The Evolution and Functional Roles of miR408 and Its Targets in Plants

MicroRNA408 (miR408) is an ancient and highly conserved miRNA, which is involved in the regulation of plant growth, development and stress response. However, previous research results on the evolution and functional roles of miR408 and its targets are relatively scattered, and there is a lack of a systematic comparison and comprehensive summary of the detailed evolutionary pathways and regulatory mechanisms of miR408 and its targets in plants. Here, we analyzed the evolutionary pathway of miR408 in plants, and summarized the functions of miR408 and its targets in regulating plant growth and development and plant responses to various abiotic and biotic stresses. The evolutionary analysis shows that miR408 is an ancient and highly conserved microRNA, which is widely distributed in different plants. miR408 regulates the growth and development of different plants by down-regulating its targets, encoding blue copper (Cu) proteins, and by transporting Cu to plastocyanin (PC), which affects photosynthesis and ultimately promotes grain yield. In addition, miR408 improves tolerance to stress by down-regulating target genes and enhancing cellular antioxidants, thereby increasing the antioxidant capacity of plants. This review expands and promotes an in-depth understanding of the evolutionary and regulatory roles of miR408 and its targets in plants.

Characterization of Bioactive Phenolics and Antioxidant Capacity of Edible Bean Extracts of 50 Fabaceae Populations Grown in Thailand

Fabaceae is the third largest family containing great variation among populations. However, previous studies mainly focus on single species, and phytochemicals at population level have never been reported. This work aims to complete this knowledge with 50 populations from throughout Thailand by (1) determining total phenolic (TPC), flavonoid (TFC), and anthocyanin (TAC) contents; and (2) investigating in vitro and cellular antioxidant potentials. Phytochemicals of 50 populations from different localities are differed, illustrating high heterogeneity occurring in polyphenols accumulations. Vigna unguiculata subsp. sesquipedalis populations showed low variability in TPC ranging from 628.3 to 717.3 mg/100 g DW gallic acid equivalent, whereas the high variability found in TFC and TAC range from 786.9 to 1536.1 mg/100 g DW quercetin equivalent, and 13.4 to 41.6 mg/100 g DW cyanidin equivalent. Red cultivar population #16 had the greatest TAC, but surprisingly the cream cultivars were relatively high in anthocyanins. HPLC quantification of genistein and daidzein showed great variations among populations. In vitro antioxidant results indicated that antioxidant capacity mediated by electron transfer. Cellular antioxidants ranged from 59.7% to 87.9% of ROS/RNS in yeast model. This study investigated at the population level contributing to better and frontier knowledge for nutraceutical/phytopharmaceutical sectors to seek potential raw plant material.

Galangin Attenuates Liver Injury, Oxidative Stress and Inflammation, and Upregulates Nrf2/HO-1 Signaling in Streptozotocin-Induced Diabetic Rats

Chronic hyperglycemia increases the risk of liver damage. Oxidative stress and aberrant inflammatory response are entangled in diabetes-associated liver injury. This study evaluated the protective effect of the flavonoid galangin (Gal) on glucose intolerance, liver injury, oxidative stress, inflammatory response, and Nrf2/HO-1 signaling in diabetic rats. Diabetes was induced by streptozotocin (STZ), and the rats received Gal for six weeks. STZ-induced rats showed glucose intolerance, hypoinsulinemia, elevated glycated hemoglobin (HbA1c), and decreased liver glycogen. Gal ameliorated glucose intolerance, reduced HbA1c%, increased serum insulin and liver glycogen and hexokinase activity, and suppressed glycogen phosphorylase, glucose-6-phosphatase and fructose-1,6-biphosphatase in diabetic rats. Circulating transaminases, ALP and LDH, and liver ROS, MDA, TNF-α, IL-1β, and IL-6 were increased and GSH, SOD, and CAT were diminished in diabetic rats. In addition, diabetic rats exhibited multiple histopathological alterations and marked collagen deposition. Treatment with Gal mitigated liver injury, prevented histopathological alterations, decreased ROS, MDA, pro-inflammatory cytokines, Bax and caspase-3, and enhanced cellular antioxidants and Bcl-2. Gal downregulated hepatic Keap1 in diabetic rats and upregulated Nrf2 and HO-1 mRNA as well as HO-1 activity. Molecular modeling studies revealed the ability of Gal to bind to and inhibit NF-κB and Keap1, and also showed its binding pattern with HO-1. In conclusion, Gal ameliorates hyperglycemia, glucose intolerance, oxidative stress, inflammation, and apoptosis in diabetic rats. Gal improved carbohydrate metabolizing enzymes and upregulated Nrf2/HO-1 signaling.

Alleviation of Cadmium Toxicity in Zea Mays L. through Up-Regulation of Antioxidant Defense System and Organic Osmolytes under Supplemental Calcium

Calcium (Ca) is a macronutrient and work as a modulator to mitigate oxidative stress induced by heavy metals. Present work was conducted to elucidate the role of Ca in modulating growth, physio-biochemical traits, and cellular antioxidant defense system in Zea mays L. seedlings under Cd stress. The experiment was designed in a complete randomized design with two levels of Cd (0 and 150 µM) and six levels of Ca (0, 0.5, 1, 2.5, 5 and 10 mM). Maize seedlings exposed to Cd at150 µM concentration showed a notable decrease in growth, biomass, anthocyanins, chlorophylls, and antioxidant enzymes activities. Higher level of Cd (150 µm) also caused an upsurge in oxidative damage observed as higher electrolyte leakage (increased membrane permeability), H2O2 production and MDA accumulation. Supplementation of Ca notably improved growth traits, photosynthetic pigments, cellular antioxidants (APX, POD and ascorbic acid), anthocyanins and level of osmolytes. The significant improvement in the osmolytes (proteins and amino acids), and enzymatic antioxidative defense system enhanced the membrane stability and mitigated the damaging effects of Cd. The present results concluded that exogenously applied Ca can potentially improve growth by regulating antioxidants and enable maize plants to withstand the Cd toxicity.

Amelioration of oxidative and inflammatory changes by Peganum harmala seeds in experimental arthritis

Background The present study was designed to investigate the therapeutic effects against oxidative stress and alleviative effects of Peganum harmala seeds (PH) in rats with Complete Freund’s Adjuvant (CFA) induced arthritis. Methods The extract was evaluated for its phytoconstituents, antiarthritic and antioxidant properties. The action of chloroform (PHC) and ethanolic (PHE) extracts of PH was evaluated in adult Lewis rats (150-200 g).with CFA induced arthritis. Arthritic rats received PH extracts 100 mg/kg orally for 28 consecutive days (Prophylactic treatment) and from 14th day of CFA injection (Therapeutic treatment). Results PHE significantly suppressed the arthritis severity in rats than PHC in 28 days. All complications shown significant reduction (p< 0.05) in arthritic rats including paw volume (63.09%), body weight loss, decreased locomotor activity, erythrocyte sedimentation rate and synovial/hepatic tissues lipid peroxidation and increase in cellular antioxidants superoxide dismutase (U/mg) activities and hemoglobin counts. The results showed the presence of alkaloids and flavonoids in PHE. Histology and radiographic analysis of arthritic ankle joints indicated abnormal changes. Marked reduction in inflammation and arthritic changes were observed after treatment with PHE. Conclusion Therefore, the investigation suggests that PHE at 100 mg/kg will be useful in the management of rheumatoid arthritis complications which may possibly be due to boosting the intracellular antioxidant defense.

A Review on Medical Properties on Spirulina and Their Futuristic Applications

Spirulina is a type of blue-green microalgae also is a type of cyanobacteria. This was established in 1967 as a "wonderful future food source". It is a rich source of minerals, vitamins, nutrients, protein, carotenoids, and essential amount of amino acids. Spirulina also a good source of antioxidants. It can protect against oxidative damage. It activates cellular antioxidants enzymes. Inhibits lipids peroxidation and also DNA damages, scavenges, free radicals, and increase the activity of superoxide dismutase and also catalyze. The Spirulina supplements seem to be affected more effectively the innate immunity and promoting the activity of natural killer cells. Also it has a high potential capacity to increase immunity power to suppress viral infections, and it is well known to be a healthy addition to one's diet. It is most commonly used as a natural dietary supplement. There is a main active compound called phycocyanin. It is a pigment-protein complex. This pigment used mainly as natural colouring in food industry. Spirulina is well tolerated when grown at under controlled conditions. Also it can be grown as a pure culture alkaline water. Spirulina products have bioactive protein with the ability to stimulate the intestinal immune system. This is available in many forms such as spirulina powder, capsules, etc and this products has many mediational uses.

Hesperidin and eugenol attenuate cadmium-induced nephrotoxicity via regulation of oxidative stress, Bax/Bcl2 and cleaved caspase 3 expression

ObjectivesCadmium (Cd) is a heavy metal that induces nephrotoxicity through stimulating the oxidative stress in kidney cells. In this study, we investigated the protective effects of hesperidin and eugenol on Cd-induced nephrotoxicity and their impact on modulating oxidative stress, Bax/Bcl2 ratio and cleaved caspase 3 level.MethodsMale Wistar rats were divided into: Normal group; Cd-treated group; hesperidin & Cd-treated group and eugenol & Cd-treated group. Rats received CdCl2 (5 mg/kg body weight/daily) via oral gavage for four weeks to induce kidney toxicity.ResultsThe results showed that, both hesperidin & Cd and eugenol & Cd- treated groups exhibited lower serum creatinine and urea levels as well as better kidney tissue integrity compared to the Cd-treated group. Moreover, they could preserve the cellular antioxidants to normal levels as was seen in a significantly lower malondialdehyde content, but significantly higher catalase and superoxide dismutase activities compared to the Cd-treated group. Furthermore, both groups significantly decreased the Cd-induced elevation in Bax/Bcl2 ratio and cleaved caspase 3 level.ConclusionAdministration of hesperidin or eugenol effectively protected from the structural and functional kidney damage induced by Cd exposure via antioxidant and anti-apoptotic effects.

The Intervention of tert-Butylhydroquinone Protects Ethanol-Induced Gastric Ulcer in Type-II Diabetic Rats: Role of Nrf2 pathway

Ethanol consumption increases the prevalence of gastric ulcer (GU) in rats with type 2 diabetes (T2D). Induction of GU by absolute ethanol (5 mL/kg or 3.94 g/kg) in the animal model resembles human ulcer characteristics. The aim was to investigate the role of the Nrf2 pathway in the treatment of GU in diabetic condition. The rats were exposed to absolute ethanol before one hour of sacrifice and T2D was induced by combined exposure of high-fat diet and low dose streptozotocin. Pre-treatment of tBHQ (25 and 50 mg/kg), metformin (500 mg/kg) and omeprazole (20 mg/kg) were given once daily for last three consecutive weeks. In ethanol-exposed diabetic rats, pretreatment with tBHQ, omeprazole, and metformin reduced gastric mucosal lesion, ulcer index, histological alterations, MDA level and apoptosis. Further, the intervention of tBHQ, omeprazole and metformin improved the integrity of the stomach mucosa, glutathione, gastric pH, collagen and goblet cells. tBHQ treatment improved ethanol-induced alterations of Nrf2, catalase, HSP70, NF-κB and endothelin-1 expressions in diabetic rats. In diabetic conditions, the incidence of GU is increased due to elevated levels of ROS, inflammatory mediators, depleted levels of cellular antioxidants, altered gastric parameters. The tBHQ intervention could be a rational strategy to protect these changes.

Identification of Six Flavonoids as Novel Cellular Antioxidants and Their Structure-Activity Relationship

This study is aimed at determining the relationship of flavonoid structures to their chemical and intracellular antioxidant activities. The antioxidant activities of 60 flavonoids were investigated by three different antioxidant assays, including 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, oxygen radical absorption capacity (ORAC), and cellular antioxidant activity (CAA) assays. The result showed 6 flavonoids as good cellular antioxidants evaluated for the first time. The cellular antioxidant activities of compounds 7-methoxy-quercetin, 3-O-methylquercetin, 8-hydroxy-kaempferol, quercetin-3-O-α-arabinofuranose, kaempferol-7-O-glucopyranoside, and luteolin6-C-glucoside were linked with the upregulation of antioxidant enzyme activities (superoxide dismutase, catalase, and glutathione peroxidase). A structure-activity relationship suggested that 2,3-double bond, 4-keto groups, 3′,4′-catechol structure, and 3-hydroxyl in the flavonoid skeleton played important roles in the antioxidant behavior. Furthermore, the cell proliferative assay revealed a low cytotoxicity for 3-O-methylquercetin. The present results provide valuable information for the dietary application of flavonoids with different structures for high antioxidant.