Table 5 Fitting equations and correlation coefficients (r) of SOD activity (y) with the levels of Zn (x₁) as well as the expression levels of SOD gene (x₂) in the brain, liver, and kidneys of rats administered 0.5g and 1.0g of NiO-NPs (II and III), 0.5g and 1.0g of Co₃O₄-NPs (IV and V), as well as mixtures of NiO-NPs + Co₃O₄-NPs (0.25g + 0.25g, VI) and (0.5g + 0.5g, VII) per kilogram body weight, respectively

y

x

II

III

IV

V

VI

VII

SOD activity (U/g tissue)

Zn levels (μg/g tissue)

Brain

y = 0.13x₁ − 0.01

r = + 0.87***

y = 0.10x₁ + 0.28

r = + 0.94***

y = 0.15x₁ −  0.33

r = + 0.93***

y = 0.13x₁ + 0.08

r = + 0.93***

y = 0.09x₁ + 0.69

r = + 0.88***

y = 0.06 x₁ + 1.28

r = + 0.88***

Liver

y = 0.02x₁ − 0.09

r = + 0.68**

y = 0.02x₁ − 0.10

r = + 0.85***

y = 0.01x₁ + 0.12

r = + 0.65**

y = 0.02x₁ − 0.20

r = + 0.69**

y = 0.01x₁ + 0.08

r = + 0.50*

y = 0.02x₁ − 0.22

r = + 0.90***

Kidney

y = 0.06x₁ + 0.69

r = + 0.81***

y = 0.13x₁ − 0.40

r = + 0.75***

y = 0.10x₁ + 0.12

r = + 0.89*

y = 0.04x₁ + 1.17

r = + 0.61*

y = 0.05x₁ + 1.08

r = + 0.96***

y = 0.06x + 0.93

r = + 0.78***

SOD gene (expression level)

Brain

y = 5.15x₂ −  1.26

r = + 0.94***

y = 4.02x₂ − 0.80

r = + 0.89***

y = 4.56x₂ − 0.98

r = + 0.94***

y = 2.64x₂ + 0.02

r = + 0.99***

y = 2.27x₂ + 0.28

r = + 0.91***

y = 1.33x₂ + 1.13

r = + 0.79***

Liver

y = 0.67x − 0.07

r = + 0.89***

y = 0.84x₂ − 0.19

r = + 0.96***

y = 0.49x₂ + 0.06

r = + 0.68**

y = 0.44x₂ + 0.11

r = + 0.62*

y = 0.39x₂ + 0.15

r = + 0.82***

y = 0.42x₂ + 0.15

r = + 0.86***

Kidney

y = 1.52x₂ + 1.07

r = + 0.84***

y = 1.73x₂ + 0.99

r = + 0.84***

y = 2.07x₂ + 0.84

r = + 0.94***

y = 1.18x₂ + 1.20

r = + 0.76***

y = 0.79x₂ + 1.46

r = + 0.95***

y = 1.00x₂ + 1.44

r = + 0.92***