Table 2.

Neuroprotective effect of HBNs 1–9, PBN and NAC after OGD-IR in human neuroblastoma SH-SY5Y cells.

	HBN	R	Neuroprotection (EC50 ± SEM), μM	P < (PBN)	P < (HBN6)	Maximal Activity (Mean ± SEM), %	P < (PBN)	P < (HBN6)
p-HBNs (1–3)	1	Me	227.07 ± 15.92	***	***	68.55 ± 3.96	*	***
	2	tert-Bu	45.09 ± 4.73	ns	***	77.82 ± 2.46	ns	***
	3	Bn	0.78 ± 0.09	**	ns	69.01 ± 0.87	*	***
m-HBNs (4–6)	4	Me	38.85 ± 4.05	ns	**	78.21 ± 2.23	ns	***
	5	tert-Bu	1.70 ± 0.18	**	ns	113.31 ± 4.69	***	ns
	6	Bn	1.24 ± 0.23	**	–	104.07 ± 3.06	**	–
o-HBNs (7–9)	7	Me	20.36 ± 1.21	ns	*	68.28 ± 2.13	**	***
	8	tert-Bu	20.58 ± 4.66	ns	*	55.43 ± 3.49	***	***
	9	Bn	10.14 ± 0.66	*	*	120.41 ± 6.63	***	ns
	PBN	–	42.01 ± 5.41	–	**	82.54 ± 6.23	–	**
	NAC	–	2.58 ± 0.91	**	ns	110.30 ± 2.81	**	ns

The estimation of EC₅₀ (in µM) and maximal activities (in % neuroprotection) values were performed by a weighted nonlinear regression of minimum squares using logistic curves, as is described in the “Statistical Analysis” section of “Neuroprotection Assessment Assays”. Values are the mean ± S.E.M. Data analysis was carried out with SigmaPlot v.12., and ANOVA one-way to get the significant statistics of HBNs respect to PBN, or to HBN6. Differences are statistically significant when P ≤ 0.05. EC₅₀ and maximal activities were calculated from the data obtained from three experiments, each one in triplicate. The statistics compares differences with PBN or HBN6 at *P < 0.05, **P < 0.01 and ***P < 0.001 (one-way ANOVA, followed by Holm–Sidak analysis as a post hoc test.