Determination of total flavonoids content in buckwheat and inhibition of α-amylase activity

Diabetes is one of the most difficult chronic diseases to cure in the world,which seriously affects people’s health and quality of life.Flavonoids in buckwheat can regulate blood glucose levels by inhibitingα-amylase activity.Therefore,sweet buckwheat produced in Inner Mongolia was used as the research object,and buckwheat fl avonoids were extracted by ultrasonic-assisted extraction method.Total fl avonoids content was determined by ultraviolet-visible spectrophotometry.With acarbose as the positive control,the inhibition test ofα-amylase was carried out by DNS colorimetry to study the inhibition behavior of fl avonoids onα-amylase activity.The results showed that the extraction process of flavonoids was stable and reliable,and the established method for the determination of flavonoids was simple,accurate and reproducible.The total flavonoids content of buckwheat samples was 2.706 mg/g,buckwheat total fl avonoids extraction solution had an inhibitory eff ect onα-amylase,and its median inhibition concentration(IC_(50))was 38.53 mg/mL.The results of this experiment provide a technical reference for the development and utilization of fl avonoids in Inner Mongolia sweet buckwheat,and provide a theoretical reference for the development and application of flavonoid-rich hypoglycemic food.

Evaluation of total phenols,total flavonoids and antioxidant activity of the leaves crude extracts of locally grown pigeon pea traditionally used in Sultanate of Oman for the treatment of jaundice and diabetes

Objective:To determine the total phenols,total flavonoids and evaluate the antioxidant activity of crude extracts from the leaves of pigeon pea native to Sultanate of Oman by a popular method.Methods:The powdered leaves samples from pigeon pea were used for extraction by maceration method with methanol solvent.The methanol free crude extract by maceration method was suspended in water and successively extracted with different polarities of solvents.The obtained crude extracts with different polarities were used for the determination of total phenols and flavonoids contents by using Folin-Ciocalteu reagent and aluminum chloride methods.The antioxidant activity of six crude extracts from pigeon pea was determined byα,αα-diphenyl-β-picrylhydrazyl method.Results:The different polarities leaves crude extracts showed a significant amount of total phenols content ranging from 97.80 to 256.00 mg of GAE/g of crude extract.The same leaves crude extracts also showed good amount of total flavonoids content ranging from 1.38 to 8.51 mg QE/g plant material.The six crude extracts from the leaves displayed significantα,αα-diphenyl-β-picrylhydrazyl free radical scavenging activity with highest value in chloroform extract followed by methanol,butanol,ethyl acetate,hexane and water crude extracts(98.13%,89.26%,88.82%,86.41%,79.95%and 69.44%,respectively).Conclusions:Leaves crude extracts from pigeon pea have high contents of total phenols and flavonoids.In this regards,it could be used as a medicine for the treatment of different diseases.

Anti-obesity effect and UHPLC-QTOF-MS/MS based metabolite profiling of Solanum nigrum leaf extract

Objective:To evaluate the antioxidant potential and pancreatic lipase inhibitory action of optimized hydroethanolic extracts of Solanum nigrum.Methods:Optimized extraction for maximum recovery of metabolites was performed using a combination of freeze-drying and ultrasonication followed by determination of antioxidant and antiobesity properties.The ultra-high performance liquid chromatography equipped with mass spectrometry was used to analyze metabolite profiling of Solanum nigrum.Computational studies were performed using molecular docking and electrostatic potential analysis for individual compounds.The hypolipidemic potential of the most potent extract was assessed in the obese mice fed on fat rich diet.Results:The 80%hydroethanolic extract exhibited the highest extract yield,total phenolic contents,total flavonoid contents along with the strongest 2,2-diphenyl-1-picrylhydrazyl scavenging activity,total antioxidant power,and pancreatic lipase inhibitory properties.The 80%hydroethanolic extract not only regulated the lipid profile of obese mice but also restricted the weight gain in the liver,kidney,and heart.The 80%hydroethanolic extract also reduced alanine transaminase and aspartate transaminase concentrations in serum.The effects of plant extract at 300 mg/kg body weight were quite comparable with the standard drug orlistat.Conclusions:Solanum nigrum is proved as an excellent and potent source of secondary metabolites that might be responsible for obesity mitigation.

In Vitro Antioxidant and Free Radical Scavenging Activity of Curcuma longa, Acorus calamus and Camellia sinensis

The purpose of the current study was to determine the total phenolic and flavonoid content and total antioxidant activity of the Curcuma longa, Acorus calamus, and Camellia sinensis ethanolic extracts and their free radical scavenging activity. The study concluded that the Curcuma longa, Acorus calamus, and Camellia sinensis ethanolic extracts have a good source of phenolics, flavonoids, and antioxidant sources in turn which opens the high possibility of the extracts being used as food preservatives. The DPPH assay for scavenging free radicals showed that the IC50 value was above 123% of Curcuma longa ethanolic extract, 129.9% μg/ml of Acorus calamus ethanolic extract and 25% of Camellia sinensis ethanolic extracts shows very strong inhibition of the free radicals. Thus, comparing the DPPH assay for scavenging free radicals of Curcuma longa, Acorus calamus and Camellia sinensis ethanolic extracts with the positive control ascorbic acid, Curcuma longa and Camellia sinensis ethanolic extracts showed strong inhibition of the free radicals.

Influence of storage duration and processing on chromatic attributes and flavonoid content of moxa floss

OBJECTIVE： Moxibustion is an important traditional Chinese medicine therapy using heat from ignited moxa floss for disease treatment. The purpose of the present study is to establish a reproducible method to assess the color of moxa floss, discriminate the samples based on chromatic coordinates and explore the relationship between chromatic coordinates and total flavonoid content （TFC）. METHODS： Moxa floss samples of different storage years and production ratios were obtained from a moxa production factory in Henan Province, China. Chromatic coordinates （L＊, a＊ and b＊） were analyzed with an ultraviolet-visible spectrophotometer and the chroma （C＊） and hue angle （h~） values were calculated. TFC was determined by a colorimetric method. Data were analyzed with correlation, principal component analysis （PCA）. RESULTS： Significant differences in the chromatic values and TFC were observed among samples of different storage years and production ratios. Samples of higher production ratio displayed higher chromatic characteristics and lower TFC. Samples of longer storage years contained higher TFC. Preliminary separation of moxa floss production ratio was obtained by means of color feature maps developed using L＊-a＊ or L＊-b＊ as coordinates. PCA allowed the separation of the samples from their storage years and production ratios based on their chromatic characteristics and TFC. CONCLUSION： The use of a colorimetric technique and CIELAB coordinates coupled with chemometrics can be practical and objective for discriminating moxa floss of different storage years and production ratios. The development of color feature maps could be used as a model for classifying the color grading of moxa floss.

Antioxidant and antibacterial activities of the ethyl acetate extracts of endophytic fungi isolated from Ageratum conyzoides L.

Accumulating evidence has demonstrated that endophytic fungi metabolites possess important biological activities.Ageratum conyzoides L.(Asteraceae)is an invasive aromatic herb with immense therapeutic importance.In the present study,we aimed to isolate and identify endophytic fungi in the roots,stems,leaves and flowers of Ageratum conyzoides L.and evaluate its antioxidant activity(DPPH,ABTS^(+) and FRAP assays),the contents of flavonoids and phenolic and antibacterial activity of their ethyl acetate extracts.Accordingly,a total of 25 endophytic fungi were isolated from Ageratum conyzoides L.and classified into 14 genera based on the Internal transcribed spacer sequence,among which Fusarium sp.(20%)were found to be the dominant groups.All fungal extracts exhibited antioxidant activity,and the extracts of fungi WZ07 exhibited antioxidant activities as well as higher flavonoids and phenolic content in all tests.Moreover,the extracts of fungi WL01 had good antibacterial activity against both Gram-positive and Gram-negative bacteria.We,for the first time,reported the antioxidant and antibacterial activity of endophytic fungi from Ageratum conyzoides L.,which may help lay the foundation for developing other medicinal components.

Antioxidant and antimicrobial activities of selected medicinal plants from Algeria

Objective:To evaluate the antioxidant and antimicrobial activity of methanolic extract extracts of selected Algerian medicinal plants.Methods:Antioxidant activity of extracts was evaluated in terms of radical scavenging potential(2,2-diphenyl-1-picrylhydrazyl)and β-carotene bleaching assay.Total phenolic contents and flavonoid contents were also measured.Antimicrobial activity of these plants was examined against Bacillus subtilis,Staphylococcus aureus,Escherichia coli,Pseudomonas aeruginosa and Candida albicans.Results:The values of IC_(50) ranged from 4.30μg/mL to 486.6μg/mL for the DPPH method,while total antioxidant activity using β-carotene/linoleic acid bleaching assay ranged from 17.03%to 86.13%.It was found that Pistacia lentiscus showed the highest antioxidant capacities using DPPH assay(IC_(50)=4.30μg/mL),while Populus trimula,Origanum glandulosum,Centaurea calcitrapa,Sysimbrium officinalis and Rhamnus alaternus showed the highest percent of total antioxidant activity in β-carotene/linoleic acid bleaching assay.Total phenolic and flavonoid contents ranged from 3.96 to 259.65 mg GAE/g extract and from 1.13 to 26.84 mg QE/g extract,respectively.The most interesting antimicrobial activity was obtained from Sysimbrium officinalis,Rhamnus alaternus,Origanum glandulosum,Cupressus sempervirens,Pinus halipensis and Centaurea calcitrapa.Conclusions:The results indicated that the plants tested may be potential sources for isolation of natural antioxidant and antimicrobial compounds.

Antioxidant and antimicrobial activity of a mangrove plant Avicennia marina(Forsk.)

Objective:To evaluate the antioxidant and antimicrobial potential of different parts(leaf,stem and pneumatophore)of a mangrove plant Avicennia marina(Forsk.)Vierh(Avicenniaceae).Methods:The extraction was done by cold percolation method using solvents of hexane,ethyl acetate,acetone,methanol and water.Total phenol and flavonoid content were measured by Folin-Ciocalteu’s reagent and aluminium chloride colorimetric method respectively.The antioxidant activity was evaluated using antioxidant assays of 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity,superoxide radical scavenging assay,2,2’-azino-bis-(3-ethyl)benzothiazoline-6-sulfonic acid,ferric reducing antioxidant power and reducing capacity assessment.The antibacterial activity was done by agar well diffusion method against four Gram-positive,four Gram-negative bacteria and four fungi.Results:Different antioxidant assays showed different levels of activity in different parts and different solvent extracts.Overall,acetone extract of stem showed the best antioxidant activity.The Gram-positive bacteria were more susceptible than Gram-negative bacteria and fungi.Conclusions:The results indicated extract of Avicennia marina can be used as a promising source of natural antioxidant.