Table 2.

Effect of Metformin administration on lung histopathology in the early stage

Groups	Lesion severity grade						Average severity grade	Lesion distribution grade						Average distribution grade
	0	1	2	3	4	5		0	1	2	3	4	5
Saline	6						–	6						–
Silica				2	3	1	3.83 ± 0.307			1	3	1	1	3.33 ± 0.42
Silica + saline				1	4	1	4.00 ± 0.25			3	2	1		2.67 ± 0.33
Silica + metformin	1	2	3				1.33 ± 0.33a	2	3	1				0.83 ± 0.32a

Values represent the means ± SD of 6 for each group

^ap < 0.05 vs. Silica + Saline group (independent-sample t-test)