Evaluation of Azadirachtin onArthrospira plantensisGomont growth parameters and antioxidant enzymes

Abstract

Azadirachtin (Aza) used as insecticide due to inhibiting growth of insects and preventing them from feeding on plants. To understand the effects of contamination of this insecticide on phototrophs, and to determine the responses of these organisms against these insecticides are extremely important in understanding how the ecosystem is affected. In this study, chlorophyll-a amount, OD 560 and antioxidant parameters (total SOD, APX, GR, Proline, MDA and H2O2) were determined in order to understand the effect of Aza on Arthrospira platensis Gomont. Aza was applied between 0–20 μg mL−1 concentrations for 7 days in the study. Enzyme analysis was conducted at the end of the 7th day. There was a statistically significant decrease in the absorbance of OD560 and the chlorophyll-a content in A. platensis cultures exposed to the Aza (0–20 μg mL−1) during 7 days due to the increase in pesticide levels. SOD activity decreased at 8, 16 and 20 μg mL−1 concentrations; GR enzyme activity showed a significant decrease compared to the control at a concentration of 20 μg mL−1. APX activity did not change significantly compared to control. The MDA content increased significantly at 16 and 20 μg mL−1 concentrations. The H2O2 content significantly increased at 12, 16 and 20 μg mL−1 concentrations (p < 0.05) while the free proline content decreased at 4 μg mL−1 concentration (p < 0.05). As a result, regarding the Aza concentrations used in this study may be a step to prevent pesticide pollution in the environment.

Algaecidal and oxidative effects of metal-free phthalocyanine beta tetra-substituted with sodium 2-mercaptoethanesulfonate

“…The culture extractions were conducted according to Tunca et al [ 25 ], and the samples were deep-freezed until enzyme assays (at −20 °C). On the assay day, samples were pounded with liquid nitrogen and specific buffers of each enzyme were used to suspend the samples.…”

“…A total of 3 mL of 0.1% TCA (Trichloroacetic acid) (4 °C) was used for homogenization of 0.2 g pellet. After centrifugation at 4100 rpm for 15 min, the supernatant was used to perform the assay as described in Tunca et al [ 25 ]. The non-specific absorbance at 600 nm and the absorbance at 532 nm were recorded, and they substracted from each other.…”

“…1 mL of 1 M KI, 0.5 mL of 0.1 M Tris–HCl (pH = 7.6), and 0.5 mL of supernatant were mixed to determinate of the H 2 O 2 content. After 90 min, the absorbance at 390 nm was measured, and H 2 O 2 content was calculated as described in Tunca et al [ 25 ].…”

“…A total of 10 Ml of 3% aqueous sulphosalicylic acid was used to homogenize 0.1 g of pellet. The samples were used to carry out as described in Tunca et al [ 25 ], and the absorbance at 520 nm was measured by spectrophotometrical methods.…”

“…GR reduces oxidized glutathione into reduced glutathione to reproduce ascorbic acid and to maintain the activity of APX in cells [ 19 – 23 ]. In non-enzymatic parameters, proline is known to increase during the oxidative stress process [ 24 – 25 ]. On the other hand, MDA is a molecule that provides the evaluation of membrane damage in cells and is formed by the oxidation of fatty acids containing more than one double bond [ 26 – 27 ].…”