Table 3. In vitro pancreatic lipase inhibition rate inhibitory concentrations (IC₅₀) of Simvastatin and protocatechuic acid (PCA)-50 and 100 mg/kg.

Inhibitor	Concentration (mg/ml)	Pancreatic lipase inhibition (%)	IC50 (mg/ml)
Simvastatin	0.25	25.77 ± 3.23	0.45
	0.5	62.13 ± 3.83
	0.75	80.92 ± 4.04
PCA (50 mg/kg)	0.5	31 ± 3.04	1.51
	1	41.86 ± 2.68
	2	76.16 ± 3.22
	3	100.1 ± 4.32
PCA (100 mg/kg)	0.5	26.08 ± 3.24	1.18
	1	35.81 ± 2.59
	2	64.78 ± 3.03
	3	80.7 ± 2.69

Values are expressed as mean ± SEM (mean of three determinations). Simvastatin in vivo dose was 20 mg/kg whilst in vitro concentrations varied from 0.25 to 0.75 mg/ml. PCA_{50 mg/kg} and PCA _{100 mg/kg} represents in vivo dose of protocatechuic acid tested at various concentrations in vitro between 0.5–3 mg/ml. The IC₅₀ against the pancreatic lipase activity of PCA_{50 mg/kg} and PCA_{100 mg/kg} were 1.51 mg/ml and 1.18 mg/ml, respectively. The IC₅₀ of PCA at both doses were higher than the simvastatin (IC₅₀=0.45 mg/ml)