Anti-inflammatory,free radical scavenging and alpha-glucosidase inhibitory activities of Hamelia patens and its chemical constituents

Context Hamelia patens Jacq. (Rubiaceae) is traditionally used to treat wounds, inflammation and diabetes. However, there is still a lack of scientific evidence to support these applications.

Objective The objective of this study is to evaluate the anti-inflammatory, antioxidant and antidiabetic activities of Hamelia patens, and identify its bioactive compounds.

Materials and methods Four extracts were obtained by maceration and liquid–liquid extraction: HEX, DCM–EtOAc, MeOH–EtOAc and MeOH–Aq. The anti-inflammatory effect was evaluated orally on rat paw carrageenan-induced oedema over 6?h (50, 200 and 500?mg/kg), and topically in mouse ear oedema induced by 12-tetradecanoylphorbol-13-acetate (TPA) after 4?h (0.5 and 1?mg/ear). We also evaluated myeloperoxidase levels in ear tissue, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging ability, and in vitro α-glucosidase inhibition. The chemical compounds were separated by column chromatography and identified by spectroscopic analysis.

Results We found that the oral administration of the HEX extract at 500 and 200?mg/kg significantly decreased the carrageenan-induced inflammation after 1 and 3?h, respectively. The MeOH–EtOAc extract significantly inhibited myeloperoxidase activity (83.5%), followed by the DCM–EtOAc extract (76%), β-sitosterol/stigmasterol (72.7%) and the HEX extract (55%), which significantly decreased oedema induced by TPA at both doses, giving a similar effect to indomethacin. We also found that the MeOH–EtOAc, MeOH–Aq and DCM–EtOAc extracts showed good DPPH scavenging activity (IC₅₀ values of 18.6, 93.9 and 158.2?μg/mL, respectively). The HEX extract showed the lowest α-glucosidase inhibition (an IC₅₀ value of 26.07?μg/mL), followed by the MeOH–EtOAc extract (an IC₅₀ value of 30.18?μg/mL), β-sitosterol/stigmasterol (IC₅₀ 34.6?μg/mL) and compound A ((6E,10E,14E,18E)-2,6,10,14,18,23-hexamethyl-2,6,10,14,18,22-tetracosahexaene, an IC₅₀ value of 114.6?μg/mL), which were isolated for the first time from Hamelia patens.

Discussion and conclusion Hamelia patens possesses anti-inflammatory, antioxidant and α-glucosidase inhibitory activities, which support its traditional use. These effects can be attributed to the identified compounds.     

Aqueous extract of Securidaca longipendunculata Oliv. and Olax subscropioidea inhibits key enzymes (acetylcholinesterase and butyrylcholinesterase) linked with Alzheimer’s disease in vitro

Context: Plants have historically been used to treat neurodegerative diseases which include Alzheimer’s disease.

Objective: This study investigated the antioxidant properties and inhibitory effect of aqueous extracts of Securidaca longipendunculata root and Olax subscropioidea leaf on the cholinergic system in rat brain in vitro.

Materials and methods: Aqueous extracts (1:20 w/v) of S. longipendunculata root and O. subscropioidea leaf was prepared and the ability of the extract to inhibit the activities of acetylcholinesterase and butyrylcholinesterase was evaluated as well as antioxidants as typified by 2,2-azino-bis-(3-ethylbenthiazoline-6-sulphonic acid (ABTS^?) radical scavenging ability and Fe chelation spectophotometrically.

Results: ABTS^? radical scavenging ability showed that S. longipendunculata (0.075?Mmol TEAC/100?g) had a higher scavenging ability than O. subscropioidea (0.07?Mmol TEAC/100?g). Also, the Fe^2+?chelating ability of both extracts revealed that S. longipendunculata (IC_50?=_?105.57?g/mL) had a significantly (p?2+?chelating ability than O. subscropioidea (IC_50?=_?255.84?g/mL). Extracts of S. longipendunculata and O. subscropioidea inhibited acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities. However, S. longipendunculata (IC_50?=_?108.02?g/mL) has the higher AChE inhibitory activity than O. subscropioidea (IC_50?=_?110.35?g/mL). Also, both extracts inhibit BChE activity in vitro but S. longipendunculata (IC_50?=_?82.55?g/mL) had a higher BChE inhibitory activity than O. subscropioidea (IC_50?=_?108.44?g/mL).

Discussion and conclusions: The mechanism by which S. longipendunculata root and O. subscropioidea leaf perform their anti-Alzheimer’s disease activity may be by their inhibition on the key enzymes linked to this disease.     

Unlocking the in vitro anti-inflammatory and antidiabetic potential of Polygonum maritimum

Context: Several Polygonum species (Polygonaceae) are used in traditional medicine in Asia, Europe and Africa to treat inflammation and diabetes.

Objective: Evaluate the in vitro antioxidant, anti-inflammatory and antidiabetic potential of methanol and dichloromethane extracts of leaves and roots of the halophyte Polygonum maritimum L.

Material and methods: Antioxidant activity was determined (up to 1?mg/mL) as radical-scavenging activity (RSA) of 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), copper (CCA) and iron (ICA) chelating activities and iron reducing power (FRAP). NO production was measured in lipopolysaccharide (LPS)-stimulated macrophages for 24?h at concentrations up to 100?μg/mL and antidiabetic potential was assessed by α-amylase and α-glucosidase inhibition (up to 10?mg/mL) assays. The phytochemical composition of the extracts was determined by gas chromatography-mass spectrometry (GC-MS).

Results: The methanol leaf extract had the highest activity against DPPH? (IC₅₀ =?26?μg/mL) and ABTS⁺? (IC₅₀ =?140?μg/mL), FRAP (IC₅₀ =?48?μg/mL) and CCA (IC₅₀ =?770?μg/mL). Only the dichloromethane leaf extract (LDCM) showed anti-inflammatory activity (IC₅₀ =?48?μg/mL). The methanol root (IC₅₀ =?19?μg/mL) and leaf (IC₅₀ =?29?μg/mL) extracts strongly inhibited baker’s yeast α-glucosidase, but LDCM had higher rat’s α-glucosidase inhibition (IC₅₀ =?2527?μg/mL) than acarbose (IC₅₀ =?4638?μg/mL). GC-MS analysis identified β-sitosterol, stigmasterol, 1-octacosanol and linolenic acid as possible molecules responsible for the observed bioactivities.

Conclusions: Our findings suggest P. maritimum as a source of high-value health promoting commodities for alleviating symptoms associated with oxidative and inflammatory diseases, including diabetes.     

Protective activity of Hertia cheirifolia extracts against DNA damage,lipid peroxidation and protein oxidation

Context: Hertia cheirifolia L. (Asteraceae), a perennial shrub widely distributed in Northern Africa, is traditionally used to treat inflammatory disorders.

Objective: The protective effect of methanol (Met E) and aqueous (Aq E) extracts of Hertia cheirifolia against DNA, lipid and protein oxidation was investigated.

Materials and methods: Different concentrations (50–1000?μg/mL) of Hertia cheirifolia aerial part extracts were examined against DNA, lipid and protein oxidation induced by H₂O_2?+?UV, FeSO₄, and Fe³⁺/H₂O₂-ascorbic acid, respectively. The DPPH^?, metal ion chelating, reducing power and β-carotene bleaching tests were conducted.

Results: Both extracts were rich in polyphenols, flavonoids and tannins, and were able to scavenge DPPH^? with IC₅₀ values of 138 and 197?μg/mL, respectively. At 300?μg/mL, Aq E exerted stronger chelating effect (99%) than Met E (69%). However, Met E reducing power (IC_50?=_?61?μg/mL) was more than that of Aq E (IC_50?=_?193?μg/mL). Both extracts protected from β-carotene bleaching by 74% and 94%, respectively, and inhibited linoleic acid peroxidation. The inhibitory activity of Aq E extract (64%) was twice more than that of Met E (32%). Interestingly, both extracts protected DNA against the cleavage by about 96–98%. At 1?mg/mL, Met E and Aq E restored protein band intensity by 94–99%.

Conclusions: Hertia cheirifolia exhibits potent antioxidant activity and protects biomolecules against oxidative damage; hence, it may serve as potential source of natural antioxidant for pharmaceutical applications and food preservation. This is the first report on the protective activity of this plant against biomolecule oxidation.     

Phytochemical analysis,antiproliferative and antioxidant activities of Chrozophora tinctoria: a natural dye plant

Context: Chrozophora tinctoria (L.) A. Juss. (Euphorbiaceae) is known as ‘dyer’s-croton’ and used to obtain dye substances. Recently, natural antioxidants and colorants have been of interest because of their safety and therapeutic effects.

Objective: This study investigates the antiproliferative and antioxidant activities of the various extracts and fractions from C. tinctoria and analyzes their phytochemical contents.

Materials and methods: The aerial parts of C. tinctoria were extracted with water, ethyl acetate, n-butanol, and methanol/chloroform. Phenolic compounds and other constituents of the extracts were analyzed by HPLC/TOF-MS. The ethyl acetate extract (EA) was fractionated by flash chromatography. The extracts, fractions, and major phenolic compounds were investigated for their antiproliferative activities on human cervical adenocarcinoma (HeLa) cell line at the concentrations of 5–100?μg/mL by using BrdU ELISA assay during 24?h of incubation. DPPH radical scavenging activities (5–150?μg/mL) and total phenolic contents of the samples were also evaluated.

Results: 4-Hydroxybenzoic acid (268.20?mg/kg), apigenin-7-glucoside (133.34?mg/kg), and gallic acid (68.92?mg/kg) were the major components of EA. CT/E-F6 (IC₅₀?=?64.59?±?0.01?μg/mL) exhibited the highest antiproliferative activity. CT/E-F2 (IC₅₀=?14.0?±?0.0?μg/mL) and some fractions displayed higher radical scavenging activity compared to synthetic antioxidant BHT (IC_50?=_?23.1?±?0.0?μg/mL). Among the main phenolics, gallic acid exhibited the highest antiproliferative and radical scavenging abilities (IC_50?<_?5?μg/mL).

Conclusion: In this study, we have determined the biologically active fractions and their high effects may be attributed to the presence of gallic acid.     

Antioxidant,anticholinesterase and antibacterial activities of Stachys guyoniana and Mentha aquatica

Context: Stachys guyoniana Noë ex. Batt. and Mentha aquatica L. are two Algerian Lamiaceae used in folk medicine.

Objective: To investigate their antioxidant, anticholinesterase and antibacterial activities.

Material and methods: n-Butanol (BESG), ethyl acetate (EESG) and chloroform (CESG) extracts of S. guyoniana and methanol (MEMA) and chloroform (CEMA) aerial part extracts of M. aquatica and methanol (MERMA) and acetone (AERMA) roots extracts of M. aquatica were evaluated for their antioxidant activity by the β-carotene-linoleic acid, DPPH^? and ABTS^?+?scavenging, CUPRAC and metal chelating assays. The anticholinesterase activity was tested against AChE and BChE. The antibacterial activity was assessed by MICs determination against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella heidelberg, Klebsiella pneumoniae, Enterobacter aerogenes and Morganella morganii strains.

Results: In the β-carotene test, the CESG (IC₅₀: 2.3?±?1.27?μg/mL) exhibited the highest activity. The BESG was the best scavenger of DPPH^? (IC₅₀: 2.91?±?0.14?μg/mL). In the ABTS test, AERMA was the most active (IC₅₀: 4.21?±?0.28?μg/mL). However, with the CUPRAC, the BESG exhibited the best activity (A_0.50: 0.15?±?0.05?μg/mL) and was active in metal chelating assay with 48% inhibition at 100?μg/mL. The BESG was the best AChE inhibitor (IC₅₀: 5.78?±?0.01?μg/mL) however, the AERMA showed the highest BChE inhibitory activity (IC₅₀: 19.23?±?1.42?μg/mL). The tested extracts exhibited a good antibacterial activity.

Conclusion: This study demonstrated good antioxidant, anticholinesterase and antibacterial potential of S. guyoniana and M. aquatica, which fits in well with their use in folk medicine.     

Anti-inflammatory effect of pomegranate flower in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages

Context: Punica granatum L (Punicaceae) flower is an important diabetes treatment in oriental herbal medicine.

Objective: This study investigates the inflammation effects of pomegranate flower (PFE) ethanol extract in LPS-induced RAW264.7 cells.

Materials and methods: PFE (10, 25, 50, 100?μg/mL) was applied to 1?μg/mL LPS-induced RAW 264.7 macrophages in vitro. Levels of nitric oxide (NO), prostaglandin E₂ (PGE₂) and pro-inflammatory cytokines interleukin (IL)-1β (IL-1β), interleukin (IL)-6 (IL-6) and tumor necrosis factor (TNF-α) in the supernatant fraction were determined using enzyme-linked immunosorbent assay (ELISA). Expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), phosphorylation of mitogen-activated protein kinase (MAPK) subgroups extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and P38, as well as nuclear factor-κB (NF-κB) activation in extracts were detected via Western blot.

Results: 10–100?μg/mL PFE decreased the production of NO (IC₅₀ value?=?31.8?μg/mL), PGE₂ (IC₅₀ value?=?54.5?μg/mL), IL-6 (IC₅₀ value?=?48.7?μg/mL), IL-1β (IC₅₀ value?=?71.3?μg/mL) and TNF-α (IC₅₀ value?=?62.5?μg/mL) in LPS-stimulated RAW 264.7 cells significantly. A mechanism-based study showed that phosphorylation of ERK1/2, p38, JNK and translocation of the NF-B p65 subunit into nuclei were inhibited by the PFE treatment.

Discussion and conclusion: These results show that PFE produced potential anti-inflammatory effect through modulating the synthesis of several mediators and cytokines involved in the inflammatory process.     

Studies on phytochemical,antioxidant, anti-inflammatory,hypoglycaemic and antiproliferative activities of Echinacea purpurea and Echinacea angustifolia extracts

Context: Echinacea (Asteraceae) is used because of its pharmacological properties. However, there are few studies that integrate phytochemical analyses with pharmacological effects.

Objective: Evaluate the chemical profile and biological activity of hydroalcoholic Echinacea extracts.

Materials and methods: Density, dry matter, phenols (Folin–Ciocalteu method), flavonoids (AlCl₃ method), alkylamides (GC-MS analysis), antioxidant capacity (DPPH and ABTS methods), antiproliferative effect (SRB assay), anti-inflammatory effect (paw oedema assay, 11 days/Wistar rats; 0.4?mL/kg) and hypoglycaemic effect (33 days/Wistar rats; 0.4?mL/kg) were determined in three Echinacea extracts which were labelled as A, B and C (A, roots of Echinacea purpurea L. Moench; B, roots, leaves, flowers and seeds of Echinacea purpurea; C, aerial parts and roots of Echinacea purpurea and roots of Echinacea angustifolia DC).

Results: Extract C showed higher density (0.97?g/mL), dry matter (0.23?g/mL), phenols (137.5?±?2.3 mEAG/mL), flavonoids (0.62?±?0.02 mEQ/mL), and caffeic acid (0.048?mg/L) compared to A and B. A, B presented 11 alkylamides, whereas C presented those 11 and three more. B decreased the oedema (40%) on day 2 similar to indomethacin. A and C showed hypoglycaemic activity similar to glibenclamide. Antiproliferative effect was only detected for C (IC₅₀ 270?μg/mL; 8171?μg/mL; 9338?μg/mL in HeLa, MCF-7, HCT-15, respectively).

Discussion and conclusion: The difference in the chemical and pharmacological properties among extracts highlights the need to consider strategies and policies for standardization of commercial herbal extracts in order to guarantee the safety and identity of this type of products.     

Antioxidant activities and molecular mechanisms of the ethanol extracts of Baccharis propolis and Eucalyptus propolis in RAW64.7 cells

Context Numerous studies have reported that propolis possesses strong antioxidant activities. However, their antioxidant molecular mechanisms are unclear.

Objective We utilize ethanol extracts of Chinese propolis (EECP) as a reference to compare ethanol extracts of Eucalyptus propolis (EEEP) with ethanol extracts of Baccharis propolis (EEBGP) based on their antioxidant capacities and underlying molecular mechanisms.

Materials and methods HPLC and chemical analysis are utilized to evaluate compositions and antioxidant activities. ROS-eliminating effects of EEBGP (20–75?μg/mL), EEEP (1.25–3.75?μg/mL) and EECP (1.25–5?μg/mL) are also determined by flow cytometry analysis. Moreover, we compared antioxidant capacities by determining their effects on expressions of antioxidant genes in RAW264.7 cells with qRT-PCR, western blot and confocal microscopy analysis.

Results EEBGP mainly contains chlorogenic acid (8.98?±?0.86?mg/g), kaempferide (11.18?±?8.31?mg/g) and artepillin C (107.70?±?10.86?mg/g), but EEEP contains 10 compositions, whereas EECP contains 17 compositions. Meantime, although EEEP shows DPPH (IC₅₀ 19.55?±?1.28), ABTS (IC₅₀ 20.0?±?0.31) and reducing power (2.70?±?0.08?mmol TE/g) better than EEBGP’s DPPH (IC₅₀ 43.85?±?0.54), ABTS (IC₅₀ 38.2?±?0.33) and reducing power (1.53?±?0.05?mmol TE/g), EEBGP exerts much higher ROS inhibition rate (40%) than EEEP (under 20%). Moreover, EEBGP strengthen antioxidant system by activating p38/p-p38 and Erk/p-Erk kinase via accelerating nucleus translocation of Nrf2. EEEP and EECP improve antioxidant gene expression only via Erk/p-Erk kinase-Nrf2 signalling pathway.

Discussion and conclusion EEBGP and EEEP exert antioxidant activities via different molecular mechanisms, which may depend on chemical compositions.     

Potential of rare actinomycetes in the production of metabolites against multiple oxidant agents

Context: Actinobacteria are a precious source of novel bioactive metabolites with potential pharmaceutical applications.

Objectives: Representatives of 11 genera of rare Actinobacteria were selected for the evaluation of antioxidant activity.

Material and methods: Fermentation broths of the Actinobacteria were extracted and dosage of 10 to 2000?µg/mL were applied for in vitro antioxidant-related bioassays. Cytotoxicity was assessed at the concentration of 2.5–20?µg/mL.

Results: In the DPPH scavenging activity, 15 out of 52 extracts showed 17.0–26.8% activity in quantitative evaluation. Metabolites of five prominent antioxidant producing strains protected the DNA (pUC19) against UV-induced photolyzed H₂O₂-oxidative degradation. The potent antioxidant extracts inhibited two oxidative enzymes of xanthine oxidase in the range of 17.5–45.2% (three extracts had IC₅₀ less than allopurinol) and lipoxygenase in the range of 36–55% (all five extracts had IC₅₀ values less than daidzein). All these extracts could also protect eythrocytes from iron-induced hemolysis with ED₅₀ values in a range of 0.014–1.25?mg/mL. Growth restoration of the yeast cells lacking the sod1 gene was observed by the antioxidant metabolite of Saccharothrix ecbatanensis UTMC 537 at the concentration of 1?mg/mL.

Conclusions: The presence of nonidentical metabolites might be responsible for antioxidant and enzyme inhibitory activities of S. ecbatanensis, newly described actinobacterium in family Pseudonocardiaceae. The scavenging of the free electrons, protection of DNA and model yeast cells against oxidative stress, in addition to the inhibition of the oxidating enzymes are the main mechanisms of the antioxidant effect of the introduced resource in this study.     

LC-MS–MS and GC-MS analyses of biologically active extracts and fractions from Tunisian Juniperus phoenice leaves

Context: Despite some studies related to Juniperus phoenicea L. (Cupressaceae), phytochemical and biological investigations of this plant remain unexplored.

Objective: This work is the first report dealing with the identification and characterization of volatile components and flavonoids in hexane and methanol extracts from J. phoenicea leaves

Materials and methods: Antioxidant activity of hexane, and methanol extracts from J. phoenicea leaves were determined by DPPH-radical scavenging assay. α-Amylase inhibitory activity was evaluated by enzyme inhibition using in vitro assay (each extract was dissolved in DMSO to give concentrations of 50, 100 and 200?mg/mL). The chemical composition of fractions (Fr1-Fr3) from methanol extract was determined by high-performance liquid chromatography coupled with mass spectroscopy (HPLC-MS) analysis.

Results and discussion: The hexane extract was analyzed by GC-MS technique which allowed the identification of 32 compounds. The main constituents were α-humulene (16.9%), pentadecane (10.2%) and α-cubebene (9.7%). Fraction Fr 2 exhibited a strong DPPH radical-scavenging activity (IC_50?=_?20.1?μg/mL) compared to that of BHT as well as the highest α-amylase inhibitory activity (IC_50?=_?28.4?μg/mL). Three flavonoids were identified in these fractions using HPLC-MS analysis: Quercetin 3-O-glucoside, isoscutellarein 7-O-pentoside and quercetin 3-O-pentoside. In addition, the more active fraction (Fr 2) was purified with semi-preparative HPLC affording one pure compound (amentoflavone) using ¹H NMR analysis. This compound exhibited powerful DPPH radical-scavenging (IC_50?=_?14.1?μg/mL) and α-amylase inhibition (IC_50?=_?20.4?μg/mL) effects.

Conclusion: This study provides scientific support to some medicinal uses of J. phoenicea found in North Africa.     

In vitro assessment of selected Korean plants for antioxidant and antiacetylcholinesterase activities

Context: Antiacetylcholinesterase (AChE) drugs have been a main therapeutic treatment for Alzheimer’s disease because increased AChE levels play a key role in reducing neurotransmission.

Objectives: Extracts from 35 Korean plants were selected and screened for antioxidant and anti-cholinesterase activity to explore new sources derived from Korean natural resources that could be used as AD therapeutic agents.

Materials and methods: The antioxidant effect of extracts from 35 selected Korean plants was determined using two most common free radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS). Additionally, the effect of extracts, identified as antioxidants, on acetylcholinesterase inhibition was assessed by an acetylcholinesterase assay kit.

Results: Out of 36 extracts of 35 plants tested, Oenothera biennis L. (9.09?μg/mL), Saururus chinensis (Lour.) Baill. (9.52?μg/mL) and Betula platyphylla var. japonica (9.85?μg/mL) showed strong DPPH scavenging activity. Twelve other extracts also exerted moderate free radical scavenging activities with IC₅₀ values ranging from 10 to 50?μg/mL. Antioxidant capacity detected by ABTS assay was only significant in O. biennis (23.40?μg/mL), while the other extracts were weak or unable to reduce the production of ABTS. Based on the antioxidant activities of these plant extracts, 19 extracts with IC₅₀ values less than 100?μg/mL in DPPH assay were selected for further AChE inhibition assay. Among the extracts tested, the IC₅₀ value for Prunella vulgaris var. lilacina NAKAI (18.83?μg/mL) in AChE inhibitory activity was the lowest, followed by O. biennis (20.09?μg/mL) and Pharbitis nil Chosy (22.79?μg/mL).

Conclusions: Considering complex multifactorial etiology of AD, the extracts of P. vulgaris var. lilacina (aerial part), O. biennis (seed) and P. nil (seed) may be safe and ideal candidates for future AD modifying therapies.     

Leishmanicidal and cytotoxic activities of Nigella sativa and its active principle,thymoquinone

Abstract

Context: Leishmaniasis is a complex disease with a broad spectrum of clinical presentations.

Objective: We evaluated the anti-leishmanial effects of Nigella sativa L. (Ranunculaceae) against Leishmania tropica and Leishmania infantum with an in vitro model.

Materials and methods: Antileishmanial effects of essential oil and methanolic extract of N. sativa (0–200?µg/mL) and thymoquinone (0–25?µg/mL) on promastigotes of both species and their cytotoxicity activities against murine macrophages were evaluated using the MTT assay at 24, 48, and 72?h. Moreover, their leishmanicidal effects against amastigotes were investigated in a macrophage model, for 48 and 72?h.

Results: The findings showed that essential oil (L. tropica IC₅₀ 9.3?μg/mL and L. infantum IC₅₀ 11.7?μg/mL) and methanolic extract (L. tropica IC₅₀ 14.8?μg/mL and L. infantum IC₅₀ 15.7?μg/mL) of N. sativa, particularly thymoquinone (L. tropica IC₅₀ 1.16?μg/mL and L. infantum IC₅₀ 1.47?μg/mL), had potent antileishmanial activity on promastigotes of both species after 72?h. In addition, essential oil (L. tropica IC₅₀ 21.4?μg/mL and L. infantum IC₅₀ 26.3?μg/mL), methanolic extract (L. tropica IC₅₀ 30.8?μg/mL and L. infantum IC₅₀ 34.6?μg/mL), and thymoquinone (L. tropica IC₅₀ 2.1?μg/mL and L. infantum IC₅₀ 2.6?μg/mL) mediated a significant decrease in the growth rate of amastigote forms of both species. Thymoquinone (CC₅₀ 38.8?μg/mL) exhibited higher cytotoxic effects against murine macrophages than the other extracts.

Conclusion: N. sativa, especially its active principle, thymoquinone, showed a potent leishmanicidal activity against L. tropica and L.infantum with an in vitro model.     

Polyphenol profile by UHPLC-MS/MS,anti-glycation,antioxidant and cytotoxic activities of several samples of propolis from the northeastern semi-arid region of Brazil

Context: Propolis has promising biological activities. Propolis samples from the Northeast of Bahia, Brazil – sample A from Ribeira do Pombal and B, from Tucano – were investigated, with new information regarding their biological activities.

Objective: This paper describes the chemical profile, antioxidant, anti-glycation and cytotoxic activities of these propolis samples.

Material and methods: Ethanol extracts of these propolis samples (EEP) and their fractions were analyzed to determine total phenolic content (TPC); antioxidant capacity through DPPH^?, FRAP and lipid peroxidation; anti-glycation activity, by an in vitro glucose (10?mg/mL) bovine serum albumine (1?mg/mL) assay, during 7?d; cytotoxic activity on cancer (SF295, HCT-116, OVCAR-8, MDA-MB435, MX-1, MCF7, HL60, JURKAT, MOLT-4, K562, PC3, DU145) and normal cell lines (V79) at 0.04–25?μg/mL concentrations, for 72?h. The determination of primary phenols by ultra high-pressure liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) and volatile organic compounds content by gas chromatography-mass spectrometry (GC-MS) were also performed.

Results: The EEP polar fractions exhibited up to 90% protection against lipid peroxidation. The IC₅₀ value for anti-glycation activity of EEP was between 16.5 and 19.2?μg/mL, close to aminoguanidine (IC₅₀?=?7.7?μg/mL). The use of UHPLC-MS/MS and GC-MS allowed the identification of 12 bioactive phenols in the EEP and 24 volatile compounds, all already reported.

Conclusions: The samples present good antioxidant/anti-glycation/cytotoxic activities and a plethora of biologically active compounds. These results suggest a potential role of propolis in targeting ageing and diseases associated with oxidative and carbonylic stress, aggregating value to them.     

Chemical composition and biological investigation of Pelargonium endlicherianum root extracts

Context: Pelargonium endlicherianum Fenzl. (Geraniaceae) roots and flowers are traditionally used in Turkey as a decoction treatment against intestinal parasites. Neither the chemical composition nor the potential bioactivity of the plant roots has been studied before.

Objectives: The phenolic content and effects of P. endlicherianum root extracts on antioxidant enzyme levels on A549 cells were studied for the first time.

Materials and methods: The chemical composition was analyzed via spectrophotometric and chromatographic (HPLC MS/MS and HPLC) techniques. The antioxidant activity was determined at different concentrations ranging from 0.001 to 2?mg/mL using DPPH^? and ABTS^?+ radical scavenging activity, β-carotene-linoleic acid co-oxidation assay, protection of 2-deoxyribose and bovine brain-derived phospholipids against a hydroxyl radical-mediated degradation assay. Glutathione peroxidase and superoxide dismutase activities were also studied as well as the effects of the extracts on nitric oxide levels on IL-1β stimulated A549 cells.

Results: The key parameters for the most active ethyl acetate extract included the following: DPPH^? IC₅₀: 0.23?mg/mL, TEAC/ABTS: 2.17?mmol/L Trolox, reduction: 0.41?mmol/g AsscE, and protection of lipid peroxidation IC₅₀: 0.05?mg/mL. Furthermore, the ethyl acetate extract increased the SOD level significantly compared to control group (4.48?U/mL) at concentrations of 100 and 200?μg/mL SOD, 5.50 and 5.67?U/mL, respectively. Apocynin was identified as the major component, and the ethyl acetate fraction was found to be rich in phenolic compounds.

Discussion and conclusion: Pelargonium endlicherianum root extracts displayed antioxidant activity and increased the antioxidant enzyme levels in IL-1β stimulated A549 cells, while decreasing the NO levels.     

Study of cytotoxic activity,podophyllotoxin, and deoxypodophyllotoxin content in selected Juniperus species cultivated in Poland

Abstract

Context: The demand for podophyllotoxin and deoxypodophyllotoxin is still increasing and commercially exploitable sources are few and one of them, Podophyllum hexandrum Royle (Berberidaceae), is a “critically endangered” species.

Objective: The first aim was to quantify the amount of podophyllotoxin and deoxypodophyllotoxin in 61 Juniperus (Cupressaceae) samples. Cytotoxic activity of podophyllotoxin and ethanolic leaf extracts of Juniperus scopulorum Sarg. “Blue Pacific” and Juniperus communis L. “Depressa Aurea” was examined against different leukemia cell lines.

Materials and methods: Ultra-performance liquid chromatography (UPLC) analysis was performed with the use of a Waters ACQUITY UPLC^TM system (Waters Corp., Milford, MA). The peaks of podophyllotoxin and deoxypodophyllotoxin were assigned on the basis of their retention data and mass-to-charge ratio (m/z). Trypan blue assay was performed to obtain IC₅₀ cytotoxicity values against selected leukemia cell lines.

Results: Juniperus scopulorum was characterized with the highest level of podophyllotoxin (486.7?mg/100?g DW) while Juniperus davurica Pall. contained the highest amount of deoxypodophyllotoxin (726.8?mg/100?g DW). Podophyllotoxin IC₅₀ cytotoxicity values against J45.01 and CEM/C1 leukemia cell lines were 0.0040 and 0.0286?µg/mL, respectively. Juniperus scopulorum extract examined against J45.01 and HL-60/MX2 leukemia cell lines gave the respective IC₅₀ values: 0.369–9.225?µg/mL. Juniperus communis extract was characterized with the following IC₅₀ cytotoxity values against J45.01 and U-266B1 cell lines: 3.310–24.825?µg/mL.

Conclusions: Juniperus sp. can be considered as an alternative source of podophyllotoxin and deoxypodophyllotoxin. Cytotoxic activity of podophyllotoxin and selected leaf extracts of Juniperus sp. against a set of leukemia cell lines was demonstrated.     

Chemical composition,antioxidant, antitumor,anticancer and cytotoxic effects of Psidium guajava leaf extracts

Context Psidium guajava L. (Myrtaceae) leaves are used in traditional medicines for the treatment of cancer, inflammation and other ailments.

Objective The current study explores scientific validation for this traditional medication.

Materials and methods We used ferric-reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picryl hydrazil (DPPH) assays to estimate antioxidant activity of P. guajava leaf extracts (methanol, hexane and chloroform). Antitumour and in vivo cytotoxic activities were determined using potato disc assay (PDA) and brine shrimp lethality assay, respectively. Three human carcinoma cell lines (KBM5, SCC4 and U266) were incubated with different doses (10–100?μg/mL) of extracts and the anticancer activity was estimated by MTT assay. NF-κB suppressing activity was determined using electrophoretic mobility shift assay (EMSA). Chemical composition of the three extracts was identified by GC-MS. Total phenolic and flavonoid contents were measured by colorimetric assays.

Results and discussions The order of antioxidant activity of three extracts was methanol?>?chloroform?>?hexane. The IC₅₀ values ranged from 22.73 to 51.65?μg/mL for KBM5; 22.82 to 70.25?μg/mL for SCC4 and 20.97 to 89.55?μg/mL for U266 cells. The hexane extract exhibited potent antitumour (IC_50? value?=_?65.02?μg/mL) and cytotoxic (LC_50? value?=_?32.18?μg/mL) activities. This extract also completely inhibited the TNF-α induced NF-κB activation in KBM5 cells. GC-MS results showed that pyrogallol, palmitic acid and vitamin E were the major components of methanol, chloroform and hexane extracts. We observed significant (p?<?0.05) difference in total phenolic and flavonoid contents of different solvent extracts.

Conclusion The present study demonstrates that P. guajava leaf extracts play a substantial role against cancer and down-modulate inflammatory nuclear factor kB.     

Aldose reductase and protein tyrosine phosphatase 1B inhibitory active compounds from Syzygium cumini seeds

Abstract

Context: Syzygium cumini (L.) Skeels (Myrtaceae), commonly known as jamun, is an Indian plant, traditionally well known for its medicinal properties including antidiabetic activity.

Objective: To isolate the antidiabetic compounds from Syzygium cumini seeds and evaluate their activity using aldose reductase (AR) and protein-tyrosine phosphatase 1B (PTP1B) inhibition assays.

Materials and methods: The dried seeds were extracted with methanol and partitioned with ethyl acetate, butanol, and water. The extracts were screened for antidiabetic activity at a concentration of 100?µg/mL using in vitro AR and PTP 1B inhibition assays.

Results and discussion: The highly enriched fractions obtained from broad ethyl acetate fraction yielded maslinic acid (1), 5-(hydroxymethyl) furfural (2), gallic acid (3), valoneic acid dilactone (4), rubuphenol (5), and ellagic acid (6). Structures were elucidated by ¹H-NMR and ¹³C-NMR. The initial ethyl acetate fraction showed AR inhibitory activity with the IC₅₀ value of 2.50?μg/mL and PTP1B enzyme inhibition with the IC₅₀ value of 26.36?μg/mL. Compounds 3, 4, 5, and 6 were found to inhibit AR with IC₅₀ values of 0.77, 0.075, 0.165, and 0.12?μg/mL while the compounds 4, 5, and 6 inhibited PTP1B with IC₅₀ values of 9.37, 28.14, and 25.96?μg/mL, respectively.

Conclusion: The results of this study demonstrate that the isolated constituents show promising in vitro antidiabetic activity and, therefore, can be candidates for in vivo biological screening using relevant models to ascertain their antidiabetic activity.     

Bioassay-guided isolation of Poliovirus-inhibiting constituents from Zephyranthes candida

Abstract

Context: Plants of the Zephyranthes genus are globally used in folk medicine. In a previous study, Zephyranthes candida Linn. (Amaryllidaceae) was identified as having antiviral properties; this led to anti-poliovirus assay-guided isolation of compounds from crude methanol extract of the plant.

Objective: Isolation of anti-poliovirus constituents from Z. candida.

Material and methods: Active chloroform fraction from crude methanol extract of Z. candida (whole plant) was subjected to bioassay-guided fractionation; repeated column and preparative thin layer chromatography led to isolation of active compounds. Chemical structures were identified using spectroscopic techniques. Using serial two-fold dilution of maximum non-toxic concentration (MNTC) of each compound (0.0625–1?µg/mL for lycorine and 0.625–10?µg/mL for trisphaeridine and 7-hydroxy-3′,4′-methylenedioxyflavan), the ability of extracts to inhibit viral-induced cell death in tissue culture was evaluated 72?h post-infection by the colorimetric method using MTT (3-[4,5-dimethylthiazol–2-yl]-2,5-diphenyltetrazolium bromide) dye. Regression analysis was used to determine 50% inhibitory concentration (IC₅₀) and 50% cytotoxicity concentration (CC₅₀), from which selective index (SI) was calculated.

Results: From the chloroform fraction, three compounds were isolated and identified, namely lycorine (1), trisphaeridine (2), and 7-hydroxy-3′,4′-methylenedioxyflavan (3) as the anti-polioviral components. Lycorine was the most active, with an IC₅₀ value of 0.058?µg/mL followed by trisphaeridine (2) with an IC₅₀ of 0.1427?µg/mL, and 7-hydroxy-3′,4′-methylenedioxyflavan (3) with an IC₅₀ of 0.2384?µg/mL.

Discussions and conclusions: The antipoliovirus activity of trisphaeridine (2) and 7-hydroxy-3′,4′-methylenedioxyflavan (3) is established in this report; these compounds are of moderate toxicity and have very good SI. They could be a potential template for the development of a new antiviral agent.     

Potential anti-inflammatory,antioxidant and antimicrobial activities of Sambucus australis

Context: Sambucus australis Cham. &; Schltdl. (Adoxaceae) is used in Brazilian folk medicine to treat inflammatory disorders.

Objective: To evaluate the in vitro anti-inflammatory, antioxidant and antimicrobial properties of S. australis.

Materials and methods: The anti-in?ammatory activity of ethanol extracts of the leaf and bark of S. australis (1–100?μg/mL) were studied in lipopolysaccharide/interferon γ stimulated murine macrophages RAW 264.7 cells (24?h incubation) by investigating the release of nitric oxide (NO) and tumour necrosis factor-alpha (TNF-α) and in the TNF-α-induced nuclear factor kappa (NF-κB) assay. Minimum inhibitory concentration (MIC) was determined by the microdilution test (24?h incubation). Antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and the NO scavenging assays. Chemical composition was assessed by LC-MS/MS.

Results: Antioxidant activities in the DPPH (IC₅₀ 43.5 and 66.2?μg/mL), FRAP (IC₅₀ 312.6 and 568.3?μg/mL) and NO radical scavenging assays (IC₅₀ 285.0 and 972.6?μg/mL) were observed in the leaf and bark ethanol extracts, respectively. Solely the leaf extract showed significant inhibition of NO and TNF-α production in RAW264.7 cells at concentrations of 2 and 100?μg/mL, respectively, and suppression of TNF-α inhibition of NF-κB by 12.8 and 20.4% at concentrations of 50 and 100?μg/mL, respectively. The extract also exhibited antibacterial activity against Salmonella typhimurium (MIC 250?μg/mL) and Klebsiella pneumoniae (MIC 250?μg/mL). LC-MS/MS revealed the presence of chlorogenic acid and rutin as major compounds.

Discussion and conclusion: The results indicate that the ethanol leaf extract of S. australis exhibit prominent anti-in?ammatory effects.