Photosensitized paraquat-induced structural alterations and free radical mediated fragmentation of serum albumin

Genotoxic fungicide methyl thiophanate as an oxidative stressor inducing 8-oxo-7,8-dihydro-2′ -deoxyguanosine adducts in DNA and mutagenesis

“…The tubes containing reaction mixture were exposed to white light (20W/m 2 ) for 2 h. Parallel reactions with MT in dark and paraquat (in light), a well-known photosensitizer and ROS producer [17] were run as controls. The absorbance of blue color developed was read at 560 nm using Cintra 10e UVVisible spectrophotometer and plotted as a function of MT concentration.…”

Studies of the interaction between paraquat and bovine hemoglobin

“…Upon exposure to fluorescence lamp, photons are absorbed providing sufficient energy to transform the bipyridilium divalent cations (PQ 2+ ) to form a monocation free radical [31]. The oxidation of the bipyridilium radical to form the original PQ 2+ results in the transfer of an electron to oxygen and the formation of superoxide anions (O ·− 2 ).…”

“…Hemoglobin is the major hemoprotein of RBC. It has been reported that about 3% of the Hb in the RBC undergoes autoxidation daily with the concomitant production of superoxide (O ·− 2 ), which is in turn partially converted to hydrogen peroxide (H 2 O 2 ) either by superoxide dismutase or spontaneous dismutation [31]. Hence, the solution of PQ-BHb was irradiated in air at room temperature using a fluorescent lamp.…”

Fungicide methyl thiophanate binding at sub-domain IIA of human serum albumin triggers conformational change and protein damage

“…Also, the herbicides (atrazine and 2,4-D) have exhibited the binding constants of 3.5 × 10 4 M −1 and 8.0 × 10 3 M −1 for HSA, and induces major changes in the HSA secondary structure [19]. Our earlier studies on herbicide paraquat-BSA interaction have reported the binding constant (K a ) and binding capacity (n) of albumin as 3.4 × 10 5 l/mol and 12.9, respectively [16]. Other spectroscopic binding analysis of herbicide paraquat with HSA also demonstrated the paraquat mediated decline in the intrinsic fluorescence of HSA by static quenching and non-radioactive energy transferring [18].…”

“…Besides, the metals [11], vitamins [12], flavonoids [13], alkaloids [14], many organic dyes and pH indicator substances have also been reported to bind to HSA [15]. However, limited studies are reported in literature on the pesticides as exogenous ligands of HSA [16][17][18], and the extent and nature of binding of the insecticides, herbicides and fungicides with albumin have not been adequately explored. Silva et al [17] reported that the organophosphorous pesticide methyl parathion interacts with HSA with an association constant of 3.07 × 10 4 M −1 for the primary binding site close to tryptophan 214 residue.…”