Inhibitory Activity Of Extracts Research Articles

HPTLC – Bioautographic methods for selective detection of the antioxidant and a-amylase inhibitory activity in plant extracts

A high-performance thin-layer chromatography (HPTLC) method was developed for quantification of a-amylase inhibitory activity and stigmasterol content in ant plant extracts. An improved HPTLC method for the determination of total free radical scavenging activity in samples using DPPH is also reported. For quantification of a-amylase inhibitory activity, the developed HPTLC plate is dipped into an a-amylase solution, and the bioautogram is then incubated at 25?°C for 30?min under humid conditions. For visualization of enzyme inhibitory activity, the starch test with an iodine indicator solution is used. The blue zone observed comes from the starch-iodine complex formed from starch that was not hydrolyzed by the amylase due to enzyme inhibition by the compound(s) present in the sample. The area of the blue zones was used to compare and quantify relative a-amylase inhibitory activity in different extracts. Location of the blue zones (hRF) on the plate was used to detect compounds that are responsible for the a-amylase inhibitory activity. Relative a-amylase activity was not related to the antioxidant activity, but was highly correlated with the stigmasterol content in the sample extracts (R?=?0.95). Therefore, plant sterols present in the extracts might be responsible for a-amylase inhibitory activities in the extracts.•The developed method for quantification of a-amylase inhibitory activity provides an efficient and effective tool that can be used to screen, detect and quantify a-amylase inhibitory activity in plant extracts.•The proposed protocol is easy to run, involves minimal sample preparation, with multiple samples able to be analyzed in parallel on the same chromatographic plate, in a short time.•There were significant differences in a-amylase inhibitory activity, stigmasterol content, and total free radical scavenging activity between methanol, ethanol, dichloromethane, and ethyl acetate ant plant extracts.

Quantitative Analysis and Antibacterial Activity of Some Coumarins Extracts

Extracts of melilot, cinnamon and ash were analyzed with TLC and molecular absorption spectrometry. With TLC method coumarin and coumarins derivatives (fraxetin, psoralen and scopoletin) contained in the studied plants were identified. The coumarin concentrations in melilot (637.84 mg/100g d.w) and cinnamon (58.594 mg/100g d.w.) were the highest. Melilot and cinnamon extracts have been tested against two reference bacterial strains and against two clinical bacterial strains in order to preliminary evaluate their antimicrobial profile. Our results showed a significant response of bacterial growth on culture media when exposed to coumarin derivatives found in melilot and cinnamon extracts. Overall, the inhibitory activity of extracts was higher on Gram positive bacteria on one hand and on clinical strains on the other hand suggesting an important practical aspect.

Phenolic profile, antioxidant and enzyme inhibitory activities of Stachys annua subsp. annua var. annua

The antioxidant and enzyme inhibitory activities of different solvent extracts of Stachys annua (L.) subsp. annua var. annua were determined. Specific phenolics were also determined by RP-HPLC. Methanol extract was found to be rich in phenolics (35.36mggallic acidequivalent/g extract). Antioxidant activities of the extracts were determined by using different complementary test systems including phosphomolybdenum, β-carotene bleaching, radical scavenging activity, reducing power, and metal chelating effect. Inhibitory activities of the extracts on acetyl cholinesterase, butyryl cholinesterase, tyrosinase, α-amylase, and α-glucosidase were also investigated. Ethyl acetate extract was found superior to the others especially in terms of its inhibitory activity on butyryl cholinesterase, tyrosinase, and α-glucosidase (6.32mggalantamine equivalent/g extract, 23.95mgkojic acid equivalent/g extract, 6.18mmolacarbose equivalent/g extract, respectively), whereas the water extract exhibited the weakest activity. These findings suggest that S. annua extracts might be considered as an alternative antioxidative and enzyme inhibitory agents.

Ethanol extract and chromatographic fractions of Tamarindus indica stem bark inhibits Newcastle disease virus replication

Context: The plethora of ethnomedicinal applications of Tamarindus indica Linn. (Leguminosae), tamarind, includes treatment of human and livestock ailments; preparations are recognized antipyretics in fevers, laxatives and carminatives. African folklore has various applications of tamarind. However, in Nyasaland, domestic fowl are fed with preparations for prophylactic properties.Objectives: The objective of this study is to evaluate the antiviral properties of T. indica extract.Materials and methods: Tamarindus indica stem bark was extracted through ethanol maceration over 24 h, and the crude extract was fractionated by gravity-propelled column chromatography. Newcastle disease virus (NDV) inhibitory activity of extract and fractions were evaluated in vivo using 10-d-old embryonated chicken egg (ECE) as the medium for virus cultivation and antivirus assay. About 240 ECE were grouped into eight (three controls and five experimental) and, 200 μL of the extract and fractions respectively inoculated into NDV pre-infected eggs and incubated at 37 °C. Allantoic fluid was harvested 5 d post-virus infection and assayed for haemagglutination (HA).Results: Anti-NDV assessment showed 62.5 mg/mL of crude extract and fractions: TiA, TiC and TiD to yield a HA titre of 1:128 each, while TiB showed 1:64 HA titre. At 125 mg/mL, a titre of 1:16 was recorded against TiB and TiD and, 1:8 against TiA. Similarly, crude extract and TiC, each recorded 1:4 HA titre. However, the minimum concentrations of extract and fraction for virus inactivation were 0.24 mg/mL and 0.49 mg/mL, respectively.Conclusion: The antiviral activity shown by T. indica portends novel antiviral drugs and, perhaps, as scaffold for new drugs.

α-Glucosidase inhibitory activity of extracts from Cordia morelosana

α-Glucosidase inhibitory activity of extracts from Cordia morelosana

In vitro α-amylase and α-glucosidase inhibitory activity of extracts and compounds from cultivated Artemisia dracunculus

In vitro α-amylase and α-glucosidase inhibitory activity of extracts and compounds from cultivated Artemisia dracunculus

Changes in Antioxidant and α‐Glucosidase inhibitory activities of Coffee bean extracts by heat processing

In the current study, we evaluated total soluble phenolics, phenolic profile and oxygen radical absorbance capacity (ORAC) of selected 4 coffee bean water extracts, with different roasting degree, such as mild (CEL), Midium (CEM), Med‐dark (CEMD), and dark (CED). We also investigated inhibitory activity of RCE against porcine α‐amylase and α‐glucosidase. CEMD had the highest α‐glucosidase inhibitory activity, ORAC value and total phenolic content. The α‐glucosidase inhibitory activity of the extracts was compared to selected specific phenolics detected in the RCE using HPLC. Chlorogenic acid and Caffeic acid, a major phenolic compound in RCE had high α‐glucosidase inhibitiory activity. The α‐glucosidase inhibitory activity of the RCE correlated to the phenolic content and antioxidant activity. These results suggest that selected RCE which has high Chlorogenic acid, Caffeic acid content with α‐glucosidase inhibitory activity and high antioxidant activity has the potential to contribute as a useful dietary supplement for controlling postprandial hyperglycemia and oxidative stress‐linked diabetes complications.

An in vitro evaluation of the Native American ethnomedicinal plant Eryngium yuccifolium as a treatment for snakebite envenomation.

Aim:At least seven North American tribes specifically mention the use of Eryngium (typically roots) as an anti-snake venom therapy. As snake envenomation is an endemic, life-threatening medical risk, is there a scientific basis for the Native American ethnomedicine? Could this be demonstrated in an assay amenable to mechanistic evaluation and high throughput screening for later isolation and possible evaluation as a source for a lead drug?Materials and Methods:Proteases, mainly metalloproteases, are thought to be the main pathological agents in most American snake venoms. Water extracts of four plant parts of Eryngium yuccifolium were tested for enzyme inhibition in three highly sensitive in vitro protease assays, with multiple venoms.Results:Interestingly, activity was found in all plant parts, not just the roots, in the general protease assay, also in the most specific assay for collagenases, but less so for elastases where enzymatic activity was low, and against five species of American snake venoms. Inhibition spared the activity of a mammalian elastase, suggesting it has some specificity. In dose response assays, inhibitory activity in extracts of Eryngium was noticeably more effective than randomly chosen plants and comparable to some others.Conclusions:All data shown here are consistent with pharmacological inhibition of proteases in at least selected venoms of common venomous snakes by Eryngium extracts. Moreover, as the genus is widely distributed in America, the ethnological practice of using this plant as an anti-snake venom treatment is supportable, may have been common, and suggests further bioactivity and phytochemical studies are warranted.

Inhibitory activity in extracts of pines, including pine wilt resistant families, against a fungus and pinewood nematodes

Inhibitory activity in extracts of pines, including pine wilt resistant families, against a fungus and pinewood nematodes

English

In view of the prevalence of urinary tract infection (UTI) worldwide, the increasing resistance of pathogenic bacteria to conventional antibiotics and their side effects, the aerial part and root of Phyllanthus amarus (Schum. and Thonn.) and Phyllanthus niruri (L.) were analysed for mineral and phytochemical constituents, and their ethanol extracts screened against five clinical isolates of Escherichia coli associated with UTI, to ascertain their effectiveness in UTI treatment, and provide basis for future clinical trials of the two plants. The isolates (10-1 × 10-6 cfu/ml) were tested against ethanol extracts (10 mg/ml) of plant parts using agar well diffusion method. Phytochemical and mineral analyses of the plant samples were done using standard protocols and all data were statistically analysed. The quantities of various phytochemical compounds and minerals were significantly (P<0.05) higher in P. niruri than P. amarus. At 10-6 cfu/ml inoculum concentration of all isolates, the inhibitory activities of extracts of P. amarus and P. niruri were the same, and significant (P<0.05) against isolates EC01, EC02, EC04 and EC05 compared to the control experiment. The inhibitory pattern varied against EC03, extract B (29.00 mm) was the most active, followed by extract C (24.00 mm), and extracts A and D gave the same diameter (19.00 mm) of inhibition. The two plants showed significant antibacterial activity against isolates and could be good alternatives to chemical antibiotics in the treatment of E. coli related UTI, however the mechanism of action of the plant extracts in treatment should be investigated. Key words: Antibacterial activity, E. coli, Phyllanthus amarus, Phyllanthus niruri, urinary tract infection.

Antimicrobial Activity of Gardenia jasminoides Callus and Crude Leaf Extracts for some Organic Solvents against some Pathogenic Bacteria and Yeasts

The study was conducted to evaluate the inhibitory activity of methanol extract of Gardenia jasminoides leaves compared with leaf crude extracts for some organic solvents namely Methanol, Ethanol, Petroleum ether, Asetone and Chloroform on growth of some pathogenic bacteria and yeast, which included four gram positive isolates Staphylococcus aureus, Enterococcus faecalis, Streptococcus pyogenes and Bacillus cereus and gram negative isolates Escherichia coli, Salmonella typhi, Proteus vulgaris and Pseudomonas aeruginosa and some yeasts Candida albicans and Saccharomyces boulardii, by using well diffusion method. The inhibitory activity of extracts in the tested bacterial strains and yeasts was varied according to the type of extracting solvents and are tested microorganisms. The methanol callus extract which grown on Murashige and Skoog (MS) media by using (Naphthalen acitic acid) NAA and (Benzyle adenine) BA as growth regulator highly effective as compared to the other extracts as for inhibition of three gram positive bacteria and three gram negative bacteria,which include Staphylococcus aureus and, Proteus vulgaris, followed by acetone and ethanolic extracts which include two gram positive bacteria and two gram negative bacteria. All extracts had highly effect in growth of Candida albicans while all crude extracts didn’t show any sensitivity against Saccharomyces boulardii, and when we’d done (High Performance Liquid Chromatography) HPLC test for detection of some active compound we found Quinic acid, Iridiods glycosides and Crocin which its rate in fresh callus was higher than fresh leaves.

Inhibition of nitric oxide production in lipopolysaccharide-activated RAW264.7 macrophages by isolated xanthones from the roots of Cratoxylum formosum ssp. pruniflorum

The inhibitory activity of extract and compounds isolated from the roots of Cratoxylum formosum ssp. pruniflorum against nitric oxide (NO) was evaluated using RAW264.7 cells. Isolation of the CH2Cl2 extract of C. formosum ssp. pruniflorum roots afforded ten known xanthones including six tri-oxygenated xanthones (1-6) and four tetra-oxygenated xanthones (7-10), respectively. Compound 7 showed the highest inhibitory activity against NO release with an IC50 value of 3.9μM, followed by compound 8 with an IC50 value of 4.3μM, respectively. In order to understand the mechanism of this anti-inflammatory activity, the transcriptional level of 7 was found to down regulate mRNA expressions of iNOS and COX-2 in dose-dependent manners, whereas 8 inhibited only iNOS mRNA expression but did not affect on that of COX-2 gene. Xanthones might be the main anti-inflammatory components in C. formosum ssp. pruniflorum.

Inhibitory Activity of Extracts from Mycelia Materials of Several Mushrooms on the Angiotensin I-Converting Enzyme

ACE inhibitory activities of water extracts from mycelia of 6 kinds of mushrooms in liquid fermentation were investigated. All strains cultivated in shaking flask containing liquid medium, and yield of mycelia ranged from 0.051 to 1.392 g mycelia/day/L liquid medium in average. Resulting mycelia were extracted with distilled water at 50°Cfor 200 min, and the yield of water extracts from mycelia ranged from 287.475 to 490.088 mg/g dried mycelia. These water extracts were used to assay their ACE inhibitory activity. Results showed that their IC50 values ranged from 1.277 to 5.250 mg/ml. The difference among IC50 values of these water extracts were significant (p&lt;0.05 or p&lt;0.001). Lactarius camphorates (IC50: 1.646±0.061mg/mL) was the specie which had relatively lower IC50 value than others, as well as relatively higher water extract yield. The results highlighted the potential for making antihypertensive functional foods or drugs from liquid cultured mycelia of Lactarius camphorates.

Inhibitory activities of extracts from Cleistocalyx operculatus flower buds on pancreatic lipase and α-amylase

In this work, we investigated the inhibitory activities of aqueous extract (Eaq), 30, 60, and 95 % ethanol extracts (E3et, E6et, and E9et), petroleum ether extract (Epe), ethyl acetate extract (Eae), and 2′,4′-dihydroxy-6′-methoxy-3′,5′-dimethylchalcone (DMC) from Cleistocalyx operculatus flower buds on pancreatic lipase and α-amylase, which were closely related to body weight and obesity. The inhibition effect of various extracts was determined by the Lineweaver–Burk plots. The results showed that the IC50 values of DMC, Epe, Eae, and E9et against pancreatic lipase were 101.5 μM, 38.65, 76.62, and 109.76 μg/ml, respectively, which were much lower than that of E3et and E6et. Eaq, E3et, E6et, and DMC strongly inhibiting the pancreatic α-amylase, with IC50 values of 73.10, 165.93, 231.23 μg/ml, and 69.35 μM, respectively. Furthermore, the kinetic analysis suggested that the inhibition mode of crude extract against pancreatic lipase was noncompetitive, while that against pancreatic α-amylase was competitive. The content of DMC and total polyphenols in each extract were determined by HPLC and spectrophotometric method, respectively. It was interestingly found that the DMC content had profound influence on pancreatic lipase activity, and the total polyphenols content significantly affected the pancreatic α-amylase activity. The findings in this work suggested that extracts from C. operculatus flower buds possess potent inhibitory activity against pancreatic lipase and α-amylase, and provided some new ideas for the prevention and treatment for obesity.

해조류의 항산화 활성 및 아세틸콜린에스테라제 저해 활성

This study was conducted to investigate the antioxidant and acetylcholinesterase (AChE) inhibitory activities of extracts from various seaweed. The extracts of Sargassum thunbergii (91.3%), Polysiphonia morrowii (90.7%), Ecklonia cava (89.9%), and Artemisia fukudo (85.9%) showed over 80% high radical scavenging activities at the final concentration of 40 μg/mL. The Artemisia fukudo extract showed the highest inhibition activity of 30.2% on AChE at the final concentration of 10 μg/mL. The extract of Porphyra tenera, Costaria costata, Monostroma nitidum, Ecklonia cava, and Agarum clathratum against AChE at a concentration of 10 μg/mL exhibited inhibition of 26.6%, 25.3%, 23.4%, 21.7%, 20.4% and 19.9%, respectively. The bioautography results showed that the mixtures of structurally diverse compounds were thought to affect AChE inhibitory activity. These results suggest that extracts from seaweed with their high quality components may be effective in the prevention of Alzheimers disease and may be used to develop various functional food products.

Study of antimicrobial activity of some active secondary compounds for Viola odorata on growth for some types of bacteria

The study was conducted to track the inhibitory activity of methanolic, flavinoid and alkaloid extracts of Viola odorata with concentrations (1, 1.5, 2, 2.5, 3) mg/ml on some bacterial species represented by S. aureus, Bacillus subtilis, Pseudomonas aeruginosa, E.coli and Klesiella sp, by using disk-diffusion method and estimated inhibitory activity of extracts on bacteria by measuring the Diametric of zone inhibition. The results showed a difference in the effect of each extract for the types of bacteria, the alkaloid gave a strong inhibitory ability against all types of bacteria compared with the methanolic extract and flavinoid respectively; this activity was enhanced with the increasing of extracts concentrations and the (3) mg/ml concentration gave highest activity, Pseudomonas aeruginosa was the most effective one, where the diameter of zone inhibition (25) mm at this concentration while E.coli was the least testing bacteria effective by the concentration and the diameter of zone inhibition was (10) mm. Methanolic extract showed antimicrobial highest activity on S. aureus, the diameter of zone inhibition was (21) mm with no antimicrobial activity on Pseudomonas aeruginosa and Klesiella sp, while the flavinoid showed highest activity on Pseudomonas aeruginosa, the diameter of zone inhibition was (13) mm with no antimicrobial activity against Klesiella sp. and E.coli.

Chemical composition of thyme seeds Thymus vulgaris and its antimicrobial activity

The chemical composition of thyme seeds Thymus vulgaris and phytochemicals were investigated using standard analytical methods in order to assess the numerous potential of the plant seeds. The proximate analysis showed the percentages of moisture, ash, crude protein, lipids and crude fibers content of the seeds on dry weight basis as 7.00%, 10.00%, 7.55%, 35.00%, 9.87 % respectively. The qualitative determination of seeds showed the presence of phytochemicals tannins, alkaloids, resins, flavonoides, phenols, saponins and free of glycosides. The aqueous extract of the plant had acidic pH 6.2. Aqueous extracts were prepared in concentrations (25,50,75,100%) and alcoholic extracts 100% Each aqueous and alcohol extracts were tested for antimicrobial activity towards seven different strains of microorganisms included three bacterial which were Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus as well as four Fungal strains which were Alternaria alternata ,Aspergillus niger, Penecillium italicum and Trichoderma harzianum. The inhibitory activity of extracts were varying based on kind of extract, concentration and microorganism. It was shown that inhibition activity of aqueous extracts against Pseudomonas aeruginosa higher compared with other bacteria. The water extracts at (25,50,75) % concentration were not showed any inhibition effect against Staphylococcus aureus. The alcoholic extract was more effect on Pseudomonas aeruginosa than another bacteria Staphylococcus aureus and Escherichia coli. Each aqueous and alcohol extracts displayed antifungal activity it was observed decline in diameter growth with increased of aqueous extracts concentrations. The aqueous extract 100% had high inhibition activity compared with other aqueous extracts This study confirms that thyme is one of plants that can used of its extracts in field of food preservation and the medicine. The presence of phytochemicals indicates its importance as a source of useful drugs.

Pods of Khejri (Prosopis cineraria) consumed as a vegetable showed functional food properties

The arid plant Prosopis cineraria (Fabaceae) is known as Khejri in India or the golden tree of Indian deserts. The dried pods are consumed as a vegetable and leaves as traditional medicine to cure a wide range of diseases in the state of Rajasthan, India. The pods of this plant have not been investigated for their bioactive components, hence we have done so in this study. The dried pods were boiled with water to afford the aqueous extract. Extraction of the residue gave methanolic extract. The lipid peroxidation (LPO) and cyclooxygenase enzymes (COX-1 and -2) inhibitory activities of extracts and major compounds present in the bioactive extracts were then determined. Purification of bioactive extracts yielded compounds 1–7. The absorbance of 1–7 at 570nm ranged between 0.15 and 0.45 at 50μg/mL whereas vitamin C and tert-butylhydroquinone (TBHQ) at 25μg/mL gave an absorbance of 0.5 in the MTT [3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide] assay. At 25μg/mL concentration, compounds 1–7 inhibited LPO, COX-1 and -2 enzymes between the ranges of 15–87%, 21–67% and 16–59%, respectively. This is the first report of the chemical and biological activities of the edible part of this plant.

Angiotensin-converting enzyme inhibitory activity of Viscum triflorum is host plant-dependent

Context: Viscum triflorum DC. (Viscaceae) is a hemiparasitic plant used in traditional medicine on Réunion Island as a remedy to treat hypertension.Objective: The in vitro angiotensin-converting enzyme (ACE) inhibitory activity of extracts of V. triflorum and the corresponding host plant species were examined to evaluate the use as a remedy against hypertension, and to investigate whether the host plants have an influence on the activity.Materials and methods: Aqueous, ethanol and acetone extracts of 24 leaf samples of V. triflorum and the corresponding host plants, representing 10 plant species, were prepared. The ACE inhibitory activities of the extracts were measured by HPLC using dansyltriglycine as substrate.Results and conclusion: Water extracts of Viscum samples from only two of the 10 host plants, namely Acacia heterophylla Willd. (Fabaceae) and Sophora denudata Bory (Fabaceae), showed significant inhibitory activity, ≥50% inhibition in a concentration of 0.33 mg crude plant extract in 1 mL test solution. From the two mentioned host plant species activity was only detected in the water extract from one of the six samples of A. heterophylla. Three host species showed pronounced activity without any detection of activity in the samples of V. triflorum. The results support the traditional use provided that V. triflorum is collected from A. heterophylla or S. denudata.

Changes in flavonoid content and tyrosinase inhibitory activity in kenaf leaf extract after far-infrared treatment

The tyrosinase inhibitory activity of ethanolic extract of kenaf (Hibiscus cannabinus L.) leaf was evaluated before and after subjecting it to far-infrared (FIR) irradiation. The main component of the extract was analyzed as kaempferitrin (kaempferol-3,7-O-α-dirhamnoside). Prior to FIR irradiation, no inhibitory activity of the extract was detected in a tyrosinase assay. However, after FIR irradiation for 1h at 60°C, significant tyrosinase inhibitory activity (IC(50)=3500 ppm) was observed in it. In HPLC analysis, derhamnosylation products (kaempferol, afzelin, and α-rhamnoisorobin) were detected. The inhibitory activity may be due to the existence of derhamnosylation products. This study demonstrated that FIR irradiation can be used as a convenient tool for deglycosylation of flavonoid glycoside.