AIM: To investigate the protective effects and mechanisms of Baicalin and octreotide on renal injury of rats with severe acute pancreatitis (SAP).METHODS: One hundred and eighty SD rats were randomly assigned to the model group, Baicalin-treated group, octreotide-treated group and sham operation group. The mortality, plasma endotoxin level, contents of blood urea nitrogen (BUN), creatinine (CREA),phospholipase A2 (PLA2), nitrogen monoxide (NO), tumor necrosis factor (TNF)-α, IL-6 and endothelin-1 (ET-1) in serum, expression levels of renal Bax and Bcl-2 protein,apoptotic indexes and pathological changes of kidney were observed at 3, 6 and 12 h after operation.RESULTS: The renal pathological changes were milder in treated group than in model group. The survival at 12 h and renal apoptotic indexes at 6 h were significantly (P ＜ 0.05) higher in treated group than in model group [66.67% vs 100%; 0.00 (0.02)% and 0.00 (0.04)% vs 0.00 (0.00)%, respectively]. The serum CREA content was markedly lower in octreotide-treated group than in model group at 3 h and 6 h (P ＜ 0.01, 29.200 ± 5.710 μmol/L vs 38.400 ± 11.344 μmol/L; P ＜ 0.05, 33.533 ±10.106 μmol/L vs 45.154 ± 17.435 μmol/L, respectively).The expression level of renal Bax protein was not significantly different between model group and treated groups at all time points. The expression level of renal Bcl-2 protein was lower in Baicalin-treated group than in model group at 6 h[P ＜ 0.001, 0.00 (0.00) grade score vs 3.00 (3.00) grade score]. The Bcl-2 expression level was lower in octreotide-treated group than in model group at 6 h and 12 h[P ＜ 0.05, 0.00 (0.00) grade score vs 3.00 (3.00) grade score; 0.00 (0.00) grade score vs 0.00 (1.25) grade score, respectively]. The serum NO contents were lower in treated groups than in model group at 3 h and 12 h[P ＜ 0.05, 57.50 (22.50) and 52.50 (15.00) μmol/L vs 65.00 (7.50) μmol/L; P ＜ 0.01,57.50 (27.50) and 45.00 (12.50) μmol/L vs 74.10 (26.15)μmol/L, respectively]. The plasma endotoxin content and serum BUN content (at 6 h and 12 h) were lower in treated groups than in model group. The contents of IL-6, ET-1, TNF-α (at 6 h) and PLA2 (at 6 h and 12 h)were lower in treated groups than in model group [P ＜0.001, 3.031 (0.870) and 2.646 (1.373) pg/mL vs 5.437(1.025) pg/mL; 2.882 (1.392) and 3.076 (1.205) pg/mL vs 6.817 (0.810) pg/mL; 2.832 (0.597) and 2.462 (1.353)pg/mL vs 5.356 (0.747) pg/mL; 16.226 (3.174) and 14.855 (5.747) pg/mL vs 25.625 (7.973) pg/mL; 18.625(5.780) and 15.185 (1.761) pg/mL vs 24.725 (3.759)pg/mL; 65.10 (27.51) and 47.60 (16.50) pg/mL vs 92.15(23.12) pg/mL; 67.91 ± 20.61 and 66.86 ± 22.10 U/mL,63.13 ± 26.31 and 53.63 ± 12.28 U/mL vs 101.46 ± 14.67 and 105.33 ± 18.10 U/mL, respectively].CONCLUSION: Both Baicalin and octreotide can protect the kidney of rats with severe acute pancreatitis. The therapeutic mechanisms of Baicalin and octreotide might be related to their inhibition of inflammatory mediators and induction of apoptosis. Baicalin might be a promising therapeutic tool for severe acute pancreatitis.