In vitro Antioxidant and Antibacterial Activities of Methanol Extract of Kyllinga nemoralis

The present study was designed to evaluate the antioxidant and antibacterial activity of methanol extract of Kyllinga nemoralis. Six different in vitro antioxidant assays including 2,2-diphenyl-1-picrylhydrazyl, hydroxyl radical, superoxide anion radical, hydrogen peroxide radical, ferric reducing antioxidant power assay and reducing power were carried out to ensure the scavenging effect of the plant on free radicals. In addition, total antioxidant capacity assay, total phenolic contents, tannins, flavonoids and flavonol contents of the plant were also analysed by the standard protocols. Kyllinga nemoralis exhibited high antioxidant activity on 2,2-diphenyl-1-picrylhydrazyl assay (IC₅₀= 90 μg/ml), superoxide radical scavenging assay (IC₅₀= 180 μg/ml) and hydrogen peroxide radical scavenging assay (IC₅₀= 200 μg/ml), compared with standards. These observations provide comprehensible supporting evidence for the antioxidant potential of the plant extract. Reducing power (IC₅₀= 213.16 μg/ml) and hydroxyl radical scavenging activity (IC₅₀= 223 μg/ml) of the plant extract was remarkable. The methanol extract of K. nemoralis exhibited significant antimicrobial activity against Gram-positive human pathogenic bacteria. Standard in vitro antioxidant assays assessed the electron donating ability of the plant extract in scavenging free radicals. The inhibitory effect of the plant extract against bacterial pathogens may be due to the presence of phytochemicals. Thus, the results suggest that Kyllinga nemoralis is a potential source of antioxidants and could serve as the base for drug development.     

Melilotus albus and Dorycnium herbaceum extracts as source of phenolic compounds and their antimicrobial,antibiofilm, and antioxidant potentials

Melilotus albus Medic. and Dorycnium herbaceum Vill. (Fabaceae) acetone, ethyl acetate, and ethanol extracts were investigated for their in vitro antimicrobial, antibiofilm, and anti-oxidant activity with quantification of phenolic compound contents. In general, D. herbaceum extracts showed better antibacterial and antioxidant activity than M. albus extracts. Bacteria Bacillus subtilis, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa, and Proteus mirabilis were the most susceptible with the minimum inhibitory concentrations (MICs), determined by microdilution method, between 1.25–10 mg/mL. Antifungal activity was lower with the detectable MICs at 10 mg/mL and 20 mg/mL. The plant extracts, using the crystal violet assay, inhibit P. aeruginosa biofilm formation in concentration range from 5 mg/mL to 20 mg/mL whereas the effect on mature bacterial biofilm was lower. The antioxidant activity was evaluated using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radicals scavenging and reducing power model systems. The intensity of DPPH radicals scavenging activity, expressed as half maximal effective concentration (EC₅₀) values, was from 84.33 μg/mL to >1000 μg/mL. The extracts demonstrated reduced power in a concentration-dependent manner, with ethanol extract as the most active. The total phenols, flavonoids, and proanthocyanidins were determined spectrophotometrically while total extractable tannins were obtained by precipitation method. The phenolic compounds showed differences in their total contents depending on solvents polarities and plant species. Although the plants M. albus and D. herbaceum have not yet been fully explored, these results contribute better understanding of their biotic properties and potential application as antimicrobial and antioxidant agents.     

Antioxidant,antimicrobial, antitumor,and cytotoxic activities of an important medicinal plant (Euphorbia royleana) from Pakistan

The aim of present study was to evaluate antioxidant, antimicrobial, and antitumor activities of methanol, hexane, and aqueous extracts of fresh Euphorbia royleana. Total phenolic and flavonoid contents were estimated as gallic acid and querectin equivalents, respectively. Antioxidant activity was assessed by scavenging of free 2,2′-diphenyl-1-picrylhydrazyl radicals and reduction of ferric ions, and it was observed that inhibition values increase linearly with increase in concentration of extract. The results of ferric reducing antioxidant power assay showed that hexane extract has maximum ferric reducing power (12.70 ± 0.49mggallic acid equivalents/g of plant extract). Maximum phenolic (47.47 ± 0.71 μg gallic acid equivalents/mg of plant extract) and flavonoid (63.68 ± 0.43 μg querectin equivalents/mg of plant extract) contents were also found in the hexane extract. Furthermore, we examined antimicrobial activity of the three extracts (methanol, hexane, aqueous) against a panel of microorganisms (Escherichia coli, Bacillus subtillis, Pasteurella multocida, Aspergillus niger, and Fusarium solani) by disc-diffusion assay, and found the hexane extract to be the best antimicrobial agent. Hexane extract was also observed as to be most effective in a potato disc assay. As hexane extract showed potent activity in all the investigated assays, it was targeted for cytotoxic assessment. Maximum cytotoxicity (61.66%) by hexane extract was found at 800 μg/mL. It is concluded that investigated extracts have potential for isolation of antioxidant and antimicrobial compounds for the pharmaceutical industry.     

α-Amylase and dipeptidyl peptidase-4 (DPP-4) inhibitory effects of Melicope latifolia bark extracts and identification of bioactive constituents using in vitro and in silico approaches

ContextMelicope latifolia (DC.) T. G. Hartley (Rutaceae) was reported to contain various phytochemicals including coumarins, flavonoids, and acetophenones.ObjectiveThis study investigates the antidiabetic and antioxidant effects of M. latifolia bark extracts, fractions, and isolated constituents.Materials and methodsMelicope latifolia extracts (hexane, chloroform, and methanol), fractions, and isolated constituents with varying concentrations (0.078–10 mg/mL) were subjected to in vitro α-amylase and dipeptidyl peptidase-4 (DPP-4) inhibitory assay. Molecular docking was performed to study the binding mechanism of active compounds towards α-amylase and DPP-4 enzymes. The antioxidant activity of M. latifolia fractions and compounds were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and β-carotene bleaching assays.ResultsMelicope latifolia chloroform extract showed the highest antidiabetic activity (α-amylase IC₅₀: 1464.32 μg/mL; DPP-4 IC₅₀: 221.58 μg/mL). Fractionation of chloroform extract yielded four major fractions (CF₁–CF₄) whereby CF₃ showed the highest antidiabetic activity (α-amylase IC₅₀: 397.68 μg/mL; DPP-4 IC₅₀: 37.16 μg/mL) and resulted in β-sitosterol (1), halfordin (2), methyl p-coumarate (3), and protocatechuic acid (4). Isolation of compounds 2–4 from the species and their DPP-4 inhibitory were reported for the first time. Compound 2 showed the highest α-amylase (IC₅₀: 197.53 μM) and β-carotene (88.48%) inhibition, and formed the highest number of molecular interactions with critical amino acid residues of α-amylase. The highest DPP-4 inhibition was exhibited by compound 3 (IC₅₀: 911.44 μM).Discussion and conclusionsThe in vitro and in silico analyses indicated the potential of M. latifolia as an alternative source of α-amylase and DPP-4 inhibitors. Further pharmacological studies on the compounds are recommended.     

In vitro Screening for Antioxidant,Antimicrobial, and Antidiabetic Properties of Some Korean Native Plants on Mt. Halla,Jeju Island

In this study, Prunus padus, Lonicera caerulea, Berberis amurensis, and Ribes maximowiczianum, which are mainly distributed on Mt. Halla, Jeju Island, have been investigated for their antioxidant, antimicrobial, and antidiabetic activities. The methanol extracts of R. maximowiczianum leaves and P. padus branches exhibited significant and dose-dependent antioxidant activity including electron-donation ability and reducing power. To analyze the antimicrobial activity, each extract was tested by a serial two-fold dilution method against five selected gram-positive bacteria and four gram-negative bacteria, and this suggested that P. padus branches possessed the maximum antimicrobial activity against most of the gram-positive bacteria tested. In addition, the methanol extracts of P. padus branches exhibited the highest α-glucosidase inhibitory activity with an IC₅₀ value of 1.0±0.1 μg/ml, indicating that P. padus is a promising source as a herbal medicine.     

Bioactive Terpenoids and Flavonoids from Daucus littoralis Smith subsp. hyrcanicus Rech.f,an Endemic Species of Iran

Background

Daucus littoralis Smith subsp. hyrcanicus Rech.f. (Apiaceae) is an endemic species in northern parts of Iran where it is commonly named Caspian carrot. The fruits have been used as condiment.

Methods

In a series of in vitro assays, antioxidant (DPPH and FRAP assays), cytotoxic and antimicrobial activities of different extracts of roots and fruits were evaluated for the first time. The separation and purification of the compounds were carried out on the most potent extracts using various chromatographic methods and identified by spectroscopic data (¹H and ¹³C NMR).

Results

The results showed that among the extracts only fruit methanol extract (FME) has significant antioxidant activity (IC₅₀ = 145.93 μg.ml^-1 in DPPH assay and 358 ± 0.02 mmol FeII/g dry extract in FRAP assay). The radical scavenging activity of FME at 400 μg.ml^-1 was comparable with α-tocopherol (40 μg.ml^-1) and with BHA (100 μg.ml^-1) (p > 0.05). FME did not show any toxicity against cancerous and normal cell lines. Fruit ethyl acetate extract (FEE) had cytotoxic activity against breast carcinoma and hepatocellular carcinoma cells (IC₅₀ 168.4 and 185 μg.ml^-1, respectively), while it did not possess antioxidant activity in comparison with α-tocopherol and BHA as standard compounds. Ethyl acetate and methanol extract of fruits showed antimicrobial activity against Staphylococcus aureus (MIC: 3.75 mg.ml^-1) and Candida albicans (MIC: 15.6 and 7.8 mg.ml^-1, respectively). Four terpenoids were isolated form FEE including: β-sitosterol (1), stigmasterol (2), caryophyllene oxide (3), β-amyrin (4). Also, three flavonoids namely quercetin 3-O-β-glucoside (5), quercetin 3-O-β-galactoside (6) and luteolin (7) were isolated from FME.

Conclusion

This study showed that FEE and FME of D. littoralis Smith subsp. hyrcanicus Rech.f. had the highest biological activities which may be correlated with in vitro cytotoxic, antimicrobial and antioxidant activities of terpenoids and flavonoids components of the extracts.     

Investigation of Phytochemical and Antioxidant Properties of Methanol Extract and Fractions of Ballota limbata (Lamiaceae)

Ballota limbata (Lamiaceae) has been used for its antispasmodic, antiulcer, diuretic, vermifuge and sedative effects in folk medicine. However, little is known about how does it work to produce these therapeutic actions. Present research investigated phytochemical components and antioxidant properties of methanol extract and different fractions of Ballota limbata. In this study, phytochemical investigation was done by performing different chemical tests. Here, antioxidant property of the extract and fractions was investigated by using 1,1-diphenyl-2-picryl hydrazyl radical scavenging activity, total antioxidant activity by the phosphomolybdenum method, linoleic acid peroxidation, ferric thiocyanate analysis and ferric-reducing antioxidant power. Methanol extract and fractions showed presence of numerous chemical principles including alkaloids, cardiac glycosides, tannins and flavonoids. The ethyl acetate fraction exhibited higher scavenging activity compared to the other fractions under investigation. This fraction displayed 84.16±1.02% 1,1-diphenyl-2-picryl hydrazyl radical inhibition at a dose of 60 μg/ml. IC₅₀ for 1,1-diphenyl-2-picryl hydrazylradical-scavenging activity was 13.53±0.22 μg/ml, relative to the standard, butylatedhydroxytoluene, having IC₅₀ of 12.33±0.88 μg/ml. Thus, Ballota limbata showed significant antioxidant activity, which may contribute in the mechanism of above pharmacological actions.     

Extracts of Agrimonia eupatoria L. as sources of biologically active compounds and evaluation of their antioxidant,antimicrobial, and antibiofilm activities

In this study, we determined the concentration of total phenols, flavonoids, tannins, and proanthocyanidins in the water, diethyl ether, acetone, and ethanol extracts of Agrimonia eupatoria L. We also investigated the antioxidant activity of these extracts using two methods [2,2-diphenyl-1-picrylhydrazyl (DPPH) and reducing power] and their in vitro antimicrobial (antibacterial and antifungal) activity on some selected species of bacteria and fungi. In addition, the effects of the acetone and water extracts on the inhibition of biofilm formation of Proteus mirabilis and Pseudomonas aeruginosa were investigated using the crystal violet method. The concentration of total phenols was measured according to the Folin–Ciocalteu method and the values obtained ranged from 19.61 mgGA/g to 220.31 mgGA/g. The concentration of flavonoids was examined by the aluminum chloride method and the values obtained ranged from 20.58 mgRU/g to 97.06 mgRU/g. The total tannins concentration was measured by the polyvinylpolypyrrolidone method and the values obtained ranged from 3.06 mgGA/g to 207.27 mgGA/g. The concentration of proanthocyanidins was determined by the butanol–HCl method and the values obtained ranged from 4.15 CChE/g to 103.72 CChE/g. Among the various extracts studied, the acetone extract exhibited good antioxidant activity (97.13%, as determined by the DPPH method). The acetone extract was active in the absorbance value range from 2.2665 to 0.2495 (as determined by the reducing power method). The strongest antimicrobial activity was detected on G⁺ bacteria, especially on probiotic species, and the acetone extract demonstrated the highest activity. Biofilm inhibitory concentration required to reduce biofilm coverage by 50% values for acetone extract was 4315 μg/mL for P. mirabilis and 4469.5 μg/mL for P. aeruginosa. The results provide a basis for further research of this plant species.     

Evaluation of In Vitro Antioxidant Potential of Cordia retusa

The present study was carried out to investigate the antioxidant potential, total flavonoid and phenolic content in extracts of aerial parts of Cordia retua (Vahl.) Masam. The samples such as ethyl acetate and ethanol extracts were tested using six in vitro models such as 2,2-diphenyl-1-picrylhydrazyl, nitric oxide radical, iron chelating, hydroxyl radical, superoxide radical scavenging activity and total antioxidant activity to evaluate the in vitro antioxidant potential of C. retusa by spectrophotometrically. Total flavonoid and phenolic content in samples were estimated using aluminum chloride colorimetric and Folin-Ciocalteu method. The results were analyzed statistically by the regression method. Half maximal inhibitory concentration (IC₅₀) of the ethanol extract was found to be 596 μg/ml for DPPH, 597 μg/ml for nitric oxide radical, 554 μg/ml for iron chelating, 580 μg/ml for hydroxyl radical, 562 μg/ml for superoxide radical and 566 μg/ml for total antioxidant capacity. Furthermore, the total flavonoid content and total phenolic content of the ethanol extract were found to be 2.71 mg gallic acid equivalent per gram of extract and 1.86 mg quercetin equivalent per gram of extract, respectively. In all the testing, a significant correlation existed between concentrations of the extract and percentage inhibition of free radicals. The results of the present comprehensive analysis demonstrated that C. retusa possess potent antioxidant activity, high flavonoid and phenolic content. The antioxidant property may be related to the polyphenols and flavonoids present in the extract. These results clearly indicated that C. retusa is effective against free radical mediated diseases as a natural antioxidant.     

Antiproliferative activity,cell-cycle arrest,apoptotic induction and LC-HRMS/MS analyses of extracts from two Linum species

ContextLinum is the largest genus of the Linaceae family; the species of this genus are known to have anticancer activity.ObjectiveIn this study, ethyl acetate extracts of L. numidicum Murb. (EAELN) and L. trigynum L. (EAELT) were examined, for the first time, for their anticancer capacity. The secondary metabolites compositions were analysed by LC-HRMS/MS.Materials and methodsThe antiproliferative effect of EAELN and EAELT (0–10.000 μg/mL) against PC3 and MDA-MB-231 cell lines were  evaluated by the MTT assay after 72 h of treatment. Flow cytometer analysis of apoptosis (Annexin V-FITC/PI) and cell cycle (PI/RNase) was also performed after treatment with EAELN and EAELT at 250, 500, and 1000 μg/mL, for 24 h.ResultsEAELN had the highest antiproliferative activity against PC3 (IC₅₀ 133.2 ± 5.73 μg/mL) and MDA-MB-231 (IC₅₀ 156.9 ± 2.83 μg/mL) lines, EAELN had also shown better apoptotic activity with 19 ± 2.47% (250 μg/mL), 87.5 ± 0.21% (500 μg/mL), and 92 ± 0.07% (1000 μg/mL), respectively, causing cell cycle arrest of PC3 cells in G2/M phase, whereas arrest in G0/G1 and G2/M phases was observed after treatment with EAELT. LC-HRMS/MS profiling of the extracts revealed the presence of known compounds that might be responsible for the observed anticancer activity such as chicoric acid, vicenin-2, vitexin and podophyllotoxin-β-d-glucoside.Discussion and conclusionsWe have shown, for the first time, that EAELN and EAELT exert anticancer activity through cell cycle arrest and induction of apoptosis. EAELN can be considered as a source to treat cancer. Further studies will be required to evaluate the effect of the active compounds, once identified, on other cancer cell lines.     

Expedient Synthesis of SMAMPs via Click Chemistry

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Antioxidant and antilisterial effect of seed essential oil and organic extracts from Zizyphus jujuba

Hydrodistilled volatile oil from the seeds of Zizyphus jujuba was analyzed by GC–MS. Twenty three compounds representing 91.59% of the total oil was identified. The oil and organic extracts revealed a great potential of antilisterial effect against all five strains of Listeria monocytogenes ATCC 19111, 19116, 19118, 19166 and 15313. Also the oil had strong detrimental effect on the viable count of the tested bacteria. The samples were also subjected to screening for the antioxidant activity by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radicals scavenging activities assay. In the first case, the IC₅₀ value of the Z. jujuba essential oil was determined to be 5.21 ± 0.01 μg/ml. Among the extracts, the strongest activity was exhibited by the methanol extract with an IC₅₀ value of 20.44 ± 0.18 μg/ml. In the superoxide radicals scavenging activities assay, methanol extract was superior to all other extracts (IC₅₀ = 18.60 ± 0.3 μg/ml). Furthermore, the amount of total phenolic compounds was determined. The results indicate that the essential oil and extracts of Z. jujuba could serve as natural antimicrobial and antioxidant agents for the food industry.     

Anti-allergic actions of a Chinese patent medicine,huoxiangzhengqi oral liquid,in RBL-2H3 cells and in mice

ContextHuoxiangzhengqi oral liquid (HXZQ-OL), a traditional Chinese medicine formula, has antibacterial, anti-inflammation and gastrointestinal motility regulation effects.ObjectiveThe study investigates the anti-allergic activity and underlying mechanism of HXZQ-OL.Materials and methodsIgE/Ag-mediated RBL-2H3 cells were used to evaluate the anti-allergic activity of HXZQ-OL (43.97, 439.7 and 4397 μg/mL) in vitro. The release of cytokines and eicosanoids were quantified using ELISA. RT-qPCR was used to measure the gene expression of cytokines. The level of intracellular Ca²⁺ was measured with Fluo 3/AM. Immunoblotting analysis was performed to investigate the mechanism of HXZQ-OL. In the passive cutaneous anaphylaxis (PCA), BALB/c mice (5 mice/group) were orally administrated with HXZQ-OL (263.8, 527.6 and 1055 mg/kg/d) or dexamethasone (5 mg/kg/d, positive control) for seven consecutive days.ResultsHXZQ-OL not only inhibited degranulation of mast cells (IC₅₀, 123 μg/mL), but also inhibited the generation and secretion of IL-4 (IC₅₀, 171.4 μg/mL), TNF-α (IC₅₀, 88.4 μg/mL), LTC4 (IC₅₀, 52.9 μg/mL) and PGD2 (IC₅₀, 195.8 μg/mL). Moreover, HXZQ-OL suppressed the expression of IL-4 and TNF-α mRNA, as well as the phosphorylation of Fyn, Lyn and multiple downstream signalling proteins including MAPK and PI3K/NF-κB pathways. In addition, HXZQ-OL (527.5 mg/kg) attenuated the IgE-mediated PCA with 55% suppression of Evans blue exudation in mice.ConclusionsHXZQ-OL attenuated the activation of mast cell and PCA. Therefore, HXZQ-OL might be used as an alternative treatment for allergic diseases.     

Biochemical characterization of a novel antioxidant and angiotensin I-converting enzyme inhibitory peptide from Struthio camelus egg white protein hydrolysis

A peptide from ostrich (Struthio camelus) egg white protein hydrolysate (OEWPH) was purified, characterized, and its antioxidant and enzyme inhibitory properties were evaluated. The OEWPH was prepared using pepsin and pancreatin, and then fractionated using reversed-phase high performance liquid chromatography. The antioxidant activity of the WG-9 peptide was investigated based on its scavenging capacity for 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, 2,20-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), superoxide ( O2•-), hydroxyl (OH^•−), and lipid peroxidation inhibition. The angiotensin-converting enzyme (ACE) inhibitory activity and kinetic parameters of the peptide were determined using N-[3-(2-Furyl)acryloyl]-L-phenylalanyl-glycyl-glycine (FAPGG) as a substrate. Tandem mass spectrometry analysis of the purified peptide revealed a sequence of WESLSRLLG (MW: 1060 Da; WG-9). This peptide inhibited linoleic acid oxidation and acted as a DPPH (IC₅₀ = 15 ± 0.4 μg/mL), ABTS (IC₅₀ = 130 ± 4.5 μg/mL), superoxide (IC₅₀ = 160 ± 6.4 μg/mL), and hydroxyl (IC₅₀ = 150 ± 6.7 μg/mL) radical scavenger. The ACE-inhibitory activity and kinetic parameters of the WG-9 peptide were determined, showing an ACE inhibitory activity with IC₅₀ of 46.7 ± 1.4 μg/mL. The parameters of peptide/ACE interactions were investigated by molecule docking. Furthermore, viability assays showed that the identified peptide had no cytotoxicity against an HFLF-PI-5 cell line. In conclusion, the WG-9 peptide showed potent antioxidant and ACE-inhibitory activity.     

In vitro α-glucosidase inhibitory activity of phenolic constituents from aerial parts of Polygonum hyrcanicum

Background and the purpose of the study

The early stage of diabetes mellitus type 2 is associated with postprandial hyperglycemia. Hyperglycemia is believed to increase the production of free radicals and reactive oxygen species, leading to oxidative tissue damage. In an effort of identifying herbal drugs which may become useful in the prevention or mitigation of diabetes, biochemical activities of Polygonum hyrcanicum and its constituents were studied.

Methods

Hexane, ethylacetate and methanol extracts of P. hyrcanicum were tested for α-glucosidase inhibitory, antioxidant and radical scavenging properties. Active constituents were isolated and identified from the methanolic extract in an activity guided approach.

Results

A methanolic extract from flowering aerial parts of the plant showed notable α-glucosidase inhibitory activity (IC₅₀ = 15 μg/ml). Thirteen phenolic compounds involving a cinnamoylphenethyl amide, two flavans, and ten flavonols and flavonol 3-O-glycosides were subsequently isolated from the extract. All constituents showed inhibitory activities while compounds 3, 8 and 11 (IC₅₀ = 0.3, 1.0, and 0.6 μM, respectively) were the most potent ones. The methanol extract also showed antioxidant activities in DPPH (IC₅₀ = 76 μg/ml) and FRAP assays (1.4 mmol ferrous ion equivalent/g extract). A total phenol content of 130 mg/g of the extract was determined by Folin-Ciocalteu reagent.

Conclusion

This study shows that P. hyrcanicum contains phenolic compounds with in vitro activity that can be useful in the context of preventing or mitigating cellular damages linked to diabetic conditions.     

Radical scavenging,prolyl endopeptidase inhibitory,and antimicrobial potential of a cultured Himalayan lichen Cetrelia olivetorum

Context: Lichens are source of natural bioactive compounds which are traditionally used to cure a variety of ailments.

Objective: The objective of this study is to assess free radical scavenging, prolyl endopeptidase inhibitory (PEPI), and antimicrobial potential of a high altitude lichen species Cetrelia olivetorum (Nyl.) W. L. Culb. & C. F. Culb (Parmeliaceae).

Materials and methods: Lichen C. olivetorum has been cultured in vitro, and optimized culture conditions were implemented in bioreactor to obtain high quantity of biomass for the study of radical scavenging, PEPI, and antimicrobial activities. Radical scavenging activity of methanol extract of Cetrelia olivetorum (MECO) was tested at 100?µg/mL, PEPI activity at 25 and 50?µg/mL, and antimicrobial activity at 5, 25, 50, and 100?µg/mL conc. All the biological activities of natural thallus extract and its derived culture extract were evaluated spectrophotometrically.

Results: Murashige and Skoog medium supplemented with 3% glucose and 100?ppb indole-3-butyric acid (IBA) supported biomass growth at flask level and yielded 5.095?g biomass in bioreactor. MECO of both the cultured and the natural lichen exhibited half inhibiting concentration (IC₅₀) for radical scavenging activities in the range of 50–60?µg/mL, whereas the IC₅₀ value of standard antioxidants was found to be in the range of 12–29?µg/mL. The IC₅₀ value of lichen extract for PEPI activity was 144–288?µg/mL, whereas the IC₅₀ value of standard prolyl endopeptidase inhibitor, Z-pro-prolinal, was 57.73?µg/mL. As far as the antimicrobial activity of MECO is concerned, minimum inhibitory concentration (MIC) value of lichen extracts against tested microorganisms was obtained in the range of 50–104?µg/mL and found to be more effective than commercially available standard erythromycin.

Discussion: Murashige and Skoog medium containing IBA was found to be suitable for maximum biomass production of C. olivetorum under bioreactor conditions. The cultured lichen biomass extract also showed antioxidant, PEPI, and antimicrobial potential.

Conclusion: The present study indicates therapeutic potential of Himalayan lichen C. olivetorum against neurodegenerative diseases owing to its radical scavenging, PEPI, and antimicrobial activities. Further, the result encourages its commercial exploitation through mass culture for production of its bioactive components and their use in pharmaceutical and nutraceutical industries.     

In vitro study on α-amylase inhibitory activity of an Indian medicinal plant, Phyllanthus amarus

Objective:

The objective of this study was to evaluate the α-amylase inhibitory activity of different extracts of Phyllanthus amarus against porcine pancreatic amylase in vitro.

Materials and Methods:

The plant extracts were prepared sequentially with ethanol, chloroform, and hexane. Each extract was evaporated using rotary evaporator, under reduced pressure. Different concentrations (10, 20, 40, 60, 80, and 100 μg/mL) of each extract were made by using dimethyl sulfoxide (DMSO) and subjected to α-amylase inhibitory assay using starch azure as a substrate. The absorbance was read at 595 nm using spectrophotometer. Using this method, the percentage of α-amylase inhibitory activity and IC₅₀values of each extract was calculated.

Results:

The chloroform extract failed to inhibit α-amylase activity. However, the ethanol and hexane extracts of P. amarus exhibited appreciable α-amylase inhibitory activity with an IC50 values 36.05 ± 4.01 μg/mL and 48.92 ± 3.43 μg/mL, respectively, when compared with acarbose (IC₅₀value 83.33 ± 0.34 μg/mL).

Conclusion:

This study supports the ayurvedic concept that ethanol and hexane extracts of P. amarus exhibit considerable α-amylase inhibitory activities. Further, this study supports its usage in ethnomedicines for management of diabetes.     

In vitro antioxidant activity and total phenolic content of ethanolic leaf extract of Stevia rebaudiana Bert.

The aim of this study was to assess the in vitro potential of ethanolic leaf extract of Stevia rebaudiana as a natural antioxidant. The DPPH activity of the extract (20, 40, 50, 100 and 200 μg/ml) was increased in a dose dependent manner, which was found in the range of 36.93–68.76% as compared to ascorbic acid 64.26–82.58%. The IC₅₀ values of ethanolic extract and ascorbic acid in DPPH radical scavenging assay were obtained to be 93.46 and 26.75 μg/ml, respectively. The ethanolic extract was also found to scavenge the superoxide generated by EDTA/NBT system. Measurement of total phenolic content of the ethanolic extract of S. rebaudiana was achieved using Folin–Ciocalteau reagent containing 61.50 mg/g of phenolic content, which was found significantly higher when compared to reference standard gallic acid. The ethanolic extract also inhibited the hydroxyl radical, nitric oxide, superoxide anions with IC₅₀ values of 93.46, 132.05 and 81.08 μg/ml, respectively. However, the IC₅₀ values for the standard ascorbic acid were noted to be 26.75, 66.01 and 71.41 μg/ml respectively. The results obtained in this study clearly indicate that S. rebaudiana has a significant potential to use as a natural antioxidant agent.     

Extract of Ganoderma sinensis spores induces cell cycle arrest of hepatoma cell via endoplasmic reticulum stress

ContextGanoderma sinensis Zhao, Xu et Zhang (Ganodermataceae) has been used for the prevention or treatment of a variety of diseases, including cancer.ObjectiveWe investigated the antitumor activity and mechanism of an extract from G. sinensis against hepatocellular carcinoma.Materials and methodsA G. sinensis extract (GSE) was obtained from sporoderm-broken G. sinensis spores by supercritical fluid carbon dioxide extraction. Hepatoma cells, HepG2 cells, were treated with emulsified sample of GSE at 12.5, 25, 50, 100 and 150 μg/mL for 24 h. The Alamar Blue assay was used to examine growth inhibitory effects. Changes in cell structure and morphology were assessed via transmission electron microscopy and confocal laser scanning microscope. Cell cycle distribution was analysed by flow cytometry.ResultsGSE suppressed the proliferation of HepG2 cells (IC₅₀=70.14 μg/mL). Extensive cytoplasmic vacuolation originating from dilation of the endoplasmic reticulum (ER) was shown in GSE-treated HepG2 cells. GSE treatment also upregulated the expression of ER stress-related proteins in HepG2 cells. Cells tended to be arrested at the G2/M cell cycle stage after GSE treatment (30.8 ± 1.4% and 42.2 ± 2.6% at GSE with 50 μg/mL and 100 μg/mL vs. 21.03 ± 1.10%, control). Pre-treatment with salubrinal, an inhibitor of ER stress, effectively attenuated cell cycle arrest induced by GSE.Discussion and conclusionsOur findings provide new evidence that GSE suppresses growth of cancer cells in vitro through activating the ER stress pathway. The GSE may be clinically applied in the prevention and/or treatment of cancer.     

Antioxidant activity and protective effects of cocoa and kola nut mistletoe (Globimetula cupulata) against ischemia/reperfusion injury in Langendorff-perfused rat hearts

Protection against cardiomyocyte damage following ischemia/reperfusion (I/R) injury is highly desirable in patients with ischemic heart disease. Hydromethanol extracts of Globimetula cupulata (mistletoe) growing on cocoa (CGCE) and kola nut (KGCE) trees were assessed for antioxidant content and cardioprotective potential against I/R. Graded concentrations (1–50 μg/mL) of CGCE or KGCE were tested on Langendorff-perfused rat hearts to evaluate the effects on the flow rate, heart rate, and force of cardiac contraction, while another set of hearts were subjected to biochemical analyses. Both extracts showed good antioxidant content and activity, but KGCE (EC₅₀: 24.8±1.8 μg/mL) showed higher hydroxyl radical scavenging activity than CGCE (70.2±4.5 μg/mL). Both extracts at 3 μg/mL reversed (p < 0.001) membrane peroxidation and the significant decrease in nitrite level, coronary flow rate, and superoxide dismutase and catalase activity caused by the I/R cycle. It is concluded that G. cupulata protects against ischemia–reperfusion injury in rat hearts via augmenting endogenous antioxidants and significant restoration of altered hemodynamic parameters.