Objective:To investigate the effects of hydro-alcoholic extract of Launaea acanthodes,a blood glucose lowering plant in folk medicine of Iran,on the structure of seminiferous tubules and serum gonadotropin and testosterone levels in hyperglycemic rats.Methods:Twenty-four Wistar rats were randomly allocated into4 groups(n=6):control,streptozotocin(STZ),STZ+insulin[STZ+Ins,5 IU/(kg·day)],and STZ+Launaea acanthodes extract[STZ+Ext,150 mg/(kg·day)].Blood samples were collected at the 2nd and 4th weeks for detection of testosterone,follicle stimulating hormone(FSH)and luteinizing hormone(LH)with enzyme-linked immuno sorbent assay(ELISA),and the right testes of rats were removed at the 7th week for the evaluation of diameter and wall thickness of seminiferous tubules and number of Leydig cells using unbiased stereological techniques.Results:In comparison with the control group,at the 2nd week FSH(0.45 vs 0.03,0.02,0.02 IU/L in STZ,STZ+Ins and STZ+Ext groups,respectively)and LH(1.02 vs 0.37,0.2,0.29 IU/L)showed significant decreases(all P<0.05)and testosterone(4.2 vs 8.37,7.78,11.8 ng/mL)showed a remarkable increase(all P<0.05).The levels of these hormones became closer in the STZ+Ext and the STZ+Ins groups to the control at the 4th week.A significant decrease in diameter and wall thickness of seminiferous tubules and number of Leydig cells were observed in the STZ group as compared with the control(P<0.01).Conclusions:Administration of Launaea extract demonstrated a beneficial impact on the protection of testis from pathogenic and degenerative effects of hyperglycemia which may be partly due to its potential antioxidative effects. Objective: To investigate the effects of hydro-alcoholic extract of Launaea acanthodes, a blood glucose lowering plant in folk medicine of Iran, on the structure of seminiferous tubules and serum gonadotropin and testosterone levels in hyperglycemic rats. Methods: Twenty-four Wistar rats were sorted allocated into4 groups: control, streptozotocin (STZ), STZ + insulin [STZ + Ins, 5 IU / (kg · day)], and STZ + Launaea acanthodes extract [STZ + Ext, 150 mg / kg · day)]. Blood samples were collected at the 2nd and 4th weeks for detection of testosterone, follicle stimulating hormone (FSH) and luteinizing hormone (LH) with enzyme-linked immuno sorbent assay (ELISA), and the right testes of rats were removed at the 7th week for the evaluation of diameter and wall thickness of seminiferous tubules and number of Leydig cells using unbiased stereological techniques. Results: In contrast with the control group, at the 2nd week FSH (0.45 vs 0.03,0.02,0.02 IU / L in STZ, STZ + Ins and STZ + Ext groups, respectively) and LH (1.02 vs 0.37 , 0.2,0.29 IU / L) showed significant decrements (all P <0.05) and testosterone (4.2 vs 8.37,7.78,11.8 ng / mL) showed a remarkable increase (all P <0.05). These levels of these hormones became closer in the STZ + Ext and the STZ + Ins groups to the control at the 4th week. A significant decrease in diameter and wall thickness of seminiferous tubules and number of Leydig cells were observed in the STZ group as compared with the control (P <0.01) .Conclusions: Administration of Launaea extract demonstrated a beneficial impact on the protection of testis from pathogenic and degenerative effects of hyperglycemia which may be partly due to its potential antioxidative effects.