Study of the inhibitory effects of chrysin and its nanoparticles on mitochondrial complex II subunit activities in normal mouse liver and human fibroblasts

Abstract

Background Mitochondrial complex ΙΙ has a unique biological role owing to its participation in both the citric acid cycle and the electron transport chain. Our goal was to evaluate the succinate dehydrogenase and ubiquinone oxidoreductase activity of mitochondrial complex II in the presence of chrysin and chrysin–chitosan nanoparticles. Chrysin chitosan nanoparticles were synthesized and characterized using ultraviolet spectroscopy, Fourier transform-infrared spectroscopy, X-ray diffraction, transmission electron microscopy, scanning electron microscopy, drug release, and zeta potential. The binding affinity of chrysin to complex II subunits was assessed by molecular docking. The IC50 values were measured in a suspension of mouse mitochondria, and the inhibitory effect of chrysin and chrysin chitosan nanoparticles on mitochondrial complex ΙΙ was determined. Results The free energy of binding between chrysin and complex ΙΙ subunits A, B, C, and D was −4.9, −5, −8.2, and −8.4 kcal/mol, respectively. The characteristic peak of chrysin was confirmed at 348 nm. The chrysin chitosan nanoparticles contained characteristic bands of both chrysin and chitosan. The crystalline nature of chrysin chitosan nanoparticles was confirmed by X-ray powder diffraction measurements showing the characteristic Bragg peaks of (11.2°), (32.2°), (19.6°), (27.6°), and (31.96°). Transmission and scanning electron microscopy revealed their spherical shape and an average particle size of 49.7 ± 3.02 nm. Chrysin chitosan nanoparticles showed a burst release within the initial 2 h followed by a steady release at 8 h. Their zeta potential was positive, between +35.5 and +80 mV. The IC50 of chrysin, chitosan nanoparticles, chrysin chitosan nanoparticles, and 5-fluorouracil was 34.66, 184.1, 12.2, and 0.05 μg/mL, respectively, in adult mice liver and 129, 311, 156, and 8.07 μg/mL, respectively, in normal human fibroblasts. When comparing the inhibitory effects on complex ΙΙ activity, application of the IC50 of chrysin, chitosan nanoparticles, chrysin chitosan nanoparticles, and 5-fluorouracil resulted in 40.14%, 90.9%, 86.7%, and 89% decreases in SDH activity and 70.09%, 86.74%, 60.8%, and 80.23% decreases in ubiquinone oxidoreductase activity in normal adult mice, but 80.9%, 89.06%, and 90% significant decreases in SDH activity, and 90%, 85%, and 95% decreases in ubiquinone reductase after treatment with chrysin, chrysin chitosan nanoparticles, and 5-fluorouracil, in normal human fibroblasts, respectively. Conclusions Chrysin and CCNPs exhibit potent inhibitory effects on SDH activity ubiquinone oxidoreductase activity.

Impairment of electron transport chain and induction of apoptosis by chrysin nanoparticles targeting succinate-ubiquinone oxidoreductase in pancreatic and lung cancer cells

“…All analytical grade reagents and chemicals used in this work were purchased from Sigma-Aldrich and were similar to those previously described (12). Superoxide dismutase (SOD) was purchased from Bio-Diagnostic Co. (Egypt).…”

“…The entrapment e ciency (EE) of chrysin was measured using a UV/Vis spectrophotometer (Shimadzu, Japan). Relevant calibration curves were established by using supernatants of standard chrysin solutions (10-100 g/mL) (12,15,16). Fourier transform-infrared (FT-IR) analysis was performed to elucidate the structures of pure chrysin and CCNPs (12,15).…”

“…Relevant calibration curves were established by using supernatants of standard chrysin solutions (10-100 g/mL) (12,15,16). Fourier transform-infrared (FT-IR) analysis was performed to elucidate the structures of pure chrysin and CCNPs (12,15). X-ray powder diffraction (XRD) was used to record XRD patterns of chitosan and CCNPs (12,17).…”

“…Morphology, size, and shape of the CNNP surface were investigated using scanning electron microscopy (SEM) after gold coating. (TESCAN VEGA 3 SBH model) (12,20). In vitro drug release was studied as previously described (12,21).…”

“…(TESCAN VEGA 3 SBH model) (12,20). In vitro drug release was studied as previously described (12,21). Brie y, the amount of chrysin released from microspheres at a given time was determined through the following equation:…”