Genistein attenuates ischemia/reperfusion injury in rat kidneys via enhancement of antioxidant defense mechanisms: Activation of Nrf-2/HO-1 signaling

Purpose: To investigate the protective role of genistein against ischemic reperfusion (I/R) injury in rat kidneys.Methods: Group I (control, n = 10) consisted of animals that were not operated on while group II (sham, n = 10) were animals surgically operated on, similar to I/R group without renal bilateral ischemia. Group III (genistein, n = 10) consisted of animals administered 10 mg/kg genistein by oral gavage for 7 consecutive days while group IV (I/R, n = 10) animals were subjected to 45 min of renal bilateral ischemia followed by 24 h of reperfusion. Group V (genistein+I/R, n = 10) received 10 mg/kg genistein by oral gavage for 7 consecutive days and then subjected to 45 min of renal bilateral ischemia followed by 24 h of reperfusion. Renal function, total oxidant capacity and total antioxidant status in serum were evaluated in the rats. Further, reactive oxygen species generation as well as levels of protein carbonyl, lipid peroxidation, and enzymatic and non-enzymatic antioxidants were determined. Nrf-2 (nuclear factor (erythroid-derived 2)-like 2) and HO-1 (Heme oxygenase-1) expressions were determined by western blot.Results: Pre-treatment with genistein (10 mg/kg) significantly (p < 0.001)  ameliorated I/R induced renal damage by reducing the levels of serum markers. Genistein pre-treatment significantly decreased (p <0.001) I/R injury induced-ROS, lipid peroxides and protein carbonyl content (p < 0.001). I/R injury significantly (p < 0.001) decreased non-enzymatic and enzymatic antioxidant activities. Genistein pretreatment also prevented renal I/R injury by significantly up-regulating Nrf-2, HO-1 expressions and antioxidant status.Conclusion: Thus, genistein may be therapeutically useful against kidney I/R injury by improving antioxidant defense mechanisms.Keywords: Oxidative stress, Genistein, Ischemic reperfusion injury, Renal damage, Antioxidant, Nuclear factor (erythroid-derived 2)-like 2, Heme oxygenase-1, Nrf-2, HO-1 Tropical Journal of Pharmaceutical Research is indexed by Science Citation Inde

Sign structure in the square-lattice tt-t′t^\prime-JJ model and numerical consequences

Understanding the doped Mott insulator is a central challenge in condensed matter physics. This study identifies an intrinsic Berry-phase-like sign structure for the square-lattice $t$-$t'$-$J$ model with the nearest-neighbor ($t$) and next-nearest-neighbor hopping ($t'$), which could help explain the origin of the quasi-long-range superconducting and stripe phases observed through density matrix renormalization group (DMRG) calculation. We first demonstrate that the hole binding underlies both the superconducting and stripe orders, and then show that the hole pairing generically disappears once the phase-string or mutual statistics component of the sign structure is switched off in DMRG calculation. In the latter case, the superexchange interaction no longer plays a crucial role in shaping the charge dynamics, where a Fermi-liquid-like phase with small hole Fermi pockets is found. It is in sharp contrast to the large Fermi surfaces in either the stripe phase found at $t'/t0$ in the original $t$-$t'$-$J$ model on the 6-leg ladder.Comment: 13 pages, 10 figure

Deconfined quantum criticality with emergent symmetry in the extended Shastry-Sutherland model

Motivated by the exotic critical phenomena observed in the Shastry-Sutherland material $\rm SrCu_2(BO_3)_2$ \blue{[Jimenez {\it et al}, Nature {\bf 592}, 370 (2021); Cui {\it et al}, Science {\bf 380}, 1179 (2023)]}, we investigate the ground state nature of the extended Shastry-Sutherland model (SSM) by the state-of-the-art 2D tensor network method. Via large-scale simulations up to $20\times 20$ sites, we identify a continuous phase transition between the plaquette valence-bond solid (PVBS) phase and the antiferromagnetic (AFM) phase accompanied by an emergent O(4) symmetry, which strongly suggests a deconfined quantum critical point (DQCP). Furthermore, we map out the phase diagram of the extended SSM and observe the same type of DQCP phenomena with emergent O(4) symmetry and similar critical exponents along the whole critical line. Our results indicate a compelling scenario for understanding the origin of the proximate DQCP observed in recent experiments.Comment: 5+6 pages; 4+5 figures; 3 table

Identification of Magnetic Interactions and High-field Quantum Spin Liquid in α\alpha-RuCl3_3

The frustrated magnet $\alpha$-RuCl$_3$ constitutes a fascinating quantum material platform that harbors the intriguing Kitaev physics. However, a consensus on its intricate spin interactions and field-induced quantum phases has not been reached yet. Here we exploit multiple state-of-the-art many-body methods and determine the microscopic spin model that quantitatively explains major observations in $\alpha$-RuCl$_3$, including the zigzag order, double-peak specific heat, magnetic anisotropy, and the characteristic M-star dynamical spin structure, etc. According to our model simulations, the in-plane field drives the system into the polarized phase at about 7 T and a thermal fractionalization occurs at finite temperature, reconciling observations in different experiments. Under out-of-plane fields, the zigzag order is suppressed at 35 T, above which, and below a polarization field of 100 T level, there emerges a field-induced quantum spin liquid. The fractional entropy and algebraic low-temperature specific heat unveil the nature of a gapless spin liquid, which can be explored in high-field measurements on $\alpha$-RuCl$_3$.Comment: To appear in Nature Communications (12 pages, 6 figures, and 5 Supplementary Notes

Transcriptional profiles of drought-responsive genes in modulating transcription signal transduction, and biochemical pathways in tomato

To unravel the molecular mechanisms of drought responses in tomato, gene expression profiles of two drought-tolerant lines identified from a population of Solanum pennellii introgression lines, and the recurrent parent S. lycopersicum cv. M82, a drought-sensitive cultivar, were investigated under drought stress using tomato microarrays. Around 400 genes identified were responsive to drought stress only in the drought-tolerant lines. These changes in genes expression are most likely caused by the two inserted chromosome segments of S. pennellii, which possibly contain drought-tolerance quantitative trait loci (QTLs). Among these genes are a number of transcription factors and signalling proteins which could be global regulators involved in the tomato responses to drought stress. Genes involved in organism growth and development processes were also specifically regulated by drought stress, including those controlling cell wall structure, wax biosynthesis, and plant height. Moreover, key enzymes in the pathways of gluconeogenesis (fructose-bisphosphate aldolase), purine and pyrimidine nucleotide biosynthesis (adenylate kinase), tryptophan degradation (aldehyde oxidase), starch degradation (β-amylase), methionine biosynthesis (cystathionine β-lyase), and the removal of superoxide radicals (catalase) were also specifically affected by drought stress. These results indicated that tomato plants could adapt to water-deficit conditions through decreasing energy dissipation, increasing ATP energy provision, and reducing oxidative damage. The drought-responsive genes identified in this study could provide further information for understanding the mechanisms of drought tolerance in tomato