1.Effect of Rehmanniae Radix on depression-like behavior and hippocampal monoamine neurotransmitters of chronic unpredictable mild stress model rats.
Ping TIAN ; Wei ZHANG ; Kai-Yan LI ; Hong-Wei LI ; Kai MA ; De-En HAN
China Journal of Chinese Materia Medica 2022;47(17):4691-4697
To investigate the effect of Rehmanniae Radix on depression-like behavior and monoamine neurotransmitters of chronic unpredictable mild stress(CUMS) model rats. CUMS combined with isolated feeding was used to induce the depression model of rats. The depression-like behavior of rats was evaluated by sucrose preference test, open field test, and forced swim test. Hematoxylin-Eosin(HE) staining was used to investigate the pathological changes of neurons in the CA1 and CA3 area of hippocampus. Ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS) was used to detect the contents of 5-hydroxytryptamine(5-HT), 5-hydroxyindoleacetic acid(5-HIAA), dopamine(DA), 3,4-dihydroxyphenylacetic acid(DOPAC), homovanillic acid(HVA), norepinephrine(NE), and 3-methoxy-4-hydroxyphenyl glycol(MHPG) in rats. Western blot was used to detect the protein expressions of tryptophan hydroxylase 2(TPH2), serotonin transporter(SERT), and monoamine oxidase A(MAO-A) in the hippocampus of rats. Compared with the normal group, depressive-like behavior of rats was obvious in the model group. The arrangements of neurons in the CA1 and CA3 area of hippocampus were loose and disorderly. The levels of 5-HT, 5-HIAA, and 5-HT/5-HIAA in the hippocampal area were decreased(P<0.01). The protein expression of TPH2 was decreased(P<0.01), but those of SERT and MAO-A were increased(P<0.01). In the Rehmanniae Radix groups with 1.8 g·kg~(-1) and 7.2 g·kg~(-1), the depression-like behavior of CUMS rats and pathological changes of neurons in CA1, CA3 area of hippocampus were improved. The protein expression of TPH2(P<0.05, P<0.01) was increased, and those of SERT and MAO-A were down-regulated(P<0.05, P<0.01). The levels of 5-HT, 5-HIAA, and 5-HT/5-HIAA in hippocampus were increased(P<0.05, P<0.01). The changes in DA, DOPAC, HVA, DA/(DOPAC +HVA), NE, DHPG, and NE/DHPG were not statistically significant. The results suggested that Rehmanniae Radix improved depression-like behavior of CUMS rats, and the mechanism might be related to the regulation of synthesis, transportation, and metabolism of 5-HT neurotransmitter in the hippocampus.
3,4-Dihydroxyphenylacetic Acid/pharmacology*
;
Animals
;
Antidepressive Agents/therapeutic use*
;
Chromatography, Liquid
;
Depression/drug therapy*
;
Disease Models, Animal
;
Dopamine
;
Eosine Yellowish-(YS)/pharmacology*
;
Hematoxylin/pharmacology*
;
Hippocampus/metabolism*
;
Homovanillic Acid/pharmacology*
;
Hydroxyindoleacetic Acid/metabolism*
;
Methoxyhydroxyphenylglycol/pharmacology*
;
Monoamine Oxidase/metabolism*
;
Neurotransmitter Agents/metabolism*
;
Norepinephrine/pharmacology*
;
Plant Extracts
;
Rats
;
Rehmannia/chemistry*
;
Serotonin/metabolism*
;
Serotonin Plasma Membrane Transport Proteins/pharmacology*
;
Stress, Psychological/metabolism*
;
Tandem Mass Spectrometry
;
Tryptophan Hydroxylase/metabolism*