OBJECTIVE To investigate the effect of Nigella sativa L.as gastric protective on indomethacin-induced rats.METHODS the design of this research is randomized post test control group design.The rats were randomly divided into 5 groups which 5 rats in each.Rats were fasted for 8h before treatment.The first group was a control group(only gave aquadest as vehicle orally).The second group was subjected to induced with indomethacin 30mg·kg-1.The rest groups were subjected to induced by indomethacin and methanolic extract of Nigella sativa L.200,300 and 400mg·kg-1 every 8h for 24 h,respectively,for third,fourth and fifth group.Rats were sacrificed after anesthetized with ketamine and gastric were washed before observed.Macroscopic observation based on a score of lesion and microscopic observation on gastric based by histological HE staining.Whole data were analysis of an ANOVA statistical program.RESULTS The administration of Nigella sativa L.significantly decreased gastric ulcer macroscopically starting at dose 100,200 and 300mg·kg-1(P<0.05).Microscopic observation showed significant decreasing at dose 200 and 300mg·kg-1(P<0.05).Interestingly,there was no significant different between control and dose 300mg·kg-1.Negative correlation between lesion and doses were-0.919,-0.953 for macroscopic and microscopic lesion respectively.It means there was strong correlation between dose and lesion,higher dose lesser lesion.The mechanism of gastric protective of NigellasativaL.may caused by the bioactive compound such as thymoquinone which known as antiinflammation and antioxidant.CONCLUSION Methanolic extract of Nigella sativa L.decreased peptic ulcer both macroscopic and microscopic conditions on indomethacin-induced rats. OBJECTIVE To investigate the effect of Nigella sativa L. as gastric protective on indomethacin-induced rats. METHODS the design of this research is randomized post test control group design. The rats were randomly divided into 5 groups which 5 rats in each. Rats were fasted for 8h before treatment. The first group was a control group (only gave aquadest as vehicle orally). second group was subjected to induced with indomethacin 30 mg · kg-1.The rest groups were subjected to induced by indomethacin and methanolic extract of Nigella sativa L.200, 300 and 400 mg · kg -1 every 8h for 24 h, respectively, for third, fourth and fifth group. Rats were sacrificed after anesthetized with ketamine and gastric were washed before observed. Macroscopic observation based on a score of lesion and microscopic observation on gastric based by histological HE staining. Wide data were analyzed of an ANOVA statistical program. RESULTS The administration of Nigella sativa L. slightly reducedly gastric ulcer macroscopic ally starting at at dose 200 and 300 mg · kg -1 (P <0.05). Microscopic observation showed significant decreasing at dose 200 and 300 mg · kg -1 (P <0.05) .Interestingly, there was no significant difference between control and dose 300 mg · kg-1.Negative correlation between lesion and doses were-0.919, -0.953 for macroscopic and microscopic lesion respectively. It means there strong strong between between and lesion, higher dose lesser lesion. The mechanism of gastric protective of Nigellasativa L.may caused by the bioactive compound such as thymoquinone which known as antiinflammation and antioxidant. CONCLUSION Methanolic extract of Nigella sativa L. decreased peptic ulcer both macroscopic and microscopic conditions on indomethacin-induced rats.