Acetylcholinesterase inhibition and antioxidant activity of the water extracts of several Hypericum species

Biological activities and polyphenolic profile of Stachys arvensis (L.) L

The n-butanol extract of Stachys arvensis (L.) L. aerial parts (BESA) was analysed by LC-HRMS/MS. 43 Polyphenols, including flavonoids, cinnamic acid derivatives, phenylethaoids, chromones, gallotannins, coumarins and chalcones with hyperoside (13.85%), panasenoside (10.31%), myricitrin (7.89%) and sayaendoside (7.16%), as the major compounds, were identified. High total phenolics (470.21 ± 1.22 mg GAE/g extract) and total flavonoids (189.05 ± 0.72 mg QE/g extract) contents were measured. In addition, the BESA exhibited a higher antioxidant effect in CUPRAC (A0.5:0.45 ± 0.03 μg/mL), DPPH (IC50:4.51 ± 0.16 μg/mL) and ABTS (IC50:7.10 ± 0.18 μg/mL) assays than the standards BHA and α-Tocopherol. Moreover the extract showed a good inhibitory effect against BChE (IC50: 145.02 ± 0.03 μg/mL) and α-amylase (IC50:2.66 ± 0.0024 mg/mL). The BESA exhibited an excellent anti-inflammatory activity (IC50:416 ± 0,056 μg/mL) which was close to that of acetylsalicylic acid, used as a control. The BESA was toxic towards T. molitor larvae and it possessed a good antibacterial activity against gram (+) and gram (-) tested strains.

Investigation of Anticholinesterase Activity of Chemically Characterised Hieracium s. str. Methanol Extracts and Their Selected Metabolites

The composition and anticholinesterase activity of the dried MeOH extracts of Hieracium scheppigianum and H. naegelianum underground parts (rhizomes and roots), as well as the anticholinesterase activity of the dried, previously chemically characterised MeOH extracts of the flowering aerial parts of these two and 26 other Hieracium species in the strict sense (s. str.), were investigated. Furthermore, the anticholinesterase activity of 12 selected secondary metabolites of these extracts was evaluated. Using semi-preparative LC-MS, five caffeoylquinic acids and the sesquiterpene lactone crepiside E were isolated from H. scheppigianum underground parts extract. All these compounds were also identified in the underground parts extract of H. naegelianum. Quantitative LC-MS analysis showed that the analysed underground parts extracts were rich in both caffeoylquinic acids (139.77 and 156.62 mg/g of extract, respectively) and crepiside E (126.88 and 116.58 mg/g). In the Ellman method, the tested extracts showed an interesting anti-AChE and/or anti-BChE activity (IC50 =0.56-1.58 mg/mL), which can be explained, at least partially, by the presence of some of their constituents. Among the metabolites tested, the best activity was revealed for the flavonoids apigenin, luteolin and diosmetin, and the sesquiterpene lactone 8-epiixerisamine A (IC50 =68.09-299.37 μM).

Biological Activity of Genus Hypericum Sect. Hypericum Species-H. tetrapterum, H. maculatum subsp. immaculatum, H. triquetrifolium

St. John's wort (Hypericum perforatum, Hypericaceae) has long been used in traditional medicine as a potent remedy, while many other species of this genus have not been thoroughly investigated. The study aimed to detect the biological activity, including antioxidant, antihyperglycemic, anticholinergic, antimicrobial and monoaminoxidase inhibitory potential, of water-alcoholic extracts of three species autochthonous for Serbia and Greece from plant genus Hypericum (section Hypericum-H. tetrapterum, H. maculatum ssp. immaculatum and H. triquetrifolium), followed by phytochemical profiling. The highest amount of phenolics was recorded in H. maculatum subsp. immaculatum extract, while the highest abundance of flavonoids was characteristic of H. tetrapterum extract. Hypericin and hyperforin, quercetin, and its flavonoid, rutin, were present in all of the evaluated species. The evaluated species were good scavengers of DPPH, OH and NO radicals, as well as potent reducers of ferric ions in FRAP assay. Furthermore, the evaluated species were shown as potent inhibitors of monoaminoxidase A and α-glucosidase and modest inhibitors of acetylcholinesterase, monoaminoxidase B and α-amylase. No anti-Candida activity was recorded, but the extracts were effective against MRSA Staphylococcus aureus and Enterococcus sp., as well as against Proteus mirabilis. The obtained results strongly highlight the need for further in vivo studies in order to better define the potential of the medicinal application of the studied species.

Novel Signposts on the Road from Natural Sources to Pharmaceutical Applications: A Combinative Approach between LC-DAD-MS and Offline LC-NMR for the Biochemical Characterization of Two Hypericum Species (H. montbretii and H. origanifolium)

The members of the genus Hypericum have great potential to develop functional uses in nutraceutical and pharmaceutical applications. With this in mind, we aimed to determine the chemical profiling and biological properties of different extracts (ethyl acetate, methanol and water) from two Hypericum species (H. montbretii and H. origanifolium). We combined two approaches (LC-DAD-MS and LC-NMR) to identify and quantify chemical compounds of the extracts. Antioxidant properties (free radical quenching, reducing power and metal chelating) and enzyme inhibitory effects (cholinesterase, tyrosinase, amylase and glucosidase) were determined as biological properties. The tested extracts were rich in caffeic acid derivatives and flavonoids, and among them, 3-caffeoyl quinic acid and myricetin-3-O-rhamnoside were found to be the main compounds. The total phenolic and flavonoid levels were determined to be 50.97-134.99 mg GAE/g and 9.87-82.63 mg RE/g, respectively. With the exception of metal chelating, the methanol and water extracts showed stronger antioxidant properties than the ethyl acetate extracts. However, different results were obtained for each enzyme inhibition assay, and in general, the ethyl acetate extracts present more enzyme-inhibiting properties than the water or methanol extracts. Results from chemical and biological analyses were combined using multivariate analysis, which allowed establishing relationships between composition and observed effects of the Hypericum extracts based on the extraction solvents. To gain more insights between chemical compounds and enzyme-inhibiting effects, we performed molecular docking analysis. We observed favorable interactions between certain compounds and the tested enzymes during our analysis, confirming the data obtained from the multivariate approach. In conclusion, the obtained results may shed light on the road from natural sources to functional applications, and the tested Hypericum species may be considered potential raw materials, with promising chemical constituents and biological activities.

Screening and identification of anti-acetylcholinesterase ingredients from Tianzhi granule based on ultrafiltration combined with ultra-performance liquid chromatography-mass spectrometry and in silico analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Tianzhi granule (TZG) is a traditional Chinese formula that is widely used for the treatment of vascular dementia (VaD).

AIM OF THE STUDY

To discover the herbs in TZG possessing acetylcholinesterase (AChE) inhibitory activity and to screen the anti-acetylcholinesterase ingredients from active herbs.

MATERIALS AND METHODS

In vitro AChE inhibitory activity assay of eleven herbal extracts was conducted. An ultrafiltration combined with ultra-performance liquid chromatography-mass spectrometry method was established to screen and identify the anti-acetylcholinesterase ingredients from active extracts. In addition, in vitro AChE inhibitory activity assay and molecular docking were adopted for further investigation. Moreover, ultra-performance liquid chromatography-mass spectrometry was performed for the content determination of active compounds in TZG.

RESULTS

Three herbs in TZG showed significant AChE inhibitory activity. A total of thirteen active ingredients were screened out and identified, and all of these compounds were present in TZG. Five available commercial standards presented moderate AChE inhibitory activity, and all of which have a relatively high content in TZG.

CONCLUSION

A number of herbs and compounds with acetylcholinesterase inhibitory activity were found in TZG, which provided a scientific basis for the material basis and quality control research of TZG.

Ethnomedicinal Plants with Protective Effects against Beta-Amyloid Peptide (Aβ)1-42 Indicate Therapeutic Potential in a New In Vivo Model of Alzheimer's Disease

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder with unmet medical need. This investigation consisted of testing a range of ethanolic ethnomedicinal plant extracts (n = 18) traditionally used in the treatment of disorders such as anxiety, delirium, and memory loss. They were then screened for in vitro inhibitory activity against acetylcholinesterase (AChE), butylcholinesterase (BuChE), beta-secretase 1/beta-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1), and antioxidant activities. Plants with potent activities were further characterised using a recently developed in vivo model of AD, Globodera pallida. The ability of phytoextracts to protect this organism against amyloid-beta Aβ (1-42) exposure was assessed by measuring chemosensing, survival rate, production of reactive oxygen species (ROS), and antioxidant responses. Extracts (n = 5) from Juglans regia (leaves), Ellettaria cardamomum (seeds), Cinnamomum zeylanicum (bark), Salvia officinalis (leaves/flowers), and Hypericum perforatum (flowers) exerted concentration-dependent inhibitory activities against AChE and BuChE. Three of these plant extracts (i.e., J. regia, E. cardamomum, and S. officinalis) possessed strong concentration-dependent inhibitory activity against BACE1. Furthermore, the five selected medicinal plant extracts not only enhanced significantly (p < 0.05) the nematode’s chemosensing, survival rate, and antioxidant responses (i.e., anti-ROS production, mitochondrial reductase activity, oxidized glutathione (GSSG) to reduced glutathione (GSH) ratio), but also greatly restored (p < 0.05) in a concentration-dependent manner the Aβ (1-42)-induced deleterious changes in these same parameters. In brief, this investigation highlights plant extracts with strong anti-AD activities which could be trialled as novel therapeutic supplements or undergo further biodiscovery research.

Phenolic composition, antioxidant and antiacetylcholinesterase activities of Opuntia ficus-indica peel and flower teas after in vitro gastrointestinal digestion

BACKGROUND

The flowers and peels of cactus Opuntia ficus-indica (OFI) are by-products generally discarded. Their beneficial properties have been linked to the chemical composition without taking into account its transformations during digestion. This study evaluated and compared the phenolic composition, antioxidant and antiacetylcholinesterase activities of OFI peel and flower teas before and after in vitro gastrointestinal digestion.

RESULTS

Results showed that OFI peel tea was a source of natural phenolic compounds and carotenoids, while OFI flower tea was a source of flavonoids. Both OFI peel and flower teas exhibited high antioxidant activities (AAs) measured by several tests [1,1-diphenyl-2-picrylhydrazyl radical (DPPH^• ), reducing power (RP), hydrogen peroxide scavenging activity (HPSA)]. Flower teas presented a higher antiacetylcholinesterase inhibition percentage than peel teas. Significant decreases of acetylcholinesterase and AAs were obtained under in vitro gastrointestinal digestion. Fourteen phenolic compounds typical of phenolic acids and flavonoids were identified in both teas. These compounds seemed to be more affected by pancreatic than by the gastric conditions.

CONCLUSION

OFI peel tea has been found as a source of natural phenolic compounds and carotenoids, while OFI dry flower tea as a source of flavonoids. The OFI flower tea phytochemicals were more stable than peel tea during the digestive process. These findings suggest that peels and flowers of OFI should be considered as sources of healthy ingredients. © 2022 Society of Chemical Industry.

Phenolic Characterization Using cLC-DAD Analysis and Evaluation of In Vitro and In Vivo Pharmacological Activities of Ruta tuberculata Forssk

The perennial aromatic plant Ruta tuberculata Forssk (Rutaceae) has been traditionally used by Mediterranean peoples as folk medicine against several types of disease to treat diverse illness. The objective of this work is to evaluate the in vitro and in vivo pharmacological activities of the aqueous (RAE) and methanolic (MeOH) 80% (RME) extracts of Algerian R. tuberculata aerial parts. Antioxidant potential, neuro-protective and anti-arthritic activities were investigated in vitro using six antioxidant approaches and by determining acetyl-cholinesterase and bovine albumin denaturation inhibitory capacities, respectively. Furthermore, in vivo anti-ulcer and anti-inflammatory activities were evaluated on EtOH-induced gastric mucosal damage and carrageenan-induced paw edema models in mice. Moreover, bio-compounds’ contents were also quantified using spectrophotometric and cLC-DAD methods. Both in vivo and in vitro investigations showed remarkable antioxidant activity of Ruta tuberculata Forssk, while methanolic extract (RME) of Ruta tuberculata Forssk exhibited more significant neuro-protective and anti-inflammatory effects. However, the antiulcer activity was more pronounced with RAE of R. tuberculata, which suggests that this plant can be considered as a natural resource of potent bioactive compounds that may act as antioxidant and anti-inflammatory agents, which underlines the importance of incorporating them in therapies in order to treat various diseases linked to oxidative stress, and they may also provide crucial data for the development of new anticholinesterase drugs to improve neurodegenerative diseases, such as Alzheimer’s.

Isolation of Some Phenolic Compounds from Plantago subulata L. and Determination of Their Antidiabetic, Anticholinesterase, Antiepileptic and Antioxidant Activity

In the current study, some phenolic compounds, including acteoside, isoacteoside, echinacoside, and arenarioside purified and characterized from Plantago subulata. These compounds were tested for its antioxidant potential, including Fe³⁺ and Cu²⁺ reductive ability and Fe²⁺ chelating effects. The inhibitory effects of isolated phenolic compounds were tested towards human carbonic anhydrase I and II isoenzymes (hCA I and hCA II), butyrylcholinesterase (BChE) acetylcholinesterase (AChE), aldose reductase (AR) and α-glycosidase (α-gly). K_i values were found these compounds in range of 0.24±0.05-1.38±0.34 μM against hCA I, 0.194±0.018-1.03±0.06 μM against hCA II, 0.043±0.01-0.154±0.02 μM against AChE, 3.92±1.08-11.93±4.45 μM against BChE, 0.082±0.0008-1.68±0.42 μM against AR, and 6.93±2.74-17.17±6.70 μM against α-glycosidase. As a result, isolated compounds displayed inhibition effects against studied all metabolic enzymes. They are promising candidates for treating disorders like Alzheimer's disease, diabetes mellitus, glaucoma, leukemia, and epilepsy.

Melanin: Production from Cheese Bacteria, Chemical Characterization, and Biological Activities

Pigments are compounds of importance to several industries, for instance, the food industry, where they can be used as additives, color intensifiers, and antioxidants. As the current trend around the world is shifting to the use of eco-friendly commodities, demand for natural dyes is increasing. Melanins are pigments that are produced by several microorganisms. Pseudomonas putida ESACB 191, isolated from goat cheese rind, was described as a brown pigment producer. This strain produces a brown pigment via the synthetic Müeller-Hinton Broth. This brown compound was extracted, purified, analyzed by FTIR and mass spectrometry, and identified as eumelanin. The maximum productivity was 1.57 mg/L/h. The bioactivity of eumelanin was evaluated as the capacity for scavenging free radicals (antioxidant activity), EC₅₀ 74.0 ± 0.2 μg/mL, and as an acetylcholinesterase inhibitor, with IC₅₀ 575 ± 4 μg/mL. This bacterial eumelanin did not show cytotoxicity towards A375, HeLa Kyoto, HepG2, or Caco2 cell lines. The effect of melanin on cholesterol absorption and drug interaction was evaluated in order to understand the interaction of melanin present in the cheese rind when ingested by consumers. However, it had no effect either on cholesterol absorption through an intestinal simulated barrier formed by the Caco2 cell line or with the drug ezetimibe.

Chemical Profile and Evaluation of the Antioxidant and Anti-Acetylcholinesterase Activities of Annona squamosa L. (Annonaceae) Extracts

This study presents the chemical profile of extracts from the pulp and seed of Annona squamosa L., as well as the evaluation of their antioxidant and acetylcholinesterase inhibition activities. In the chemical prospection, qualitative assays were performed, and the contents of total phenols, flavonoids, vitamin C, and carotenoids were quantified. For the compounds identification, analyses of the extracts were performed by liquid chromatography coupled to mass spectrometry. Antioxidant evaluation was performed using the DPPH, ABTS, Fe³⁺ reduction, 2-DR protection, and β-carotene protection methods. The assay for inhibition of acetylcholinesterase activity was determined using the method described by Ellman. The secondary metabolites identified were anthocyanidins, flavones, flavonols, and alkaloids. Phenol analysis showed a higher quantitative value of total phenols and flavonoids for the seed extract, and the vitamin C content was higher in the pulp extract. There was no significant difference in relation to the carotenoids quantification. The best results obtained for antioxidant activity, for both seed and pulp extracts, were with the ABTS method with IC₅₀ of 0.14 ± 0.02 and 0.38 ± 0.02 mg/mL, respectively. Compared to A. squamosa seed extract, the pulp extract demonstrates higher AChE inhibitory activity with IC₅₀ of 18.82 ± 0.17 µg/mL. A. squamosa is a nutritious food source. The continuity of the studies is fundamental to relate the consumption of this food and its effects on neurodegenerative diseases.

Six Common Herbs with Distinctive Bioactive, Antioxidant Components. A Review of Their Separation Techniques

Rosemary, oregano, pink savory, lemon balm, St. John’s wort, and saffron are common herbs wildly grown and easily cultivated in many countries. All of them are rich in antioxidant compounds that exhibit several biological and health activities. They are commercialized as spices, traditional medicines, or raw materials for the production of essential oils. The whole herbs or the residues of their current use are potential sources for the recovery of natural antioxidant extracts. Finding effective and feasible extraction and purification methods is a major challenge for the industrial production of natural antioxidant extracts. In this respect, the present paper is an extensive literature review of the solvents and extraction methods that have been tested on these herbs. Green solvents and novel extraction methods that can be easily scaled up for industrial application are critically discussed.

Interactions between Ginkgo biloba L. and Scutellaria baicalensis Georgi in multicomponent mixtures towards cholinesterase inhibition and ROS scavenging

This study gives new insights to understand the type of interactions between Ginkgo biloba L. and Scutellaria baicalensis Georgi, two Chinese medicinal plants with well documented neuroprotective effects, on three targets in Alzheimer's disease (AD): acetylcholinesterase (AChE) and butyrylcholnesterase (BuChE) inhibition and hydrogen peroxide scavenging. Individual samples, binary mixtures with different proportions of both plant species, and also a commercial multicomponent combination containing both plants together with unroasted Coffea arabica L. and quercetin-3-O-rutinoside were used to perform this in vitro evaluation. Sample phenolic profiles were also determined by HPLC-DAD, showing the presence of several flavonoid glycosides, phenolic acids and a methylxanthine. In order to investigate the possible synergism/antagonism interaction, data obtained were analyzed by CompuSyn software. The results showed that G. biloba and S. baicalensis alone display better activities than in mixtures, most of the interactions exhibiting different degrees of antagonism. A slight synergism interaction was only observed for the commercial multicomponent mixture tested against H₂O₂. Further analysis was carried out to understand which compounds could be responsible for the antagonistic interaction. Seventeen single pure compounds present in all extracts were tested against AChE inhibition, most of them displaying weak or no activity. Only caffeine had a remarkable activity. Five different binary and quaternary mixture compositions were design to deepen the interaction between these compounds, revealing mainly phenolic acid-flavonoid, flavonoid-flavonoid and methylxanthine-flavonoid-phenolic acid antagonistic interactions. These results clearly show that, for the targets evaluated, there is no potentiation of the neuroprotective effect by combining S. baicalensis and G. biloba extracts.

Biochemical profile and in vitro biological activities of extracts from seven folk medicinal plants growing wild in southern Tunisia

Recently, much attention has been paid to the extracts obtained from plant species in order to analyse their biological activities. Due to the climate diversity in Tunisia, the traditional pharmacopoeia consists of a wide arsenal of medicinal plant species since long used in folk medicine, in foods as spices, and in aromatherapy. Although many of these species are nearly facing extinction, only a small proportion of them have been scientifically studied. Therefore, this study explores the biochemical properties of seven spontaneous plants, which were harvested in the arid Tunisian desert: Marrubium vulgare (L.), Rhus tripartita (Ucria) D.C., Thymelaea hirsute (L.) Endl., Plantago ovata (Forsk.), Herniaria fontanesii (J. Gay.), Ziziphus lotus (L.) and Hyoscyamus albus (L.). Extracts from these plants were found to contain different types of secondary metabolites (polyphenols, flavonoids, condensed tannins, crude saponins, carotenoids and alkaloids) that are involved in important biological activities. The biological activity of the extracts obtained from each Tunisian plant was assessed: first of all, leukaemia and colon cancer cell lines (K-562 and CaCo-2 respectively) were treated with different concentrations of extracts, and then the anti-proliferative activity was observed. The results showed, in particular, how the plant extract from Rhus tripartita significantly inhibits cell proliferation, especially on the K-562 tumour cell line. Subsequently, the anti-inflammatory activity was also assessed, and the results showed that Herniaria fontanesii and Marrubium vulgare possess the highest activity in the group of analysed plants. Finally, the greatest acetylcholinesterase inhibitory effect was exhibited by the extract obtained from Rhus tripartita. In conclusion, all the Tunisian plants we analysed were shown to contain a remarkable amount of different bio-active compounds, thus confirming their involvement in several biological activities. Rhus tripartita and Ziziphus lotus were shown to be particularly effective in anti-proliferative activity, while Herniaria fontanesii were shown to have the best anti-inflammatory activity.

Spondias mombim L. (Anacardiaceae): Chemical fingerprints, inhibitory activities, and molecular docking on key enzymes relevant to erectile dysfunction and Alzheimer's diseases

Due to the exceptional wide range in biochemical activities of natural plant products, Spondias mombim L. are attaining a new height because they present great prospects for drug advancement. This research was designed to analyze the pharmaceutical properties of S. mombim L. ethyl acetate fraction (SMEAF) on key enzymes relevant to erectile and cognitive dysfunction. SMEAF inhibitory activities of the specified enzymes were determined spectrophotometrically. Chemical profile of SMEAF were assessed by HPLC/MS analysis. Thereafter, molecular docking of the studied enzymes with chlorogenic acid, lutein, and zeaxanthin were carried out using PATCHDOCK. SMEAF had remarkable enzyme inhibitory effects against phosphodiesterase-5 (PDE-5), arginase, angiotensin I-converting enzyme (ACE), cholinesterase, monoamine oxidase A (MAO), ecto-5' nucleotidase (E-NTDase), tyrosinase, and stimulated sodium-potassium ATPase (Na+/K+-ATPase) activities. HPLC/MS analysis revealed that phenolics and carotenoids were major components in these fraction notably, chlorogenic acid, lutein, and zeaxanthin. Our results suggested that SMEAF could be explored as phytopharmaceuticals. PRACTICAL APPLICATIONS: Spondias mombim L. are cooked as green vegetable with enormous medicinal value probably due to its polyphenols with potent antioxidant activity. Furthermore, the leaves could also be useful for therapeutic purposes against erectile dysfunction and central nervous system disorders.

The mutagenic, antimutagenic and antioxidant properties of Hypericum lydium

CONTEXT

There is a growing market demand for Hypericum sp., a pharmacologically active plant that has been traditionally used to treat various ailments. However, there have been limited studies on the extract or essential oil of Hypericum lydium Boiss (Hypericaceae).

OBJECTIVE

This study investigates for the first time the antioxidant, mutagenic and antimutagenic activity of an ethanol extract of H. lydium.

MATERIAL AND METHODS

Ethanol extract from aerial parts of H. lydium harvested from Turkey were tested for this mutagenic and antimutagenic activities (2.0-0.002 mg/plate) using Ames Salmonella/microsome test system. 4-Nitro-o-phenylenediamine (4-NPD) (3 μg/plate) for the Salmonella typhimurium TA98 and sodium azide (NaN3) (8 μg/plate) for the S. typhimurium TA100 were used as positive controls. The antioxidant activity, total antioxidant activity and phenolic constituent of the extract (2.0-0.002 mg/mL) was determined by the inhibition of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), β-carotene-linoleic acid model and by means of Folin-Ciocalteu reagent, respectively.

RESULTS

The extract showed no sign of mutagenicity at the tested concentrations (0.002-2.0 mg/mL), and showed concentration-dependent antimutagenic activity against NaN3 and 4-NPD ranging from 26.8 to 81.5%. The extract was found to be an efficient scavenger of DPPH (IC50 0.165 ± 0.23 mg/mL) and to inhibit β-carotene-linoleic acid bleaching (IC50 0.39 ± 0.11 mg/mL).

DISCUSSION AND CONCLUSION

These findings indicate ethanol extract of H. lydium to be a safe and effective agent that may be incorporated into new strategies for the prevention of cancer and mutagenesis.

Comparative Analysis of Phenolic Compounds in Seven Hypericum Species and Their Antioxidant Properties

A comparative analysis of the phenolic compounds in the 70% EtOH extracts of Hypericum acutum, H. androsaemum, H. barbatum, H. hirsutum, H. maculatum, and H. richeri has been carried out using high-performance liquid chromatography coupled with photodiode array UV detection and high resolution TOF mass spectrometry. Quercetin, astilbin, I3, II8-biapigenin, orientin, 2”- O-acetylorientin, three phenolcarboxylic acids, and eight flavonols 3- O-glycosides were identified in the extracts on the basis of their on-line UV spectra, accurate mass spectral data, and in comparison of retention times with those from the standards. Fingerprint analysis of the extracts revealed significant differences in the qualitative and quantitative chemical composition of the studied species. Antioxidant assays with various reaction mechanisms were used including ferric reducing antioxidant power (FRAP) assay, DPPH, ABTS, superoxide anion radical scavenging capacity and inhibition of liposome peroxidation induced by Fe2+. The most potent were extracts of H. acutum and H. maculatum indicating this Hypericum species interesting for further research aimed as a potentially new source of biologically active compounds.

Protective effects of flavonoids against Alzheimer's disease-related neural dysfunctions

Senile ages of human life is mostly associated with developmental of several neurological complicated conditions including decreased cognition and reasoning, increased memory loss and impaired language performance. Alzheimer's disease (AD) is the most prevalent neural disorder associated with dementia, consisting of about 70% of dementia reported cases. Failure of currently approved chemical anti-AD therapeutic agents has once again brought up the idea of administering naturally occurring compounds as effective alternative and/or complementary regimens in AD treatment. Polyphenol structured neuroprotecting agents are group of biologically active compounds abundantly found in plants with significant protecting effects against neural injuries and degeneration. As a subclass of this family, Flavonoids are potent anti-oxidant, anti-inflammatory and signalling pathways modulatory agents. Phosphatidylinositol 3-kinase (PI3K)/AKT and mitogen activated protein kinase (MAPK) pathways are both affected by Flavonoids. Regulation of pro-survival transcription factors and induction of specific genes expression in hippocampus are other important anti AD therapeutic activities of Flavonoids. These agents are also capable of inhibiting specific enzymes involved in phosphorylation of tau proteins including β-secretases, cyclin dependent kinase 5 and glycogen synthase. Other significant anti AD effects of Flavonoids include neural rehabilitation and lost cognitive performance recovery. In this review, first we briefly describe the pathophysiology and important pathways involved in pathology of AD and then describe the most important mechanisms through which Flavonoids demonstrate their significant neuroprotective effects in AD therapy.

Hyperoside protects against chronic mild stress-induced learning and memory deficits

Hyperoside (quercetin-3-O-b-d-galactosidepyranose) is a plant-derived flavonoid mainly found in fruits, fruit juices (most notably flavanols, flavanones, and anthocyanins) and Chinese traditional medicines. It has been applied to relieve pain and improve cardiovascular functions in clinic. However, the effects of hyperoside on cognitive impairment induced by chronic stress and the underlying molecular mechanisms remain unclear. In the current study, we used chronic mild stress (CMS) rats to investigate the effects of hyperoside on learning and memory and further explore the possible mechanisms. Our results demonstrated that hyperoside reduced the escape latency and the swimming distance of CMS rats in Morris water maze test and reversed depressive symptoms in forced swim test (FST) and sucrose preference test. In addition, hyperoside increased the expression of brain-derived neurotrophic factor (BDNF) in hippocampus of CMS rats without influencing the corticosterone (CORT) level in blood plasma. Furthermore, K252a, an inhibitor of the BDNF receptor TrkB, prevented the protective effects of hyperoside on learning and memory in CMS rats. Taken together, these results indicate that hyperoside reverses the cognitive impairment induced by CMS, which is associated with the regulation of BDNF signaling pathway.

Bioactive properties and functional constituents of Hypericum androsaemum L.: A focus on the phenolic profile

Hypericum androsaemum L. ethanol:water extract acted as a lipid peroxidation inhibitor and free radical scavenger. A marked inhibition of the growth of breast, lung, cervical and hepatocellular human carcinoma cell lines was also observed, whereas no toxicity was shown against non-tumor porcine liver cells (>400μg/mL). The extract was also effective in inhibiting nitric oxide production, as an indicator of the anti-inflammatory potential. The anti-Candida effects varied among different strains of the same species, C. glabrata and C. tropicalis being the most sensible species with an effect directly related with the extract concentrations tested. A significant anti-biofilm formation potential was also observed, namely for C. glabrata and C. tropicalis (biofilm reduction >90%). 5-O-Caffeoylquinic and 3-O-caffeoylquinic acids were the most abundant phenolic compounds identified in the extract, and might be related with the observed bioactive effects. Nevertheless, future studies should be carried out to obtain dose-response curves of the isolated active compounds, in order to perform further pre-clinically testing to quantify the presence of the most active compounds in the extract.

Biochemical Constituents and in Vitro Antioxidant and Anticholinesterase Potential of Seeds from Native Korean Persimmon Genotypes

In the current study, the functional and biochemical potential of the seeds of four persimmon cultivars (PC1, PC2, PC3 and PC4) and their role against oxidative stress and acetylcholinesterase (AChE) inhibition were evaluated. In terms of biochemical compositions, free amino acids, fatty acids and organic acids analysis was performed. The free amino acids ranged from 2617.31 (PC2) to 3773.01 μg∙g(-1) dry weight (PC4). Oleic acid and linoleic acid were the principal fatty acids, which were significantly higher in PC4 and PC1, respectively. PC4 presented the highest amount of organic acid content (4212 mg∙kg(-1)), whereas PC2 presented the lowest (2498 mg∙kg(-1)). PC2 contained higher total phenolic content and flavonoid content, whereas PC3 had the lowest amount as compared to other cultivars. The in vitro DPPH, ABTS and superoxide anion radicals scavenging activity increased in a dose-dependent manner, whereas PC2 showed significantly higher scavenging activities as compared to PC1, PC2 and PC4 types. In the case of AChE inhibition, PC4 showed a moderate activity (67.34% ± 1.8%). In conclusion, the current findings reveal that the studied persimmon seeds cultivars are a source of bioactive natural antioxidants and AChE inhibitors. Such natural products could be employed in pharmaceutical and food industries, whilst can also be considered for the treatment of neurodegenerative diseases such as Alzheimer's.

Metabolic and antioxidant profiles of herbal infusions and decoctions

This study implements NMR metabolomics and spectrophotometric studies (Folin-Ciocalteu, FRAP, ABTS) to infusions and decoctions of ten plant species in order to assess and compare the metabolic and antioxidant profiles for each botanical family. Multivariate and univariate data analyses highlighted the differences among the samples and pinpointed specific classes of compounds for each plant species as well as infusions and decoctions. The identified phenolic compounds by NMR, as well as the antioxidant profile, framed a trend of increased values in infusions compared to the decoctions. Moreover, the infusion procedure positively affected the extractability of the phenolic compounds compared to decoctions. The highest total phenolic content was found in Mentha spicata, while the lowest in Matricaria chamomilla preparations, irrespective of the preparation method. The preparation time for the decoctions was examined showing that the 15min preparations were generally found richer in phenolics and of higher antioxidant capacity.

Digestibility and Bioavailability of the Active Components of Erica australis L. Aqueous Extracts and Their Therapeutic Potential as Acetylcholinesterase Inhibitors

Erica australis L. (Ericaceae) is used in traditional medicine to treat many free-radical related ailments. In the present work, the stability and biological activity of the plant aqueous extracts submitted to an in vitro digestive process were investigated. Chemical stability was monitored by HPLC-DAD and LC-MS/MS, while the bioactivities were evaluated through the inhibition of acetylcholinesterase (AChE) and DPPH radical scavenging activity. Both extracts, whose main components were flavonol glycosides, inhibited AChE, showing IC₅₀ values of 257.9 ± 6.2 µg/mL and 296.8 ± 8.8 µg/mL for the decoction and for the infusion, respectively. Significant radical scavenging activities were also revealed by both extracts, as denoted by the IC₅₀ values for the decoction, 6.7 ± 0.1 µg/mL, and for the infusion, 10.5 ± 0.3 µg/mL. After submission to gastric and pancreatic juices, no remarkable alterations in the composition or in the bioactivities were observed, suggesting that the extracts may pass through the gastrointestinal tract, keeping their composition and therefore their biological properties. Moreover, the bioavailability of the components of both extracts, as studied in a Caco-2 cell model, showed that compounds can permeate the membrane, which is a condition to exert their biological activities. Our results add further support to the potential of E. australis for its antioxidant and neuroprotective properties.

Impact of origin and biological source on chemical composition, anticholinesterase and antioxidant properties of some St. John's wort species (Hypericum spp., Hypericaceae) from the Central Balkans

The study shows the influence of the origin of plant material and biological source on the in vitro antioxidant (neutralization of DPPH and OH radical, nitric oxide, and inhibition of lipid peroxidation) and anticholinesterase activity of chemically characterized and quantified ethanol extracts of ten St. John's wort samples. The investigated samples were: five Hypericum perforatum species representatives collected at different localities, one commercial sample of Hyperici herba purchased at a local market and four Hypericum species autochtonous to the Balkan Peninsula (H. maculatum subsp. immaculatum, H. olympicum, H. richeri subsp. grisebachii and H. barbatum). All the examined extracts exhibited notable antioxidant potential, but in most of the cases indigenous Hypericum species expressed stronger effects compared to the original source of the drug, H. perforatum. The changes in the content of phenolic compounds, especially flavonoids, hyperforin and hypericin, related to the source of the drug affected the investigated activities. Since all of the investigated species have shown prominent inhibition of acetylcholinesterase in vitro activity, they could be further investigated as potential substances in preventing of Alzheimer's disease.

HPLC-UV-ESI-MS analysis of phenolic compounds and antioxidant properties of Hypericum undulatum shoot cultures and wild-growing plants

LC-UV and LC-MS analysis were used to study the phenolic composition of water extracts of Hypericum undulatum (HU) shoot cultures and wild-growing (WG) plants. Total phenolic content (TPC), determined using the Folin-Ciocalteu assay, and the antioxidant activity measured by two complementary methods were also performed for each sample. Mass spectrometry revealed several phenolics acids with quinic acid moieties, flavonols, mostly quercetin, luteolin and apigenin glycosides, flavan-3-ols (catechin and epicatechin) and the xanthonoid mangiferin. Differences in phenolic composition profile and TPC were found between the samples. The major phenolic in HU culture-growing (CG) samples is chlorogenic acid, followed by epicatechin, quercitrin and isoquercitrin. The WG plants presents hyperoside as the main phenolic, followed by isoquercitrin, chlorogenic acid and quercetin. The TPC and antioxidant activity were higher in samples from WG plants.

Acetylcholinesterase inhibition, antioxidant activity and toxicity of Peumus boldus water extracts on HeLa and Caco-2 cell lines

This work aimed to study the inhibition on acetylcholinesterase activity (AChE), the antioxidant activity and the toxicity towards Caco-2 and HeLa cells of aqueous extracts of Peumus Boldus. An IC(50) value of 0.93 mg/mL, for AChE inhibition, and EC(50) of 18.7 μg/mL, for the antioxidant activity, was determined. This activity can be attributed to glycosylated flavonoid derivatives detected, which were the main compounds, although boldine and other aporphine derivatives were also present. No changes in the chemical composition or the biochemical activities were found after gastrointestinal digestion. Toxicity of P. boldus decoction gave an IC(50) value 0.66 mg/mL for HeLa cells, which caused significant changes in the cell proteome profile.

Protective effect of fruits of Morinda citrifolia L. on scopolamine induced memory impairment in mice: a behavioral, biochemical and cerebral blood flow study

ETHNOPHARMACOLOGICAL RELEVANCE

Noni (Morinda citrifolia L.) is widely used for different illnesses including CNS disorders. Recently Noni has been reported to prevent amyloid beta induced memory impairment in mice. However, the influence of Noni on cholinergic system has not been explored so far. Therefore, present study was designed to investigate effect of Noni fruit on memory, cerebral blood flow (CBF), oxidative stress and acetylcholinesterase (AChE) activity in scopolamine induced amnesia model.

MATERIALS AND METHODS

Mice were orally treated with ethanolic extract of Noni fruit and chloroform, ethyl acetate and butanol fractions of ethanolic extract for three days. Scopolamine was administered 5 min prior to acquisition trial and memory function was evaluated by passive avoidance test. CBF was measured by laser doppler flowmetry. AChE activity and oxidative stress parameters were estimated in mice brain at the end of behavioral studies. Further, effect of ethanolic extract and its fractions (5-400 μg/ml) on AChE activity was measured in vitro.

RESULTS

Scopolamine caused memory impairment along with reduced CBF, increased AChE activity and oxidative stress in mice brain. Ethanolic extract of Noni fruits and its chloroform and ethyl acetate fractions significantly improved memory and CBF. However, butanol fraction had no effect. Further, increased oxidative stress and AChE activity following scopolamine was significantly attenuated by ethanolic extract of Noni and its fractions. Moreover ethanolic extract and its fractions showed dose dependent inhibition of AChE activity in vitro.

CONCLUSION

These observations suggest that Noni may be useful in memory impairment due to its effect on CBF, AChE and oxidative stress.

In vitro antioxidant, xanthine oxidase and acetylcholinesterase inhibitory activities of Balanites aegyptiaca (L.) Del. (Balanitaceae)

The present study aimed to test the validity of Balanites aegyptiaca remedies used for the treatment of rheumatisms and mental disorders by examining the antioxidant, xanthine oxidase and acetylcholinesterase inhibitory activities of galls and leaves extracts and fractions. The total phenolics and flavonoids were measured using Folin-Ciocalteu and AlCl3 reagents, respectively. Two methods i.e., FRAP and ABTS were used to estimate the total antioxidant capacity of the plant materials. The FRAP and ABTS antioxidant activities showed that among all extracts and fractions tested, the best antioxidant activities were found with the galls dichloromethane and the leaves ethyl acetate fractions. The antioxidant activities did correlated significantly with the total phenolic and flavonoid contents. The study also showed that B. aegyptiaca galls and leaves fractions exhibited a moderate xanthine oxidase inhibitory activity comparatively to the acetylcholinesterase which was weakly inhibited by the tested extracts and fractions.