Paraquat (PQ), an effective and widely used herbicide, has been proven to be safe when appropriately applied to eliminate weeds. However, PQ poisoning is an extremely frustrating clinical condition with a high mortality and with a lack of effective treatments in humans. PQ is known to induce injury via a redox cyclic reaction. The purpose of this study was to investigate the effect of aqueous extract Matricaria chamomilla.L (M. chamomilla) against PQ-induced liver injury in association with its antioxidant activity.The male rats were treated by gastric gavage daily with PQ (5 mg/kg/day) and M. chamomilla (50 mg/kg/day) were administered alone or in combination for 7 days. After treatments, total antioxidant capacity (TAC), total thiol molecules (TTG) levels and catalase (CAT) activity in liver tissue were measured. At the end of the experiment, plasma and lung tissue of the animals was separated. The activity of enzymatic scavengers such as CAT, TAC and TTG were measured in liver homogenate.In this sample, the TAC and TTG were lower in the PQ group as compared with control group. Co-administration of PQ with M. chamomilla extract increased TAC and TTG in liver tissue as compared with PQ group.In conclusion, M. chamomilla as natural antioxidant may be considered beneficial for the protection oxidative liver injury in PQ poisoning.

-Mitotic chromosome numbers are reported for fourteen populations of Tanactum polycephalum Schultz Bip. (L.) collected from west of Iran. In T. polycephalum, chromosome numbers were varied from 2n= 2x=18 to 2n=6x= 54. One diploid population (2n=2x=18) and two populations with both diploid and tetraploid chromosome numbers (2n=2x=18 and 36) were identifi ed. Five populations with chromosome number (2n=4x=36) and a population with two different chromosome numbers (2n=4x=36 and 54) were found for the fi rst time. In this species, four populations with hexaploidy (2n=6x=54) were detected for the fi rst time. Results indicate that polyploidy is confi rmed as the most signifi cant evolutionary trend in chromosome number within this species. This species is also a problemic and polymorph taxnon and our results indicate that its polyploidy can be regarded as the reason.

-Mitotic chromosome numbers are reported for thirty-three populations representing four species of Artemisia. In A. incana, chromosome numbers were varied from 2n = 2x = 16, 18 to 2n = 3x = 24. In A. fragrans eight diploid populations (2n = 2x = 18) and three populations with both diploid and tetraploid chromosome number (2n = 2x = 18, 36) were identifi ed. In A. scoparia six populations with chromosome number (2n = 2x = 16) and two populations with different chromosome number (2n = 2x = 16, 18) were found. The highest variation in chromosome number was observed in A. spicigera. In this species; different chromosome numbers (2n = 2x = 18, 2n = 3x = 27, 2n = 4x = 36, 2n = 5x = 45, 2n = 6x = 54 and 2n = 8x = 72) were identifi ed in different populations that collected from different parts of Iran. Polyploidy is confi rmed as the most signifi cant evolutionary trend in chromosome number within the genus.

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