Table 3. Direct effect, indirect effect, and the total effect of one variable on other variable.

	Effect
	Direct		Indirect		Total
	β	p-value*	β	p-value*	β	p-value*
Purple potato on p53	-0.659	<0.001†	–	–	-0.659	<0.001†
Purple potato on TNF-α	-0.495	<0.001†	–	–	-0.495	<0.001†
Purple potato on GFAP	-0.754	<0.001†	–	–	-0.754	<0.001†
Purple potato on BDNF	–	–	0.355	0.013†	0.355	0.013†
Purple potato on memory	–	–	0.400	0.004†	0.400	0.004†
P53 on BDNF	-0.113	0.522	–	–	-0.113	0.522
P53 on memory	-0.232	0.188	-0.013	0.645	-0.246	0.171
TNF-α on BDNF	0.173	0.295	–	–	0.173	0.295
TNF-α on memory	-0.235	0.158	0.020	0.573	-0.215	0.202
GFAP on memory	-0.488	0.003†	–	–	-0.488	0.003†
GFAP on BDNF	-0.117	0.556	-0.058	0.516	-0.175	0.334
BDNF on memory	0.119	0.501	–	–	0.119	0.501

TNF-α: tumor necrosis factor-α, GFAP: glial fibrillary acidic protein, BDNF: brain-derived neurotrophic factor.

^*Student's t-test;

^†significant; β=standardized coefficient.