Physiochemical properties and neuroprotective function of Korean major yuzu varieties

Abstract

Three major yuzu varieties, Native, Namhae, and Tadanishiki in Korea were investigated on physiochemical properties and functional characterizations with respect to neuroprotective function (SH-SY5Y cells) or anti-inflammatory (Raw 264.7 cells). Among the three cultivars tested, Namhae had significantly higher fruit weight and total dietary fibers, while Tadanishiki had higher values of both total flavonoid and antioxidant activity. As functional compounds, Tadanishiki contained a 133% of hesperidin and 164% of naringin, compared to those of Native or Namhae. In comparison to other yuzu, Tadanishiki showed the higher cell viability, lower AChE content, lower protein levels of Bcl-2 /Bax, Caspase 3, and PARP at scopolamine-treated SH-SY5Y nerve cell. Tadanishiki and Namhae were effective for anti-inflammation by decreasing of NO production in LPSinduced Raw 264.7 cells. These results indicate that Tadanishiki yuzu, could be useful for application as a possible natural functional additive with high hesperidin content and excellent neuroprotective and anti-inflammation effects.

Therapeutic effects of phlorotannins in the treatment of neurodegenerative disorders

“…Numerous studies on phlorotannins have demonstrated their effects on cognitive processes such as learning and memory ( Table 1 ), which are accompanied by changes in neurotransmitter levels such as acetylcholine (ACh), glutamate, γ-aminobutyric acid (GABA), 5-hydroxytryptamine (5-HT), and norepinephrine (NE; Myung et al, 2005 ). In one study, mice exposed to fear-stressed learning were subjected to the Morris water maze test ( Lee and Stein, 2004 ). Mice that consumed brown kelp extract daily for 4 weeks performed significantly better than control mice during the learning and retention phases, suggesting that phlorotannins enhance cognitive resistance to stress.…”

“…Purified PFF-A, eckol, and dieckol were shown to inhibit AChE ( Myung et al, 2005 ; Yoon et al, 2008 ; Kannan et al, 2013 ; Choi et al, 2015 ) and BuChE activity ( Choi et al, 2015 ; Nho et al, 2020 ) in colorimetric enzyme assays. Phlorotannin-rich fractions of brown kelp extract were also shown to inhibit AChE and BuChE activity ( Lee and Stein, 2004 ; Choi et al, 2015 ). It has not yet been determined whether phlorotannins affect ACh levels in vivo using animal models of AD.…”

“…Aβ-induced spikes in intracellular ROS and Ca 2+ levels, as well as microglial activation, recruitment, and pro-inflammatory signaling, are suppressed. Adapted from Lee and Stein (2004) and Choi et al (2015) . (B) In PD, phlorotannins may inhibit MAOs to counteract the loss of dopamine.…”

“…Phlorotannins have also been shown to regulate the biosynthesis ( Jung et al, 2010 ; Kang et al, 2013 ; Choi et al, 2015 ) and oligomerization ( Kang et al, 2011 ; Seong et al, 2019 ) of Aβ, as well as the neuroinflammatory ( Lee et al, 2018 ; Yang et al, 2021 ) and neurotoxic ( Kang et al, 2011 ; Ahn et al, 2012 ; Yang et al, 2015 ) pathways related to Aβ ( Figure 3 ). In animal experiments, phlorotannins exerted neuroprotective effects against the development and progression of AD ( Yang et al, 2015 , 2018 ), PD ( Ryu et al, 2013 ; Figure 4 ), and other CNS disorders ( Cho et al, 2012 ; Kim et al, 2012 ), and yielded measurable improvements in behavioral aspects such as learning ( Lee and Stein, 2004 ), memory ( Myung et al, 2005 ), movement ( Li et al, 2021 ), sleep ( Cho et al, 2012 , 2014 ; Yoon et al, 2014 ; Yoon et al, 2020 ), and symptomatic pain ( Li et al, 2021 ; Table 1 ). The anti-inflammatory ( Table 2 ) and antioxidative effects ( Table 3 ) of phlorotannins may provide generally neuroprotective effects in the brain.…”

Modulating flavanone compound for reducing the bitterness and improving dietary fiber, physicochemical properties, and anti-adipogenesis of green yuzu powder by enzymatic hydrolysis

“…It is distinguished from other citrus fruits by having a potent, distinctive aroma and is well-recognized for the delightful fragrance of its outer peel. Yuzu contains high levels of bioactive compounds, such as flavonoids, phenolic compounds, organic acids, and minerals that contribute to its biological activities, including antioxidant, antidiabetic, anti-inflammatory, neuroprotective, anticarcinogenic, and antihypertensive activities ( Kim et al, 2013 ; Lee et al, 2022 , Nam et al, 2021 ). Moreover, yuzu peel is rich in dietary fiber, primarily composed of cellulose, polysaccharides, lignin, and proteins that give their superior physicochemical properties, enhance their biodegradable properties, and contribute to human health benefits as dietetic ingredients ( Lv, Liu, Zhang, & Wang, 2017 ; Karra et al, 2020 , Nam et al, 2021 ).…”