Highest Free Radical Scavenging Activity Research Articles

Calabash (Lagenaria siceraria) potency to ameliorate hyperglycemia and oxidative stress in diabetes

• Calabash ( Lagenaria siceraria ) fruit aqueous reduced hyperglycemia. • L. siceraria fruit extracts did not produce hypoglycemia. • L. siceraria fruit aqueous extract could ameliorate oxidative stress. • Protocatechuic acid and luteolin-7-glucoside were detected in L. siceraria fruit. Calabash fruit is traditionally used as an antidiabetic remedy in the Kurdistan region. Different extracts (400 mg/kg) were investigated for antihyperglycemic potency on normal and alloxan-induced diabetic mice. The significant potency exhibited by the aqueous extract produced a decrease in fasting blood glucose level (52.685%, P ≤ 0.05) in diabetic mice with no apparent effect using extracts in the normoglycemic model. The antihyperglycemic extract was evaluated for in vitro antidiabetic efficacy based on HepG2 cells, and the 2-NDBG indicator showed a significant glucose uptake (164.87%, P ≤ 0.05), whereas the in vitro antioxidant study showed high ABTS free radical scavenging activity (EC 50 64.4 ± 2.12 µg/mL). The extract phytochemical study recorded a high phenolic content with the identification of two compounds, protocatechuic acid, and luteolin-7-glucoside, using liquid chromatography-tandem mass spectrometry. The results revealed the benefits of the fruit in the reduction of hyperglycemia and attenuating oxidative stress associated with diabetes.

Techno-functional characterization of indigenous Lactobacillus isolates from the traditional fermented foods of Meghalaya, India

The rural tribal people of Meghalaya depend mostly on their ethnic fermented foods as a part of their regular diet and these fermented foods are considered to be a hub of healthy microorganisms. However, the efficacy of probiotic microorganisms is considered to be population-specific because of gut microflora variation in food habits and specific host-microbial interactions. Hence, a strong need for exploring novel indigenous microorganisms with rich probiotic potentiality is required. A few indigenous Lactobacillus isolates (from traditional fermented foods of Meghalaya) were studied extensively for its technological and probiotic attributes. The isolates could survive at pH 2–3 (L. fermentum K16 showed high cell count: pH 2–5.12 log CFU/ml; pH 3–5.76 log CFU/ml), against bile salts (L. fermentum K7 showed high cell count-5.36 log CFU/ml), gastric juices (pepsin and trypsin), and intestinal juice (pancreatin). The isolates showed α-galactosidase activity from 0.104-0.412 μM/ml and β-glucosidase activity ranging from 0.122-0.409 μM/ml. Exopolysaccharide production was in between 410 and 950 mg/L. Cell surface hydrophobicity was 71.57% (L. rhamnosus K4E) and auto-aggregation was 83% (L. fermentum K16) during the study. Highest proteolytic activity (0.671 nm) and cholesterol assimilation (52.57%) was exhibited by L. fermentum K16. The isolates showed high free radical scavenging activity by ABTS method up to 80.78% by isolate L. fermentum K7. Antibacterial activity and co-aggregation efficacy was also tested against B. cereus, E. faecalis, S. dysenteriae, S. aureus, E. coli, L. monocytogenes, S. typhi. These indigenous Lactobacillus isolates with high probiotic potentials could be exploited in the development of the traditional fermented foods of Meghalaya.

Preliminary phytopharmacological analysis, proximate composition analysis and product development with the leaves and fruits of Muntingia calabura L.

Muntingia calabura, commonly known as the Jamaican cherry tree is a widely distributed, fast-growing avenue tree that can be easily identified by its green canopy and small, red cherry-like fruits. This study was carried out to evaluate the in vitro antioxidant, antimicrobial and anti-arthritic activity of the chloroform and methanol extract of the leaves and fruits of M. calabura collected from Visakhapatnam, India. The moisture content, ash value, the amount of calcium, vitamin C, fiber and fat, the phosphorous iron, calcium, copper, potassium, magnesium, sodium, zinc and protein content in the leaves and green fruits of M. calabura were determined by standard protocols. Five items (one health drink, three spicy snack items and two sweet snack items) in total were prepared with the selected sample and organoleptic evaluation of the developed products was done by 11 selected panel members. Nutritive values were computed for all the recipes based on the nutrient information database of raw ingredients. The chloroform and methanol extracts were rich in a diverse array of phytochemicals like alkaloids, glycosides, phenolic compounds, tannins, phytosterols, flavonoids and triterpenes. Considerably high free radical scavenging activity (chloroform extract 91.9459±0.25% at a concentration of 100μl and methanol extract 81.0405±10.35% at a concentration of 300μl) and anti-arthritic activity (chloroform extract 96.6983±0.20% at a concentration of 100μl and methanol extract 98.1407±0.05% at a concentration of 600μl) was exhibited by both extracts. While the chloroform extract exhibited greater antifungal activity, the methanol extract showed greater antibacterial activity. Proximate composition analysis revealed that the leaves had almost equal amounts of moisture (54±0.5%) and fiber (54.5%). The green fruits had high moisture content (74.685±1.59%) and a significant amount of crude protein (2.0424±0.01 mg/g). Significant amounts of potassium, phosphorus and iron were found in both the leaves and green fruits of M. calabura. Both the leaves and green fruits had high amounts of magnesium (18.5672±0.6 mg/g and 18.4847±0.23 mg/g respectively) and sodium (13.0325±1.27mg/g and 12.735±1.48mg/g). Calcium and zinc were present in low amounts in the leaves and green fruits. Trace amounts of vitamin C was found in both the leaves (0.0645μg/100g) and the green fruit (0.0166μg/100g) samples of M. calabura. The five food items prepared were well accepted and appreciated for good taste, flavor, appearance and texture. In conclusion, M. calabura is a wonder plant loaded with phytochemicals and minerals having potent pharmacognostic activity and the tea of the leaves and the green/ripe fruits can be innovatively incorporated into food items and consumed to avail the health benefits of this plant.

Free Radical Scavenging Principles of Salvia reuterana Boiss. Aerial Parts.

Salvia reuterana Boiss. is an aromatic perennial plant traditionally used for its anxiolytic and sedative properties. In the present study, various fractions and essential oil of S. reuterana aerial parts were investigated to find its free radical scavenging principles. Hydroalcoholic fraction with IC50 value of 112.6 ±3.2 μg mL-1 in DPPH assay demonstrated the highest free radical scavenging activity and was selected to further phytochemical investigation. RP-18 and Sephadex LH-20 column chromatography of the hydroalcoholic fraction resulted in the isolation and structural elucidation of four phenolic derivatives, including apigenin-7-O-β-D-glucopyranoside (1), luteolin-7-O-β-D-glucopyranoside (2), rosmarinic acid (3), and luteolin (4). Isolated compounds showed potent free radical scavenging activities (5.1-34.2 μg mL-1), compared with BHT (21.30 ± 1.9 μg mL-1). Twenty four compounds were also identified in GC-MS analysis of the plant essential oil, of which benzyl benzoate (26.64%), n-hexyl benzoate (22.99%) and n-hexyl isovalerate (6.04%) were the main compounds. The results of the present study introduced S. reuterana as a valuable source of natural phenolic antioxidants which can be utilized in prevention of oxidative stress related diseases. Moreover, interesting composition of S. reuterana essential oil, dominated by non-terpenes compounds (76.17%) especially aromatic derivatives, make it an appropriate candidate for more detailed studies.

Spice fixed oils as a new source of γ-oryzanol: nutraceutical characterization of fixed oils from selected spices.

γ-Oryzanol is an important group of nutraceuticals that play a key role in addressing metabolic disorders. This study, for the first time, examined volatile-free spice fixed oils (FOs) as an alternate plant source for γ-oryzanol and other nutraceuticals (phenolics, flavonoids, phytosterols, and tocopherols) using HPLC, HR-MS and NMR. The in vitro antioxidant activities of FOs were also analysed. The selected spices were Alpinia galanga, Cinnamomum zeylanicum, Trigonella foenum-graecum, Foeniculum vulgare and Myristica fragrans. The major polyphenols and flavonoids quantified were gallic, protocatechuic, vanillic, syringic, para-coumaric, ferulic, rutin, trans-cinnamic, and quercetin. T. foenum-graecum FOs recorded high levels of ergosterol (48.56 mg/100 g) and stigmasterol (247.36 mg/100 g). The fucosterol levels were high in A. galanga (268.31 mg/100 g) FOs, whereas C. zeylanicum FOs showed high content of β-sitosterols (7037.77 mg/100 g). C. zeylanicum and T. foenum-graecum FOs recorded high α-tocopherol content (47.55 and 15.96 mg/100 g respectively). C. zeylanicum FOs showed high levels of three ferulates, namely, cycloartenyl ferulate, 24-methylene cycloartenyl ferulate and β-sitosteryl ferulate, whose contents were 89.42, 170.23 and 50.23 mg/100 g respectively which was confirmed by HRMS with a molecular mass (m/z) of 601.45, 615.47, and 589.45 respectively. Further, γ-oryzanol ferulates in C. zeylanicum FOs were confirmed by 1H-NMR analysis. The acidified methanolic extractives of FOs showed high free radical scavenging activity and antioxidant potential. These spice FOs have excellent antioxidant activities, and are novel potential functional ingredients against lifestyle disorders.

Structural Analysis and Antioxidant Activity of Extracellular Polysaccharides Extracted from Culinary-Medicinal White Jelly Mushroom Tremella fuciformis (Tremellomycetes) Conidium Cells.

Using Tremella fuciformis conidium cells for submerged fermentation is a cost-effective way to harvest bioactive compounds. In this study, we emphasized the structural and functional analysis of extracellular polysaccharides (EPS) extracted from T. fuciformis conidium cells. An EPS high-yield strain tyc63 was selected and a 6-day optimum fermentation period was determined. Crude EPS was extracted and three high molecular weight (5189, 171.6, and 661 kDa) polysaccharides TFP-1, TFP-2, and TFP-3 were isolated and purified. TFP-1 is mainly composed of glucose, xylose, mannose, and fucose, while both TFP-2 and TFP-3 are mainly composed of rhamnose, arabinose, mannose, galactose, and glucose. FT-IR analysis revealed that TFP-1, TFP-2, and TFP-3 have typical polysaccharide structure. The antioxidant assay revealed that the crude EPS, TFP-1, TFP-2, and TFP-3 presented high free radical scavenging activities but low ferric reducing power, suggesting that the EPS produced by liquid fermentation could be used as a potent radical scavenger.

Antioxidant properties of the extract from culture filtrate of Schizophyllum commune

Schizophyllum commune mushroom is a wood decay fungus, widely consumed in traditional food and medicine. The study aimed to investigate the antioxidant activity, total phenolic and flavonoid content in the extract from culture filtrate of S. commune. Results showed that the total phenolic content present in the extract was found to be 672.17±9.55mg gallic acid equivalent (GAE)/g dry extract and total flavonoid content was 211.52±4.01mg quercetin equivalent (QAE)/g dry extract. The extract from culture filtrate of S. commune showed the highest free radical scavenging activity with IC50 values of 6.88±0.41 and 1.58±0.08μg/mL against DPPH and ABTS radicals, respectively. In FRAP assay, the extract showed high activity of 17,328.23±310.72mM Fe (II) equivalent/g dry extract. These results suggested that the extract from culture filtrate of S. commune can be used as a source of natural antioxidants and dietary supplements.

Antimicrobial and antioxidant potential of Tylophora indica (Burm. f.) Merrill and development of an efficient micropropagation system for its therapeautic use

Infectious diseases caused by pathogenic microorganisms are the leading cause of human mortality worldwide. Emergence of multidrug resistance in these pathogens and negative effects of available antibiotics have necessitated the search for new potent antimicrobial agents of plant origin. Tylophora indica commonly known as “Antamool” or “Asthama herb” is a valuable medicinal plant traditionally used as a folk remedy for the treatment of a variety of diseases and disorders. An efficient and reproducible in vitro protocol was established for the mass cloning of this valuable plant through de novo adventitious shoot formation directly from the leaf explant. The antimicrobial activity of different solvent extracts of leaves of both native and in vitro plants was tested against bacterial strains (Staphylococcus aureus, Escherichia coli) and fungal strains (Aspergillius niger, Penicillium chrysogenum) using agar well diffusion method. The leaf extracts prepared by Rao and Book's method and methanolic leaf extracts exhibited a significant microbial inhibition at all tested concentrations (25, 50, 100 μg/ml), whereas very less activity was observed with acetone extract. Likewise the methanolic root extract of in vitro plants exhibited significant antioxidant activity. The highest free radical scavenging activity i.e. 75% was seen at 1000 μg/ml concentration depicting strong antioxidant effect. The present study suggests that T. indica may prove to be a potential natural source of antimicrobial and antioxidant agents which needs to be further explored.

Quantification of Total Phenolics, Flavonoids and Evaluation of in vitro Free Radical Scavenging Activities in Psidium guajava L.

The present study was undertaken to quantify total phenolics and flavonoids and investigate in vitro free radical scavenging activities of leaf extracts of two varieties of Psidium guajava L. viz., Lalit and Allahabad safeda. Leaf extracts of Lalit and Allahabad safeda were prepared by Soxhlet extraction and ethanol extracts were used for in vitro assays. Total phenolic and flavonoid contents, 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), 2,2-diphenyl-1-picrylhydrazyl, nitric oxide and super oxide free radical scavenging activities were determined at 100, 200, 300, 400, 500, 600 and 700 µg/ml concentrations of Lalit and Allahabad safeda leaf extracts. Results indicated the presence of higher phenolic and flavonoid contents in the leaf extract of Lalit compared to that of Allahabad safeda. The leaf extracts of Lalit and Allahabad safeda showed dose-dependent increase in 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), 2,2-diphenyl-1-picrylhydrazyl and nitric oxide radical scavenging activities and a decrease in super oxide radical scavenging activities. However, Lalit showed higher free radical scavenging activity compared to that of Allahabad safeda. Further, the IC50 values of Lalit for DPPH, 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), nitric oxide and super oxide free radicals were 229.56, 503.07, 430.40, 07 and 377.96 µg/ml, respectively. In addition, the IC50 values of Allahabad safeda for 2,2-diphenyl-1-picrylhydrazyl, 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), nitric oxide and super oxide free radicals were, 270.24, 543.63, 469.99 and 515.50 µg/ml, respectively. This study clearly demonstrated antioxidant activity in both the extracts of Lalit and Allahabad safeda. The better antioxidant activity of Lalit extract could be due to the presence of higher phenolic content compared to Allahabad safeda.

In vitro Screening of Sesamum indicum Seeds for Antioxidant, Phytochemical and Biological Properties

Herbal medicines has been the most cost-effective and valuable medical practice to cure diseases and emphasize modern health care treatment. The present research was conducted to assess the biological activities of 10 fractions obtained from methanolic extract which was derived from dried seeds of Sesamum indicum. Antioxidant activity was assessed using DPPH radical scavenging, total antioxidant capacity and total reducing power assays. Highest free radical scavenging activity (80.3 ± 1.36%), total antioxidant capacity (104.7 ± 4.04 μg AAE/mg) and ferric reducing power activity (238.76 ± 1.23 μg AAE/mg) was shown by fraction SE. Fraction SE showed the highest phenolic contents (63.72 ± 1.5 μg GAE/mg) while fraction SG sample showed highest flavonoid contents (54.62 ± 2.61 μg QE QE/mg). Antibacterial activity was performed against four selected bacterial strains including Staphylococcus aureus, Escherichia coli, Enterobacter aerogens and Bacillus subtilis. Highest inhibition was shown by fraction SD (11 ± 1.04 mm) against Staphylococcus aureus, fraction SH against Bacillus subtilis (11 ± 1.06 mm) and fraction SB against Escherichia coli. All fractions were found inactive against the selected fungal strains. While performing antileishmanial activity, fraction SC showed highest percent mortality (78%) of Leishmania tropica. In brine shrimp lethality bioassay, fraction SG showed significant LD50 value (23.48 μg/mL).

Chemical composition, antimicrobial and free- radical scavenging activity of essential oils from Khaya senegalensis (Desr) A. Juss

Investigations were conducted to evaluate the chemical composition, free-radical scavenging activity and the antimicrobial efficacy of essential oils obtained from the leaf and stem bark of Khaya senegalensis (Desr) A. Juss. The plant materials (leaf and stem bark) were dried under shade, blended and sieved to obtain their respective powders. The essential oils obtained by subjecting the powders to hydro distillation method for 3hr in a Clevenger type apparatus were then investigated using standard methods. The average percentage yields of the oils were 0.85± 0.01%) and 0.50± 0.00% for the leaf and stem bark respectively. The major constituents of the essential oils were khayasinine (39.11%), 7-diacetyl-7oxogedunine (27.09%) and methyl- angolensate (11.51%) for the leaf oil and ivorenolide (28.77%), khivorine (16.33) and 3-diacetyl khivorine (16.10%) for the stem oil. The inhibitory concentration (IC50) of the free radical scavenging activity of the oils were 1.40± 0.29 and 1.00± 0.02 for the leaf and stem oils respectively. The mean diameter of the zones of inhibition exhibited by the oils at 50 µg/ml was between 7.67± 0.67mm and 16.33 ±0.33mm while the MIC was between 5 µg/ml and 40µg/ml for the plant materials. The plant oils remarkably inhibited the growth of Bacillus subtilis ATCC6633, Candida albicans ATCC10231, Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus. The activity of the plant oils compared favourably with the antibiotics used as positive control. The demonstration of significant antimicrobial and high free radical scavenging activities in addition to the presence of bioactive compounds in the plant materials could explain the basis for the use of K. senegalensis in the traditional treatment of diseases caused by the test microorganisms.

Green synthesis of silver nanoparticles using Tridax procumbens: their characterization, antioxidant and antibacterial activity against MDR and reference bacterial strains

Silver nanoparticles (AgNPs) were synthesized by reducing 2 mM solution of AgNO3 using leaf extract of Tridax procumbens. Synthesized AgNPs were characterized by UV spectroscopy, FTIR-ATR, SEM, and TEM analyses. Antibacterial activity of AgNPs was evaluated against reference and MDR bacterial strains. Phytochemical estimation and antioxidant activity were carried out for aqueous extract of T. procumbens leaves as well as for AgNPs. The nanoparticles were reported oval to spherical in shape with an average size of 54.34 nm. The synthesized AgNPs showed considerable antibacterial activity against bacterial strains. The zone of inhibition ranged between 11.00 ± 1.00 and 15.33 ± 0.58 mm. Among reference bacterial strains, E. coli (15.33 ± 0.58 mm) and S. aureus (15.33 ± 0.58 mm) were found to be the most susceptible with MIC range in between 11.43 and 102.8 µg/ml. Among the MDR strains, P. aeruginosa and E. coli showed inhibition zone of 14.33 ± 0.58 mm with MIC of 102.8 µg/ml. Cell leakage analysis showed an increase in protein leakage level and degradation of nucleic acid after treatment with AgNPs. Synthesized AgNPs showed higher amounts of total phenolic and flavonoids contents as compared to aqueous extract of Tridax procumbens leaves. The antioxidant activity of synthesized AgNPs and aqueous extract of Tridax procumbens leaves was determined using DPPH free radical scavenging, metal chelating, and β-carotene linoleic assays and nanoparticles represented the higher free radical scavenging activity in all the assays. The present study concluded that Tridax procumbens can be used as a source for green synthesis of AgNPs which possesses potent antibacterial and antioxidant activities.

Metabolic engineering of rice endosperm for betanin biosynthesis.

Betanin has been widely used as an additive for many centuries, and its use has increased because of its market application as an additive, high free radical scavenging activity, and safety, health-promoting properties. The main source of betanin is red beet, but many factors notably affect the yield of betanin from red beets. Betanin is not produced in cereal grains. Thus, developing biofortified crops with betanin is another alternative to health-promoting food additives. Here, rice endosperm was bioengineered for betanin biosynthesis by introducing three synthetic genes (meloS, BvDODA1S, and BvCYP76AD1S). The overexpression of these genes driven by rice endosperm-specific promoter established the betanin biosynthetic pathways in the endosperm, resulting in new types of germplasm - 'Betanin Rice' (BR). The BR grains were enriched with betanin and had relatively high antioxidant activity. Our results proved that betanin can be biosynthesized de novo in rice endosperm by introducing three genes in the committed betanin biosynthetic pathway. The betanin-fortified rice in this study can be used as a functional grain to promote health and as a raw material to process dietary supplements.

Phytochemical Fingerprinting and In Vitro Bioassays of the Ethnomedicinal Fern Tectaria coadunata (J. Smith) C. Christensen from Central Nepal.

Tectaria coadunata, an ethnomedicinal fern used in Nepal to treat a large number of diseases, has been poorly studied with regard to its phytochemical composition and possible bioactivity. This study was performed with the aim of supporting traditional medicine as a new source of bioactive constituents. Phytochemical compositions of methanol extracts were determined by nuclear magnetic resonance (NMR), liquid chromatography–diode array detector–mass spectrophotometry (LC-DAD-MS), and liquid chromatography–fluorescence–mass spectrometry. Quali-quantitative data revealed large amount of procyanidins, mainly of the A-type, as well as eriodictyol-7-O-glucuronide and luteolin-7-O-glucoronide as main constituents. The antioxidant, cytotoxic, and inhibitory activity of five enzymes that are implicated in human diseases was evaluated for the extract and fractions. High free-radical scavenging activity in 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays and inhibitory activities against cholinesterases and tyrosinase were observed. Furthermore, a moderate cytotoxic effect was observed on the 2008 and BxPC3 cell lines. Overall results showed potential usefulness of this fern as a source of phytochemicals for pharmaceutical uses.

In vitro and in vivo evaluation of pharmacological potentials of Campsis radicans L

BackgroundCampsis radicans L. is a flowering plant in Bangladesh, traditionally used for the treatment of several human diseases. In this study, in vitro antioxidant, thrombolytic, membrane stabilizing and in vivo analgesic, hypoglycemic, anti-diarrheal and CNS antidepressant activities of organic soluble fractions of crude methanol extract of C. radicans leaf were investigated using appropriate experimental models.MethodsThe leaves of C. radicans were collected, authenticated, dried and extracted with methanol at room temperature for 30 days. The concentrated methanol extract was partitioned to petroleum-ether (PESF), dichloromethane (DMSF) and ethyl acetate (EASF) soluble fractions. The antioxidant activity of these fractions was determined by DPPH free radical scavenging method. Total phenolic content was determined by the Folin-Ciocalteau’s spectrophotometric method. The thrombolytic activity was assessed by measuring clot lysis ability whereas the membrane stabilizing activity was evaluated by heat- and hypotonic solution-induced hemolysis assay. Tail immersion procedure and acetic acid- induced writhing model were used to measure the analgesic activity of C. radicans. The hypoglycemic, anti-diarrheal and CNS antidepressant activities were determined by oral glucose tolerance test, castor oil-induced diarrheal model and thiopental-sodium induced sleeping time test in mice, respectively.ResultsAll the organic soluble fractions of C. radicans contained phenolic compounds varying from 6.38 to 60.13 mg of GAE/gm of extractive, while in DPPH assay, EASF showed the highest free radical scavenging activity with IC50 is 4.69 μg/ml. The PESF exhibited highest thrombolytic activity (57.14% clot lysis) and the DMSF showed maximum 53.95% inhibition of heat-induced hemolysis of human RBCs. In both tail immersion and acetic acid induced writhing models, the PESF, DMSF, EASF at the doses of 200 and 400 mg/kg body weight, induced a significant (P < 0.001) decrease in the painful sensation in mice. Substantial (P < 0.05) anti-hyperglycemic activity of test samples was found in mice loaded with glucose at the same doses mentioned earlier. Castor oil induced diarrheal test of the plant extractives has shown significant effect in comparison to control group. In CNS antidepressant activity assay, the test samples were able to reduce the duration of sleep in mice caused by thiopental administration.ConclusionAll these findings revealed that C. radicans possess significant antioxidant, thrombolytic, membrane stabilizing, analgesic, hypoglycemic, anti-diarrheal and CNS antidepressant activities.

Phytochemical Constituent’s Comparison Using Various Drying Effects on Rubus Fraxinifolius Pour Leaves

Rubus fraxinifolius is a genus that belongs to the Rosaceae family, which grows in the mountainous forests in Indonesia. The study aimed to determine the effects of air-drying (AD) and oven drying (OD) of the young R. fraxinifolius leaves and compare them to the fresh leaves (FL) to observe the phytochemical content and bioactivities. Phytochemical contents of the samples were determined based on qualitative assay, total phenolics, and total flavonoid, whereas bioactivities were evaluated on antioxidant DPPH free radical scavenging effect, α-glucosidase inhibitory activity, and antibacterial assays. LCMS-MS was used for the quantitative investigation of naturally occurring phytochemicals. The methanol exttract of FL had the highest free radical scavenging activity against DPPH with IC50of 45.51± 5.03µg/mL, total phenolic content (25.35 ± 1.06 mg GAE/100 mg extract), and total flavonoid content (28.71 ± 2.07 equivalent quercetin mg/ 100 mg extract) compared to those of AD and OD. However, AD had the highest α-glucosidase inhibitory activity (IC50= 8.86 ± 1.41µg/mL) among others. The antibacterial activity of the young leaves showed that there was no activity difference in both fresh and dried conditions. Based on LCMS-MS analysis, it was revealed that Luteolin-7-O-glucoronide, an active antioxidant flavonoid glycoside, had been detected in FL and AD leaf extracts, but it was not found in OD leaf extract. Our findings showed that drying could influence the phytochemical contents, which significantly affect the production of characteristic active compounds in R. fraxinifolius leaves.

Antioxidant and antibacterial activity of three herbs belonging to Zingiber genus of Bangladesh

Apart from boosting flavor, herbs and spices are also known for their preservative, antioxidant, antimicrobial and other medicinal properties. Bioactive metabolites with aspiring prospect have guided the present study to screen for antibacterial and antioxidant activity of three Zingiber plants available in Bangladesh. For that purpose, rhizomes of Zingiber officinale, Z. montanum and Z. zerumbet were extracted with ethanol as solvent system for bioactivity analysis. Antioxidant activity was assessed by employing DPPH free radical scavenging assay, reducing power assay and ferric reducing antioxidant power (FRAP) assay. Z. officinale extract demonstrated the highest free radical scavenging activity (IC50: 43.65 µg/ml), reducing power (EC50: 189.026 µg/ml) and FRAP value (137.18 ± 0.116 µM Fe(II)/100 µg dry weight of extract). Moreover, total phenolic, flavonoid and tannin content were determined which significantly correlated (Pearson correlation) with the antioxidant activities. For the evaluation of antibacterial activity, zone of inhibition (ZOI) was measured by disc diffusion bioassay against four Gram positive bacteria Bacillus megaterium, Staphylococcus aureus, Micrococcus spp., and S. epidermidis as well as ten Gram negative bacteria Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, S. paratyphi, Vibrio cholera, Shigella dysenteriae, S. flexneri, Proteus spp., Mycobacterium spp., and Campylobacter spp. Z. montanum extract exhibited significant activity against E. coli (13.67 ± 0.577 mm ZOI) and Micrococcus spp. (14.33 ± 0.763 mm ZOI) if compared to standard erythromycin with ZOI 15.33 ± 0.577 mm and 15.67 ± 0.577 mm, respectively. Furthermore, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Z. montanum extract were determined against B. megaterium, Micrococcus spp., E. coli and S. paratyphi. Thus, Z. officinale and Z. montanum extracts could be utilized as source and template for the synthesis of potential drugs and food supplements as well.

Nano CuO–Ag‐catalyzed synthesis of some novel pyrano[2,3‐d] pyrimidine derivatives and evaluation of their bioactivity

AbstractA simple, highly efficient, and green method is developed for the synthesis of pyrano[2,3‐d] pyrimidine derivatives via Knoevenagel and Michael addition in the presence of nano CuO–Ag as a catalyst. The structures of synthesized target compounds 5a–l were confirmed by spectral and elemental analysis and were screened for their antioxidant activity by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH), H2O2, and NO methods. Their antibacterial activity against Gram‐negative bacteria Pseudomonas aeruginosa and Escherichia coli, against Gram‐positive bacteria such as Bacillus subtilis and Staphylococcus aureus, and antifungal activity against Candida albicans and Candida glabrata was also evaluated. The compounds showed higher bacterial activity than the standard used. Compounds 5b, 5d, 5g, 5h, and 5i exhibited higher free radical scavenging activity than the standard butylated hydroxy toluene (BHT). Compounds 5b, 5d, and 5h showed higher activity on Gram‐positive bacteria, and compounds 5b, 5d, 5h, and 5i showed higher activity on Gram‐negative bacteria than that of standard tetracycline. Compounds 5b, 5j, and 5l showed much higher antifungal activity against Candida globrata and C. albicans than that of standard Griseofulvin.

Optimization of supercritical fluid extraction of Mariposa Christia Vespertilionis leaves towards antioxidant using response surface methodology

Mariposa Christia Vespertilionis (MCV) or also known as butterfly wing leaves, is popular in the traditional medicine practice. The objective of this study is to optimize the antioxidant components (based on antioxidant activity analysis) from the MCV leaves extract using Supercritical Fluid Extraction (SFE) based on different temperature, pressure, and particle size via Response Surface Methodology (RSM). Besides that, it is also to evaluate the optimal condition of different extracting antioxidant activity from MCV leaves using Design Expert 10 software. The condition range for both pressure and temperature were between 150-350 bar and 30-70 °C with constant extraction time. The size of particle samples were between 63 μm-1000 μm. The antioxidant was analyzed using UV–vis Spectrophotometer (UV-vis). The lowest antioxidant activity was 8.20 % and higher antioxidant activity was obtained at 49.76 %. Lower absorbance indicated highest free radical scavenging activities. Maximum percentage (%) indicated high scavenging activities, thus higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) is a good indication for antioxidant. The predicted RSM optimal condition of antioxidant activity was at temperature 50 °C, pressure 282 bar, and particle size 500 μm, which the predicted antioxidant was 50.62 %. Upon verification through experiment, it was found out that the antioxidant activity value was close to the predicted value with an average error of less than 1%.

Effect of traditional sun-drying and oven-drying on carotenoids and phenolic compounds of apricot (Prunus armeniaca L.)

Background: The indubitable role of phytochemicals such as carotenoids and phenolic compounds in human health has prompted the researchers to study the factors affecting the stability and the availability of these compounds. Aims: This study investigates the effect of two drying processes; oven-drying (OD) and traditional sun-drying (TSD) on carotenoids and phenolic compounds of apricots. Material and Methods: OD was performed at 65°C, and TSD was performed by direct exposure of apricot to sunlight at daytime temperatures around 40°C and relative humidity between 25 and 35%, following an Algerian traditional method of drying. Carotenoids and phenolic compounds were extracted, and then total carotenoids (TC), total phenolic compounds (TPC), total flavonoids (TF) and total tannins (TT) were spectrophotometrically quantified. The free radical scavenging activity (FRSA) of the phenolic extracts was measured by the DPPH method. Results: Carotenoids and phenolic compounds were significantly affected by both drying methods. OD decreased TC and TT by 44% and 12%, respectively, and increased TPC and TF by 4%. TDS affected negatively all the measured components, where TC, TPC, TF, and TT decreased by 67%, 15%, 43%, and 36%, respectively. However, the highest FRSA was reported for the TSD apricots (40%) followed by OD apricots (36%), and fresh apricots (32%). Conclusions: The effect of drying on apricot antioxidants depends on the applied drying method and the studied component. The direct sunlight exposure and the duration of drying condemned TSD to be more harmful on carotenoids and phenolic compounds compared to OD, where carotenoids where more fragile during TSD. In addition, OD improved the content of phenolic compounds by improving their extractability. However, TSD apricots seem to be a better source of free radical scavenging compounds. Keywords: Apricot, traditional sun-drying, oven-drying, carotenoids, phenolic compounds.