Comparison of the Phenolic Compound Profile and Antioxidant Potential of Achillea atrata L. and Achillea millefolium L.

In the present study, Achillea atrata L. and A. millefolium L. were compared for the first time with regard to their phenolic compound profile and antioxidant activity by applying the 2,2-diphenyl-picryl hydrazyl radical assay. For this purpose, aerial plant parts were consecutively extracted with solvents of increasing polarity (dichloromethane, n-butanol, ethyl acetate), revealing that the A. atrata ethyl acetate fraction showed the highest antioxidant activity with an IC50 value of 12.2 ± 0.29 µg/mL compared to 17.0 ± 0.26 µg/mL for A. millefolium. Both species revealed the presence of luteolin, apigenin, centaureidin, and nevadensin exclusively in this most polar fraction, which are known as effective 2,2-diphenyl-picryl hydrazyl radical scavengers. The antioxidant capacity of the aforementioned fractions strikingly correlated with their total phenolic contents, which was highest in the ethyl acetate fraction of A. atrata. Characterization of the metabolite profiles of both Achillea species showed only marginal differences in the presence of key compounds, whereas the concentrations of individual compounds appeared to be species-specific. Our results suggest that A. atrata, based on its compound pattern and bioactivity characteristics, has similar qualities for phytotherapy as A. millefolium.

The Effect of UV Irradiation on Vitamin D2 Content and Antioxidant and Antiglycation Activities of Mushrooms

Mushroom irradiation has been considered a sustainable process to generate high amounts of vitamin D2 due to the role of this vitamin for human health and of the global concerns regarding its deficient or inadequate intake. Mushrooms are also receiving increasing interest due to their nutritional and medicinal properties. However, there is still a knowledge gap regarding the effect of UV irradiation on mushroom bioactive compounds. In this study, two of the most cultivated mushroom species worldwide, Agaricus bisporus and Pleurotus ostreatus, were irradiated with UV-B, and the effect of processing was investigated on the contents of vitamin D2 as well as on antioxidant and antiglycation activities. UV irradiation increased vitamin D2 up to 57 µg/g d.w, which is an adequate level for the fortification of a number of target foods. UV irradiation decreased the antioxidant activity when measured by the Folin–Ciocalteu reagent, the 2,2-diphenyl-1-(2,4,6 trinitrophenyl) hydrazyl radical assay and the ferric ion-reducing antioxidant power assay, but did not decrease the mushroom’s ability to inhibit glycation of a target protein. These results open up a new area of investigation aimed at selecting mushroom species with high nutraceutical benefits for irradiation in order to maintain their potential properties to inhibit oxidative and glycation processes responsible for human diseases.

Synthesis and evaluation of antibacterial and antioxidative activities of carbazole derivatives

Seven compounds were synthesized by known methods, and their antibacterial activity was evaluated against Bacillus subtilis and Escherichia coli using a disk diffusion method. Antioxidative activity was evaluated using free 1,1-diphenyl-2-picryl-hydrazyl radical scavenging assay and ferric reducing antioxidant power methods. The disk diffusion method revealed that 6 out of 7 tested compounds showed antibacterial activity against tested strains, they inhibited the growth of bacteria at various concentrations, from 31.25 to 250 μg/ml. 3-Cyano-9H-carbazole, 3-iodo-9Hcarbazole and 3,6-diiodo-9H-carbazole showed a stronger antibacterial activity against Bacillus subtilis compared to the reference drug amoxicillin. 1,3,6-Tribromo-9H-carbazole showed a stronger activity against Escherichia coli. All tested compounds showed a weak antioxidative activity by the 1,1-diphenyl-2-picryl-hydrazyl radical scavenging assay and ferric reducing antioxidant power assay methods.

EFFECT OF GAMMA IRRADIATION ON ANTIOXIDANT POTENTIAL AND BIOACTIVES OF A COSMECEUTICALLY SIGNIFICANT CHLORELLA EMERSONII KJ725233

Objective : Gamma radiation induces free radicals with a corresponding alteration in the cell’s antioxidant defense system. The present study thus aimed at determining the role of gamma irradiation in improving the cosmeceutical potential of CEK in terms of antioxidants. Methods : C.emersonii KJ725233 was subjected to low (100 Gy) and high (1000 Gy) gamma irradiation doses and its effect on the chlorophyll content was evaluated. The quantitative alterations in the antioxidant content of CEK were evaluated by phosphomolybdenum assay (TAC), ferric reducing antioxidant potential (FRAP), 2, 2 - Dipheny-1-picryl hydrazyl radical scavenging assay (DPPH), total phenolic (TPC) and total flavonoid content (TFC). Also, the corresponding qualitative alterations in the bioactives of CEK were determined by GC-HRMS analysis. Results : A 179.57±2.55% increase in the total chlorophyll content alongwith a 71.76±2.96%, 32.08±2.16%, 11.67±0.89%, 42.85±8.0% and 31.37±3.18% increase was observed in the TAC, FRAP, DPPH radical scavenging, TPC and TFC was observed in CEK irradiated at 1000 Gy. GC-HRMS analysis revealed the induction of Vitamin E on irradiation at both the doses with a corresponding decrease in the phytol content whereas 100 Gy stimulated the induction of phytosterols. Conclusion : The potent intrinsic antioxidant activity of cosmeceutically significant CEK can be elevated with the induction of the most sought after antioxidant in cosmetology – Vitamin E on irradiation.

SYNERGISTIC EFFECT OF BINARY QUERCETIN–MONOSACCHARIDE MIXTURES IN THE RE-ACTION WITH FREE RADICALS

The presence of a synergistic effect of binary mixtures of quercetin–monosaccharide in the model reaction with the 2,2'-diphenyl-1-picrylhydrazyl radical in deoxygenated ethanol was established. It was shown that the studied carbohydrates related to the tetrose, pentose and hexose groups exhibit a synergistic effect to some extent enhancing the anti-radical effect of quercetin. The synergistic effect of the mixture is determined by the number of hydroxyl substituents and by the presence of aldehyde or ketone groups in carbohydrate molecules. The synergistic compositions of quercetin with glucose and galactose in the ratio of 60:40% showed the highest antiradical activity. The maximum synergistic effect of the mixture is 75%. It is achieved due to the fact that, firstly, when dissolved in water, quercetin transforms into a tautomeric diketo form where hydrogen bonds form between its carbonyl groups and hydroxy groups of the monosaccharide, promoting the formation of molecular complexes, improving solubility of flavonoid in water and the manifestation of a synergistic effect in a mixture with carbohydrate. Secondly, reducing carbohydrates are able to restore oxidized forms of quercetin, which is confirmed by the great synergistic effect of aldose in comparison with ketoses, regardless of the number of hydroxy groups in the molecule. The synergistic effect of the quercetin–monosaccharide compositions, established in a model reaction with a hydrazyl radical, was compared to that in the autoxidation process of cottonseed oil. In the reaction with the peroxy radicals of cottonseed oil, the synergistic effect of the quercetin monosaccharide compositions increases up to 300% only for sugars capable of reducing quercetin radicals and reacting with air oxygen, reducing the steady-state concentration of peroxy radicals in the system.

PHYTOSYNTHESIS OF SILVER NANOPARTICLES USING HYGROPHILA AURICULATA LEAF EXTRACT AND ASSESSMENT OF THEIR ANTIBACTERIAL AND ANTIOXIDANT PROPERTIES

Objective: In this study, the phytosynthesis of silver nanoparticles (AgNPs) using leaf extracts of Hygrophila auriculata (HA) and their biological activities was investigated.Methods: The synthesis of AgNPs was done by using the green synthetic method and analyzed by UV-Visible spectroscopy, X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and further characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The antibacterial activity of HA AgNPs was studied by agar well diffusion method and micro broth dilution method for determination of minimum inhibitory concentration (MIC). The antioxidant potentials of HA AgNPs were detected by Diphenyl-1-picryl hydrazyl radical scavenging assay (DPPH), Phosphomolybdenum assay, reducing power assay.Results: The prepared HA AgNPs showed characteristic absorption peak at 420 nm in the UV-Vis spectrum. FTIR spectra had shown that the biomolecules present in leaf extract were responsible for the reduction and capping material of silver nanoparticles. XRD study showed the particles found to be crystalline in nature, with a face-centered cubic (fcc) structure. TEM and DLS results revealed that the AgNPs were mostly spherical with an average size ranging from ~15-115 nm with a mean diameter of 40.96 nm. The HA AgNPs showed good antibacterial activity and MIC against Staphylococcus aureus (ATCC 6538), Bacillus cereus (NCIM 2106), Pseudomonas aeruginosa (ATCC 9027) and Escherichia coli (ATCC 8739). In agar well diffusion method, the maximum zone of inhibition was found against Pseudomonas aeruginosa (ATCC 9027) with 18 mm and minimum zone of inhibition was found to be against Escherichia coli (ATCC 8739) with 13 mm. The MIC of the HA AgNp was found to be 5µg against all the test organisms. In addition, the Diphenyl-1-picryl hydrazyl radical scavenging assay (DPPH), Phosphomolybdenum assay, reducing power assay revealed they can be used as the potential scavenger against deleterious damages caused by the free radicals.Conclusion: The present study explored that Hygrophila auriculata which are efficient producers of AgNPs and could act as safe and cost-effective with potential antibacterial and antioxidant activities. These findings encourage studying HA AgNP further for their potential biological applications.

Phytochemical Analysis and Antioxidant Potential of Raphia Hookeri Leaf and Epicarp

The contribution of oxidative stress to the pathogenesis of several health conditions and its association with life-threatening diseases such as malaria has necessitated the search for more phytochemicals with antioxidant properties. Various parts of Raphia hookeri such as the leaves, fruit and sap have been moderately studied and applied in different areas of industry. However, the epicarp is generally discarded. The ethanolic extracts of Raphia hookeri leaf and epicarp were herein investigated for their total phenolic and flavonoid contents using spectrometric methods. 1,1-diphenyl-2-picryl hydrazyl radical (DPPH) and 2,2-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) cation assays were used to determine the antioxidant potential of the extracts. The recorded Total Phenolic Content (TPC) of both extracts are comparable while the Total Flavonoid Content of the leaf extract is higher. Consequently, the antioxidant activity of the leaf extract was higher. Although the antioxidant potential of the leaf is higher (351.170±22.950 mg/g RE), the comparable TPC and the antioxidant activity exhibited by Raphia hookeri epicarp extract projects it as a rich phytochemical bio-resourse which may have future relevance in the pharmaceutical industry.

Antioxidant and Antimicrobial Activities of Phenolic Components and Organic Acids from Camellia Oleifera Cake

There is a great interest in finding antioxidants and products with antimicrobial activities from natural sources. The aim of this study was to obtain and identify the phenolic components and organic acids from Camellia oleifera cake. In addition, their antioxidant and antimicrobial activities were also investigated. The purity of phenolic components and organic acids obtained were 94.1 ± 0.5% w/w and 96.0 ± 0.3% w/w, respectively. There are 15 phenolic components have been detected and identified by HPLC-ESI-MS. Oxalic, citric, acetic, malic, and succinic acids are found to be major organic acids. The phenolic components and organic acids both had good antioxidant capacity, evaluated by 4 antioxidant activity assays (hydroxyl radical scavenging, superoxide radical scavenging, 1,1-diphenyl-2-picryl-hydrazyl radical scavenging and lipid peroxidation inhibition). In addition, the phenolic components and organic acids exhibited significant inhibitory activity against bacteria Staphylococcus aureus, Escherichia coli, Bacillus subtilis, and fungi Mucor racemosus, Aspergillus oryzae, Rhizopus stolonifer. The phenolic components and organic acids from C. oleifera cake both showed good antioxidant capacity and exhibited antimicrobial activities. These results may be useful for the future use of phenolic components and organic acids from C. oleifera cake.