Changes in activities of antioxidant enzymes in radish (Raphanus sativus) seedlings in response to allelopathic effect of safflower (Carthamus tinctorius)

Abstract ROS (Reactive Oxygen Species) production is a usual plant reaction to environmental stresses such as allelopathy. Plants possess antioxidant enzymes to scavenge cells and resist against the ROS. This study was conducted to evaluate changes in antioxidant enzymes (CAT, GPX, APX) in radish seedlings in response to allelopathic effect of safflower root and shoot residues grown under normal irrigation and drought stress. Safflower allelopathic effect led to an increase in antioxidant enzymes activities. GPX activity increased more than CAT and APX. Radish seedlings exposed to safflower residue grown under drought stress showed more antioxidant enzymes activities. Root residues enhanced the activities of antioxidant enzymes greater than shoot. Seedlings exposed to root residues grown under drought stress had the highest level of antioxidant enzymes activities.

The effect of melatonin on in vitro maturation fertilization and early embryo development of mouse oocytes and expression of HMGB1 gene in blastocysts

Antioxidants are commonly used for maturation, fertilization and early development of embryos. Melatonin as an antioxidant have been recently proven to be useful for the assisted reproductive technology. In the present study, we evaluated the roles of melatonin in the in vitro maturation, fertilization, development and also the gene expression of high mobility group box-1 (HMGB1) in the blastocysts. The immature oocytes of BDF1 mice were transferred to the media containing different doses of melatonin (10-6, 10-9, 10-12 M). The blastocysts that developed under in vitro fertilization from each group were stained to determine the cell number of embryos and analyzed to determine the expression level of HMGB1 by real-time PCR. The most effective doses of melatonin for maturation of oocytes were 10-6 and 10-12M (P<0.05). Fertilization rate, early development and the cell number of blastocysts were significantly higher in the group that treated with 10-12 M of melatonin comparing to the other groups. The HMGB1 expression decreased in groups that treated with 10-6M and 10-9M of melatonin and increased in the group that treated with 10-12 M of melatonin, but did not show a significant difference (p˃0.05). From the results, it may be concluded that the melatonin could be effective when the embryos undergo maturation, fertilization and early developmental processes. The HMGB1 expression, as a marker of early development in mice embryos, increased in the groups that treated with low doses of melatonin

Cryptococcus neoformans isolation from swallow (Hirundo rustica) excreta in Iran / Isolamento de Cryptococcus neoformans de excrementos de andorinhas (Hirundo rustica) do Irã

Cryptococcus neoformans is an encapsulated yeast that can cause cryptococcosis, a life-threatening infection that mainly occurs in immunocompromised patients. The major environmental sources of C. neoformans have been shown to be soil contaminated with avian droppings. In the present study, we evaluated the isolation of C. neoformans from swallow (Hirundo rustica) excreta in two northern cities of Iran. Ninety-seven swallow droppings were evaluated and 498 yeast-like colonies were isolated and identified as Rhodotorula spp. (62.8 percent), Candida spp. (28.5 percent)and C. neoformans (8.7 percent). Cryptococcus neoformans was isolated from 5/97 (5.2 percent) of collected samples. Min-Max colony forming units (CFU) per one gram for the positive samples were 3-10 C. neoformans colonies. The total mean CFU per one gram for the positive samples was 4.8. The results of this study demonstrate that excreta of swallow may harbor different species of potentially pathogenic yeasts, mainly C. neoformans, and may be capable of disseminating these fungi in the environment.

Cryptococcus neoformans é levedura encapsulada que pode causar criptococose, infecção potencialmente mortal que ocorre principalmente em pacientes imunocomprometidos. As principais fontes ambientais de C. neoformans são o solo contaminado com fezes de aves. No presente estudo, avaliamos o isolamento de C. neoformans de excreta de andorinhas (Hirundo rustica) em duas cidades do norte do Irã. Noventa e sete amostras de fezes de andorinhas foram avaliadas e 498 colonias semelhantes à levedura foram isoladas e identificadas como Rhodotorula spp. (62,8 por cento), Candida spp. (28,5 por cento), C. neoformans (8,7 por cento). Cryptococcus neoformans foi isolado a partir de 5/97 (5,2 por cento) das amostras coletadas. Unidades Min-Max formadoras de colonias (CFU) por 1 grama das amostras positivas foram 3-10 coloniasde C. neoformans. A média total de CFU por 1 grama das amostras positivas foi de 4,8. Os resultados deste estudo demonstram que excrementos de andorinhas podem abrigar diferentes espécies de leveduras potencialmente patógenas, principalmente C. neoformans, e podem ser capazes de disseminar estes fungos no meio ambiente.