Anti-diabetic and anti-cancer related health food properties of selected Sri Lankan traditional rice based porridges.

Four Sri Lankan porridges including madathawalu (MWP), kaluheenati (KHP), mixed rice of sudu heenati, goda heenati, masuran, and dikwee (MXP) and special traditional porridge (STP) were screened for in vitro glycemic indices (GI), α-amylase inhibition and anti-glycation activities. All four porridges had the medium GI values, those were in the range of 40.5 ± 4 to 63.9 ± 2. The highest antiglycation activity was reported for MWP demonstrating IC50 of 228.20 ± 4.20 µg/mL. In relation to the α-amylase inhibition activity, the porridge extracts of MWP and STP low IC50 values (117.54 ± 1.92 µg/mL and 128.75 ± 5.91 µg/mL) showed their high capability to inhibit α-amylase enzyme. Due to the medium to low GI values and high antiglycation and α-amylase inhibition activities, traditional rice based porridges can be considered as effective for the prevention of diabetic conditions as well as from various complications in diabetic patients. Anticancer activity against human lung and HeLa cell lines revealed that KHP and MXP exhibited anticancer activity (IC50 of 274.6 µg/mL and 940.2 µg/mL respectively) against HeLa- human cervical cancer cells. In conclusion, porridge composites prepared using Sri Lankan traditional rice helped to eliminate or notably reduce nutrient deficiencies, and it provided numerous health benefits and economical gains.

The inner membrane histidine kinase EnvZ senses osmolality via helix-coil transitions in the cytoplasm.

Two-component systems mediate bacterial signal transduction, employing a membrane sensor kinase and a cytoplasmic response regulator (RR). Environmental sensing is typically coupled to gene regulation. Understanding how input stimuli activate kinase autophosphorylation remains obscure. The EnvZ/OmpR system regulates expression of outer membrane proteins in response to osmotic stress. To identify EnvZ conformational changes associated with osmosensing, we used HDXMS to probe the effects of osmolytes (NaCl, sucrose) on the cytoplasmic domain of EnvZ (EnvZ(c)). Increasing osmolality decreased deuterium exchange localized to the four-helix bundle containing the autophosphorylation site (His(243)). EnvZ(c) exists as an ensemble of multiple conformations and osmolytes favoured increased helicity. High osmolality increased autophosphorylation of His(243), suggesting that these two events are linked. In-vivo analysis showed that the cytoplasmic domain of EnvZ was sufficient for osmosensing, transmembrane domains were not required. Our results challenge existing claims of robustness in EnvZ/OmpR and support a model where osmolytes promote intrahelical H-bonding enhancing helix stabilization, increasing autophosphorylation and downstream signalling. The model provides a conserved mechanism for signalling proteins that respond to diverse physical and mechanical stimuli.

In Vitro Antioxidant and Antimicrobial Properties of Composite Flour Formulations Developed Using Selected Local Grain Varieties.

The aim of this study was to determine the in vitro antioxidant potential of four extruded and domestically prepared composite flour formulations developed by composting selected locally available grain varieties in Sri Lanka. The potential of the flour extracts to scavenge free radicals were evaluated by performing DPPH, ABTS, and FRAP assays. Furthermore, the antimicrobial activities of the flour formulations against selected Gram-positive and Gram-negative pathogenic microorganisms were comparatively evaluated using agar well diffusion and disk diffusion assays. Ethanol and water extracts of the samples were evaluated for their antimicrobial potential. The results showed that extruded samples possessed high antioxidant properties than samples prepared using the conventional cooking. Furthermore, the antioxidant potential of the formulations evaluated using different assays was strongly correlated. Moreover, the formulations reported positive antimicrobial potential against tested Gram-negative and Gram-positive bacteria. The ethanol extracts of flour formulations exhibited higher susceptibility to tested microbes than that of water extracts while agar well diffusion resulted significantly high inhibition against pathogenic bacteria than that of agar disk diffusion method (p < 0.05). In overall, the highest inhibition zone of 17.64 mm was depicted by F4 against Salmonella, while the lowest diameter of 6.09 mm was depicted by F1 against Listeria. In conclusion, the developed flour formulations contained natural antimicrobial agents which can combat common food spoilage and pathogenic bacteria and can be promoted as value-added products with health benefits beyond nutrition.

Synthesis of a Dual-Functional Nanofertilizer by Embedding ZnO and CuO Nanoparticles on an Alginate-Based Hydrogel.

Recent scientific breakthroughs in the field of agriculture have led to the abundant usage of nanoparticles in agrochemicals to maintain proper nutrient uptake in plants. Since less attention has been given to the supply of vital micronutrients to crop plants, the objective of this study was to develop a nanofertilizer capable of releasing micronutrients while nourishing its surrounding soil. As the initial nanonutrients, Zn and Cu were used in their metal oxide forms, which promote seed germination. Alginic acid was used as the agent responsible for soil conditioning. To form the fertilizing complex, nanoparticles were reacted with sodium alginate, which resulted in a hydrogel where alginate chains were cross-linked with Zn(II) and Cu(II) and excess metal oxide nanoparticles were distributed on the hydrogel. Spectroscopic characterization of the nanofertilizer confirmed that alginate chains were cross-linked by Zn(II) and Cu(II), while morphological analysis by scanning electron microscopy (SEM) showed that ZnO and CuO nanoparticles were embedded on the alginate matrix. The release behavior of cations in soil and water environments, experimented using the tea bag method, revealed that the cationic release was slowly increasing with time. Micronutrient uptake by plants was studied by conducting leaf analyses in tomato plants for 30 consecutive days. To experiment the release behavior of micronutrients in the presence of compost, the nanofertilizer was added with predetermined amounts of compost to tomato plants. Flame atomic absorption spectroscopy (FAAS) results indicated that in the fertilizer-applied plants, Cu concentrations showed a steady increase with time while Zn concentrations remained undetected.

Adsorptive removal of Co(II) in aqueous solutions using clearing nut seed powder.

The present study assessed the potential use of clearing nut seed powder (Strychnos potatorum) as an adsorbent for the removal of Co(II) ions from aqueous solutions. Based on FTIR analysis, the adsorbent possesses hydroxyl, C-N, and C-O functional groups and SEM analysis indicated the presence of uneven porous surface structure, which is important for adsorption. Batch adsorption studies were performed to investigate the effect of contact time, initial pH, initial Co(II) concentration, adsorbent dosage, and temperature on adsorption. The Langmuir isotherm model provided the best explanation to experimental data with the highest correlation coefficient and the maximum monolayer adsorption capacity obtained was 4.245 mg/g. The pseudo-second-order kinetic model fitted well with the adsorption kinetic data. Sorption thermodynamic data showed that the adsorption process is spontaneous and exothermic in nature. The clearing nut seed powder obtained after surface modification by acid treatment showed a higher adsorption capacity.

Corrigendum to "Adsorptive removal of Co(II) in aqueous solutions using clearing nut seed powder" [Heliyon 6 (4) (2020) Article e03684].

[This corrects the article DOI: 10.1016/j.heliyon.2020.e03684.].

In Vitro Antioxidant and Antidiabetic Potentials of Syzygium caryophyllatum L. Alston.

Syzygium caryophyllatum L. Alston (Family: Myrtaceae, Sinhala: Heendan) is a red-listed plant that has been used in traditional medicine in Sri Lanka for the treatment of diabetes, but it is yet to be exploited for its potential uses as a functional food or a source of supplements. The present study focused on the evaluation of antidiabetic property of S. caryophyllatum fruits and leaves assessing antioxidant, antiglycation, and antiamylase activities and functional mineral element composition. The crude extracts (CR) of leaves and fruits were fractionated into hexane (Hex) ethyl acetate (EA) and aqueous (AQ) and evaluated for bioactivities along with the crude extracts. The isolated fraction (C3) of Hex fraction of fruit showed significantly high (p < 0.05) antiamylase activity with IC50 value 2.27 ± 1.81 µg/mL where the Hex fraction of fruits exhibited the IC50 value as 47.20 ± 0.3 µg/mL which was higher than acarbose (IC50: 87.96 ± 1.43 µg/mL). The EA fraction of leaves showed highest values for DPPH radical scavenging activity, ferric reducing antioxidant power, and oxygen radical absorbance capacity. Significantly high (p < 0.05) ABTS radical scavenging activity and iron chelating activity were observed in Hex fraction of fruit. The composition of volatiles in leaf oil was studied with GC-MS, and 58 compounds were identified. Inductively coupled plasma-mass spectrometry data revealed the presence of biologically significant trace elements such as Fe, Zn, Mg, Cu, Se, and Sr in leaves and fruits. It is concluded that the Hex fraction of S. caryophyllatum fruits will be a good source for the formulation of supplements for diabetic management with further evaluation of potency and efficacy.

Therapeutic Efficacy of Nyctanthes arbor-tristis Flowers to Inhibit Proliferation of Acute and Chronic Primary Human Leukemia Cells, with Adipocyte Differentiation and in Silico Analysis of Interactions between Survivin Protein and Selected Secondary Metabolites.

Although the antidiabetic efficacy of Nyctanthes arbor-tristis flowers has been reported, antiproliferative and anti-obesity activities are yet to be explored. We examined the anti-obesity and antiproliferative potentials of different fractions (hexane, chloroform, ethyl acetate, methanol) of N. abor-tristis flower extract for the first time using 3T3-L1 cells, primary peripheral blood mononuclear cells (PBMC) isolated from healthy and adult acute myeloid (AML) and chronic lymphocytic leukemia (CLL) patients, recombinant Jurkat T cells, and MCF7 cell lines. The in vitro hypoglycemic activity was evaluated using the inhibition of -amylase enzyme and glucose uptake by yeast cells. The percentage glucose uptake and -amylase inhibitory activity increased in a dose-dependent manner in the crude and the tested fractions (hexane and ethyl acetate). Inhibition of the 3T3-L1 cells' differentiation was observed in the ethyl acetate and chloroform fractions, followed by the hexane fraction. Antiproliferative analyses revealed that Nyctanthes exerted a high specific activity against anti-AML and anti-CLL PBMC cells, especially by the hexane and ethyl acetate fractions. The gas chromatography/mass spectrometry analysis indicated the presence of 1-heptacosanol (hexane fraction), 1-octadecene (hexane and chloroform fractions), and other organic compounds. Molecular docking demonstrated that phenol,2,5-bis(1,1-dimethylethyl) and 4-hydroxypyridine 1-oxide compounds showed specificity toward survivin protein, indicating the feasibility of N. abor-tristis in developing new drug leads against leukemia.

Migration of BTEX and phthalates from natural rubber latex balloons obtained from the Sri Lankan market.

The current study evaluates the migration of benzene, toluene, ethylbenzene, xylene (BTEX) and phthalates into artificial saliva from natural rubber latex (NRL) balloons available for sale in Sri Lanka. It was discovered that at least one BTEX compound migrated from almost all the brands. The migration of four phthalates; diethyl phthalate, dibutyl phthalate, di-isobutyl phthalate and butyl benzyl phthalate were also observed. Migratory levels of BTEX and phthalates in most of the balloon brands were above the permissible levels set by the European Union. Assessment of factors affecting the migratory levels indicated migration under active mouthing conditions and migration from the neck region of the balloons were significantly higher. The migratory levels were observed to decrease with storage time, and in certain brands the BTEX levels decreased below the permissible level. One-way ANOVA indicated no significant differences (p ≥ 0.05) in migratory levels of each individual compound within the same brand for both BTEX and phthalates. When compared among different brands, BTEX levels indicated significant differences (p ≤ 0.05), while phthalate levels were observed to not be significantly different (p ≥ 0.05). A significant difference was also observed (p ≤ 0.05) among the migratory levels of compounds under each test condition evaluated as factors affecting the migratory level. Furthermore, the solvent based colorants added to color the latex were found to be the source of BTEX and phthalates in the NRL balloons.

Identifying proteins that can form tyrosine-cysteine crosslinks.

Protein cofactors represent a unique class of redox active posttranslational protein modifications formed in or by metalloproteins. Once formed, protein cofactors provide a one-electron oxidant, which is tethered to the protein backbone. Twenty-five proteins are known to contain protein cofactors, but this number is likely limited by the use of crystallography as the identification technique. In order to address this limitation, a search of all reported protein structures for chemical environments conducive to forming a protein cofactor through tyrosine and cysteine side chain crosslinking yielded three hundred candidate proteins. Using hydrogen bonding and metal center proximity, the three hundred proteins were narrowed to four highly viable candidates. An orphan metalloprotein (BF4112) was examined to validate this methodology, which identifies proteins capable of crosslinking tyrosine and cysteine sidechains. A tyrosine-cysteine crosslink was formed in BF4112 using copper-dioxygen chemistry, as in galactose oxidase. Liquid chromatography-MALDI mass spectrometry and optical spectroscopy confirmed tyrosine-cysteine crosslink formation in BF4112. This finding demonstrates the efficacy of these predictive methods and the minimal constraints, provided by the BF4112 protein structure, in tyrosine-cysteine crosslink formation. This search method, when coupled with physiological evidence for crosslink formation and function as a cofactor, could identify additional protein-derived cofactors.