Cell suspension cultures of Trigonella foenum graecum L. (fenugreek) were initiated from the cotyledon portions of sterile germinated seeds and maintained on MS medium supplemented with 2,4-dichlorophenoxy acetic acid (2, 4-D) (1 mg/l), kinetin (0.1 mg/l) and sucrose (5%). The changes in cell mass and both trigonelline and 4- hydroxyisoleucine content were followed between days zero and 12. The linear increase in fresh weight was found to be parallel to both trigonelline and 4-hydroxyisoleucine production. Cell suspension cultures treated with 100 μM methyl jasmonate (MJ) for 24 hours showed a noticeable increase in the level of trigonelline and 4-hydroxyisoleucine. The marked improvement in the histological and electron microscopically pictures of pancreas of STZ-diabetic rats fed with extract of cells treated with MJ is coincided with more effective and significant hypoglycemic activity than that for seeds extract. The extract of cultured cells treated with MJ lowered blood glucose from 284 ± 7.4 to 123 ± 8.1 units and increased the insulin level from 4.42 ± 0.23 μU/ml to a high level 8.33 ± 0.41 μU/ml.