Individual polyphenolic profiles and antioxidant activity in sorghum grains are influenced by very low and high solar UV radiation and genotype

Guabijú (Myrcianthes pungens): A comprehensive evaluation of anthocyanins and free, esterified, glycosylated, and insoluble phenolic compounds in its peel, pulp, and seeds

Guabijú (Myrcianthes pungens) is a Brazilian native fruit from the Myrtaceae family, with few studies on the presence of phenolic compounds. Free, esterified, glycosylated, and insoluble phenolic compounds were studied for the first time in guabijú peel, pulp, and seed, by liquid chromatography coupled to mass spectrometry (LC-ESI-QTOF-MS/MS and LC-ESI-QqQ-MS/MS). Eighty-one phenolic compounds were tentatively identified in the three fractions, and eighteen were quantified using authentic standards. Furthermore, six anthocyanins were quantified in guabijú peel. Among the tentatively identified phenolic compounds, most belonged to the flavonols class. Major compounds quantified in the different fractions were ellagic and gallic acids, mainly in the hydrolyzed fractions. The peel presented the highest contents for most phenolic compounds, followed by the seed and pulp. This new data will add value to the fruit and facilitate the development of new products, as well as favoring and stimulating the consumption of the fruit.

Chemical Composition, Antioxidant Potential, and Nutritional Evaluation of Cultivated Sorghum Grains: A Combined Experimental, Theoretical, and Multivariate Analysis

Sorghum grain (Sorghum bicolor L. Moench) is a gluten-free cereal with excellent nutritional value and is a good source of antioxidants, including polyphenols, as well as minerals with proven health benefits. Herein, the phenolic composition, elemental profile, and antioxidant activity of sixteen food-grade sorghum grains (S1-S16) grown under agroecological conditions in Serbia were determined. Nine phenolic compounds characteristic of sorghum grains, such as luteolinidin, 5-methoxyluteolinidin, luteolidin derivative, luteolidin glucoside, apigeninidin, 7-methoxyapigeninidin, apigeninidin glucoside, and cyanidin derivative, were quantified. The antioxidant potential of the analyzed sorghum grains was evaluated by UV/Vis (DPPH, ABTS, and FRAP) and Electron Paramagnetic Resonance spectroscopy (hydroxyl and ascorbyl radical scavenging assays). The content of macro- and microelements was determined by Inductively Coupled Plasma Optical Emission spectroscopy. Theoretical daily intakes of selected major and trace elements were assessed and compared with the Recommended Daily Allowance or Adequate Intake. Sample S8 had the highest amount of phenolic compounds, while S4, S6, and S8 exhibited the strongest antioxidative potential. The sorghum studied could completely satisfy the daily needs of macro- (K, Mg, and P) and microelements (Se, Zn, Fe). Pattern recognition techniques confirmed the discrimination of samples based on phenolic profile and elemental analysis and recognized the main markers responsible for differences between the investigated samples. The reaction between hydroxyl radicals and luteolinidin/apigeninidin was investigated by Density Functional Theory and thermodynamically preferred mechanism was determined.

Formulation of a Synergistic Enzyme Cocktail for Controlled Degradation of Sorghum Grain Pericarp

Sorghum is one of the major grains produced worldwide for food and fodder, owing to its nutritional profile advantages. However, the utilisation of whole grain sorghum as an ingredient in conventional food formulations is limited due to its poor digestibility, which requires the removal of the outer fibrous layers. Grain breakage and loss of essential nutrients also disadvantage traditional milling practices. Using carbohydrate degrading enzymes to hydrolyse the grain pericarp is a novel approach to biopolishing, where selective degradation of the pericarp layers occurs without adversely affecting the nutrient profile. A collective synergism of enzymes has been proven to cause effective hydrolysis compared to individual enzymes due to the complex presence of non-starch polysaccharides in the grain's outer layers, which comprise a variety of sugars that show specific degradation with respect to each enzyme. The present study aimed to formulate such an enzyme cocktail with xylanase, cellulase, and pectinase in different proportions for hydrolysing sorghum grain pericarp by determining the yield of specific sugars in the pericarp extract after a certain period of incubation. The results showed that the xylanase enzyme has a major effect on the grain bran composition compared to cellulase and pectinase; however, a synergistic mixture yielded more hydrolysed sugars and anti-nutrients in the extract compared to each of the enzymes individually. The results were confirmed by morphological and crystallinity studies of the soaked grain. Compared to conventional water-soaked samples, grains soaked in a cocktail with 66.7% xylanase, 16.7% cellulase, and 16.7% pectinase had visibly thinner and more degraded fibre layers.

Nano-insecticides against the black cutworm Agrotis ipsilon (Lepidoptera: Noctuidae): Toxicity, development, enzyme activity, and DNA mutagenicity

Frequent applications of synthetic insecticides might cause environmental pollution due to the high residue. In addition, increasing insecticide resistance in many insect pests requires novel pest control methods. Nanotechnology could be a promising field of modern agriculture, and is receiving considerable attention in the development of novel nano-agrochemicals, such as nanoinsectticides and nanofertilizers. This study assessed the effects of the lethal and sublethal concentrations of chlorantraniliprole, thiocyclam, and their nano-forms on the development, reproductive activity, oxidative stress enzyme activity, and DNA changes in the black cutworm, Agrotis ipsilon, at the molecular level. The results revealed that A. ipsilon larvae were more susceptible to the nano-forms than the regular forms of both nano chlorine and sulfur within the chlorantraniliprole and thiocyclam insecticides, respectively, with higher toxicities than the regular forms (ca. 3.86, and ca.2.06-fold, respectively). Significant differences in biological parameters, including developmental time and reproductive activity (fecundity and hatchability percent) were also observed. Correspondingly, increases in oxidative stress enzyme activities were observed, as were mutagenic effects on the genomic DNA of A. ipsilon after application of the LC50 of the nano-forms of both insecticides compared to the control. These promising results could represent a crucial step toward developing efficient nanoinsecticides for sustainable control of A. ipsilon.

From Fighting Critters to Saving Lives: Polyphenols in Plant Defense and Human Health

Polyphenols, such as flavonoids and phenolic acids, are a group of specialized metabolites in plants that largely aid in plant defense by deterring biotic stressors and alleviating abiotic stress. Polyphenols offer a wide range of medical applications, acting as preventative and active treatments for diseases such as cancers and diabetes. Recently, researchers have proposed that polyphenols may contribute to certain applications aimed at tackling challenges related to the COVID-19 pandemic. Understanding the beneficial impacts of phytochemicals, such as polyphenols, could potentially help prepare society for future pandemics. Thus far, most reviews have focused on polyphenols in cancer prevention and treatment. This review aims to provide a comprehensive discussion on the critical roles that polyphenols play in both plant chemical defense and human health based on the most recent studies while highlighting prospective avenues for future research, as well as the implications for phytochemical-based applications in both agricultural and medical fields.

Sorghum (Sorghum bicolor L.) as a potential source of bioactive substances and their biological properties

Sorghum is the fifth cereal most produced in the world after wheat, rice, maize, and barley. In some regions, this crop is replacing maize, due to its high yield, resistance to drought and heat. There are several varieties of sorghum, whose coloration varies from cream, lemon-yellow, red, and even black. Pigmented sorghum grain is a rich source of antioxidants like polyphenols, mainly tannins, which have multiple benefits on human health such as, antiproliferative properties associated with the prevention of certain cancers, antioxidant activities related to the prevention of associated diseases to oxidative stress, antimicrobial and anti-inflammatory effects, it also improves glucose metabolism. Despite having these types of compounds, it is not possible to assimilate them, their use in the food industry has been limited, since sorghum is considered a food of low nutritional value, due to the presence of anti-nutritional factors such as strong tannins which form complexes with proteins and iron, thus reducing their digestibility. Based on these restrictions that this product has had as food for humans, the analysis of this review emphasizes the valorization of sorghum as a source of bioactive substances and the importance they confer on human health because of the biological potential it has.

Effects of extruded whole-grain sorghum (Sorghum bicolor (L.) Moench) based diets on calcium absorption and bone health of growing Wistar rats

Apparent calcium absorption, total bone mineral content and density, and mineral contents of the right femur were studied using a growing rat model. Twenty-four male Wistar rats were fed with diets based on extruded whole grain red (RSD) or white sorghum (WSD), and control diet (CD) up to 60 days. The animals fed with sorghum diets consumed less and gained less weight compared to those fed with CD, but the efficiency of all diets was similar. Calcium intake was lower in animals fed with sorghum diets, related to the lower total intake of these animals. Apparent calcium absorption in animals fed with RSD was lower than in those fed with CD (CD: 72.7%, RSD: 51.0%, WSD: 64.8%). No significant differences in bone mineral density of total body, spin, femur, distal femur, tibia and proximal tibia were observed among the groups. However, Ca and P contents in the right femur of the rats consuming RSD were lower, indicating a certain imbalance in the metabolism of these minerals.

Phenotypic, Phytochemical, and Transcriptomic Analysis of Black Sorghum (Sorghum bicolor L.) Pericarp in Response to Light Quality

Black sorghum [Sorghum bicolor (L.) Moench] is characterized by the black appearance of the pericarp and production of 3-deoxyanthocyanidins (3-DOA), which are valued for their cytotoxicity to cancer cells and as natural food colorants and antioxidant additives. The black pericarp phenotype is not fully penetrant in all environments, which implicates the light spectrum and/or photoperiod as the critical factor for trait expression. In this study, black- or red-pericarp genotypes were grown under regimes of visible light, visible light supplemented with UVA or supplemented with UVA plus UVB (or dark control). Pericarp 3-DOAs and pericarp pigmentation were maximized in the black genotype exposed to a light regime supplemented with UVB. Changes in gene expression during black pericarp development revealed that ultraviolet light activates genes related to plant defense, reactive oxygen species, and secondary metabolism, suggesting that 3-DOA accumulation is associated with activation of flavonoid biosynthesis and several overlapping defense and stress signaling pathways.

Plant Responses to UV Blocking Greenhouse Covering Materials: A Review

Pure polyethylene (PE) is enriched with several additives to make it a smart application material in protected cultivation, as a cover material for either greenhouses or screenhouses. When this material completely or partially absorbs ultraviolet (UV) solar radiation, then it is called UV blocking material. The current work presents a review on the effects of the UV blocking covering materials on crop growth and development. Despite the passage of several years and the evolution of the design technology of plastic greenhouse covers, UV blocking materials have not ceased to be a rather interesting technique for the protection of several vegetable and ornamental species. Much of the research on UV blocking materials focuses on their indisputable effect on reducing the activity of pests and viral-related diseases, rather than on the effects on the crop physiology itself. In the present paper, representative studies dealing with the effect of the UV blocking materials on the agronomic factors of different crops are presented and discussed. The results reveal that UV blocking materials have mainly positive effects on the different plant physiological functions, such as photosynthesis and transpiration rate, and on growth characteristics, while they might have a negative effect on the production and content of secondary compounds, as anthocyanins and total phenolics.

Climate Change Enhanced Carotenoid Pro-Vitamin A Levels of Selected Plantain Cultivars

Diet diversification and the exploitation of traditional, micronutrient-rich germplasm of staple crops are generally regarded as sustainable and low-cost approaches to increase the micronutrient intake of resource-poor people. Sun's UV index was collected daily throughout the year. The study assessed the seasonality of provitamin A carotenoids in three plantain cultivars in response to climatic condition. Fruits were harvested at three maturities and freeze-dried before analysis. The results showed that there were high levels of the sun's UV-B radiations throughout the year with the highest occurring from November to May when the area experienced clear skies with minimal cloud cover. These high levels of the sun's UV-B index occurred between 9.00 h GMT and 17.00 h GMT. The study also showed that α-carotene content increased with maturity in "Apantu" during the rainy seasons ranging from 95 to 172 μg/100 g of dry pulp. Similar trends were observed during the dry season with a range of 28 to 489 μg/100 g. The α-carotene contents were very high in the periods of high sun's UV-B radiations compared to the periods of low sun's UV-B radiations. The α-carotene levels in the giant French plantains showed similar trends. Intermediate French "Oniaba" and False Horn "Apantu" plantain cultivar showed the highest content of β-carotene during the dry season. The high provitamin A carotenoid levels in the cultivars coincided with the high levels of the sun's UV index.

Apoptosis Induction Pathway in Human Colorectal Cancer Cell Line SW480 Exposed to Cereal Phenolic Extracts

Cereal phenolic extracts have previously been investigated for their potential anticancer properties; however, the exact mechanisms involved in the inhibition of tumour growth are unclear. One possible mechanism is the induction of apoptosis which is characterised by cell shrinkage, protein fragmentation, and DNA degradation followed by rapid engulfment of cell debris by macrophages. This study examines the ability of phenolic extracts from four cereals: rice, barley, oats and sorghum to induce apoptosis on colorectal cancer cells SW480. Wholegrain extracts from pigmented varieties of red rice, purple rice, black sorghum, and brown sorghum showed a significant reduction in cancer cell proliferation. Morphological observation using APOPercentage™ dye indicated positive for apoptosis. Further analyses of Yunlu29 (rice), Shawaya Short Black 1 and IS1136 (sorghum) showed expression of p53 and confirmed activation of multiple caspases, specifically for caspase 3 and 7. Purple rice, on the other hand, did not upregulate caspase 3 and 7, hence, suggestive of cell cycle arrest. Therefore, phenolic compounds present in cereals such as pigmented rice and sorghum may suppress cancer cell proliferation through the activation of the apoptosis.

Beyond Arabidopsis: Differential UV-B Response Mediated by UVR8 in Diverse Species

Ultraviolet-B radiation (UV-B, 280-315 nm) is an important environmental signal that regulates growth and development in plants. Two dose-dependent UV-B response pathways were described in plants: a specific one, mediated by UVR8 (the specific UV-B receptor) and an unspecific one, activated by the oxidative damage produced by radiation. The constitutively expressed receptor appears inactive as a dimer, with the two monomers dissociating upon UV-B irradiation. The monomer then interacts with COP1, an ubiquitin ligase, hindering its ability to poly-ubiquitinate transcriptional factor HY5, thus averting its degradation and activating the photomorphogenic response. HY5 induces the synthesis of proteins RUP1 and RUP2, which interact with UVR8, releasing COP1, and inducing the re-dimerization of UVR8. This mechanism has been thoroughly characterized in Arabidopsis, where studies have demonstrated that the UVR8 receptor is key in UV-B response. Although Arabidopsis importance as a model plant many mechanisms described in this specie differ in other plants. In this paper, we review the latest information regarding UV-B response mediated by UVR8 in different species, focusing on the differences reported compared to Arabidopsis. For instance, UVR8 is not only induced by UV-B but also by other agents that are expressed differentially in diverse tissues. Also, in some of the species analyzed, proteins with low homology to RUP1 and RUP2 were detected. We also discuss how UVR8 is involved in other developmental and stress processes unrelated to UV-B. We conclude that the receptor is highly versatile, showing differences among species.

Linkages between stratospheric ozone, UV radiation and climate change and their implications for terrestrial ecosystems

Linkages between stratospheric ozone, UV radiation and climate change: terrestrial ecosystems.

Environmental effects of ozone depletion, UV radiation and interactions with climate change: UNEP Environmental Effects Assessment Panel, update 2017

The Environmental Effects Assessment Panel (EEAP) is one of three Panels of experts that inform the Parties to the Montreal Protocol. The EEAP focuses on the effects of UV radiation on human health, terrestrial and aquatic ecosystems, air quality, and materials, as well as on the interactive effects of UV radiation and global climate change. When considering the effects of climate change, it has become clear that processes resulting in changes in stratospheric ozone are more complex than previously held. Because of the Montreal Protocol, there are now indications of the beginnings of a recovery of stratospheric ozone, although the time required to reach levels like those before the 1960s is still uncertain, particularly as the effects of stratospheric ozone on climate change and vice versa, are not yet fully understood. Some regions will likely receive enhanced levels of UV radiation, while other areas will likely experience a reduction in UV radiation as ozone- and climate-driven changes affect the amounts of UV radiation reaching the Earth's surface. Like the other Panels, the EEAP produces detailed Quadrennial Reports every four years; the most recent was published as a series of seven papers in 2015 (Photochem. Photobiol. Sci., 2015, 14, 1-184). In the years in between, the EEAP produces less detailed and shorter Update Reports of recent and relevant scientific findings. The most recent of these was for 2016 (Photochem. Photobiol. Sci., 2017, 16, 107-145). The present 2017 Update Report assesses some of the highlights and new insights about the interactive nature of the direct and indirect effects of UV radiation, atmospheric processes, and climate change. A full 2018 Quadrennial Assessment, will be made available in 2018/2019.