Chemical constituents isolated from Paeonia lactiflora roots and their neuroprotective activity against oxidative stress in vitro

Figures & data

Table 1.  Neuroprotective activity of the methanol extract and the fractions of P. lactiflora roots against H₂O₂-induced neurotoxicity in primary cultures of rat cortical cells.

Fractions	Neuroprotection (%)
Control	100.0 ± 4.4
H2O2-treated	0.0 ± 2.8
Methanol extract	83.9 ± 8.5***
n-hexane fraction	10.6 ± 2.5***
CHCl3 fraction	49.5 ± 3.2***
EtOAc fraction	73.1 ± 14.7***
n-butanol fraction	48.8 ± 7.9***

The 10 day old cortical cell cultures were pretreated with a test sample (100 μg/mL) for 1 h. Then the cultures were exposed to 50 μM H₂O₂ and maintained for 24 h. After the incubation, the neuroprotective activity of these fractions was assessed by MTT assay. Neuroprotection (%) was calculated as 100 × (abs of H₂O₂ + sample-treated – abs of H₂O₂-treated)/(abs of control – abs of H₂O₂-treated). The values are expressed as the mean ± SD (n = 3). H₂O₂-treated value differs significantly different from the control at a level of p < 0.001. Results differ significantly from the H₂O₂-treated, *p < 0.05, **p < 0.01 and ***p < 0.001, respectively.

Figure 1.  Structures of the compounds isolated from P. lactiflora.

Table 2.  Neuroprotective activity of compounds 1−7 against H₂O₂-induced neurotoxicity in primary cultures of rat cortical cells.

Compounds	Neuroprotection (%)
	0.1 μM	1.0 μM	10.0 μM
1	11.2 ± 6.2	5.2 ± 8.8	3.7 ± 7.2
2	7.0 ± 5.1	28.5 ± 2.7*	38.7 ± 3.1**
3	13.4 ± 3.9	15.7 ± 6.4	17.7 ± 2.9
4	9.4 ± 4.1	27.7 ± 3.6*	48.9 ± 5.2**
5	3.2 ± 3.4	18.2 ± 2.4	26.5 ± 3.9*
6	5.4 ± 4.5	28.7 ± 3.1*	27.4 ± 4.9*
7	3.5 ± 2.2	6.9 ± 4.9	28.7 ± 5.4*
EGCG^a	21.5 ± 3.9	39.5 ± 2.4**	68.2 ± 3.4***

The 10 day old cortical cell cultures were pretreated with a test sample for 1 h. Then the cultures were exposed to 50 μM H₂O₂ and maintained for 24 h. After the incubation, the neuroprotective activity of these fractions was assessed by MTT assay. Neuroprotection (%) was calculated as 100 × (abs of H₂O₂ + sample-treated – abs of H₂O₂-treated) / (abs of control – abs of H₂O₂-treated). The values are expressed as the mean ± SD (n = 3). H₂O₂-treated value differs significantly different from the control at a level of p < 0.001. Results differ significantly from the H₂O₂-treated, *p < 0.05, **p < 0.01 and ***p < 0.001, respectively. ^aEGCG (epigallocatechin-3-gallate) was used as a positive control.