Pre‐clinical evidence of safety and protective effect of isatin and oxime derivatives against malathion‐induced toxicity

Exogenous acetone O-(2-naphthylsulfonyl)oxime improves the adverse effects of excess copper by copper detoxification systems in maize

The current study is to elucidate the responses of maize seedlings to excess copper and acetone O-(2-naphthylsulfonyl)oxime (NS) pretreatment. The study was divided into the following experimental groups: 18 h distilled water (DW) control (C), 6 h 0.3 mM NS + then 12 h DW (NS), 6 h DW + then 12 h 1 mM CuSO4.5H2O (CuS), 0.3 mM NS for 6 h + then 1 mM CuSO4.5H2O (NS + CuS) for 12 h. When the NS + CuS group is compared with the CuS group; It accumulated 10% more copper, while the ABA, H2O2, MDA, and carotenoid contents decreased significantly, the total chlorophyll, proline, gallic acid, ascorbic acid, catechol, trans-P-qumaric acid, and cinnamic acid contents increased. While SOD activity, which is one of the antioxidant system enzymes, decreased with NS application, GPX, CAT, and APX activities increased despite copper stress. When all the findings are evaluated as a whole, exogenous NS, despite excessive copper, ameliorated the adverse effects of copper stress by increasing the effectiveness of the enzymatic and non-enzymatic components of the antioxidant system and the contents of phenolic substances. In addition, increasing the copper content by 10% reveals its importance in terms of NS phytoremediation.Abbreviation: Style-sheet: When full form and abbreviated form both are used as keywords, retain both as provided by the author.

Exogenous acetone O-(4-chlorophenylsulfonyl) oxime alleviates Cd stress-induced photosynthetic damage and oxidative stress by regulating the antioxidant defense mechanism in Zea mays

Cadmium (Cd) toxicity in leaves decreases their photosynthetic efficiency by degrading photosynthetic pigments, reducing the activity of gas exchange parameters and photosystem II (PSII), and producing reactive oxygen species. Although acetone O-(4-chlorophenylsulfonyl) oxime (AO) alleviates stress due to heavy metals in plants, its effects on the photosynthetic apparatus and redox balance under Cd stress are not clear. Herein, the role of AO in modulating the relationship between the antioxidant defense system and photosynthetic performance including chlorophyll fluorescence and gas exchange in mitigating the stress damage caused by Cd in maize seedlings was investigated. Three-week-old maize seedlings were pre-treated with AO (0.66 mM) and exposed to 100 µM Cd stress. Our findings indicated that AO application increased Cd accumulation, thiobarbituric acid-reactive substances (TBARS), photosynthetic rate, hydrogen peroxide (H2O2), total chlorophyll and carotenoid, transpiration, stomatal conductance, maximum photochemical efficiency of PSII (Fv/Fm), effective quantum yield of PSII (ΦPSII), intercellular CO2 concentration, photochemical quenching (qP), superoxide dismutase, electron transport rate, proline, ascorbate peroxidase, catalase, guaiacol peroxidase, 4-hydroxybenzoic acid, catechol, and cinnamic acid in maize seedling under Cd stress. Conversely, AO significantly reduced oxidative damage levels (H2O2, TBARS). It was concluded that exogenous AO can overcome Cd-mediated oxidative damage and hence protect the photosynthetic machinery by providing stress tolerance and regulating the antioxidant defense mechanism, which includes proline, phenolic compounds, and antioxidant enzyme activities.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12298-022-01258-5.

Could acetone O-(4-chlorophenylsulfonyl)oxime be a copper chelating and antioxidative molecule on maize seedlings?

The main purpose of study is to determine if Acetone O- (4-chlorophenylsulfonyl) oxime (AO) has a positive effect on maize seedlings under copper (Cu) stress or not. Seedlings were allocated to following experimental groups: 18-hour distilled water (DW) Control (C), ago 6-hour 0.66 mM AO + later 12-hour DW (AO), ago 6-hour DW + later 12-hour 1 mM Cu (Cu), ago 6-hour 0.66 mM AO + later 12-hour 1 mM Cu (AO + Cu). The results showed that AO + Cu caused approximately three times more copper accumulation compared to Cu treatment. AO and AO + Cu treatments significantly decreased membrane damage and H₂O₂ formation compared to its control. The proline content was significantly increased in AO and AO + Cu compared to its control. While the highest catalase, Guaiacol Peroxidase and superoxide dismutase activity was observed in Cu application, the highest ascorbate peroxidase activity was determined in AO application. It was observed that AO had a protective effect on chlorophyll content and RWC, but a positive effect on carotenoid content could not be determined. In addition, the effects of AO on the content of 17 phenolic substances in maize leaves were determined. In the light of the current findings, AO may prevent the formation of radical compounds.

Potential role of a newly AChE reactivator in the depressive-like behavior induced by malathion

AChE inhibition caused by exposure to organophosphate (OP) compounds is strongly related to behavioural disorders such as depression. Malathion is an OP that already has a relationship between its exposure and behavioural changes, although few data still have its effects in a longer exposure protocol. In addition, intoxication therapy is based on the use of atropine-oxime which still has its controversial efficacy depending on the type of compound. For this, (3Z)-5-Chloro-3-(hydroxyimino)indolin-2-one (Cℓ-HIN), a compound that has properties of isatin and oxime in its structure, have shown reactivating properties in the activity of AChE that have been added to antidepressant-like effects in rats exposed to malathion in acute protocol. In this sense, effects of Cℓ-HIN on the depressive-like behaviour and AChE activity were evaluated in a protocol of subchronic exposure to malathion in rats. Male wistar rats were co-treated with Cℓ-HIN [5 mg/kg, p.o.] and/or malathion [1 or 10 mg/kg, i.p] for 20 days. The exposure to both doses of malathion increased immobility time of rats on the forced swimming test (FST). Besides, malathion inhibited the AChE activity in the prefrontal cortex of rats, but any significant difference was observed in the hippocampus. Cℓ-HIN protected against increased immobility time in the FST of those rats exposed to a dose of 1 mg/kg of malathion. Similarly, Cℓ-HIN was able to reactivate AChE activity only in that group exposed to the lowest dose of malathion. Collectively, the results of this study suggest that Cℓ-HIN is an oxime capable of reactivating AChE inhibited and presents na antidepressant-like effect in cases of prolonged exposure to malathion.