Lipid Peroxidation Content Research Articles

Molecular mechanisms of ferroptosis and the potential therapeutic targets of ferroptosis signaling pathways for glioblastoma.

Ferroptosis is a newly identified form of cell death that differs from autophagy, apoptosis and necrosis, and its molecular characteristics include iron-dependent lipid reactive oxygen species accumulation, mitochondrial morphology changes, and membrane permeability damage. These characteristics are closely related to various human diseases, especially tumors of the nervous system. Glioblastoma is the most common primary malignant tumor of the adult central nervous system, and the 5-year survival rate is only 4%-5%. This study reviewed the role and mechanism of ferroptosis in glioblastoma and the research status and progress on ferroptosis as a potential therapeutic target. The mechanism of ferroptosis is related to the intracellular iron metabolism level, lipid peroxide content and glutathione peroxidase 4 activity. It is worth exploring how ferroptosis can be applied in disease treatment; however, the relation between ferroptosis and other apoptosis methods is poorly understood and methods of applying ferroptosis to drug-resistant tumors are insufficient. Ferroptosis is a promising therapeutic target for glioblastoma. In-depth studies of its mechanism of action in glioblastoma and applications for clinical treatment are expected to provide insights for glioblastoma patients.

Biochemical and Transcriptional Responses in Cold-Acclimated and Non-Acclimated Contrasting Camelina Biotypes under Freezing Stress.

Cold-acclimated and non-acclimated contrasting Camelina (Camelina sativa L.) biotypes were investigated for changes in stress-associated biomarkers, including antioxidant enzyme activity, lipid peroxidation, protein, and proline content. In addition, a well-known freezing tolerance pathway participant known as C-repeat/DRE-binding factors (CBFs), an inducer of CBF expression (ICE1), and a cold-regulated (COR6.6) genes of the ICE-CBF-COR pathway were studied at the transcriptional level on the doubled-haploid (DH) lines. Freezing stress had significant effects on all studied parameters. The cold-acclimated DH34 (a freezing-tolerant line) showed an overall better performance under freezing stress than non-acclimated plants. The non-cold-acclimated DH08 (a frost-sensitive line) showed the highest electrolyte leakage after freezing stress. The highest activity of antioxidant enzymes (glutathione peroxidase, superoxide dismutase, and catalase) was also detected in non-acclimated plants, whereas the cold-acclimated plants showed lower enzyme activities upon stress treatment. Cold acclimation had a significantly positive effect on the total protein and proline content of stressed plants. The qRT-PCR analysis revealed significant differences in the expression and cold-inducibility of CsCBF1-3, CsICE1, and CsCOR6.6 genes among the samples of different treatments. The highest expression of all CBF genes was recorded in the non-acclimated frost-tolerant biotype after freezing stress. Interestingly a significantly higher expression of COR6.6 was detected in cold-acclimated samples of both frost-sensitive and -tolerant biotypes after freezing stress. The presented results provide more insights into freezing tolerance mechanisms in the Camelina plant from both a biochemical point of view and the expression of the associated genes.

Therapeutic Efficacy of Natural Product 'C-Phycocyanin' in Alleviating Streptozotocin-Induced Diabetes via the Inhibition of Glycation Reaction in Rats.

Diabetes is a long-term metabolic disorder characterized by persistently elevated blood sugar levels. Chronic hyperglycemia enhances glucose-protein interactions, leading to the formation of advanced glycation end products (AGEs), which form irreversible cross-links with a wide variety of macromolecules, and accumulate rapidly in the body tissues. Thus, the objective of this study was to assess the therapeutic properties of C-phycocyanin (C-PC) obtained from Plectonema species against oxidative stress, glycation, and type 2 diabetes mellitus (T2DM) in a streptozotocin (STZ)-induced diabetic Wistar rat. Forty-five days of C-PC administration decreased levels of triglycerides (TGs), blood glucose, glycosylated hemoglobin, (HbA1c), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), liver and kidney function indices, and raised body weight in diabetic rats. C-PC suppressed biochemical glycation markers, as well as serum carboxymethyllysine (CML) and fluorescent AGEs. Additionally, C-PC maintained the redox state by lowering lipid peroxidation and protein-bound carbonyl content (CC), enhancing the activity of high-density lipoprotein cholesterol (HDL-C) and renal antioxidant enzymes, and preserving retinal and renal histopathological characteristics. Thus, we infer that C-PC possesses antidiabetic and antiglycation effects in diabetic rats. C-PC may also act as an antidiabetic and antiglycation agent in vivo that may reduce the risk of secondary diabetic complications.

Effect of systemic ozone use on oxidative modification of lipids and proteins in the colon in experimental colitis

Introduction. The processes of free radical oxidation play a significant role in the pathogenesis of inflammatory bowel diseases. The aim of the work was to study the clinical status, the content of lipid peroxidation products, oxidative modification of proteins in the lesion of the colon in oxazole-induced colitis (OIC) under conditions of intraperitoneal application of ozone. Materials and methods. Wistar rats were modeled for OIC using oxazolone solution. Ozone-oxygen mixture (OX) was injected intraperitoneally once a day for six days. The clinic was assessed by disease activity index (DAI), the content of products of lipid peroxidation (LPO) and oxidative modification of proteins (OMB) was determined in colonic homogenate. Results. Under OIK DAI increases, the level of primary and secondary products in the heptane phase increases in the colonic homogenate; the level of secondary products and end products increased in the isopropanol phase. Under conditions of intraperitoneal application of ozone, DAI decreased, the level of isopropanol-soluble primary, secondary, final LPO products increased in colon homogenate on the 2nd day, the level of heptane- and isopropanol-soluble primary, secondary, final LPO products decreased on the 6th day, early and late LPO products decreased on the 4th, 6th day. We found a moderate and significant relationship on the Cheddock scale between DAI and the content of LPO and OMB products in the colonic homogenate mainly on day 6 of OIC under conditions of intraperitoneal application of ozone. Discussion. The increased content of LPO and OMB products in the lesion of the colon after the use of ozone is probably due to its mediated action (through the activation of ROS) and its ability to act as an oxidant of lipids and proteins of the cells of the mucosa of the colon. Conclusions. The positive effects of intraperitoneal application of ozone in OIC are the basis for further research in studying the mechanism of the protective effect of ozone with the possibility of further application in clinical conditions in inflammatory bowel diseases.

Impact of nitrite exposure on oxidative stress and antioxidative-related genes responses in the gills of Procambarus clarkii

Nitrite is the major environmental pollutant in the freshwater aquaculture environment, which has a negative impact on aquatic species growth. Currently, we know that the main way nitrite enters crustaceans is through their gills. In this study, a total of 96 h acute nitrite stress (60 mg/L) experiments were conducted, and the impact of the serum biochemical parameters, gill oxidase activity and oxidative-related gene expression of red swamp crayfish were evaluated. After exposure to nitrite for 0, 6, 12, 24, 48, and 96 h, hemolymph and gills samples were taken at each time point. In the serum, acute nitrite stress significantly increased glutamic-oxaloacetic transaminase (GOT) and alanine aminotransferase (ALT) activities after 6 h of exposure, decreased total protein (TP) and albumin (ALB) levels after 24 h and 48 h of exposure, respectively. In the gills, the activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were enhanced to the maximum level at 12 h, 24 h and 24 h, respectively. The contents of malondialdehyde (MDA) and lipid peroxide (LPO) were increased significantly after 12 h and 24 h exposure, respectively. In addition, the expression levels of antioxidative-related genes, including hsp70, fer and mt, were significantly upregulated in the gills after 6 h of exposure. The results indicated that acute nitrite stress changed the serum physiological status, induced oxidative stress and caused damage to gill cells in P. clarkii.

Comparative screening of cadmium stress responses among three rice cultivars

Plants are frequently confronted with heavy metal stress, which is one of the major environmental concerns in agriculture. Cadmium is a potent toxic and hazardous soil contaminant that is introduced into the atmosphere by industrial pollution. It can impose detrimental effects on plant growth, crop productivity and quality. To evaluate Cd-induced physio-biochemical stress response, a comparative study was conducted with three rice (Oryza sativa L.) cultivars (‘Maharaj’, ‘Pratiksha’ and ‘Khitish’) treated with 10 µM CdCl2. Cytotoxicity assessments were performed to determine cell death rates. The study confirmed that cv. ‘Maharaj’ was the most Cd stress tolerant due to high proline, phytochelatin, and antioxidant concentration, resulting in lower cell death rate. Cv. ‘Pratiksha’ was moderately tolerant while cv. ‘Khitish’ was more susceptible to Cd stress, showing drastic reduction in cysteine and sugar concentration, and Hill activity, with noticeable increase of lipid peroxidation, methylglyoxal and starch concentration.

Protein Carbonyl, Lipid Peroxidation, Glutathione and Enzymatic Antioxidant Status in Male Wistar Brain Sub-regions After Dietary Copper Deficiency.

Copper a quintessential transitional metal is required for development and function of normal brain and its deficiency has been associated with impairments in brain function. The present study investigates the effects of dietary copper deficiency on brain sub-regions of male Wistar rats for 2-, 4- and 6-week. Pre-pubertal rats were divided into four groups: negative control (NC), copper control (CC), pairfed (PF) and copper deficient (CD). In brain sub regions total protein concentration, glutathione concentration and Cu-Zn SOD activity were down regulated after 2-, 4- and 6weeks compared to controls and PF groups. Significant increase in brain sub regions was observed in protein carbonyl and lipid peroxidation concentration as well as total SOD, Mn SOD and catalase activities after 2-, 4- and 6weeks of dietary copper deficiency. Experimental evidences indicate that impaired copper homeostasis has the potential to generate reactive oxygen species enhancing the susceptibility to oxidative stress by inducing up- and down-regulation of non-enzymatic and enzymatic profile studied in brain sub regions causing loss of their normal function which can consequently lead to deterioration of cell structure and death if copper deficiency is prolonged.

Pengaruh Pemberian Dehydroepiandrosterone (DHEA) terhadap Aktivitas Peroksidasi Lipid dan Kadar Nitrit Oksida pada Aorta Tikus Wistar Jantan yang Terpapar Asap Rokok

The research aimed to investigate the effect of dehydroepiandrosterone (DHEA) on lipid peroxidation activity and nitric oxide concentration in the aorta of male Wistar rats due to exposure to cigarette smoke. This study was a laboratory experiment using 21 rats that were divided into 3 groups: KN-14 (negative control that is given smoke exposure within 14 days), DHEA-1 (15 mg/kgBW + smoke exposure for 14 days), and DHEA-2 (30 mg/kgBW + smoke exposure for 14 days). The exposure was carried out in 25-45 minutes with 4 cigarettes/day. Surgery was performed in the 15th days to remove the aorta to examine malondialdehyde (MDA) as a biomarker of lipid peroxidation and nitric oxide (NO) concentration using Enzyme-linked Immunosorbent Assay (ELISA). The results showed that a significant increase in MDA concentrations was found in the group administered with DHEA, particularly at a dose of 30 mg/kgBW (p<0.05). Meanwhile, the administration of DHEA at doses of 15 and 30 mg/kgBW did not have a significant effect (p>0,05) on aortic NO concentrations compared to the group KN-14. Therefore, it can be concluded that the administration of DHEA could increase lipid peroxidation activity, as indicated by a significant increase in aortic MDA concentrations, without affecting aortic NO concentrations in rats exposed to cigarette smoke for 14 days.Keyword: Dehydroepiandrosterone (DHEA), MDA, NO, lipid peroxidation, exposure of cigarettes smoke

Ferroptosis Induction and YAP Inhibition as New Therapeutic Targets in Gastrointestinal Stromal Tumors (GISTs).

Simple SummaryDespite targeted therapy with tyrosine kinase inhibitors (TKIs), unresectable or metastatic human GISTs generally relapse under treatment. Thus, alternative therapeutic approaches are needed to overcome GIST resistance. Ferroptosis, a cell death driven by iron-dependent phospholipid peroxidation, is an emerging therapeutic approach in cancers. However, the potential of ferroptosis induction in GISTs remains largely unknown. This study shows that GIST cell lines are highly sensitive to the type II ferroptosis inducer, RSL3. We also provide evidence that inhibition of YAP by verteporfin (VP) promotes ferroptosis in GIST cells while, surprisingly, CA3 mediates ferroptosis independently of YAP inhibition. Finally, we highlight a positive correlation between the highly expressed transferrin receptor protein 1 (TFRC), GISTs with elevated mitotic counts or higher risk, and with YAP expression/activation in human GIST tissue microarrays (TMA). Taken together, our results suggest that induction of ferroptosis and/or modulation of YAP activity offer promising perspectives for GIST treatment.GISTs are sarcomas of the gastrointestinal tract often associated with gain-of-function mutations in KIT or PDGFRA receptor genes. While most GISTs initially respond to tyrosine kinase inhibitors, relapses due to acquired resistance frequently occur. The induction of ferroptosis, an iron-dependent form of non-apoptotic cell death, emerged as a novel therapeutic approach in cancers and remains poorly characterized in GISTs. We studied hallmarks of ferroptosis, i.e., lipid peroxidation, iron and glutathione content, and GPX4 protein expression in imatinib-sensitive (GIST882) and -resistant (GIST48) GIST cell lines. GIST cells were highly sensitive to the induction of ferroptosis by RSL3, which was reversed by liproxstatin and deferoxamine. Lipid peroxidation and ferroptosis were mediated by VP and CA3 in GIST cells through a significant decrease in antioxidant defenses. Moreover, VP, but surprisingly not CA3, inhibited a series of target genes downstream of YAP in GIST cells. The ferroptosis marker TFRC was also investigated by immunohistochemistry in GIST tissue arrays. TFRC expression was observed in all samples. High TFRC expression was positively correlated with high-risk GISTs, elevated mitotic count, and YAP nuclear localization, reflecting YAP activation. This study highlights ferroptosis as a novel cell death mechanism in GISTs, and a potential therapeutic target to overcome resistance to tyrosine kinase inhibitors.

BSA-assisted synthesis of nanoreactors with dual pH and glutathione responses for ferroptosis and photodynamic synergistic therapy of colorectal cancer

Colorectal cancer (CRC) is the third most common cancer in global incidence and second most common cancer in global mortality rates, accounting for 10% of all cancer cases and 9.4% of all cancer-related deaths. CRC is a heterogeneous disease, mostly comprising sporadic tumors. Approximately 19%–28% of patients have postoperative metastasis. In this study, we report an epigallocatechin gallate (EGCG)-based metal polyphenol network (MPN) with CD44 targeting, glutathione (GSH) sensitivity and pH response for the codelivery of the photosensitizers chlorin e6 (Ce6) and Fe3+. Photodynamic therapy (PDT) has become a potential clinical treatment method because of its noninvasive nature, low toxicity and spatiotemporally controlled treatment capability. Ferroptosis is a nonapoptotic cell death caused by peroxidative modification of phospholipid membranes via iron-dependent mechanisms. We unified ferroptosis and PDT into a nanoreactor (BSA-Ce6@MPN, BCM) to treat CRC. In vitro analysis showed that laser-irradiated BCM increased the cellular reactive oxygen species (ROS) and lipid peroxide (LPO) contents and decreased the expression levels of GSH and glutathione peroxidase 4 (GPX4). BCM-mediated ferroptosis and PDT synergistic therapy were significantly effective in the CT26 tumor-bearing mouse model, demonstrating the efficacy of the combination therapy. These results suggest that the nanoreactor for the synergistic treatment of ferroptosis and PDT holds great promise for clinical translation.

Effects of drought stress on flowering soybean physiology under different soil conditions

Soybean is highly sensitive to drought stress during its flowering period. Heinong84 (HN84) and Hefeng46 (HF46) were planted in clay loam, silty loam, and sandy clay. We studied the effects of drought stress on the content of membrane lipid peroxides in flowering soybean leaves, the activity of antioxidant enzymes, and the activity of key enzymes of nitrogen metabolism under different soil conditions. Our results showed that soybean had clear physiological responses to drought stress. With increasing drought stress, the malondialdehyde, glutathione reductase, and glutathione peroxidase levels in soybean leaves increased continuously. Superoxide dismutase, peroxidase, glutamine synthase, and glutamate synthase levels increased with drought stress, reaching a maximum under moderate drought stress and then decreased; nitrate reductase activity decreased continuously. Under the condition of sufficient water, the performance of soybean in the three soils is almost the same, but there are differences under drought stress; particularly, soybean grown in clay loam shows the strongest drought resistance. In summary, the physiological state of soybean is easily affected by drought stress, which varies greatly among different cultivars and in different soil types.

Impact of 17-β estradiol on growth and metabolism of marine diatom Thalassiosira weissflogii

• Cultivation of T.weissflogii on synthetically designed media of seawater and estradiol. • Biomass productivity and cell number declined with increase of E2 concentration in samples. • Enhanced production of protein and carbohydrate content mainly in samples T4 and T5. • The level of oxidative stress induced was assessed through MDA and other enzymatic reactions. The inefficiency of existing effluent treatment systems to eliminate pharmaceutical chemicals like endocrine disrupting estrogenic compounds from contaminated waters has raised global environmental and ecological concerns. Diatoms are unicellular, eukaryotic phytoplankton that inhabits ubiquitously and possess adaptive plasticity which enables them to withstand rapid environmental fluctuations. Thus, diatoms can be employed as indicators organisms and bioremediation agents of even trace amounts of Pharmaceutical Contaminants (PCs) like the estrogenic compounds. In this study, the influence of simulated wastewater containing pharmaceutical effluent 17-β Estradiol (E2) on the growth, cellular metabolites and oxidative stress response of the diatom, Thalassiosira weissflogii was assessed. Though an increasing concentration of the chemical displayed a negative correlation with growth, number of cells and biomass productivity; the photosynthetic profile of the diatom showed varied responses with significant enhancement in chlorophyll a and carotenoid content. The test concentrations T1 and T3 showed elevated carbohydrate and protein levels (0.82 ± 0.003 g L -1 and 2.04 ± 0.020 g L -1 ) establishing that E2 stress can be optimised to enhance primary metabolite secretion in diatoms, thereby valorizing its potential as suitable aqua feed. Besides this, an elevation in the antioxidative response against the reactive oxygen species generated was also distinctly recorded with respect to the increased release of catalase (152.70 ± 0.05–265.52 ± 0.06 k mg -1 ) and ascorbate peroxidases (0.959 ± 0.008–1.92 ± 0.021 U mg -1 ) as well as a conspicuous increment in the lipid peroxidation and hydrogen peroxide content was also there. Thus, this novel strategy of employing diatom for multitude of biorefinery aspects besides reacclimating contaminated water reveals the perspective application of this approach. .

Investigating the using potential of Schiff base molecule as an exogenous antioxidant on barley seeds under salt stress conditions

Salt stress is one of the most important environmental factors that affect agricultural lands and causes product loss. Today, the application of various natural or synthetic molecules exogenously to plants and efforts to increase plant tolerance against environmental stresses as a result of these applications have been widely investigated by scientists. In this study, a Schiff base molecule (0, 3, 6, and 9 µM), which has shown in vitro antioxidant properties, was applied to barley seeds under salt stress (0, 50, 150, and 250 mM NaCl). In order to evaluate the effects of this molecule on barley under salt stress, seed germination, growth parameters, lipid peroxidation, proline content, histochemical detection of superoxide and hydrogen peroxide radicals, and mitotic index analysis were conducted. According to the results, salt stress decreased germination parameters, plumule and radicle lengths, and mitotic index while it increased proline content, lipid peroxidation, and radical contents. Schiff base treatment clearly reduced lipid peroxidation and radical content in all groups. However, it also decreased germination and growth parameters and mitotic index. The obtained results showed that the antioxidant property of this molecule was also preserved in plants under stress, but it was also determined that the molecule had negative effects, primarily on cell division. If necessary modifications can be made to the molecule, the negative effects on cell division can be eliminated, and this molecule, which is very easy and cheap to obtain, may be widely used to increase the tolerance of plants against environmental stress.

Single cell RNA-seq analysis identifies ferroptotic chondrocyte cluster and reveals TRPV1 as an anti-ferroptotic target in osteoarthritis.

SummaryBackgroundOsteoarthritis (OA) is the most common degenerative joint disease primarily characterized by cartilage destruction. The aim of this study was to investigate the role, molecular characteristics and potential therapeutic target of chondrocyte ferroptosis in the pathogenesis of OA.MethodsThe expression of ferroptotic hallmarks (iron and lipid peroxidation accumulation, glutathione deletion) were analyzed in paired intact and damaged cartilages from OA patients. Single cell RNA sequencing (scRNA-seq) analysis was performed on 17,638 chondrocytes to verify the presence, investigate the molecular signatures and unveil the potential therapeutic target of ferroptotic chondrocyte cluster in human OA cartilages. Destabilization of medial meniscus (DMM)-induced OA model and tert-butyl hydroperoxide (TBHP)-treated primary mouse chondrocytes and human cartilage explants were used to evaluate the protective effect of pharmacologically activated transient receptor potential vanilloid 1 (TRPV1). The downstream molecular mechanisms of TRPV1 was further investigated in glutathione peroxidase 4 (Gpx4) heterozygous genetic deletion mice (Gpx4+/−).FindingsThe concentrations of iron and lipid peroxidation and the expression of ferroptotic drivers in the damaged areas of human OA cartilages were significantly higher than those in the intact cartilage. scRNA-seq analysis revealed a chondrocyte cluster characterized by preferentially expressed ferroptotic hallmarks and genes, namely ferroptotic chondrocyte cluster. Comprehensive gene set variation analysis revealed TRPV1 as an anti-ferroptotic target in human OA cartilage. Pharmacological activation of TRPV1 significantly abrogated cartilage degeneration by protecting chondrocytes from ferroptosis. Mechanistically, TRPV1 promoted the expression of GPX4, and its anti-ferroptotic role was largely mitigated in the OA model of Gpx4+/− mice.InterpretationTRPV1 activation protects chondrocytes from ferroptosis and ameliorates OA progression by upregulating GPX4.FundingNational Key R&D Program of China (2018YFC1105904), Key Program of NSFC (81730067), National Science Foundation of China (81772335, 81941009, 81802196), Natural Science Foundation of Jiangsu Province, China (BK20180127), Jiangsu Provincial Key Medical Talent Foundation, Six Talent Peaks Project of Jiangsu Province (WSW-079).

Effect of daidzein on growth, development and biochemical physiology of insect pest, Spodoptera litura (Fabricius)

Anti- insecticidal potential of daidzein was studied by feeding second instar larvae of Spodoptera litura (Fabricius) on artificial diet incorporated with different concentrations (5 ppm, 25 ppm, 125 ppm, 625 ppm) of diadzein. Results revealed high larval mortality, prolongation of pupal and total developmental period of the larvae treated with diadzein. Anti-nutritional/post ingestive toxicity of diadzein was also revealed by the decrease in the nutritional indices such as relative growth rate (RGR), relative consumption rate (RCR), efficiency of conversion of digested food (ECD), efficiency of conversion of ingested food (ECI) and approximate digestibility (AD). The suppression of immune function due to decline in the total hemocytes count was also observed in treated S. litura larvae. Profiles of detoxifying enzymes viz. superoxide dismutases (SOD), catalase (CAT), ascorbate peroxidases (APOX) and glutathione S-transferase (GST) were also significantly increased with diadzein treatment. The hydrogen peroxide content (H2O2), lipid peroxide content (LP) and protein carbonyl content were also significantly enhanced in the treated larvae thus, indicating oxidative stress in the insect. Our findings suggest that daidzein can be used as the alternative to conventional pesticides for controlling S. litura population.

How does UV‐B stress affect secondary metabolites of Scutellaria baicalensis in vitro shoots grown at different 6‐benzyl aminopurine concentrations?

Ultraviolet-B (UV-B) radiation is one of the abiotic stresses that can significantly affect the secondary metabolite accumulation in in vitro tissue cultures of medicinal plants. The present study investigated the effects of UV-B radiation on the secondary metabolites and antioxidant activities of Scutellaria baicalensis in vitro shoots grown at different concentrations of 6-benzyl aminopurine (6-BA), which is the cytokinin most widely used in plant tissue culture. The UV-B radiation caused significant increases in lipid peroxidation, total phenolic, and flavonoid contents, and antioxidant activities in the in vitro shoots grown at lower 6-BA concentrations (0 and 1mg L-1 ), while it did not cause any significant changes in those grown at higher 6-BA concentrations (2 and 3mg L-1 ). However, the UV-B radiation significantly altered the contents of main individual flavonoids at both lower and higher 6-BA concentrations. Upon UV-B radiation, aglycones (including baicalein, wogonin, and scutellarein) increased, while glucuronides such as baicalin and wogonoside decreased; this was more evident at higher 6-BA concentrations. This study demonstrated that the effects of UV-B radiation on the secondary metabolites of S. baicalensis in vitro shoots highly depended on the 6-BA concentration in the culture medium.

Lipid peroxidation and lipid-soluble antioxidants as quality control markers in cold-stored fruit for establishing commercial acceptability in Bacon avocados

Avocados are prone to chilling injury disorders when stored at low temperatures. Although most studies have been performed in the worldwide distributed ‘Hass’ variety, other less exploited commercial varieties such as ‘Bacon’ might be more cold-tolerant. Aiming at evaluating how cold storage influences chilling injury, the extent of lipid peroxidation and the contents of lipophilic antioxidants were measured in ‘Bacon’ avocados. Harvested fruit were divided into two groups: one stored for 6 weeks at 4 °C and sampled at various time intervals for 42 days, and the other maintained at low temperatures for 3 and 6 weeks and then exposed to room temperature for 5 days until ripened. Long-term cold storage negatively influenced tocochromanols and carotenoids composition in unripen fruit, decreasing progressively both vitamin E and plastochromanol-8 contents, and most particularly carotenoids; yet chilling injury was prevented during cold storage for 6 weeks. When these fruits were ripened at room temperature, chilling injury increased 20% in the peel but only 5% in the mesocarp (edible part). Enhanced chilling injury in the mesocarp was associated with a 2.3-fold increase in lipid hydroperoxides (a primary lipid peroxidation product) and a 2.5-fold increase in plastochromanol-8 content, while contents of other tocochromanols, carotenoids and malondialdehyde (a secondary product of lipid peroxidation) kept unaltered. Interestingly, medium-term cold storage (3 weeks at 4 °C) did not lead to chilling injury in ripe fruit, therefore cold storage for 3 weeks is considered optimal to prevent large antioxidant vitamin degradation and maintain fruit quality in ripen avocados. In conclusion, despite the high cold tolerance shown by ‘Bacon’ avocados, fruit showed a strong depletion (60%) in carotenoids content after 6 weeks of storage at 4 °C, negatively affecting their commercial acceptability. Aside from evaluating visual chilling injury symptoms, evaluation of lipid peroxidation markers and contents of lipid-soluble antioxidants are deemed to be essential to establish commercial acceptability in cold-stored fruit.

Cannabidiol attenuates hypersensitivity and oxidative stress after traumatic spinal cord injury in rats

Neuropathic pain (NP) arises as a direct consequence of traumatic spinal cord injury (SCI), which leads to devastating consequences for people suffering from this condition since no specific treatment has been defined. One relevant mechanism in generating painful stimuli involves the direct participation of reactive oxygen species (ROS) at the cellular and subcellular levels. Cannabidiol (CBD) is one of the two most crucial cannabinoid components of the cannabis plant and has been proposed as a potential treatment for NP. Its antioxidant, neuroprotective and anti-inflammatory properties have been documented. However, there is insufficient evidence regarding CBD as treatment of NP induced by SCI or the mechanisms that underlie this effect. In this study, we evaluated the antinociceptive effect of CBD as an acute treatment after the nociceptive behaviors characteristic of NP were established (hypersensitivity threshold and hypersensitivity response). Furthermore, the participation of oxidative stress was determined by lipid peroxidation (LP) and glutathione concentration (GSH) in female Wistar rats with SCI. Acute treatment with CBD (2.5–20 mg/kg, i.p.) decreased nociceptive behaviors in a dose-dependent manner, decreased LP, and increased GSH concentration in injured tissue 15 days after injury. The findings of this study suggest that the antinociceptive effect induced by CBD is regulated by reducing oxidative stress by decreasing the LP and increasing the concentration of antioxidant (GSH) defenses.

Grafting enhances drought tolerance by regulating stress-responsive gene expression and antioxidant enzyme activities in cucumbers

Water scarcity is a major limiting factor for crop yield production in arid and water-stressed areas worldwide. Cucumber plants have a high transpiration ratio and are vulnerable to drought. Grafting commercial genotypes onto selected strong rootstocks has been useful in mitigating the effects of drought. Therefore, this study aimed to evaluate the possibility of using a novel rootstock plant’s tolerance to water-deficit stress in inducing drought tolerance in cucumbers by activating the stress-response gene expression and the antioxidant system, which improved the cucumber quality and yield under water-deficit conditions. This field experiment was conducted for > 2 years, 2020 and 2021, with five drought stress tolerant genotypes (i.e., rootstock) and drought-sensitive genotype Luerans (i.e., a scion). They were subjected to various deficit irrigation levels for 12 days, and their agro-physiological and molecular responses to water-deficit stress were assessed. The results of the study showed that the agronomical parameters, including the leaf area (LA), leaf water content (LWC), number of leaves, plant height, root dry matter shoot dry matter, rates of leaf appearance and stem elongation, and total yield significantly increased with grafted cucumber plants than with non-grafted cucumber plants (control) under normal and stressful conditions.Similar results were observed in the physiological measurements in terms of antioxidant enzymes, abscisic acid levels, gibberellic acid content, and lower lipid peroxidation (malondialdehyde, MDA). Grafting of Luerans (section) on five rootstocks significantly raised the activity of antioxidant enzymes (catalase and peroxidase), improved the gibberellic acid and proline accumulation, and reduced the content of lipid peroxidation and abscisic acid. Furthermore, the real-time polymerase chain reaction expression results revealed that transcript levels of the stress-response genes CsAGO1 and CsDCLs increased rapidly and continuously in five rootstock grafting. Concurrently, these findings suggest that grafting with local varieties of novel drought-tolerant rootstock genotypes could improve drought tolerance in drought-sensitive cucumber genotypes.

Does drought increase the antioxidant nutrient capacity of tomatoes?

SummaryTomato fruit has long been regarded as a valuable functional food due to its potential role in the prevention of chronic diseases and thus its positive impacts on human health. In this study, the effect of drought under the climate change threat on increasing antioxidant enzyme activities and non‐enzymatic antioxidants in terms of functional food properties of tomato fruits was investigated. Nine drought‐tolerant tomato genotypes and two commercial cultivars were grown in an open field that was well watered and exposed to drought stress conditions. The biochemical effects of drought stress in fruit were determined by evaluating the fruits' contents of lipid peroxidation, vitamin C (l‐ascorbic acid), total phenols, total flavonoids, lycopene, and beta‐carotene and the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR), total soluble solids and pH. Significant differences (P < 0.05) were found between tomato genotypes in the antioxidant capacity. Antioxidants such as vitamin C, total phenolics, flavonoids, TSS and beta‐carotene increased, in tomato fruit under drought. However, pH was slightly decreased. A slight increase in lycopene was observed. The activities of the antioxidative enzymes SOD, CAT, APX and GR were significantly increased in tomato fruit under drought. The increased antioxidant capacity of drought‐tolerant tomatoes has been found promising in terms of human nutrition under the threat of climate change.