Inhibitory effect of the Kampo medicinal formula Yokukansan on acute stress-induced defecation in rats

Figures & data

Table 1 Component galenicals of YKS

Plant name	Weight	Major active components
Uncariae cum Uncis ramulus	3.0 g	Rhynchophylline, Geissoschizine methyl ether
Cnidii rhizoma	3.0 g	Ligustilide, Senkyunolide
Bupleuri radix	2.0 g	Saikosaponin a, c, d, e, f
Atratylodis Lanceae rhizoma	4.0 g	Atractylodin, β-eudesmol
Poria	4.0 g	Eburicoic acid, Pachymic acid
Angelicae radix	3.0 g	Ligustilide, n-butylidenphthalide
Glycyrrhizae radix	1.5 g	Glycyrrhizin, Glycyrrhizic acid

Note: Weights show the amounts mixed.

Abbreviation: YKS, Yokukansan.

Table 2 Drugs administered in the study of stress-induced defecation

Groups	Day 1–3	Day 4
Stress (n = 9)	Water (PO)	Water (PO) + saline (IP)
Stress+YKS (n = 9)	YKS (300 mg/kg/day, PO)	YKS (300 mg/kg/day, PO) + saline (IP)
Stress+YKS+B (n = 9)	YKS (300 mg/kg/day, PO)	YKS (300 mg/kg/day, PO) + Atosiban (1 mg/kg, IP)
Stress+OT (n = 9)	Water (PO)	Water (PO) + OT (0.04 mg/kg, IP)

Note: Drugs administered in the study of stress-induced defecation.

Abbreviations: B, blocker of oxytocin receptor; IP, intraperitoneal administration; OT, oxytocin; PO, per os; YKS, Yokukansan.

Figure 1 Plasma oxytocin levels (pg/mL) following administration of YKS and acute stress load.

Notes: Data are presented as mean ± SEM. Statistical analysis: one-way ANOVA followed by Tukey’s post hoc test, ^#P < 0.05 (vs Control group), **P < 0.01 (vs other groups).
Abbreviations: ANOVA, analysis of variance; SEM, standard error of mean; YKS, Yokukansan.

Table 3 Plasma OT concentrations

(pg/mL)	Control (n = 6)	OT (0.02) (n = 6)	OT (0.04) (n = 6)	OT (0.20) (n = 6)
Average	15.36	15.13	27.70	270.45
SEM	1.58	3.41	9.12	10.25

Note: Plasma OT concentrations (pg/mL) following the intraperitoneal administration of OT (0, 0.02, 0.04 and 0.20 mg/mL).

Abbreviations: OT, oxytocin; SEM, standard error of mean.

Figure 2 Amount of defecation (g) following the acute stress load.

Notes: Data are presented as mean ± SEM. Statistical analysis: one-way ANOVA followed by Tukey’s post hoc test, **P < 0.01 (vs Stress group).
Abbreviations: ANOVA, analysis of variance; B, blocker of oxytocin receptor; OT, oxytocin; SEM, standard error of mean; YKS, Yokukansan.

Figure 3 Plasma corticosterone levels (ng/mL) following administration of YKS and the acute stress procedure.

Notes: Data are presented as mean ± SEM. Statistical analysis: one-way ANOVA followed by Tukey’s post hoc test, **P < 0.01 (vs Control group).
Abbreviations: ANOVA, analysis of variance; OT, oxytocin; SEM, standard error of mean; YKS, Yokukansan.

Figure 4 Effect of YKS on isolated colonic motility. Representative contraction wave acquired when administering YKS (1 mg/mL) (A) and (5 mg/mL) (B). Contractile amplitudes (g) obtained by integrating area under the contractile wave above baseline (1 mg/mL) (C) and (5 mg/mL) (D).

Notes: Data are presented as mean ± SEM. Statistical analysis: paired t-test.
Abbreviations: ns, not significant; SEM, standard error of mean; YKS, Yokukansan.