Gintonin Attenuates D-Galactose-Induced Hippocampal Senescence by Improving Long-Term Hippocampal Potentiation, Neurogenesis, and Cognitive Functions

Nam, Sung Min,Hwang, Hongik,Seo, Misun,Chang, Byung-Joon,Kim, Hyeon-Joong,Choi, Sun-Hye,Rhim, Hyewhon,Kim, Hyoung-Chun,Cho, Ik-Hyun,Nah, Seung-Yeol S. Karger AG 2018 Gerontology Vol.64 No.6

<P><B><I>Background:</I></B> Ginseng has been used to improve brain function and increase longevity. However, little is known about the ingredients of ginseng and molecular mechanisms of its anti-brain aging effects. Gintonin is a novel exogenous ginseng-derived lysophosphatidic acid (LPA) receptor ligand; LPA and LPA1 receptors are involved in adult hippocampal neurogenesis. D-galactose (D-gal) is used to induce brain ­aging in animal models because long-term treatment with D-gal facilitates hippocampal aging in experimental adult animals by decreasing hippocampal neurogenesis and inducing learning and memory dysfunction. <B><I>Objective:</I></B> To investigate the protective effects of gintonin on D-gal-induced hippocampal senescence, impairment of long-term potentiation (LTP), and memory dysfunction. <B><I>Methods:</I></B> Brain hippocampal aging was induced by D-gal administration (150 mg/kg/day, s.c.; 10 weeks). From the 7th week, gintonin (50 or 100 mg/kg/day, per os) was co-administered with D-gal for 4 weeks. We performed histological analyses, LTP measurements, and object location test. <B><I>Results:</I></B> Co-administration of gintonin ameliorated D-gal-induced reductions in hippocampal Ki67-immunoreactive proliferating cells, doublecortin-immunoreactive neuroblasts, 5-bromo-2’-deoxyuridine-incorporating NeuN-immunoreactive mature neurons, and LPA1 receptor expression. Co-administration of gintonin in D-gal-treated mice increased the expression of phosphorylated cyclic adenosine monophosphate response element binding protein in the hippocampal dentate gyrus. In addition, co-administration of gintonin in D-gal-treated mice enhanced LTP and restored the cognitive functions compared with those in mice treated with D-gal only. <B><I>Conclusion:</I></B> These results show that gintonin administration restores D-gal-induced memory deficits by enhancing hippocampal LPA1 receptor expression, LTP, and neurogenesis. Finally, the present study shows that gintonin exerts anti-brain aging effects that are responsible for alleviating brain aging-related dysfunction.</P>

Gintonin stimulates autophagic flux in primary cortical astrocytes

Rahman, Md. Ataur,Hwang, Hongik,Nah, Seung-Yeol,Rhim, Hyewhon The Korean Society of Ginseng 2020 Journal of Ginseng Research Vol.44 No.1

Background: Gintonin (GT), a novel ginseng-derived exogenous ligand of lysophosphatidic acid (LPA) receptors, has been shown to induce cell proliferation and migration in the hippocampus, regulate calcium-dependent ion channels in the astrocytes, and reduce β-amyloid plaque in the brain. However, whether GT influences autophagy in cortical astrocytes is not yet investigated. Methods: We examined the effect of GT on autophagy in primary cortical astrocytes using immunoblot and immunocytochemistry assays. Suppression of specific proteins was performed via siRNA. LC3 puncta was determined using confocal microscopy. Results: GT strongly upregulated autophagy marker LC3 by a concentration- as well as time-dependent manner via G protein-coupled LPA receptors. GT-induced autophagy was further confirmed by the formation of LC3 puncta. Interestingly, on pretreatment with an mammalian target of rapamycin (mTOR) inhibitor, rapamycin, GT further enhanced LC3-II and LC3 puncta expression. However, GT-induced autophagy was significantly attenuated by inhibition of autophagy by 3-methyladenine and knockdown Beclin-1, Atg5, and Atg7 gene expression. Importantly, when pretreated with a lysosomotropic agent, E-64d/peps A or bafilomycin A1, GT significantly increased the levels of LC3-II along with the formation of LC3 puncta. In addition, GT treatment enhanced autophagic flux, which led to an increase in lysosome-associated membrane protein 1 and degradation of ubiquitinated p62/SQSTM1. Conclusion: GT induces autophagy via mTOR-mediated pathway and elevates autophagic flux. This study demonstrates that GT can be used as an autophagy-inducing agent in cortical astrocytes.

Effects of a gintonin-enriched fraction on hair growth: an in vitro and in vivo study

이나은,Sang-Deuk Park,Hongik Hwang,최선혜,이라미,Sung Min Nam,Jong Hee Choi,Hyewhon Rhim,조익현,Hyoung-Chun Kim,황성희,나승열 고려인삼학회 2020 Journal of Ginseng Research Vol.44 No.1

Background: Ginseng has been widely used as a health-promoting tonic. Gintonin present in ginseng actsas a lysophosphatidic acid (LPA) receptor ligand that activates six LPA receptor subtypes. The LPA6subtype plays a key role in normal hair growth, and mutations in the LPA6 receptor impair normalhuman hair growth. Currently, human hair loss and alopecia are concerning issues that affect peoples’social and day-to-day lives. Objective: We investigated the in vitro and in vivo effects of a gintonin-enriched fraction (GEF) on mousehair growth. Methods: Human hair follicle dermal papilla cells (HFDPCs) and six-week-old male C57BL/6 mice wereused. The mice were divided into the four groups: control, 1% minoxidil, 0.75% GEF, and 1.5% GEF. Thedorsal hair was removed to synchronize the telogen phase. Each group was treated topically, once a day,for 15 days. We analyzed hair growth activity and histological changes. Results: GEF induced transient [Ca2þ]i, which stimulated HFDPC proliferation and caused 5-bromo-20-deoxyuridine (BrdU) incorporation in a concentration-dependent manner. GEF-mediated HFDPC proliferationwas blocked by the LPA receptor antagonist and Ca2þ chelator. HFDPC treatment with GEFstimulated vascular endothelial growth factor release. Topical application of GEF and minoxidil promotedhair growth in a dose-dependent manner. Histological analysis showed that GEF and minoxidil increasedthe number of hair follicles and hair weight. Conclusion: Topical application of GEF promotes mouse hair growth through HFDPC proliferation. GEFcould be one of the main components of ginseng that promote hair growth and could be used to treathuman alopecia.

Ginsenoside Rk1 is a novel inhibitor of NMDA receptors in cultured rat hippocampal neurons 490

Nayeon Ryoo,Md. Ataur Rahman,Hongik Hwang,Sung Kwon Ko,Seung-Yeol Nah,Hyoung-Chun Kim,Hyewhon Rhim 고려인삼학회 2020 Journal of Ginseng Research Vol.44 No.3

Background: Ginsenoside Rk1, a saponin component isolated from heat-processed Panax ginseng Meyer,has been implicated in the regulation of antitumor and anti-inflammatory activities. Although ourprevious studies have demonstrated that ginsenoside Rg3 significantly attenuated the activation ofNMDA receptors (NMDARs) in hippocampal neurons, the effects of ginsenosides Rg5 and Rk1, which arederived from heat-mediated dehydration of ginsenoside Rg3, on neuronal NMDARs have not yet beenelucidated. Methods: We examined the regulation of NMDARs by ginsenosides Rg5 and Rk1 in cultured rat hippocampalneurons using fura-2ebased calcium imaging and whole-cell patch-clamp recordings. Results: The results from our investigation showed that ginsenosides Rg3 and Rg5 inhibited NMDARswith similar potencies. However, ginsenoside Rk1 inhibited NMDARs most effectively among the fivecompounds (Rg3, Rg5, Rk1, Rg5/Rk1 mixture, and protopanaxadiol) tested in cultured hippocampalneurons. Its inhibition is independent of the NMDA- and glycine-binding sites, and its action seems toinvolve in an interaction with the polyamine-binding site of the NMDAR channel complex. Conclusion: Taken together, our results suggest that ginsenoside Rk1 might be a novel componentcontributable to the development of ginseng-based therapeutic treatments for neurodegenerativediseases.

Effects of a gintonin-enriched fraction on hair growth: an in vitro and in vivo study

Lee, Na-Eun,Park, Sang-Deuk,Hwang, Hongik,Choi, Sun-Hye,Lee, Ra Mi,Nam, Sung Min,Choi, Jong Hee,Rhim, Hyewhon,Cho, Ik-Hyun,Kim, Hyoung-Chun,Hwang, Sung-Hee,Nah, Seung-Yeol The Korean Society of Ginseng 2020 Journal of Ginseng Research Vol.44 No.1

Background: Ginseng has been widely used as a health-promoting tonic. Gintonin present in ginseng acts as a lysophosphatidic acid (LPA) receptor ligand that activates six LPA receptor subtypes. The LPA6 subtype plays a key role in normal hair growth, and mutations in the LPA6 receptor impair normal human hair growth. Currently, human hair loss and alopecia are concerning issues that affect peoples' social and day-to-day lives. Objective: We investigated the in vitro and in vivo effects of a gintonin-enriched fraction (GEF) on mouse hair growth. Methods: Human hair follicle dermal papilla cells (HFDPCs) and six-week-old male C57BL/6 mice were used. The mice were divided into the four groups: control, 1% minoxidil, 0.75% GEF, and 1.5% GEF. The dorsal hair was removed to synchronize the telogen phase. Each group was treated topically, once a day, for 15 days. We analyzed hair growth activity and histological changes. Results: GEF induced transient [Ca<SUP>2+</SUP>]<SUB>i</SUB>, which stimulated HFDPC proliferation and caused 5-bromo-2'-deoxyuridine (BrdU) incorporation in a concentration-dependent manner. GEF-mediated HFDPC proliferation was blocked by the LPA receptor antagonist and Ca<SUP>2+</SUP> chelator. HFDPC treatment with GEF stimulated vascular endothelial growth factor release. Topical application of GEF and minoxidil promoted hair growth in a dose-dependent manner. Histological analysis showed that GEF and minoxidil increased the number of hair follicles and hair weight. Conclusion: Topical application of GEF promotes mouse hair growth through HFDPC proliferation. GEF could be one of the main components of ginseng that promote hair growth and could be used to treat human alopecia.

Ginsenoside Rk1 is a novel inhibitor of NMDA receptors in cultured rat hippocampal neurons

Ryoo, Nayeon,Rahman, Md. Ataur,Hwang, Hongik,Ko, Sung Kwon,Nah, Seung-Yeol,Kim, Hyoung-Chun,Rhim, Hyewhon The Korean Society of Ginseng 2020 Journal of Ginseng Research Vol.44 No.3

Background: Ginsenoside Rk1, a saponin component isolated from heat-processed Panax ginseng Meyer, has been implicated in the regulation of antitumor and anti-inflammatory activities. Although our previous studies have demonstrated that ginsenoside Rg3 significantly attenuated the activation of NMDA receptors (NMDARs) in hippocampal neurons, the effects of ginsenosides Rg5 and Rk1, which are derived from heat-mediated dehydration of ginsenoside Rg3, on neuronal NMDARs have not yet been elucidated. Methods: We examined the regulation of NMDARs by ginsenosides Rg5 and Rk1 in cultured rat hippocampal neurons using fura-2-based calcium imaging and whole-cell patch-clamp recordings. Results: The results from our investigation showed that ginsenosides Rg3 and Rg5 inhibited NMDARs with similar potencies. However, ginsenoside Rk1 inhibited NMDARs most effectively among the five compounds (Rg3, Rg5, Rk1, Rg5/Rk1 mixture, and protopanaxadiol) tested in cultured hippocampal neurons. Its inhibition is independent of the NMDA- and glycine-binding sites, and its action seems to involve in an interaction with the polyamine-binding site of the NMDAR channel complex. Conclusion: Taken together, our results suggest that ginsenoside Rk1 might be a novel component contributable to the development of ginseng-based therapeutic treatments for neurodegenerative diseases.

Visualization of the binding between gintonin, a Panax ginsengderived LPA receptor ligand, and the LPA receptor subtypes and transactivation of the EGF receptor

Sun-Hye Choi,이라미,Han-Sung Cho,Sung-Hee Hwang,Hongik Hwang,Hyewhon Rhim,Hyoung-Chun Kim,김도근,Ik-Hyun Cho,나승열 고려인삼학회 2022 Journal of Ginseng Research Vol.46 No.3

Gintonin is a ginseng-derived exogenous G-protein-coupled lysophosphatidic acid (LPA)receptor ligand. Gintonin exerts its neuronal and non-neuronal in vitro and in vivo effects through LPAreceptor subtypes. However, it is unknown whether gintonin can bind to the plasma membrane of cellsand can transactivate the epidermal growth factor (EGF) receptor. In the present study, we examinedwhether gintonin-biotin conjugates directly bound to LPA receptors and transactivated the EGF receptor. Methods: We designed gintonin-biotin conjugates through gintonin biotinylation and examined whethergintonin-biotin conjugate binding sites co-localized with the LPA receptor subtype binding sites. Wefurther examined whether gintonin-biotin transactivated the EGF receptor via LPA receptor regulationvia phosphor-EGF and cell migration assays. Results: Gintonin-biotin conjugates elicit [Ca2þ]i transient similar to that observed with unbiotinylatedgintonin in cultured PC3 cells, suggesting that biotinylation does not affect physiological activity ofgintonin. We proved that gintonin-biotin conjugate binding sites co-localized with the LPA1/6 receptorbinding sites. Gintonin-biotin binding to the LPA1 receptor transactivates the epidermal growth factor(EGF) receptor through phosphorylation, while the LPA1/3 receptor antagonist, Ki16425, blocked phosphorylation of the EGF receptor. Additionally, an EGF receptor inhibitor AG1478 blocked gintonin-biotinconjugate-mediated cell migration. Conclusions: We observed the binding between ginseng-derived gintonin and the plasma membranetarget proteins corresponding to the LPA1/6 receptor subtypes. Moreover, gintonin transactivated EGFreceptors via LPA receptor regulation. Our results suggest that gintonin directly binds to the LPA receptorsubtypes and transactivates the EGF receptor. It may explain the molecular basis of ginseng physiology/pharmacology in biological systems.

Gintonin Mitigates MPTP-Induced Loss of Nigrostriatal Dopaminergic Neurons and Accumulation of α-Synuclein via the Nrf2/HO-1 Pathway

Jo, Min Gi,Ikram, Muhammad,Jo, Myeung Hoon,Yoo, Lang,Chung, Kwang Chul,Nah, Seung-Yeol,Hwang, Hongik,Rhim, Hyewhon,Kim, Myeong Ok Springer-Verlag 2019 Molecular neurobiology Vol.56 No.1

Gintonin, a Ginseng-Derived Exogenous Lysophosphatidic Acid Receptor Ligand, Protects Astrocytes from Hypoxic and Re-oxygenation Stresses Through Stimulation of Astrocytic Glycogenolysis

Choi, Sun-Hye,Kim, Hyeon-Joong,Cho, Hee-Jung,Park, Sang-Deuk,Lee, Na-Eun,Hwang, Sung-Hee,Cho, Ik-Hyun,Hwang, Hongik,Rhim, Hyewhon,Kim, Hyoung-Chun,Nah, Seung-Yeol Springer-Verlag 2019 Molecular Neurobiology Vol.56 No.5