Antidepressant-like activity, active components and related mechanism of Hemerocallis citrina Baroni extracts

Abstract

Hemerocallis citrina Baroni [Asphodelaceae], which is traditional herbal medicine, has been widely used for treating depressive disorders in Eastern-Asia countries. However, the active compounds and corresponding mechanism of anti-depression are not yet completely clarified. In this study, the anti-depressive activities of six H. citrina extracts were primarily evaluated. The results showed that the water extract of H. citrina flowers (HCW) displays significant anti-depressive activity. A total of 32 metabolites were identified from HCW by high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (HPLC-Q-TOF-MS) and nuclear magnetic resonance (NMR). And then, the anti-depressive activity of the high-level compound (rutin) in HCW was also estimated. The results indicated that rutin displayed significant anti-depressive activity and was one of the main active ingredients. Finally, the anti-depressive mechanisms of HCW and rutin were investigated based on the intestinal microorganisms. The results showed that HCW and rutin increase the diversity and richness of the intestinal flora and regulate the specific intestinal microorganisms such as Bacteroides and Desulfovibrio genera in depressed mice. This work marks the first comprehensive study of the active components, anti-depressive activities and corresponding mechanisms of different H. citrina extracts, which provide a potential possibility for developing new antidepressants.

Keywords: CUMS mice; HPLC-Q-TOF-MS; antidepressant-like effect; chemical constituents; hemerocallis citrina baroni [asphodelaceae]; intestinal flora.

FIGURE 1

The effects of different dose extracts of H. citrina flowers and fresh flower buds on the behaviors of CUMS mice. (A) Sucrose preference test, (B) ingestion latency test, (C) tail suspension activity test, and (D) tail suspension still time test. Data are reported as mean ± SD. For statistical significant, ^# p < 0.05, ^## p < 0.01 compared with the normal control group; *p < 0.05, **p < 0.01 compared with the model control group. NC, normal group; MC, model group; FH, Fluoxetine hydrochloride group; WHCWL and WHCWH, low and high-dose of water extracts of fresh flower buds; HCWL and HCWH, low and high-dose of water extracts of flowers; WHCEL and WHCEH, low and high-dose of 80% ethanol extracts of fresh flower buds; HCEL and HCEH, low and high-dose of 80% ethanol extracts of flowers; low-dose: 200 mg/kg; high-dose, 500 mg/kg.

FIGURE 2

The effects of different dose extracts of H. citrina flowers and dried flower buds on the behaviors of CUMS mice. (A) Sucrose preference test, (B) ingestion latency test, (C) tail suspension activity test, and (D) tail suspension still time test. Data are reported as mean ± SD. For statistical significant, ^# p < 0.05, ^## p < 0.01 compared with the normal control group; *p < 0.05, **p < 0.01 compared with the model control group. NC, normal group; MC, model group; FH, Fluoxetine hydrochloride group; HCWL and HCWH, low and high-dose of water extracts of flowers; DHCWL and DHCWH, low and high-dose of water extracts of dried flower buds; DHCEL and DHCEH: low and high-dose of 80% ethanol extracts of dried flower buds; low-dose, 200 mg/kg; high-dose, 500 mg/kg.

FIGURE 3

Total ion chromatograms (TICs, (A) and (C) in ESI⁻ mode and UV chromatograms (254 nm, (B) and (D) of HCW and HCE.

FIGURE 4

The MS/MS spectra of standard 7 (A) and the metabolite 6 (B) in ESI⁻ mode, and corresponding fragmentation behaviors.

FIGURE 5

The effects of different dose groups of rutin on the behaviors of CUMS mice. (A) Sucrose preference test, (B) ingestion latency test, (C) tail suspension activity test, and (D) tail suspension still time test. Data are reported as mean ± SD. For statistical significant, ^# p < 0.05, ^## p < 0.01 compared with the normal control group; *p < 0.05, **p < 0.01 compared with the model control group. NC, normal group; MC, model group; FH, Fluoxetine hydrochloride group; RTL, low-dose of rutin (0.7 mg/kg); RTM, medium-dose of rutin (1.8 mg/kg); RTH: high-dose of rutin (6.3 mg/kg); RTE, extra high-dose of rutin (10.0 mg/kg).

FIGURE 6

Reflectance curve (A) and Venn diagram (B) of intestinal microbial OTUs from HCW and HCE-treated CUMS mice and controls, (C) the alpha diversity of the ACE, Chao 1, Shannon and Simpson index of intestinal microflora. Data are reported as mean ± SD. For statistical significant, *p < 0.05 compared with the model control group. NC, normal group; MC, model group; FH, Fluoxetine hydrochloride group; HCW, water extract of flowers; HCE, 80% ethanol extract of flowers.

FIGURE 7

Comparison of the relative abundance of intestinal flora at the phylum level (A). Comparison of Firmicutes and Bacteroidetes relative abundance in different groups (B). Data are reported as mean ± SD. For statistical significant, ^## p < 0.01 compared with the normal control group; **p < 0.01 compared with the model control group. NC, normal group; MC, model group; FH, Fluoxetine hydrochloride group; HCW, water extract of flowers; HCE, 80% ethanol extract of flowers.

FIGURE 8

Comparison of the relative abundance of intestinal flora at the genus level (A). Comparison of Bacteroides and Desulfovibrio relative abundance in different groups (B). Data are reported as mean ± SD. For statistical significant, ^# p < 0.05 compared with the normal control group; *p < 0.05 compared with the model control group. NC, normal group; MC, model group; FH, Fluoxetine hydrochloride group; HCW, water extract of flowers; HCE, 80% ethanol extract of flowers.