leaves ( Morus alba L.), a high-quality animal feed resource, possess pharmacological effects, including antioxidant, blood glucose reduction, cholesterol regulation (impacting lipid metabolism), immune modulation, and anti-inflammatory properties ( Ma et al, 2022 ). Various in vitro and in vivo experiments have linked the excellent antioxidant properties of mulberry leaves to their flavonoid compounds, particularly rutin ( Katsube et al, 2006 ; Shilpi Singh et al, 2019 ), quercetin ( Wang et al, 2013 ; Lin et al, 2022b ), and astragalin ( Choi et al, 2013 ; Yang et al, 2014 ). These flavonoid compounds are proven effective antioxidants and xanthine oxidase inhibitors ( Wan et al, 2018a ).…”

“…However, the composition of mulberry leaf flavonoids (MLFs) is influenced by various extraction processes. For instance, Lin et al ( Lin et al, 2022a ) extracted MLFs using ethanol reflux and AB-8 macroporous resin, yielding predominantly quercetin, kaempferol, and their derivatives. Conversely, Zheng et al ( Zheng et al, 2022 ) used ultrasound-assisted and D101 macroporous resin to extract MLFs, yielding mainly hesperidins, rutin, hyperoside, isoquercetin, cyanidin, and their derivatives.…”