Hydroxylated polyphenols, also called flavonoids, are richly present in vegetables, fruits, cereals, nuts, herbs, seeds, stems, and flowers of numerous plants. They possess numerous medicinal properties such as antioxidant, anti-cancer, anti-microbial, neuroprotective, and anti-inflammation. Studies show that flavonoids activate antioxidant pathways that render an anti-inflammatory effect. They inhibit the secretions of enzymes such as lysozymes and β-glucuronidase and inhibit the secretion of arachidonic acid, which reduces inflammatory reactions. Flavonoids such as quercetin, genistein, apigenin, kaempferol, and epigallocatechin 3-gallate modulate the expression and activation of a cytokine such as interleukin-1beta (IL-1β), Tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-8 (IL-8); regulate the gene expression of many pro-inflammatory molecules such s nuclear factor kappa-light chain enhancer of activated B cells (NF-κB), activator protein-1 (AP-1), intercellular adhesion molecule-1 (ICAM), vascular cell adhesion molecule-1 (VCAM), and E-selectins; and also inhibits inducible nitric oxide (NO) synthase, cyclooxygenase-2, and lipoxygenase, which are pro-inflammatory enzymes. Understanding the anti-inflammatory action of flavonoids provides better treatment options, including coronavirus disease 2019 (COVID-19)-induced inflammation, inflammatory bowel disease, obstructive pulmonary disorder, arthritis, Alzheimer’s disease, cardiovascular disease, atherosclerosis, and cancer. This review highlights the sources, biochemical activities, and role of flavonoids in enhancing human health.

No abstract

No abstract

Growth, development and plants productivity are usually affected by photosynthetic pigments activity. Magnetic fields are known to induce biochemical changes and could be used as a stimulator for growth related reactions including affecting photosynthetic pigments. The impact of magnetic field strengths on chlorophyll and carotenoids were investigated in this study through the use of date palm (Phoenix dactylifera L.) seedlings. To study the effects of magnetic treatments on photosynthetic pigments, date palm seedlings were exposed to magnetic fields in two experiments. In the first experiment, seedlings were treated with static magnetic field at three levels of (10, 50 and 100 mT) and different durations (30, 60, 180, 240 and 360 min). At the second experiment, seedlings were treated with alternating magnetic field at 1.5 T for different durations (1, 5, 10 and 15 min). The photosynthetic pigments (chlorophyll a, chlorophyll b, carotenoids and total pigments) were assayed using spectrophotometric methods. Results indicated that pigments content (chlorophyll a, chlorophyll b, carotenoids and total pigments) was significantly increased under static magnetic field. The highest measurements were recorded at 100 mT, after 360 min of exposure. On the other hand, alternating magnetic field has decreased photosynthetic pigments content after 10 min of treatment with 1.5 T. Low magnetic field doses had a simulative effect on photosynthetic pigments whereas high doses had a negative effect. Chlorophyll a and carotenoids were more affected than chlorophyll b. Magnetic fields treatment could be used to enhance plant growth and productivity.

No abstract

This study was conducted to examine the effect of biotin and thiamine concentrations on callus growth and somatic embryogenesis of date palm (Phoenix dactylifera L.). Embryogenic callus derived from offshoot tip explants was cultured on hormone-free MS medium containing biotin at 0, 0.1, 1, or 2 mg l 21 combined with thiamine at 0.1, 0.5, 2, or 5 mg l 21 . Embryogenic callus weight, number of resultant embryos, and embryo length were significantly influenced by thiamine and biotin concentration. The optimum callus growth treatment consisted of 0.5 mg l 21 thiamine and 2 mg l 21 biotin. This treatment also gave the highest number of embryos. Embryo elongation was greatest at 0.5 or 2 mg l 21 thiamine combined with 1 mg l 21 biotin. Embryos from all treatments germinated and regenerants exhibited normal growth in soil. This study provides an insight into the importance of optimizing various culture medium components to overcome in vitro recalcitrance of date palm.

A plant regeneration system applicable to 17 cowpea genotypes was developed. Cotyledons were initiated on 1/3 MS medium containing 15 to 35 mg N6-benzyladenine (BA) per 1 (66.6 to 155.3 gM) for 5 to 15 d. For shoot regeneration, the explants were transferred to a medium containing 1 mg BA per ! (4.4 ~tM). Within 1 wk, shoot formation was visible at the proximal end of the cotyledons. Regeneration percentages (1% to 11%) and the numbers of shoots (4 to 12 per explant) were significantly influenced by genotype. Culture duration and BA concentration in the initiation stage significantly affected regeneration capacity. Explants initiated on media containing 15 mg BA per 1 for 5 d resulted in the highest percentage of explants capable of regeneration. Conversely, the highest number of shoots was obtained from explants initiated on media supplemented with 35 mg BA per 1. Whole plants were obtained on a plant growth regulator-free medium. To our knowledge, this is the first report of plant regeneration from U.S. commercial cowpea cuhivars and breeding lines. This system is adaptable to diverse cowpea genotypes and will facilitate cowpea genetic transformation.

Tissue culture methods could enhance development of improved cultivars of zoysiagrass (Zoysia japonica Steudel). A tissue culture system for callus induction and plant regeneration of zoysiagrass was developed. Embryos were aseptically excised from seeds and over 90% produced callus. Embryogenic callus was produced on Murashige‐Skoog (MS) agar medium supplemented with 2,4‐D (2,4‐dichlorophenoxy) acetic acid, but not on N6 medium. A 2,4‐D concentration of 1.0 mg L−1 resulted in greater callus production than higher concentrations. A 16‐h photoperiod of fluorescent light (65 μmol photon m−2 s−1) increased callus production over dark conditions. Direct elimination of 2,4‐D and dark callus induction resulted in greater regeneration frequency and a higher number of plantlets per callus than gradual elimination and light callus induction. Normal plantlets were transplanted to soil and grown to maturity in the field, where overwinter survival was exhibited.