Traditional Medicinal Herbs and Food Plants Have the Potential to Inhibit Key Carbohydrate Hydrolyzing Enzymes In Vitro and Reduce Postprandial Blood Glucose Peaks In Vivo

We hypothesized that some medicinal herbs and food plants commonly used in the management of diabetes can reduce glucose peaks by inhibiting key carbohydrate hydrolyzing enzymes. To this effect, extracts of Antidesma madagascariense (AM), Erythroxylum macrocarpum (EM), Pittosporum senacia (PS), and Faujasiopsis flexuosa (FF), Momordica charantia (MC), and Ocimum tenuiflorum (OT) were evaluated for α-amylase and α-glucosidase inhibitory effects based on starch-iodine colour changes and PNP-G as substrate, respectively. Only FF and AM extracts/fractions were found to inhibit α-amylase activity significantly (P < 0.05) and coparable to the drug acarbose. Amylase bioassay on isolated mouse plasma confirmed the inhibitory potential of AM and FF extracts with the ethyl acetate fraction of FF being more potent (P < 0.05) than acarbose. Extracts/fractions of AM and MC were found to inhibit significantly (P < 0.05) α-glucosidase activity, with IC50 comparable to the drug 1-deoxynojirimycin. In vivo studies on glycogen-loaded mice showed significant (P < 0.05) depressive effect on elevation of postprandial blood glucose following ingestion of AM and MC extracts. Our findings tend to provide a possible explanation for the hypoglycemic action of MC fruits and AM leaf extracts as alternative nutritional therapy in the management of diabetes

Oxidative DNA damage preventive activity and antioxidant potential of plants used in Unani system of medicine

<p>Abstract</p> <p>Background</p> <p>There is increasing recognition that many of today's diseases are due to the "oxidative stress" that results from an imbalance between the formation and neutralization of reactive molecules such as reactive oxygen species (ROS) and reactive nitrogen species (RNS), which can be removed with antioxidants. The main objective of the present study was to evaluate the antioxidant activity of plants routinely used in the Unani system of medicine. Several plants were screened for radical scavenging activity, and the ten that showed promising results were selected for further evaluation.</p> <p>Methods</p> <p>Methanol (50%) extracts were prepared from ten Unani plants, namely <it>Cleome icosandra, Rosa damascena, Cyperus scariosus, Gardenia gummifera, Abies pindrow, Valeriana wallichii, Holarrhena antidysenterica, Anacyclus pyrethrum, Asphodelus tenuifolius </it>and <it>Cyperus scariosus</it>, and were used to determine their total phenolic, flavonoid and ascorbic acid contents, in vitro scavenging of DPPH^·, ABTS^·+, NO, ^·OH, O₂^.-and ONOO^-, and capacity to prevent oxidative DNA damage. Cytotoxic activity was also determined against the U937 cell line.</p> <p>Results</p> <p>IC₅₀values for scavenging DPPH^·, ABTS^·+, NO, ^·OH, O₂^.-and ONOO^-were in the ranges 0.007 ± 0.0001 - 2.006 ± 0.002 mg/ml, 2.54 ± 0.04 - 156.94 ± 5.28 μg/ml, 152.23 ± 3.51 - 286.59 ± 3.89 μg/ml, 18.23 ± 0.03 - 50.13 ± 0.04 μg/ml, 28.85 ± 0.23 - 537.87 ± 93 μg/ml and 0.532 ± 0.015 - 3.39 ± 0.032 mg/ml, respectively. The total phenolic, flavonoid and ascorbic acid contents were in the ranges 62.89 ± 0.43 - 166.13 ± 0.56 mg gallic acid equivalent (GAE)/g extract, 38.89 ± 0.52 - 172.23 ± 0.08 mg quercetin equivalent (QEE)/g extract and 0.14 ± 0.09 - 0.98 ± 0.21 mg AA/g extract. The activities of the different plant extracts against oxidative DNA damage were in the range 0.13-1.60 μg/ml. Of the ten selected plant extracts studied here, seven - <it>C. icosandra, R. damascena, C. scariosus, G. gummifera, A. pindrow, V. wallichii </it>and <it>H. antidysenterica - </it>showed moderate antioxidant activity. Finally, potentially significant oxidative DNA damage preventive activity and antioxidant activity were noted in three plant extracts: <it>C. icosandra, R. damascena </it>and <it>C. scariosus</it>. These three plant extracts showed no cytotoxic activity against U937 cells.</p> <p>Conclusions</p> <p>The 50% methanolic extracts obtained from different plant parts contained significant amounts of polyphenols with superior antioxidant activity as evidenced by the scavenging of DPPH^·, ABTS^·+, NO, ^·OH, O₂^.-and ONOO^-. <it>C. icosandra, R. damascena </it>and <it>C. scariosus </it>showed significant potential for preventing oxidative DNA damage and radical scavenging activity, and the <it>G. gummifera, A. pindrow, V. wallichii, H. antidysenterica, A. pyrethrum, A. tenuifolius </it>and <it>O. mascula </it>extracts showed moderate activity. The extracts of <it>C. icosandra, R. damascena </it>and <it>C. scariosus </it>showed no cytotoxicity against U937 cells. In conclusion, these routinely used Unani plants, especially <it>C. icosandra, R. damascena </it>and <it>C. scariosus</it>, which are reported to have significant activity against several human ailments, could be exploited as potential sources of natural antioxidants for plant-based pharmaceutical industries.</p

Blechnum Orientale Linn - a fern with potential as antioxidant, anticancer and antibacterial agent

<p>Abstract</p> <p>Background</p> <p><it>Blechnum orientale </it>Linn. (<it>Blechnaceae</it>) is used ethnomedicinally for the treatment of various skin diseases, stomach pain, urinary bladder complaints and sterilization of women. The aim of the study was to evaluate antioxidant, anticancer and antibacterial activity of five solvent fractions obtained from the methanol extract of the leaves of <it>Blechnum orientale </it>Linn.</p> <p>Methods</p> <p>Five solvent fractions were obtained from the methanol extract of <it>B. orientale</it> through successive partitioning with petroleum ether, chloroform, ethyl acetate, butanol and water. Total phenolic content was assessed using Folin-Ciocalteu's method. The antioxidant activity was determined by measuring the scavenging activity of DPPH radicals. Cytotoxic activity was tested against four cancer cell lines and a non-malignant cell using MTT assay. Antibacterial activity was assessed using the disc diffusion and broth microdilution assays. Standard phytochemical screening tests for saponins, tannins, terpenoids, flavonoids and alkaloids were also conducted.</p> <p>Results</p> <p>The ethyl acetate, butanol and water fractions possessed strong radical scavenging activity (IC₅₀8.6-13.0 μg/ml) and cytotoxic activity towards human colon cancer cell HT-29 (IC₅₀27.5-42.8 μg/ml). The three extracts were also effective against all Gram-positive bacteria tested: <it>Bacillus cereus, Micrococcus luteus</it>, methicillin-susceptible <it>Staphylococcus aureus </it>(MSSA), methicillin-resistant <it>Staphylococcus aureus </it>(MRSA) and <it>Stapylococcus epidermidis</it>(minimum inhibitory concentration MIC 15.6-250 μg/ml; minimum bactericidal concentration MBC 15.6-250 μg/ml). Phytochemical analysis revealed the presence of flavonoids, terpenoids and tannins. Ethyl acetate and butanol fractions showed highest total phenolic content (675-804 mg gallic acid equivalent/g).</p> <p>Conclusions</p> <p>The results indicate that this fern is a potential candidate to be used as an antioxidant agent, for colon cancer therapy and for treatment of MRSA infections and other MSSA/Gram-positive bacterial infectious diseases.</p

Analyzing factors that influence the folk use and phytonomy of 18 medicinal plants in Navarra

BACKGROUND: This article analyzes whether the distribution or area of use of 18 medicinal plants is influenced by ecological and cultural factors which might account for their traditional use and/or phytonymy in Navarra. This discussion may be helpful for comparative studies, touching as it does on other ethnopharmacological issues: a) which cultural and ecological factors affect the selection of medicinal plants; b) substitutions of medicinal plants in popular medicine; c) the relation between local nomenclature and uses. To analyze these questions, this paper presents an example of a species used for digestive disorders (tea and camomile: Jasonia glutinosa, J. tuberosa, Sideritis hyssopifolia, Bidens aurea, Chamaemelum nobile, Santolina chamaecyparissus...), high blood pressure (Rhamnus alaternus, Olea europaea...) or skin diseases (Hylotelephium maximum, H. telephium, Anagallis arvensis, A. foemina). METHODS: Fieldwork began on January 2004 and continued until December 2006. During that time we interviewed 505 informants in 218 locations in Navarra. Information was collected using semi-structured ethnobotanical interviews, and we subsequently made maps using Arc-View 8.0 program to determine the area of use of each taxon. Each map was then compared with the bioclimatic and linguistic map of Navarra, using the soil and ethnographic data for the region, and with other ethnobotanical and ethnopharmacological studies carried out in Europe. RESULTS: The results clearly show that ecological and cultural factors influence the selection of medicinal plants in this region. Climate and substrate are the most important ecological factors that influence the distribution and abundance of plants, which are the biological factors that affect medicinal plant selection. CONCLUSION: The study of edaphological and climatological factors, on the one hand, and culture, on the other, can help us to understand why a plant is replaced by another one for the same purposes, either in the same or in a different area. In many cases, the cultural factor means that the use of a species is more widespread than its ecological distribution. This may also explain the presence of synonyms and polysemies which are useful for discussing ethnopharmacological data

AN AFRICAN HERBAL PHARMACOPEIA COULD UNDERPIN THE MEDICINAL PLANT INDUSTRY ON THE AFRICAN CONTINENT

Paper prepared and presented on behalf of the ’Association of African Medicinal Plants Standards – AAMPS’ Africa is a continent endowed with enormous wealth of plant resources. Over 5000 distinct species are known to occur in the forest regions alone and most of them have been used for several centuries in traditional medicine for the prevention and treatment of diseases. African traditional medicine is the oldest and perhaps the most diverse of all medicine systems. The biological and cultural diversity of Africa is reflected in the marked regional differences in healing practices and unfortunately the various systems are poorly recorded and remain so to this day. Yet ancient kingdoms and empires of Africa had extensively codified healing practices. African Materia Medica consists of a mixture of many elements and includes many potent herbs. Few of these are, however, yet recognised in modern pharmacopoeias. Exceptions are Strophanthus, Kola, Catharanthus and Harpagophytum which have been included in several western pharmacopoeias. Although there are several important research publications on medicinal plants from Africa, the study of African medicinal plants has remained fragmented and neglected as compared to India and China. To date Africa has only contributed 83 of the world’s 1100 leading commercial medicinal plants despite the fact that the Sub-Saharan region as well as the Indian Ocean Islands, contain approximately 60.000 plant species – roughly a quarter of the world’s total. The potential that this represents for the business and agricultural sectors is enormous but Africa will lag behind unless it prepares internationally recognised medicinal plant standards. The Medicinal Plants Forum for Commonwealth Africa held in Cape Town in 2000, highlighted the lack of suitable technical specifications and quality control standards as a major constraint to the African herbal industry. Moreover the lack of official recognition from governments generally has been the major handicap to what could become an important income and foreign exchange earner for the continent. A follow up meeting in 2005 witnessed the creation of the Association of African Medicinal Plants Standards (AAMPS) a non profit making company registered in Mauritius set up to implement recommendations outlined in the Centurion Declaration which advocated the preparation of an African Herbal Pharmacopoeia. Over 50 standards have since then been prepared by a team of internationally renowned experts covering most of the most important African medicinal plants. The Association hopes that the publication of these monographs will inter alia, increase Africa’s capacity to build a viable herbal industry incorporating Good Agricultural, Good Manufacturing and Good Laboratory Practices and above all increase the visibility of African Medicinal plants as a source of income generation. Since 2005, AAMPS has established itself as the leading organisation working on medicinal plant standards on the continent. A Scientific Advisory Committee has been established and a number of long term projects have been launched to enable AAMPS to become a self-sustaining entity. These include AAMPS Publishing, which will produce books, manuals and some simple merchandising products including possibly a photo-library service specialising in African medicinal plants and herbal products. AAMPS aims at providing also a laboratory and technical network and a Consultancy and Management Service. In collaboration with other international bodies such as the International Foundation for Sciences (IFS), AAMPS will today launch a joint Fellowship programme and award an annual AAMPS/IFS prize for lifetime achievements in the promotion of African medicinal and aromatic plants. More details on the services to be provided for AAMPS can be obtained form the website: http://www.aamps.or

Medicinal plants volume 2

Liberally illustrated throughout, with geographical distribution maps and botanical line drawings, this is the second of four volumes dealing with medicinal plants of Tropical Africa. Here 409 plants are described in 146 review articles. A useful accompanying CD-ROM contains additional photos and allows for easy text searches