Ntu 1: Echinacoside Inhibits Glutamate Release Los Ntawm Kev Tiv Thaiv Voltage-Dependent Ca2 ntxiv rau Kev Nkag Mus Thiab Protein Kinase C hauv Rat Cerebrocortical Nerve Terminals

Hu rau: Audrey Hu Whatsapp / hp: 0086 13880143964 Email:audrey.hu@wecistanche.com

Cheng Wei Lu 1,2, Tzu Yu Lin 1,2, Shu Kuei Huang 1 thiab Su Jane Wang 3,*

Abstract:

Lub glutamatergic system tuaj yeem koom nrog cov teebmeem ntawm kev kho mob neuroprotectant.Echinacoside, phenylethanoid glycoside muab rho tawm los ntawm cov tshuaj suav tshuaj ntsuabHerba Cistanche, muaj cov teebmeem neuroprotective. Txoj kev tshawb no tshawb xyuas qhov cuam tshuam ntawmechinacoside cov tshuajntawm 4-aminopyridine-evoked glutamate tso tawm hauv nas cerebrocortical paj hlwb terminals (synaptosomes). Echinacoside inhibited Ca2 plus -dependent, tab sis tsis yog Ca2 ntxiv - ywj siab, 4-aminopyridine-evoked glutamate tso tawm nyob rau hauv ib tug concentration-dependent yam. Echinacoside kuj txo qhov 4-aminopyridine-evoked nce nyob rau hauv cytoplasmic dawb Ca2 ntxiv rau concentration tab sis tsis hloov lub synaptosomal membrane muaj peev xwm. Cov nyhuv inhibitory ntawm echinacoside ntawm 4-aminopyridine-evoked glutamate tso tawm tau tiv thaiv los ntawm o-conotoxin MVIIC, qhov dav-spectrum blocker ntawm Cav2.2 (N-type) thiab Cav2.1 (P / Q-type) channels , tab sis yog insensitive rau intracellular Ca2 ntxiv tso tawm-inhibitors dantrolene thiab 7-chloro-5-(2-chlorophenyl)-1, 5-dihydro-4 , 1-benzodiazepine-2(3H)-ib (CGP37157). Tsis tas li ntawd, echinacoside txo qis 4-aminopyridine-induced phosphorylation ntawm protein kinase C, thiab protein kinase C inhibitors tshem tawm cov nyhuv ntawm echinacoside ntawm glutamate tso tawm. Raws li cov txiaj ntsig no, peb pom zoo tias cov nyhuv inhibitory ntawm echinacoside ntawm evoked glutamate tso tawm yog cuam tshuam nrog txo qis voltage-dependent Ca2 ntxiv rau kev nkag thiab tom qab kev tawm tsam ntawm cov protein kinase C.

Ntsiab lus:echinacoside; glutamate tso tawm; cerebrocortical paj hlwb terminals; voltage-dependent Ca2 ntxiv raws; protein kinase C

1. Taw qhia

Echinacosideyog ib qho tseem ceeb phenylethanoid glycoside tam sim no hauvHerbaCistanche, ib lub npe nrov suav tshuaj siv los kho qhov tsis nco qab, tsis muaj zog, thiab cem quav [1].Echinacosidemuaj ntau yam bioactivities xws li tshuaj tiv thaiv oxidation, tiv thaiv kab mob, tshuaj tiv thaiv kab mob, hepatoprotection, thiab kev tiv thaiv kab mob [2-4]. Tshwj xeeb, echinacoside muaj cov teebmeem neuroprotective; Piv txwv li, nws muaj peev xwm tiv thaiv oxidative kev nyuaj siab-los yog neurotoxin-induced neurotoxicity nyob rau hauv thawj nas cortical neurons, tib neeg neuroblastoma SH-SY5Y hlwb, thiab pheochromocytoma (PC12) hlwb [5–8]. Tsis tas li ntawd, echinacoside txo qis kev puas hlwb ntawm lub hlwb thiab txhim kho kev txawj ntse hauv cov tsiaj ua qauv ntawm Parkinson's disease, Alzheimer's disease, thiab nruab nrab cerebral artery occlusion [9-12]. Txawm li cas los, lub mechanism ntawm uasechinacoside cov tshuajinduces neuroprotection tsis to taub tag nrho.

Neuroprotection yog cov txheej txheem nyuaj ntawm kev khaws cov qauv neuronal thiab ua haujlwm raws li kev thuam thuam. Glutamate excitotoxicity txo yog suav tias yog lub peev xwm txheej txheem koom nrog hauv hlwb neuroprotection. Glutamate, ib qho excitatory amino acid neurotransmitter, muaj lub luag haujlwm tseem ceeb hauv ntau lub hlwb ua haujlwm [13]. Txawm li cas los xij, overactivation ntawm glutamate receptors nyob rau hauv siab glutamate concentrations ua rau intracellular Ca2 ntxiv rau overload, mitochondrial dysfunction, dawb radical ntau lawm, thiab neuronal tuag [14,15]. Cov txheej txheem pathological no cuam tshuam rau ntau lub hlwb mob xws li cerebral ischemia, raug mob lub hlwb, mob vwm, thiab kab mob neurodegenerative [16,17]. Li no, inhibitors thaiv kab mob pathophysiological glutamatergic kis tau tus mob yog suav hais tias muaj peev xwm neuroprotective tshuaj. Cov piv txwv tseem ceeb ntawm cov no yog glutamate receptor antagonists [18,19]; Txawm li cas los xij, kev sim tshuaj rau cov tshuaj no tau ua tsis tiav vim tias tsis muaj txiaj ntsig thiab tsis xav tau, lossis txawm tias muaj kev mob tshwm sim cytotoxic [20,21]. Ntxiv rau qhov ncaj qha glutamate receptor blockade, glutamate tso tawm inhibition tuaj yeem yog lub tswv yim zoo rau kev tiv thaiv kab mob. Ntau cov neuroprotectants (xws li, memantine thiab riluzole) tuaj yeem txo glutamate tso tawm hauv nas hlwb [22–24].

Xav txog lub luag haujlwm ntawm glutamate hauv excitotoxicity thiab neuroprotective profile ntawm echinacoside, txoj kev tshawb no tau siv cov paj hlwb cais tawm (synaptosomes) purified los ntawm nas cerebral cortex los tshawb xyuas cov txiaj ntsig ntawm echinacoside ntawm glutamate tso tawm thiab ntxiv tshawb xyuas cov peev txheej. Kev npaj cov paj hlwb cais tawm yog ib qho qauv tsim zoo rau kev kawm cov kev cai presynaptic ntawm neurotransmitter tso tawm los ntawm cov tshuaj thaum tsis muaj cov teebmeem postsynaptic [25]. Los ntawm kev siv cov qauv no, peb tau soj ntsuam cov txiaj ntsig ntawm echinacoside ntawm glutamate tso tawm, daim nyias nyias muaj peev xwm, presynaptic Ca2 ntxiv rau influx, thiab protein kinase C kev ua haujlwm. Raws li peb qhov kev tshuaj xyuas ntawm cov ntaub ntawv, qhov no yog thawj daim ntawv tshaj tawm sau cov txheej txheem los ntawm qhov uas echinacoside inhibits endogenous glutamate tso tawm ntawm qib presynaptic.

2. Cov txiaj ntsig

2.1. EchinacosideInhibits 4-Aminopyridine-Evoked Glutamate tso tawm los ntawm nas Cerebrocortical Nerve Terminals los ntawm Txo Cov Vesicular Exocytosis

Daim duab 1 qhia txog qhov concentration-dependent nyhuv ntawm echinacoside ntawm 4-aminopyridine-evoked glutamate tso tawm los ntawm purified nas cerebrocortical synaptosomes. Hauv synaptosomes incubated nrog 1 mM CaCl2, 1 mM 4-aminopyridine evoked glutamate tso tawm ntawm 7.4 ± {{1{{20}}}}}.1 nmol / mg / 5 min, uas tau txo. los ntawm 1, 5, 10, 30, thiab 50 uM echinacoside rau 6.5 ± 0.2, 5.8 ± 0.3, 4.8 ± 0.2,

4.1 ± 0.1, los yog 2.3 ± 0.4 nmol/mg/5 min, ntsig txog (F(5,24)=67.1, p=0. 000). Tus nqi IC50 rau echinacoside-mediated inhibition ntawm 4-aminopyridine-evoked glutamate tso tawm, muab los ntawm cov koob tshuaj tiv thaiv kab mob, yog 24 uM. Ntxiv mus, glutamate tso tawm evoked los ntawm 1 mM 4-aminopyridine nyob rau hauv ib qho extracellular Ca2 ntxiv -free tov uas muaj 300 uM ethylene glycol bis (-aminoethyl ether)-N, N, N /, N / - tetraacetic acid (EGTA) yog 2.1 0.2 nmol/mg/5 min (F(2,12)=310.65, p=0.000),

thiab qhov no Ca2 ntxiv - ywj pheej ntawm 4-aminopyridine-evoked glutamate tso tawm tsis cuam tshuam los ntawm 20 uM echinacoside (1.8 ± 0.2 nmol/mg/5 min; p {{1} 0}}.58; Daim duab 1). Hauv synaptosomes kho nrog 0.1 uM balomycin A1, vesicular transporter inhibitor [26], 4-aminopyridine-evoked glutamate tso tawm tau txo qis (2.2 ± 0}.2 nmol/mg/ 5 min; F (2,12)=249.518, p=0 000). Nyob rau hauv lub xub ntiag ntawm bafilomycin A1, 20 uM echinacoside ua tsis tau tejyam kom tsis txhob muaj qhov tso tawm ntawm glutamate (2.1 ± 0.2 nmol / mg / 5 min; p=0.94; Daim duab 1). Los ntawm qhov sib txawv, 10 uM DL-threo-beta-benzyl-oxyaspartate (DL-TBOA, glutamate reuptake inhibitor) [27], nce 4-aminopyridine-evoked glutamate tso tawm rau 11.8 ± 0.4 nmol / mg / 5 min ( t(8)=-11.31, p=0 000). Txawm tias muaj DL-TBOA, 20 uM echinacoside inhibited 4-aminopyridine-evoked glutamate tso tawm qhov tseem ceeb (7.7 ± 0.2 nmol / mg / 5 min; F(2,12)=87.23, p=0 000; Daim duab 1).

2.2 Echinacoside Txo Cytosolic Ca2 ntxiv rau Kev Ntseeg tab sis Tsis Hloov Synaptosomal Membrane Muaj Peev Xwm

Synaptosome depolarization tshwm sim los ntawm 1 mM 4-aminopyridine nce Ca2 ntxiv rau concentration (p=0000; Table 1). Daim ntawv thov ntawm 20 uM echinacoside tsis cuam tshuam rau basal Ca2 ntxiv rau concentration (t(8)=0.06, p=0.95) tab sis tseem ceeb txo qhov 4-aminopyridine-induced nce hauv Ca2 plus concentration (t(10)=6.16, p=0.000). Tsis tas li ntawd, 1 mM 4-aminopyridine nce hauv 3',3',3'-dipropylthiadicarbocyanine iodide [DiSC3(5)] uorescence (p=0.000). Qhov sib ntxiv ntawm 20 uM echinacoside tsis hloov pauv lub peev xwm so ntawm daim nyias nyias (t(8)=0.976, p=0.36) lossis qhov tseem ceeb hloov pauv 4-aminopyridine-mediated nce hauv DiSC3 (5) Fluorescence (t(8)=-0.014, p=0.99; Table 1).

2.3 Txo Ca2 ntxiv Influx los ntawm Cav2.2 (N-Type) thiab Cav2.1 (P/Q-Type) Raws Tej zaum yuav koom nrog Inhibition ntawm 4-Aminopyridine-Evoked Glutamate tso tawm los ntawm Echinacoside

Daim duab 2 qhia tau hais tias 2 uM o-conotoxin MVIIC, ib qho N- thiab P/Q-hom Ca2 ntxiv rau channel blocker, txo 4-aminopyridine-evoked glutamate tso tawm los ntawm 7.4 ± {{10}}. 2 mus rau 2. Nyob rau hauv lub xub ntiag ntawm o-conotoxin MVIIC, cov nyhuv ntawm 20 uM echinacoside ntawm 4-aminopyridine-evoked glutamate tso tawm tsis tseem ceeb (1.8 2± ntxiv rau 0.2 nmol / mg / 5 min; t(8)=1.06, p=0.32). Dantrolene (10 uM), ib qho inhibitor ntawm intracellular Ca tso tawm los ntawm endoplasmic

reticulum [28], txo 4-aminopyridine-evoked glutamate tso tawm (5.6 ± 0.3 nmol/mg/5 min; F(2,14) {{10}}. 95, p=0 000). Txawm li cas los xij, nyob rau hauv lub xub ntiag ntawm dantrolene, 20 uM echinacoside tseem tuaj yeem inhibit glutamate tso tawm qhov tseem ceeb (3.3 ± 0.2 nmol / mg / 5 min; p=0.000). Cov txiaj ntsig zoo sib xws tau pom tias siv 100 uM 7-chloro-5-(2-chloropheny)-1, 5-dihydro-4,1-benzothiazepin -2(3H)-ib tug (CGP37157), ib tug membrane-permeable blocker ntawm mitochondrial Na plus / Ca2 ntxiv pauv. Hauv tsib kev tshuaj xyuas synaptosomal npaj, 20 uM echinacoside ua ke nrog 100 uM CGP37157 txo 4-aminopyridine-evoked glutamate tso tawm los ntawm 48.3 feem pua ​​± 5.2 feem pua ​​(F(2,13) ​​{{47} {}.79, p. 49}}.

2.4 EchinacosideInhibits 4-Aminopyridine-Evoked Glutamate tso tawm los ntawm Kev Tshaj Tawm los ntawm Protein Kinase C

Raws li tau piav qhia hauv daim duab 3, 10 uM 2-[1-(3-dimethylaminopropyl)indol-3-yl]-3-(indol-3-}yl) maleimide (GF109203X), ib tug general protein kinase C inhibitor [29], txo 4-aminopyridine-evoked glutamate tso (F(2,13) ​​= 19.46, p=0.{{17 }}). Hauv GF109203X-kho synaptosomes, 20 uM echinacoside txo 4-aminopyridine-evoked glutamate tso tawm tsuas yog 5.5 feem pua ​​± 1.8 feem pua ​​(p=0.89), tsawg dua li ntawm echinacoside ib leeg (42.3 feem pua ​​± 2.4%) feem pua ​​; p=0 000). Cov txiaj ntsig zoo sib xws tau txais nrog 5,6,7,13-tetrahydro-13-methyl-5-oxo-12H-indolo[2,3-a]pyrrolo[3 ,4-c]carbazole-12-propanenitrile (Go6976), ib qho kev xaiv rau Ca2 ntxiv -dependent protein kinase C isoforms ( , I, II, y) [29]. Nyob rau hauv lub xub ntiag ntawm 3 uM Go6976, 20 uM echinacoside txo glutamate tso tawm los ntawm 11.9 feem pua ​​± 2.9 feem pua ​​(p=0.59), qhia txog qhov tseem ceeb txo qis piv nrog qhov ntawd los ntawm echinacoside ib leeg (42.4 feem pua ​​2.3 feem pua ​​; p {{ 65}} 000; Daim duab 3). Los ntawm qhov sib txawv, 3 uM rottlerin, ib qho Ca2 ntxiv -independent protein kinase C6 inhibitor [30], tsis tau hloov pauv 4-aminopyridine (1 mM)-evoked glutamate tso tawm (p=0.45). Txawm li cas los xij, nyob rau hauv lub xub ntiag ntawm rottlerin, 20 uM echinacoside ua tau zoo ua rau qhov nruab nrab inhibition ntawm 37.1 feem pua ​​± 5.6 feem pua ​​​​ntawm kev tso tawm (F(2,13) ​​= 19.72, p=0.{{88 } }), zoo ib yam li ntawm echinacoside ib leeg (p=0.41; Daim duab 3). Tsis tas li ntawd, mitogen-activated protein kinase inhibitor 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-ib qho) (PD98059 ) (50 uM) thiab cov protein kinase A inhibitor N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide (H89) (100 uM) txo 4-aminopyridine-evoked glutamate tso tawm (p=0}000). Txawm nyob rau hauv lub xub ntiag ntawm PD98059 los yog H89, 20 uM echinacoside txo qhov tso tawm (F(2,13) ​​= 52.3, p=0.000; Daim duab 3).

Daim duab 4 qhia tau hais tias 1 mM 4-aminopyridine nce phosphorylation ntawm protein kinase C hauv synaptosomes (t(4)=-6.871, p=0.002). Thaum synaptosomes tau pretreated nrog 20 uM echinacoside rau 10 min ua ntej ntxiv ntawm 4-aminopyridine, 4-aminopyridine induced phosphorylation ntawm protein kinase C txo qis (F(2,6)=29.202 , p=0.001).

2.5 Echinacoside-Mediated Inhibition ntawm Glutamate Release Tsis Koom Nrog Gamma-Aminobutyric Acid Hom A (GABAA) Receptor

Hauv daim duab 5, cov nyhuv ntawm echinacoside ntawm 4-aminopyridine-evoked glutamate tso tawm thaum tsis muaj lossis muaj SR95531 (tus antagonist ntawm GABAA receptor) tau muab piv. Tsis tas li ntawd, 100 uM SR95531 tsis tau hloov pauv 4-aminopyridine (1 mM)-evoked glutamate tso tawm. Hauv SR95531- kho synaptosomes, daim ntawv thov ntawm 20 uM echinacoside ua rau 43 feem pua ​​​​ inhibition ntawm 4-aminopyridine-evoked glutamate tso tawm (F(2,12)=42.63, p { {18}}. Ib qho txiaj ntsig zoo sib xws tau txais nrog lwm tus GABAA receptor antagonist, bicuculline (50 uM). Qhov tso tawm ntsuas nyob rau hauv lub xub ntiag ntawm bicuculline thiab echinacoside yog qhov txawv ntawm qhov uas tau txais nyob rau hauv lub xub ntiag ntawm bicuculline ib leeg (p=0.000).

3. Kev sib tham

Hauv qhov kev tshawb fawb no,echinacoside cov tshuaj, ib qho active compound hauv HerbaCistanche, inhibited 4-aminopyridine-evoked glutamate tso tawm hauv nas cerebral cortex paj hlwb terminals. Qhov ua tau hauv qab mechanisms rau covechinacoside cov tshuaj-mediated inhibition ntawm glutamate tso tawm yog tshawb xyuas ntxiv thiab tham ntawm no.

3.1 Mechanisms Hauv qab Echinacoside-Mediated Inhibition ntawm Glutamate tso tawm

Glutamate tso tawm evoked los ntawm 4-aminopyridine muaj ob yam: ib tug physiologically cuam tshuam Ca2 ntxiv -dependent tivthaiv, uas yog tsim los ntawm exocytosis ntawm synaptic vesicles uas muaj glutamate; thiab Ca2 ntxiv - ywj pheej tivthaiv, uas tshwm sim los ntawm lub sijhawm ntev depolarization ua rau lub membrane muaj peev xwm-mediated hloov ntawm glutamate transporter khov kho-lub xeev mus rau sab nraud, yog li cuam tshuam rau cytosolic glutamate efflux [31]. Ntawm no, peb tau pom tias echinacoside tsis muaj qhov cuam tshuam rau 4-aminopyridine-evoked glutamate tso tawm nyob rau hauv lub xub ntiag ntawm Ca2 ntxiv -dawb nruab nrab (Ca2 ntxiv - ywj siab tso tawm). Tsis tas li ntawd, qhov pom echinacoside-mediated inhibition ntawm 4-aminopyridine-evoked glutamate tso tawm tau zoo tiv thaiv los ntawm bafilomycin A1 (uas depletes glutamate cov ntsiab lus ntawm synaptic vesicles), tab sis tsis yog los ntawm DL-TBOA (uas nonselectively inhibits amino acids. transporter subtypes). Cov txiaj ntsig no qhia tias echinacoside cuam tshuam rau Ca2 ntxiv -dependent exocytosis ntawm glutamate tso tawm yam tsis muaj kev cuam tshuam rau Ca2 ntxiv - ywj siab cytosolic efflux ntawm glutamate los ntawm kev thim rov qab ntawm cov hlab ntsha plasma membrane glutamate transporter. Nyob rau hauv synaptic terminals, Na ntxiv channel inhibition los yog K ntxiv channel ua kom stabilizes membrane excitability thiab thiaj li txo cov evoked Ca2 ntxiv nkag thiab neurotransmitter tso [32,33]. Yog li, lub peev xwm txheej txheem hauv qab echinacoside-mediated glutamate tso tawm inhibition cuam tshuam nrog kev txo qis hauv synaptosomal excitability. Txawm li cas los xij, qhov ua tau no tsis tuaj yeem ua tau raws li ob qhov kev soj ntsuam: (1) 4-aminopyridine-evoked membrane muaj peev xwm depolarization, ntsuas nrog daim nyias nyias muaj peev xwm dye DiSC3(5) tsis cuam tshuam los ntawm kev sib ntxiv ntawm echinacoside; thiab (2) echinacoside tsis cuam tshuam rau 4-aminopyridine-evoked Ca2 ntxiv -independent glutamate tso tawm, ib feem ntawm kev tso tawm uas nyob ntawm tsuas yog cov membrane muaj peev xwm [31]. Yog tias cov nyhuv tsis tshwm sim los ntawm kev tawm tsam ntawm synaptosomal excitability, nws yuav tshwm sim los ntawm kev txo qis hauv kev ua haujlwm ntawm Cav2.2 (N-type) thiab Cav2.1 (P / Q-type) Ca2 ntxiv rau cov kab txuas nrog glutamate exocytosis hauv cov kab mob. paj ntaub terminals [34–36]. Los ntawm kev siv fura-2, peb pom tau tias echinacoside tseem ceeb txo qhov 4-aminopyridine-evoked nce hauv Ca2 ntxiv rau qhov concentration. Tsis tas li ntawd, peb cov ntaub ntawv qhia tau hais tias cov nyhuv inhibitory ntawm echinacoside ntawm 4-aminopyridine-evoked glutamate tso tawm tau txo qis los ntawm 42.4 feem pua ​​2.3 feem pua ​​​​rau 12.1 feem pua ​​3.9 feem pua ​​tom qab raug tus blocker ntawm Cav2.2 (N-type) thiab Cav2. .1 (P/Q-type) Ca2 ntxiv raws. Tsis tas li ntawd, peb tau pom tias echinacoside txuas ntxiv tseem ceeb inhibit 4-aminopyridine-evoked glutamate tso tawm nyob rau hauv lub xub ntiag ntawm intracellular Ca2 ntxiv rau tso tawm inhibitors. Cov txiaj ntsig no qhia tau hais tias kev tawm tsam ib txhij ntawm Cav2.2 (N-hom) thiab Cav2.1 (P / Q-type) Ca2 ntxiv rau kev ua haujlwm channel yog qhov muaj peev xwm ua haujlwm hauv qab ntawm echinacoside-mediated glutamate tso tawm inhibition. Txawm li cas los xij, kev sib xyaw ua ke ntawm Cav2.2 (N-hom) thiab Cav2.1 (P / Q-type) Ca2 ntxiv rau kev ua haujlwm hauv channel tsis tuaj yeem thaiv qhov kev txiav txim ntawm echinacoside kiag li. Li no, lwm yam tsis paub txog Ca2 ntxiv cov channel lossis lwm txoj hauv kev presynaptic tuaj yeem koom nrog hauv kev txwv. Piv txwv li, GABAA receptors tam sim no nyob rau theem presynaptic, thiab lawv qhov kev ua kom pom tau tias inhibit Ca2 ntxiv rau kev nkag mus thiab glutamate tso tawm [37]. Nyob rau hauv txoj kev tshawb no, GABAA receptor antagonists SR95531 thiab bicuculline tsis thaiv echinacoside-mediated inhibition ntawm glutamate tso tawm, qhia tias GABAA receptors tsis koom nrog qhov txo qis ntawm voltage-dependent Ca2 ntxiv rau channel kev ua haujlwm thiab tom qab inhibition ntawm glutamate tso tawm. Ca2 ntxiv rau kev nkag mus los ntawm qhov hluav taws xob-dependent Ca2 ntxiv cov channel ua kom muaj ntau cov protein kinases cuam tshuam nrog glutamate tso tawm hauv cov hlab ntsha nrog rau mitogen-activated protein kinase, protein kinase C, thiab protein kinase A. Ntawm no, peb qhia tau tias cov protein kinase C inhibitors muaj txiaj ntsig zoo antagonized echinase. -mediated inhibition ntawm glutamate tso tawm; Txawm li cas los xij, mitogen-activated protein kinase inhibitor PD98059 lossis protein kinase A inhibitor H89 tsis zoo. Tsis tas li ntawd, qhov 4-aminopyridine-induced phosphorylation ntawm protein kinase C txo qis hauv synaptosomes tom qab pretreatment nrog echinacoside ntawm ib tug concentration zoo rau inhibiting glutamate tso tawm. Yog li ntawd, txoj kev taw qhia ntawm echinacoside-mediated glutamate tso tawm inhibition yuav cuam tshuam nrog protein kinase C. Protein kinase C yog ib qho tseem ceeb intracellular signaling system uas tam sim no nyob rau theem presynaptic thiab muaj lub luag haujlwm tseem ceeb hauv neurotransmitter exocytosis. Piv txwv li, ntau cov synaptic proteins koom nrog hauv synaptic vesicle trafficking lossis recruitment thiab exocytosis, xws li myristoylated alanine-nplua nuj C kinase substrate, yog phosphorylated los ntawm protein kinase C [38,39]. Cov txheej txheem phosphorylation no tuaj yeem nce ntxiv los ntawm depolarization-stimulated Ca2 ntxiv rau kev nkag, uas pab txhawb kev tso tawm glutamate [40]. Yog li, peb tuaj yeem xav tias qhov cuam tshuam ntawm echinacoside ntawm Ca2 ntxiv rau kev nkag tau pom ntawm no tuaj yeem txo cov protein kinase C kev ua haujlwm thiab yog li glutamate tso tawm.

Pls nyem qhov no mus rau Ntu 2