Bioactivity studies and chemical profile of the antidiabetic plant Genista tenera

Can Isoflavone-Rich Legume Plants Be Useful in the Chemoprevention of Hormone-Dependent Cancers?-A Systematic Review

Plants from the Fabaceae family are widely distributed around the world, especially in Europe, Asia and North America. They are a rich source of isoflavones, compounds with estrogen-like activity, which are suspected of having a chemopreventive effect against hormone-dependent cancers. Following the PRISMA guidelines, we conducted a systematic review aimed at assessing the impact of Fabaceae plant extracts on hormone-dependent cancer cells and the content of active compounds in plant raw materials. We analyzed the results of 63 articles from in vitro and in vivo studies describing the effect of plant extracts containing isoflavones on cancer cells, along with their anti-inflammatory and antioxidant potential. In the process, we determined the research limitations and future research directions. The collected results indicate the plant species with potentially high contents of phytoestrogens and anti-inflammatory, antioxidant and cytotoxic properties. They point to the potential use of plants in the diet as a source of compounds offering cancer prevention.

Chemical composition of the essential oils of three taxa of Cytisus growing wild in Sicily, Italy

The genus Cytisus is native Canary Islands, Europe to Mediterranean, Morocco, Algeria and Tunisia and several species of the genus are used in folk medicine of different countries. In this work the chemical composition of the essential oils from the aerial parts of three taxa of this genus growing wild in Sicily, Cytisus scoparius (L.) Link, C. villosus Pourr. and C. aeolicus Guss., has been investigated. No one report has been published on the Sicilian accession of the former two species, and, at the best of our knowledge, C. aeolicus is devoid of any chemical investigation. Cytisus scoparius and C. aeolicus essential oils have similar composition characterised by the occurrence of almost the same amount of compounds belonging to "other" class (59.5-52.0%) and carbonyl compounds (22.2-19.6%). Cytisus villosus showed a different composition with hydrocarbons as the main class (52.0%), totally absent in the other two species.

Identification of Anti-Proliferative Compounds from Genista monspessulana Seeds through Covariate-Based Integration of Chemical Fingerprints and Bioactivity Datasets

Genista monspessulana (L.) L.A.S. Johnson (Fabaceae) is a Mediterranean plant introduced to South America and other regions for ornamental purposes. However, it is considered an invasive shrub due to its reproductive vigor in many areas. Unlike other Genista plants, G. monspessulana has few studies disclosing its biologically active components, particularly cytotoxic agents against cancer cells. Thus, as part of our research on anti-proliferative bioactives, a set of ethanolic seed extracts from ten accessions of G. monspessulana, collected in the Bogotá plateau, were evaluated against four cell lines: PC-3 (prostate adenocarcinoma), SiHa (cervical carcinoma), A549 (lung carcinoma), and L929 (normal mouse fibroblasts). Extracts were also analyzed through liquid chromatography coupled with mass spectrometry (LC/MS) to record chemical fingerprints and determine the composition and metabolite variability between accessions. Using multiple covariate statistics, chemical and bioactivity datasets were integrated to recognize patterns and identify bioactive compounds among studied extracts. G. monspessulana seed-derived extracts exhibited dose-dependent antiproliferative activity on PC-3 and SiHa cell lines (>500 µg/mL < IC50 < 26.3 µg/mL). Seven compounds (1−7) were inferred as the compounds most likely responsible for the observed anti-proliferative activity and subsequently isolated and identified by spectroscopic techniques. A tricyclic quinolizidine (1) and a pyranoisoflavone (2) were found to be the most active compounds, exhibiting selectivity against PC-3 cell lines (IC50 < 18.6 µM). These compounds were used as precursors to obtain a quinolizidine-pyranoisoflavone adduct via Betti reaction, improving the activity against PC-3 and comparable to curcumin as the positive control. Results indicated that this composition−activity associative approach is advantageous to finding those bioactive principles efficiently within active extracts. This correlative association can be employed in further studies focused on the targeted isolation of anti-proliferative compounds from Genista plants and accessions.

The genus Genista L.: A rich source of bioactive flavonoids

The genus Genista L. (family Fabaceae, subfamily Papilionoideae), with its cosmopolitan distribution, has attracted the human interest since ancient times, as it is used in folk medicine and mainly in the Mediterranean area for the treatment of respiratory diseases, rheumatic disorders, diabetes and ulcer, while it is also well known for its yellow pigment. The chemical composition of the Genista species revealed the presence of more than 108 flavonoids. Isoflavones, belonging to the group of phytoestrogens, are important secondary metabolites of the genus. The extracts of the Genista species may act as important source of bioactive phytochemicals for the treatment of many human ailments, mainly inflammation and pain, estrogen related pathology, hyperglycaemia, cancer and microbial infections. Therefore, the present review summarizes and discusses the flavonoid derivatives from the genus Genista, together with their structural features and pharmacological properties, aiming to highlight the recent advances in current knowledge on Genista species as a source of bioactive flavonoids.

Isoflavonoid Profiling and Estrogen-Like Activity of Four Genista Species from the Greek Flora

As part of our ongoing research on phytoestrogens, we investigated the phytochemical profile and estrogen-like activities of eight extracts from the aerial parts of four Genista species of Greek flora using estrogen-responsive cell lines. Ethyl acetate and methanolic extracts of G. acanthoclada, G. depressa,G. hassertiana, and G. millii were obtained with accelerated solvent extraction and their phytochemical profiles were compared using ultra-high-performance liquid chromatography-high-resolution mass spectrometry (uHPLC-HRMS). Fourteen isoflavonoids, previously isolated from G. halacsyi, were used as reference standards for their identification in the extracts. Thirteen isoflavonoids were detected in both extracts of G. acanthoclada and G. hassertiana, while fewer and far fewer were detected in G. millii and G. depressa, respectively. The ethyl acetate extracts of G. hassertiana and G. acanthoclada displayed 2.45- and 1.79-fold higher, respectively, estrogen-like agonist activity in Ishikawa cells compared to MCF-7 cells at pharmacologically relevant concentrations. Both these extracts, but not that of G. depressa, contained mono- and di-O-β-d-glucosides of genistein as well as the aglycone, all three of which are known to display full estrogen-like activity at lower-than-micromolar concentrations. The possibility of using preparations rich in G. hassertiana and/or G. acanthoclada extracts as a potentially safer substitute for low-dose vaginal estrogen for menopausal symptoms is discussed.

Bioactive Phytochemicals Isolated from Akebia quinata Enhances Glucose-Stimulated Insulin Secretion by Inducing PDX-1

Chocolate vine (Akebia quinata) is consumed as a fruit and is also used in traditional medicine. In order to identify the bioactive components of A. quinata, a phytosterol glucoside stigmasterol-3-O-β-d-glucoside (1), three triterpenoids maslinic acid (2), scutellaric acid (3), and hederagenin (4), and three triterpenoidal saponins akebia saponin PA (5), hederacoside C (6), and hederacolchiside F (7) were isolated from a 70% EtOH extract of the fruits of A. quinata (AKQU). The chemical structures of isolates 1-7 were determined by analyzing the 1D and 2D nuclear magnetic resonance (NMR) spectroscopic data. Here, we evaluated the effects of AKQU and compounds 1-7 on insulin secretion using the INS-1 rat pancreatic β-cell line. Glucose-stimulated insulin secretion (GSIS) was evaluated in INS-1 cells using the GSIS assay. The expression levels of the proteins related to pancreatic β-cell function were detected by Western blotting. Among the isolates, stigmasterol-3-O-β-d-glucoside (1) exhibited strong GSIS activity and triggered the overexpression of pancreas/duodenum homeobox protein-1 (PDX-1), which is implicated in the regulation of pancreatic β-cell survival and function. Moreover, isolate 1 markedly induced the expression of extracellular signal-regulated protein kinases 1 and 2 (ERK1/2), insulin receptor substrate-2 (IRS-2), phosphoinositide 3-kinase (PI3K), and Akt, which regulate the transcription of PDX-1. The results of our experimental studies indicated that stigmasterol-3-O-β-d-glucoside (1) isolated from the fruits of A. quinata can potentially enhance insulin secretion, and might alleviate the reduction in GSIS during the development of T2DM.

In Vitro Screening for Acetylcholinesterase Inhibition and Antioxidant Activity of Quercus suber Cork and Corkback Extracts

Purpose

Acetylcholinesterase (AChE) inhibitors are used to treat Alzheimer's patients because they enhance cholinergic neurotransmission. It is urgent to find new and efficient inhibitors from natural sources, highly bioavailable with low or no toxicity. The plant kingdom is extremely rich in a variety of compounds that are potent AChE inhibitors: flavonoids and other phenolic compounds have been recognized as promising Alzheimer's treatment agents. In this study, in vitro acetylcholinesterase inhibition, antioxidant activities, and total flavonoid and phenolic contents of ethanol-water extracts from Quercus suber cork and corkback were evaluated.

Methods

The acetylcholinesterase activity was determined by a colorimetric assay based on Ellman's methodology. The Folin–Ciocalteu colorimetric method was used for total phenolic content determination and the aluminium chloride method for the determination of total flavonoid content. Antioxidant activity assays were performed using the DPPH and FRAP assays.

Results

The acetylcholinesterase inhibitory activity from Q. suber cork and corkback ethanol-water extracts was as follows: 62% inhibition with corkback extracts over 0.5 mg/mL and around 49% inhibition in cork extracts over 1.0 mg/mL extracts' concentration. Regarding the DPPH radical scavenging activity, the concentrations of cork and corkback ethanol-water extracts required for 50% DPPH inhibition (IC50) were 3.2 μg/mL and 4.0–5.2 μg/mL. Corkback extracts are less effective than Trolox standard (3.2 μg/mL) but cork extracts showed the same free radical scavenging activity compared to Trolox. Cork and corkback extracts have antioxidant power of 750.9–775.4 mg TEAC/g extract and 1051.2–2052.4 mg TEAC/g extract, respectively, which are significantly higher than the ones obtained with Trolox: 19.6–21.0 mg TEAC/g extract (cork assays) and 57.4–66.3 mg TEAC/g extract (corkback assays). The amounts of total phenolic (TPC) and flavonoid (TFC) compounds were 8.7–32.3 mg GAE/g and 4.8–10.7 mg CE/g dry mass for cork and 5.4–5.7 mg GAE/g and 42.5 mg CE/g dry mass for corkback extracts, respectively, using catechin (CE) and GAE (gallic acid) as standards.

Conclusion

These findings demonstrate the remarkable potential of these extracts as valuable source of antioxidants with interesting acetylcholinesterase inhibitory activity.

Management of diabetes using herbal extracts: review

Diabetes is a group of metabolic diseases characterised by hyperglycemia resulting from defects in insulin secretion, insulin action, or both. The chronic hyperglycemia of diabetes is associated with long-term damage and dysfunction of many organs. Diabetes caused 1.5 million deaths in 2012, with hyperglycemia causing an additional 2.2 million deaths, as it is associated with increased risk of cardiovascular and other diseases. Various types of plants have been used for several centuries worldwide not only as dietary supplements but also as traditional treatment regimens for many diseases. So far, a large number of traditionally claimed plant medicine has been tested for diabetes and some of them showed a promising therapeutic potential. The main focus of this review is to describe what we know to date of herbal extracts, along with their glucose-lowering mechanisms, which are either through insulin-mimicking activity, enhanced β-cells regeneration, or glucose uptake.

A New Triterpene Glucoside from Genista numidica

A new oleanolic acid triterpene glucoside, 3- O-β-D-glucopyranosyl-3β,21β,28-trihydroxy-olean-12-en-27-oic acid (1), has been isolated together with twelve known compounds from the chloroform and ethyl acetate extracts of Genista numidica Spach (Fabaceae) aerial parts. The structures were elucidated by spectroscopic and spectrometric analyses, mainly 1D-, 2D-NMR and MS data, and comparison with the literature. The antiproliferative activity of isolates was investigated on Jurkat, HeLa, and MCF7 cell lines. The most active triterpene, 3- O-β-D-glucopyranosyl-olean-12-en-3β,27,28,29-tetraol, showed activity in all cell lines. Further studies revealed that this compound induced in HeLa cells a cytostatic response.

Bridging Type 2 Diabetes and Alzheimer's Disease: Assembling the Puzzle Pieces in the Quest for the Molecules With Therapeutic and Preventive Potential

Type 2 diabetes (T2D) and Alzheimer's disease (AD) are two age-related amyloid diseases that affect millions of people worldwide. Broadly supported by epidemiological data, the higher incidence of AD among type 2 diabetic patients led to the recognition of T2D as a tangible risk factor for the development of AD. Indeed, there is now growing evidence on brain structural and functional abnormalities arising from brain insulin resistance and deficiency, ultimately highlighting the need for new approaches capable of preventing the development of AD in type 2 diabetic patients. This review provides an update on overlapping pathophysiological mechanisms and pathways in T2D and AD, such as amyloidogenic events, oxidative stress, endothelial dysfunction, aberrant enzymatic activity, and even shared genetic background. These events will be presented as puzzle pieces put together, thus establishing potential therapeutic targets for drug discovery and development against T2D and diabetes-induced cognitive decline-a heavyweight contributor to the increasing incidence of dementia in developed countries. Hoping to pave the way in this direction, we will present some of the most promising and well-studied drug leads with potential against both pathologies, including their respective bioactivity reports, mechanisms of action, and structure-activity relationships.

Protective Activity of Total Polyphenols from Genista quadriflora Munby and Teucrium polium geyrii Maire in Acetaminophen-Induced Hepatotoxicity in Rats

Oxidative stress is a major cause of drug-induced hepatic diseases and several studies have demonstrated that diet supplementation with plants rich in antioxidant compounds provides a variety of health benefits in these circumstances. Genista quadriflora Munby (Gq) and Teucrium polium geyrii Maire (Tp) are known to possess antioxidant and numerous biological properties and these endemic plants are often used for dietary or medicinal applications. Herein, we evaluated the beneficial effect of rich-polyphenol fractions of Gq and Tp to prevent Acetaminophen-induced liver injury and investigated the mechanisms involved in this protective action. Rats were orally administered polyphenolic extracts from Gq or Tp (300 mg/kg) or N-acetylcysteine (NAC: 200 mg/kg) once daily for ten days prior to the single oral administration of Acetaminophen (APAP: 1 g/kg). The results show that preventive administration of polyphenolic extracts from Gq or Tp exerts a hepatoprotective influence during APAP treatment by improving transaminases leakage and liver histology and stimulating antioxidant defenses. Besides, suppression of liver CYP2E1, GSTpi and TNF-α mRNA levels, with enhancement of mitochondrial bioenergetics may contribute to the observed hepatoprotection induced by Gq and Tp extracts. The effect of Tp extract is significantly higher (1.5–2 fold) than that of Gq extract and NAC regarding the enhancement of mitochondrial functionality. Overall, this study brings the first evidence that pretreatment with these natural extracts display in vivo protective activity against APAP hepatotoxicity through improving mitochondrial bioenergetics, oxidant status, phase I and II enzymes expression and inflammatory processes probably by virtue of their high total polyphenols content.

New In Vitro Studies on the Bioprofile of Genista tenera Antihyperglycemic Extract

The inhibition of α-glucosidase and glucose-6-phosphatase, two enzymes involved in the carbohydrate metabolism, is an important target to control glycaemia on individuals with type 2 diabetes. In this work we report for the first time the inhibition of both enzymes by the antihyperglycemic n-butanol extract from Genista tenera (Fabaceae). This extract decreased α-glucosidase and glucose-6-phosphatase activities to 0.97 and 80.25 %, respectively, being more effective than acarbose, and phlorizin, the positive controls, which reduced enzymes activities only to 17.39 and 96.06 %. Once inflammation and oxidative stress are related to diabetic impairments, the anti-inflammatory activity of the extract was also evaluated, through its inhibitory activity over COX-1 enzyme (47.5 % inhibition). Moreover, after induction of oxidative stress by UV radiation, the viability of irradiated rat liver hepatoma cells exposed to the extract was significantly higher (67.82 %) than that promoted by ascorbic acid, the positive control (45.05 %). In addition, the stability of the extract under gastrointestinal conditions was evaluated by HPLC-DAD-ESI-MS/MS. Flavonoid diglycosides were identified as the main constituents of the extract, and no alterations in the chemical composition nor in the antioxidant activity were observed after in vitro digestion with artificial gastric and pancreatic juices.

Antioxidant plants and diabetes mellitus

The incidence of diabetes mellitus (DM) is increasing rapidly and it is expected to increase by 2030. Other than currently available therapeutic options, there are a lot of herbal medicines, which have been recommended for its treatment. Herbal medicines have long been used for the treatment of DM because of the advantage usually having no or less side-effects. Most of these plants have antioxidant activities and hence, prevent or treat hard curable diseases, other than having the property of combating the toxicity of toxic or other drugs. In this review other than presenting new findings of DM, the plants, which are used and have been evaluated scientifically for the treatment of DM are introduced.

Chemical profile and in vivo hypoglycemic effects of Syzygium jambos, Costus speciosus and Tapeinochilos ananassae plant extracts used as diabetes adjuvants in Puerto Rico

BACKGROUND

The increasing numbers of people who use plant-based remedies as alternative or complementary medicine call for the validation of less known herbal formulations used to treat their ailments. Since Puerto Rico has the highest rate of Type 2 diabetes within all the states and territories of the United States, and Puerto Ricans commonly use plants as diabetes adjuvants, it is important to study the plants' physiological effects, and identify their bioactive compounds to understand their role in modulation of blood glucose levels. We present the phytochemical profiles and hypoglycemic effects of Tapeinochilus ananassae, Costus speciosus and Syzygium jambos.

METHODS

Phytochemicals in methanolic and aqueous extracts were analyzed by thin layer chromatography (TLC). Alkaloids (Bromocresol green, λ=470 nm), flavonoids (AlCl3, λ=415 nm), saponins (DNS, λ=760 nm), tannins (FeCl3/K4Fe(CN)6, λ=395 nm) and phenolics (Folin-Ciocalteau, λ=765 nm) were quantified. Male C57BLKS/J (db/db) and C57BL/J (ob/ob) genetically obese mice were orally gavaged with aqueous extracts of lyophilized plant decoctions for 10 wks.

RESULTS

Our results show that T. ananassae had significantly greater amounts of flavonoids and tannins, while S. jambos showed the greatest concentration of phenolics and C. speciosus exhibited higher amounts of alkaloids. C57BLKS/J db/db treated with plant extracts show better glucose modulation when the extracts are administered in complement with an insulin injection. Finally, C57BL/J ob/ob mice on T. ananassae and S. jambos treatments show better blood glucose modulation over time.

CONCLUSION

These results document for the first time the chemical profile of T. ananassae and provide evidence for a potential anti-diabetic efficacy of T. ananassae and S. jambos.

Investigation of antidiabetic action of Antidesma bunius extract in type 1 diabetes

CONTEXT

Antidesma bunius L (Phyllanthaceae) is commonly known to local people in North-east Thailand as a medicinal plant.

OBJECTIVES

To investigate hypoglycaemic activities of methanolic extract of A. bunius in type 1 diabetes.

MATERIALS AND METHODS

A daily dose of A. bunius extract (250 mg/kg body weight) was given orally to alloxan-induced diabetic rats for 28 days. Blood glucose, insulin, TC, TG, amylase, lipase, liver glycogen were analysed.

RESULTS

Extract revealed a significant reduction in blood glucose level (80.5%) along with an increase in serum insulin (134%), lipase (90.7%) and liver glycogen level (160%). Also amylase (28.2%) activity, TC (40.2%), and TG (28.8%) levels were significantly decreased when compared with diabetic control rats. A. bunius extract improved the histo-architectural of the β-cells.

DISCUSSION AND CONCLUSION

The results suggested that A. bunius extract possess anti-diabetic activity, through the enhancement of hepatic glycogen storage and regeneration of the islet of Langerhans.

Rapid identification of antioxidant compounds of Genista saharae Coss. & Dur. by combination of DPPH scavenging assay and HPTLC-MS

Genista species are sources of antioxidant phenolic compounds such as O- and C-glycosylflavonoids and isoflavonoids. A combination of a DPPH scavenging assay with HPTLC-MS, a fast and efficient method for identification of bioactive compounds, has been applied for evaluation of the radical scavenging activity of metabolites from Genista saharae Coss. & Dur. Different organs collected at various periods have been compared. Identification of antioxidant compounds was obtained by elution of the major DPPH-inhibition zones. The resulting HPTLC-MS analysis under moderately polar conditions, coupled to the DPPH results led to the putative identification of two antioxidant isoflavone aglycones: 3',4',5,7-tetrahydroxyisoflavone (1) and ficuisoflavone (3), whereas polar migration conditions led to the identification of the glycosides 5-methoxy-4',7-trihydroxy-8-glucopyranosylisoflavone (4) and 4',5-dihydroxy-7-methoxyisoflavone-4'-O-β-d-gluco-pyranoside (5). Evaluation of percentage of inhibition of DPPH radical by the purified isoflavone 4 from the root extract showed that it affords a moderate contribution to the total radical scavenging activity of the extract.

Intervention in cyclophosphamide induced oxidative stress and DNA damage by a flavonyl-thiazolidinedione based organoselenocyanate and evaluation of its efficacy during adjuvant therapy in tumor bearing mice

A novel flavonyl-thiazolidinedione based organoselenocyanate compound was synthesized and established as nontoxic at the doses of 2.5 and 5 mg/kg b.w. in mice. Oral administration of the compound in combination with cyclophosphamide (CP) resulted in an improved therapeutic efficacy which was mostly evidenced in terms of tumor burden and protection of normal cells. The adjuvant therapy was proved to be immensely significant in increasing the mean survivability of the tumor bearing hosts. Reduction in the tumor volume was manifested through the induction of apoptosis and generation of ROS in transformed cells. Moreover, the organoselenium compound could efficiently suppress CP-induced DNA damage, chromosomal aberration, hepatic damage and enhanced the activities of various antioxidant enzymes in normal cells.

A new iced tea base herbal beverage with Spergularia rubra extract: metabolic profile stability and in vitro enzyme inhibition

Beverages are an ideal format to offer nutrients, specific health-promoting functionality, and desirable sensory attributes to consumers. Taking into account previous research on Spergularia rubra (L.) J. Presl & C. Presl, the aim of this work was to describe the chemistry and biochemistry associated with the production of a new iced tea base herbal beverage containing a hydroethanolic extract of this species, including both naturally occurring and added components. Phenolic compounds of S. rubra hydroethanolic extract and of the iced tea base herbal beverage were determined by HPLC-DAD. Thirty compounds, comprising nonacylated C-glycosyl flavones, C-glycosyl flavones acylated with aromatic acids, and C-glycosyl flavones acylated with aliphatic acids, were identified, being essentially represented by apigenin derivatives. Organic acids of both samples were determined by HPLC-UV, malic acid being the major one. A strong inhibition of α-glucosidase, acetylcholinesterase, and butyrylcholinesterase was observed. Furthermore, the influence of the pH of the digestive tube on the chemical composition of both extract and iced tea base herbal beverage and, consequently, on their biological activity, was assessed. In a general way, pH variation significantly decreased (p < 0.05) the metabolites content and enzymes inhibitory capacity. Nevertheless, the beverage enriched with S. rubra extract represents a valuable addition to consumer's health and nutrition, once the loss of activity is lower than the one verified for the base iced tea. Thus, the results suggest that the ingestion of this beverage could be of potential interest for several chronic disorders, particularly Alzheimer's disease.

Triterpene saponins of Genista ulicina Spach

From the n-BuOH extract of the aerial parts of Genista ulicina, six triterpene saponins, 3-O-β-D-glucopyranosyl-olean-12-ene-3β,27,28,30-tetraol, 3-O-β-D-glucopyranosyl-olean-12-ene-3β,27,28,29-tetraol, 3,29-di-O-β-D-glucopyranosyl-olean-12-ene-3β,27,28,29-tetraol, 3-O-β-D-glucopyranosyl-olean-12-ene-3β,28,29-triol-27-oic acid, 3-O-β-D-glucopyranosyl-olean-12-ene-3β,27,28-triol-29-oic acid, and 3-O-β-D-glucopyranosyl-14-H-27-nor-olean-12-ene-3β,28,29-triol, were isolated together with eight known triterpene saponins and six flavonoids. Their structures were established mainly by means of spectroscopic methods (1D and 2D-NMR as well as HR-ESI-MS). The n-BuOH extract, investigated for its antitumor growth inhibition of human colon cancer HT-29 cells, presented no significant activity (IC50>100 μg).

Characterization of flavonoids and phenolic acids in Myrcia bella Cambess. using FIA-ESI-IT-MS(n) and HPLC-PAD-ESI-IT-MS combined with NMR

The leaves of Myrcia DC. ex Guill species are used in traditional medicine and are also exploited commercially as herbal drugs for the treatment of diabetes mellitus. The present work aimed to assess the qualitative and quantitative profiles of M. bella hydroalcoholic extract, due to these uses, since the existing legislation in Brazil determines that a standard method must be developed in order to be used for quality control of raw plant materials. The current study identified eleven known flavonoid-O-glycosides and six acylated flavonoid derivatives of myricetin and quercetin, together with two kaempferol glycosides and phenolic acids such as caffeic acid, ethil galate, gallic acid and quinic acid. In total, 24 constituents were characterized, by means of extensive preparative chromatographic analyses, along with MS and NMR techniques. An HPLC-PAD-ESI-IT-MS and FIA-ESI-IT-MS(n) method were developed for rapid identification of acylated flavonoids, flavonoid-O-glycosides derivatives of myricetin and quercetin and phenolic acids in the hydroalcoholic M. bella leaves extract. The FIA-ESI-IT-MS techinique is a powerful tool for direct and rapid identification of the constituents after isolation and NMR characterization. Thus, it could be used as an initial method for identification of authentic samples concerning quality control of Myrcia spp extracts.

Natural AChE Inhibitors from Plants and their Contribution to Alzheimer's Disease Therapy

As acetylcholinesterase (AChE) inhibitors are an important therapeutic strategy in Alzheimer's disease, efforts are being made in search of new molecules with anti-AChE activity. The fact that naturally-occurring compounds from plants are considered to be a potential source of new inhibitors has led to the discovery of an important number of secondary metabolites and plant extracts with the ability of inhibiting the enzyme AChE, which, according to the cholinergic hypothesis, increases the levels of the neurotransmitter acetylcholine in the brain, thus improving cholinergic functions in patients with Alzheimer's disease and alleviating the symptoms of this neurological disorder. This review summarizes a total of 128 studies which correspond to the most relevant research work published during 2006-2012 (1st semester) on plant-derived compounds, plant extracts and essential oils found to elicit AChE inhibition.

Quantification of genistein and daidzein in two endemic Genista species and their antioxidant activity

In the current research, the total and free genistein and daidzein contents were determined in two endemic Genista species (G. sandrasica and G. vuralii) by an HPLC method. The highest amount of total genistein and total daidzein was found in G. sandrasica, 0.582 % and 0.113 %, respectively, whereas only the free daidzein content of G. sandrasica was higher than that of G. vuralii. The antioxidant activity of the crude methanol and hydrolyzed extracts of these species was evaluated by three in vitro methods; namely DPPH free radical scavenging, ferrous ionchelating and ferric-reducing antioxidant power (FRAP) tests at 0.25, 0.50, and 1.0 mg ml. The hydrolyzed extracts of both species displayed greater antioxidant activity than the crude methanol extracts in all tests. Total phenol and flavonoid contents in the extracts were determined via the Folin-Ciocalteau and AlCl3 reagents, respectively. G. vuralii was richer in terms of total phenol and flavonoid contents compared to G. sandrasica.