α-Amylase and lipase inhibitory activity and structural characterization of acacia bark proanthocyanidins

The bark extract of Acacia mearnsii showed strong lipase and α-amylase inhibition activities. Fractionation of the extract by column chromatography and subsequent (13)C NMR and MALDI-TOF-MS analysis revealed that the active substances are proanthocyanidin oligomers mainly composed of 5-deoxyflavan-3-ol units. In addition, 4'-O-methylrobinetinidol 3'-O-β-D-glucopyranoside, fisetinidol-(4α,6)-gallocatechin, and epirobinetinidol-(4β,8)-catechin were isolated as new compounds, and their structures were determined from spectroscopic data. Furthermore, a modified thiol degradation method using strongly acidic conditions was applied to the extract to yield three thiol degradation products derived from robinetinidol units. This method is useful for characterizing acacia proanthocyanidins (wattle tannins).     

α-Glucosidase and α-Amylase Inhibitory Activity of Senna surattensis

In this study, we investigated the inhibitory effects of ethanolic extract of the leaves of Senna surattensis (EESS) on α-glucosidase and α-amylase. We also studied the in vitro antidiabetic activity of S. surattensis using the glucose uptake by isolated rat hemidiaphragm model. In vitro studies using mammalian α-glucosidase extracted from the small intestine homogenate of mouse showed that the extract was found to be more effective in inhibiting the activities of maltase [half maximal inhibitory concentration (IC₅₀): 209.15 μg/mL] and sucrase (IC₅₀: 366.44 μg/mL) when compared with the control group (acarbose). The extract of S. surattensis were further quantified with respect to porcine pancreatic α-amylase inhibition using the chromogenic 3,5-dinitrosalicylic acid method. Interestingly, S. surattensis was also found to exhibit α-amylase (IC₅₀: 123.95 μg/mL) inhibitory activity. The glucose uptake in the rat hemidiaphragm was significantly (p < 0.01) increased by EESS (220.95 ± 5.4 mg/g/30 minute) when compared with the control group. The total polyphenolic content of EESS was found to be 98 μg pyrocatechol/mg of the extract. These results suggest that EESS inhibited carbohydrate digestive enzymes and increased the peripheral uptake of glucose. This study endorses the use of this plant for further studies to determine their potential for managing type II diabetes.     

Antitrypanosomal and antiplasmodial activity of medicinal plants from Côte d'Ivoire

The antitrypanosomal activity of 101 crude ethanol extracts derived from 88 medicinal plants from Côte d’Ivoire was determined in vitro using Trypanosoma brucei rhodesiense. Of those extracts 8 showed good activity (IC₅₀ values ≤8 μg/ml), 37 revealed a weak activity (IC₅₀ values between 25 and 8.1 μg/ml) and 56 did not show any activity at all (IC₅₀ values>25 μg/ml). The extracts of Enantia polycarpa (Annonaceae) and Trichilia emetica (Meliaceae) were the most promising ones. Their IC₅₀ values were 0.5 and 0.04 μg/ml, respectively, and the selectivity index 616 and 209, respectively. This is the first report of in vitro antitrypanosomal activity of these two plants. Their high activities render them candidates for the isolation of compounds which could develop into new lead structures for drug development programs against African trypanosomiasis. Seven of the tested extracts exhibited an antiplasmodial activity against K1 strain of Plasmodium falciparum with IC₅₀ values below 4 μg/ml. The highest activity was found for Enantia polycarpa stem bark with an IC₅₀ value of 0.126 μg/ml.     

Intestinal α-glucosidase inhibitory activity and toxicological evaluation of Nymphaea stellata flowers extract

Aim of the study

Nymphaea stellata willd. flowers (NSF) are used as a traditional medicine in India and Nepal to treat diabetic disease. Different works have demonstrated that NSF extract showed antihyperglycemic effect on alloxan-induced diabetic rats. In the present work we evaluated in vitro intestinal α-glucosidase inhibition as the possible mode of action of NSF extract on suppressing postprandial hyperglycemia for curing diabetic mellitus. In addition, NSF extract was studied to assess its possible acute oral toxicity and genotoxicity.

Materials and methods

Rat intestinal crude enzyme preparation and Caco-2 monolayer were used to evaluate α-glucosidase inhibitory activity of NSF extract. The main α-glucosidase inhibitors were detected by HPLC. For acute toxicity test, NSF extract was administered at doses of 2000, 5000 and 10,000 mg/kg body to three groups of 10 ICR mice each, and then clinical symptoms including mortality, clinical sign and gross findings were observed once a day for 14 days. In Ames test, histidine-dependent auxotrophic mutants of Salmonella typhimurium (strains TA97, TA98, TA100, TA102 and TA1535) were used and incubated in the presence and absence of S9 metabolic activation using NSF extract with concentrations of 150-5000 μg/plate. The chromosome aberration test was conducted with Chinese hamster lung (CHL) cells treated with NSF extract at doses of 150-5000 μg/ml in the presence and absence of S9 metabolic activation. In the in vivo mouse micronucleus assay, 9-week-old male and female ICR mice (n = 90, 25-30 g) were administered daily by oral gavage at doses of 2.5, 5.0 and 10.0 g/kg body for 1 or 2 days. Bone marrow smears were prepared from each treatment group 24 h after last administration and then polychromatic erythrocytes (PCEs) and normochromatic erythrocytes (NCEs) were identified.

Results

NSF extract showed potent rat intestinal α-glucosidase inhibitory activity for maltose hydrolysis with ED₅₀ value of 0.1 mg/ml. In Caco-2 monolayer, α-glucosidase activity for the maltose hydrolysis was down-regulated by NSF extract at a concentration of 0.05 mg/well level, showing 74% inhibition compared to the saline treated control. NSF was rich in phenol contents and the main α-glucosidase inhibitor, 1,2,3,4,6-penta-O-galloyl-β-d-glucose, was identified together with two phenolic compounds of gallic acid and corilagin. In acute toxicity test, NSF extract did not produce any toxic signs or deaths and the LD₅₀ value of this extract could be greater than 10,000 mg/kg body weight. These results of genotoxicity assessment showed that NSF extract did not cause genotoxic effects in Ames test, in the in vitro chromosomal aberration assay and in the in vivo micronucleus assay.

Conclusion

The current study shows that the extract from Nymphaea stellata flowers exhibits significant intestinal α-glucosidase inhibitory activity, without showing any acute toxicity or genotoxicity, which may be useful in suppressing postprandial hyperglycemia in diabetics. The results presented here suggest that the use of NSF in folk medicine as a natural antidiabetic treatment could be safe as well as beneficial.     

α-Glucosidase Inhibitory Hydrolyzable Tannins from Eugenia jambolana Seeds

Three new hydrolyzable tannins including two gallotannins, jamutannins A (1) and B (2), and an ellagitannin, iso-oenothein C (3), along with eight known phenolic compounds were isolated from the seeds of Eugenia jambolana fruit. The structures were elucidated on the basis of spectroscopic data analysis. All compounds isolated were evaluated for α-glucosidase inhibitory effects compared to the clinical drug acarbose.     

Traditional medicine in north Côte-d'Ivoire: screening of 50 medicinal plants for antibacterial activity

Sixty-seven crude ethanol extracts from 50 plants (31 families), which are used in North C?te-d'Ivoire as traditional remedies for bacterial diseases, were screened for in vitro activity against Gram negative (Escherichia coli and Pseudomonas aeruginosa) and Gram positive (Staphylococcus aureus, Enterococcus faecalis, Streptococcus pyogenes and Bacillus subtilis) bacteria. Thirty-one extracts showed antibacterial activity only on Gram positive bacteria. Of these, 10 extracts from 10 plant species had a promising level of activity against bacteria including strains resistant to antibiotics such as aminosides, penicillin M, macrolides, lincosamide and streptrogramin B. The most active was Erythrina senegalensis DC (Fabaceae) followed by Bobgunnia madagascariensis (Desv.) J.H. Kirkbr. & Wiersema (Caesalpinaceae), Waltheria lanceolata R. Br. ex Mast. (Sterculiaceae), Uapaca togoensis Pax. (Euphorbiaceae), Ximenia americana L. (Olacaceae), Khaya senegalensis (Ders.) A. Juss. (Meliaceae), Lannea acida A. Rich. (Anacardiaceae), Cissus populnea Guill. & Perr. (Vitaceae), Keetia hispida (Benth.) Bridson (Rubiaceae) and Ficus thonningii (Miq.) A. Rich. (Moraceae). This is the first report of the antibacterial potency of these 10 plant species on a range of bacteria. The results provided evidence that some of the studied plants might indeed be potential sources of new antibacterial agents, also against some antibiotic-resistant strains.     

Phytochemical, antioxidant and anti-α-glucosidase activity evaluations of Bergenia cordifolia

The antioxidant, anti-α-glucosidase and anticholinesterase activity of the leaves and rhizomatous extract of Bergenia cordifolia were investigated. The rhizomes extract that showed a higher degree of 1,1-diphenyl-2-picrylhydrazyl radical scavenging and anti-α-glucosidase activity than reference compounds (rutin and acarbose respectively) were subjected to phytochemical analysis. The study revealed that previously unknown minor constituents from the plant, (+)-catechin 3-O-gallate, (+)-catechin 3,5-di-O-gallate and 1,2,4,6-tetra-O-galloyl-β-D-glucopyranoside, were the radical scavenging and anti-α-glucosidase principles. These compounds as well as the crude extracts were weak acetylcholienesterase inhibitors, suggesting a higher degree of selectivity against α-glucosidase enzyme. In comparison with the minor constituents, the previously known major constituents of the plant, bergenin and arbutin, were poor radical scavengers and enzyme inhibitors.     

α-Glucosidase inhibition and the in vivo hypoglycemic effect of butyl-isobutyl-phthalate derived from the Laminaria japonica rhizoid

The rhizoid of Laminaria japonica is widely used in Chinese medicine as a treatment for diabetes. Therefore, a bioactivity-tailored isolation and detailed chemical characterization was used to identify the antidiabetes compounds found in the L. japonica rhizoid. Liquid chromatography/mass spectrometry (LC/MS), proton NMR and carbon NMR spectra analyses demonstrated that the active compound was butyl-isobutyl-phthalate (BIP). BIP demonstrated a significant concentration-dependent, non-competitive inhibitory activity against α-glucosidase in vitro, with an IC(50) of 38 μm. In vivo, the ethyl acetate fraction (EAF) and purified BIP displayed a significant hypoglycemic effect in streptozocin-induced diabetic mice. The present study indicates BIP could be considered as an α-glucosidase inhibitor and developed as an important antidiabetes agent for type II diabetes therapy.     

Antimalarial activity of medicinal plants used in traditional medicine in S. Tomé and Príncipe islands

The present study investigates the antimalarial activity of 13 medicinal plants used in traditional medicine in S. Tomé and Príncipe (STP) islands in the Gulf of Guinea, aiming at identifying the most effective plants for further research. Fieldwork was carried out with the collaboration of 37 traditional healers from both islands, during an ethnobotanical study, which was conducted from 1993 to 1999. Our results indicate that the traditional healers in STP use several medicinal plants against fever and/or 'malaria' which reveal strong antiparasitic activity in vitro: four of the plant extracts have evident antiplasmodial activity against chloroquine resistant Plasmodium falciparum, with IC(50) values <10 microg/ml, and also revealed hepatic schizontocidal activity (<5-35 microg/ml). In vivo, the extracts caused partial reduction of Plasmodium berghei parasitaemia in mice.     

Antimicrobial activity of plants used as medicinals on an indigenous reserve in Rio das Cobras, Paraná, Brazil

Ethnopharmacological relevance

A considerable percentage of global biodiversity is located in Brazil, a country that also has rich cultural and ethnic diversity. In the community of Rio das Cobras, Paraná, plants are still widely used in the health care not only by indigenous people but also by the non-indigenous population that inhabits the region. The investigation of the efficacy and safety of these plants in the treatment of infectious diseases provides insights for future studies of these species allowing the appropriated use by the indigenous people, since few or none study has been conducted so far.

Aim of the study

Evaluate the antimicrobial activity and cytotoxicity of some plants used as medicinal on an indigenous reserve in Rio das Cobras, Paraná, Brazil.

Materials and methods

The aqueous extracts were obtained by decoction and the 50% and 70% hydroalcoholic extracts by turbo extraction. The extracts were tested against strains of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Candida albicans, Candida parapsilosis, Candida tropicalis, Leishmania amazonensis, Poliovirus and HSV-1. Cytotoxicity assay using VERO cells were also performed.

Results

None of the extracts had a selectivity index (SI)>1 for any of the tested bacteria. Only Campomanesia eugenioides and Schinus terebinthifolius had an SI>1.0 for all of the tested Candida species. The best anti-Leishmania activity was obtained with Zanthoxylum rhoifolium and Schinus terebinthifolius. Extracts of Cordia americana were the most effective against herpes simplex virus type 1. Zanthoxylum rhoifolium was the most effective against Poliovirus, and Ocimum gratissimum was effective against both Poliovirus and Herpes Simplex virus. Among the plants investigated in the present study, Zanthoxylum rhoifolium had the fewest cytotoxic effect.

Conclusions

The plants investigated in the present study exhibited potential for future pharmacological uses, but additional studies, especially with regard to in vivo toxicity, must be conducted. The results of this preliminary survey are important for the Rio das Cobras Reserve community for the safe and effective use of plants in the treatment of some infectious diseases.     

5α-reductase inhibition and hair growth promotion of some Thai plants traditionally used for hair treatment

Ethnopharmacological relevance

Many Thai traditional herbs have been used for hundreds of years for hair treatment and nourishment, including hair loss. However, scientific evidence about their mechanisms of action has not yet been elucidated.

Aims of the study

The purpose of this research is to define the possible mechanisms involved in hair loss treatment of the selected plants by determining the 5α-reductase enzyme inhibition and hair growth promoting activities, and the relationship between these two activities.

Materials and methods

Seventeen Thai plants traditionally used for hair treatment were selected. The plants were dried, ground and extracted by maceration with ethyl alcohol. These extracts were further tested for 5α-reductase inhibition using enzymes from rat livers. Hair growth promoting activity was tested in C57BL/6 mice.

Results

Carthamus tinctorius L. was the most potent 5α-reductase inhibitor, with a finasteride equivalent 5α-reductase inhibitory activity (FEA) value of 24.30 ± 1.64 mg finasteride equivalent per 1 g crude extract. Phyllanthus emblica L. was the second most potent inhibitor, with FEA of 18.99 ± 0.40. Rhinacanthus nasutus (L.) Kurz. was the least potent 5α-reductase inhibitor (FEA 10.69 ± 0.96). Carthamus tinctorius also was the most potent hair growth promoter in C57BL/6 mice. There were strong relationships between 5α-reductase inhibitory activity and hair growth promoting activity (r = 0.719), and between 5α-reductase inhibitory activity and hair follicle count (r = 0.766).

Conclusions

Ethanolic extract of Carthamus tinctorius was the most potent 5α-reductase inhibitor and hair growth promoter. This discovery may lead to the development of new alternative medicines for hair loss prevention and treatment.     

The inhibitory activity of atractylenolide Ш, a sesquiterpenoid,on IgE-mediated mast cell activation and passive cutaneous anaphylaxis (PCA)

Ethnopharmacological relevance

AT Ш, a sesquiterpenoid, is the major component of Atractylodes japonica Koidz that has been used as a traditional oriental medicine.

Aim of the study

We investigated the anti-allergic activity of AT Ш and its mechanism of action.

Materials and methods

The released amount of β-hexosaminidase in mast cells, a key parameter of degranulation, was measured. Anti-allergic potential of AT Ш was evaluated using passive cutaneous anaphylaxis in vivo. The anti-allergic mechanism of AT Ш was investigated by immunoblotting analysis, RT-PCR and measurement of [Ca²⁺]i in mast cells.

Results

AT Ш significantly inhibited IgE/Ag-mediated degranulation with an IC₅₀ value (36±4 μM) in RBL-2H3 cells without affecting cell viability. It also suppressed IgE/Ag-mediated passive cutaneous anaphylaxis (PCA) response with an ED₅₀ value (65±41 mg/kg) in vivo. AT Ш suppressed the production of interleukin (IL-4) and tumor necrosis factor (TNF)-alpha mRNAs more potent than the Src-family kinase inhibitor PP2 in RBL-2H3 cells at all concentrations. In order to elucidate the anti-allergic mechanisms of AT Ш in mast cells, we examined the activated levels of signaling molecules. AT Ш inhibited the phosphorylation of Lyn, Fyn, Syk, LAT, PLCγ, Gab2, Akt, p38, and JNK kinases expression. IgE/Ag-mediated [Ca²⁺]i elevation was significantly inhibited by AT Ш.

Conclusions

Our study suggests that AT Ш might be used as a therapeutic agent for allergic diseases.     

Ethnobotany and antibacterial activity of some plants used in traditional medicine of Zapotitlán de las Salinas,Puebla (México)

The village of Zapotitlán de las Salinas is situated in the Valley of Tehuacán-Cuicatlán, Puebla, Mexico. Plant species used by the local inhabitants to treat gastrointestinal diseases were identified using ethnobotanical, ethnographic and taxonomic methods. Out of 119 interviews, 44 plant species were registered, of which the following are the most frequently used (listed in descending order): Lippia graveolens H.B. et K. (Verbenaceae), Lantana achyranthifolia Desf. (Verbenaceae), Turnera diffusa (Willd.) ex Schult. (Turneraceae), Lippia oaxacana Rob. et Greenm. (Verbenaceae), Gymnolaena oaxacana (Greenm.) Rydb. (Asteraceae), Cordia curassavica (Jacq.) Roem. et Schult. (Boraginaceae), Lantana camara L. (Verbenaceae) and Acalypha hederacea Torrey (Euphorbiaceae). From these plants, hexane, chloroform and ethanol extracts were prepared in order to assess their antibacterial activity against 14 bacterial strains causing the most common gastrointestinal diseases in Mexican population. All hexane extracts showed antibacterial activity against Gram-positive and Gram-negative bacteria. There is a correlation between the frequency of mention (of plant use) and the antibacterial activity. In conclusion, the knowledge of plants most frequently used for gastrointestinal infections in Zapotitlán de las Salinas is supported by scientific rationale.     

Informant consensus factor and antibacterial activity of the medicinal plants used by the people of San Rafael Coxcatlán, Puebla, México

Using ethnobotanical techniques, the medicinal flora used by the inhabitants of San Rafael Coxcatlán, Puebla was determined. During the field work, two types of interviews were applied (free listing and semi-structured) to 60 informants, who supplied consistent information concerning the use of 46 species of medicinal plants. Further analysis showed 13 categories of different medicinal use. An informant consensus factor was calculated and 16 species were selected due to their utilization in the treatment of diseases of possible bacterial origin. Of these 16 plants, sequential extractions were made with hexane, ethyl acetate and methanol. The obtained extracts were used to assess their antibacterial activity against 14 bacterial strains; 75% of the plants presented antibacterial activity. The medicinal species Jatropha neopauciflora Pax (Euphorbiaceae) and Juliania adstringens (Schldl.) Schldl. (Julianiaceae) were those that showed the biggest activity. Moreover, these species also had the highest informant consensus factor values.     

Evaluation of bioactive flavonoids in Citri Reticulatae Pericarpium from different regions and its association with antioxidant andα-glucosidase inhibitory activities

Background:To explore the differences of 14 batches of Citri Reticulatae Pericarpium from different regions.Methods:The main aim of this study was to develop a high-performance liquid chromatography method-photodiode array detection for determining the contents of five flavonoids and the chromatographic fingerprints of Citri Reticulatae Pericarpium from different regions.Theα-glucosidase inhibitory activities and antioxidant properties of Citri Reticulatae Pericarpium,based on free-radical scavenging assays against 1,1-diphenyl-2-picrylhydrazyl,2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid),and hydroxyl radicals,were estimated and compared.Results:Among the tested compounds,the content of hesperidin(13.386-68.235 mg/g)was the highest and that of hesperitin(0.045-0.277 mg/g)was the lowest.In comparing different sources of Citri Reticulatae Pericarpium,the contents of narirutin in Citri Reticulatae Pericarpium from Guangdong(0.824-0.851 mg/g)and Sichuan(1.069-1.204 mg/g)provinces of China were lower than in other provinces.In contrast,nobiletin(8.429-12.237 mg/g)and tangeretin(3.947-4.613 mg/g)were most abundant in Guangdong sources of Citri Reticulatae Pericarpium,followed by samples from Sichuan Province(nobiletin:6.761-7.658 mg/g;tangeretin:3.422-3.933 mg/g).Correlation analysis showed that nobiletin and tangeretin were the main contributors to the antioxidant capacity,and narirutin was the main active component inhibiting theα-glucosidase activity of Citri Reticulatae Pericarpium.Conclusion:This work revealed that the intrinsic quality of Citri Reticulatae Pericarpium was affected by different growing regions,which provides a scientific basis for controlling the quality of Citri Reticulatae Pericarpium and rationally developing and utilizing Citri Reticulatae Pericarpium.     

Traditional uses of medicinal plants in Elazığ (Turkey)

Ethnopharmacological relevance

This study has identified not only the wild plants collected for medical purposes by local people of Elaz?? Province in the Eastern Anatolia Region, but also the uses and local names of these plants. These resources are usually regarded as part of a culture?s traditional knowledge. Therefore, the aim of this study is to collect information from local population concerning the use of medicinal plants of the Elaz?? region; identify the most important medicinal plants used; determine the relative importance of the species surveyed and calculate the informant consensus factor (FIC) in relation to medicinal plant use.

Materials and methods

A field study had been carried out for a period of approximately 2 years (2012–2013). A questionnaire was administered to the local people, through face-to-face interviews (Appendix A). Demographic characteristics of participants, names of the local plants, their utilized parts and preparation methods were investigated and recorded. The plant species were collected within the scope of the study; herbarium materials were prepared; and the specimens were entitled. The collected data were used to calculate the FIC and the plant use values.

Results

74 Plants were found to be used for medical purposes before in the literature analysis of the plants used in our study, while 6 plants were found to have no literature records. Our results showed that the highest use values were recorded for the species Urtica dioica L. (0.46) and Rosa canina L. (0.42), while the highest FIC was cited for skin diseases (0.60).

Conclusion

Data obtained showed that in the studied area the folk use of plants is alive and still derives from daily practice. Evaluation of pharmacological activity for the promising medicinal plants is suggested.     

Are West African plants a source of future antimalarial drugs?

Ethnopharmacology is a very interesting resource in which new therapies may be discovered. In the case of malaria, two major antimalarial drugs widely used today came originally from indigenous medical systems, that is quinine and artemisinin, from Peruvian and Chinese ancestral treatments, respectively. There is an urgent need for the discovery of new drugs due to the critical epidemiological situation of this disease. New inexpensive therapies that are simple to use and that will limit the cost of drug research are good justifications for this ethnopharmacological approach. Therefore, the aim of this review is to empirically analyse plants that are used for antimalarial treatment in West Africa, and to determine those with real promising antimalarial activity. The major leads such as those extracted from Cochlospermum, Cryptolepsis, Guiera and Azadirachta have been highlighted. Indeed, some extracts seem to be promising in future research, but development of new isolation and characterization techniques, for designing new derivatives with improved properties need to be discussed.     

A search for natural bioactive compounds in Bolivia through a multidisciplinary approach. Part VI. Evaluation of the antimalarial activity of plants used by Isoceño-Guaraní Indians

Seventy-seven plant extracts (corresponding to 62 different species) traditionally used by the Isoce?o-Guaraní, a native community living in the Bolivian Chaco, were screened for antimalarial activity in vitro on Plasmodium falciparum chloroquine sensitive strain (F32), and on ferriprotoporphyrin (FP) IX biocrystallisation inhibition test (FBIT). Among these extracts, seven displayed strong in vitro antimalarial activity, and 25 were active in the FBIT test. Positive results on both tests were recorded for six extracts: Argemone subfusiformis aerial part, Aspidosperma quebracho-blanco bark, Castela coccinea leaves and bark, Solanum argentinum leaves and Vallesia glabra bark. Results are discussed in relation with Isoce?o-Guaraní traditional medicine. Further studies to be undertaken in relation with these results are also highlighted.