Covering: up to 2010
This review focuses on recent developments in the use of natural products as therapeutics for Alzheimer's disease. The compounds span a diverse array of structural classes and ...are organized according to their mechanism of action, with the focus primarily on the major hypotheses. Overall, the review discusses more than 180 compounds and summarizes 400 references.
This review focuses on recent developments in the use of natural products as therapeutics for Alzheimer's disease. The compounds span a diverse array of structural classes and are organized according to their mechanism of action, with the focus primarily on the major hypotheses. Overall, the review discusses more than 180 compounds and summarizes 400 references.
Cognitive decline can occur with normal ageing and in age‐related brain disorders, such as mild cognitive impairment and dementia, including Alzheimer's disease, with limited pharmacological ...therapies available. Other approaches to reduce cognitive decline are urgently needed, and so, the role of dietary interventions or nutraceuticals has received much attention in this respect. In this review, we examine the evidence for dietary plants and their chemical constituents as nutraceuticals, relevant to both cognitive decline in normal ageing and in dementia. Pharmacological (in vitro and in vivo), clinical and epidemiological evidence is assessed for both frequently consumed plants and their dietary forms, including tea, coffee, cocoa (chocolate), red wine, grapes, citrus and other fruits; in addition to plants used less frequently in certain diets and those that cross the blurred boundaries between foods, nutraceuticals and medicinal plants. For the latter, turmeric, saffron, sage, rosemary and lemon balm are examples of those discussed.
Linked Articles
This article is part of a themed section on The Pharmacology of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.6/issuetoc
In 1960, the US National Cancer Institute embarked on a screening programme to discover new anticancer compounds from plants, but although more than 100 000 compounds have been screened over the past ...50 years, relatively few plant-derived drugs have been approved by the US Food and Drug Administration (FDA).Thousands of trees would be needed to obtain sufficient quantities to meet demands for clinical use-clearly a major conservation issue....attempts to find a sustainable way of obtaining this useful anticancer drug without overharvesting trees were initiated.A related compound, 10-deacetylbaccatin III, was found at higher concentrations in leaves and twigs of the common yew (Taxus baccata); therefore, this compound was used for the semi-synthesis of both paclitaxel (FDA approved in 1992), which has uses that include treatment of ovarian and breast cancers and Kaposi's sarcoma; and its analogue docetaxel (FDA approved in 1996), which is given to patients with breast and non-small-cell lung cancer.Conservation strategies to protect biodiversity are essential, but legislative and due diligence procedures might be complex and could discourage natural product drug discovery research, and perhaps reduce the chances of finding other useful oncology drugs.
Perilla frutescens is cultivated in East Asian countries including Thailand, and the nutlets (single‐seeded fruits) are used as traditional and medicinal food. Perilla nutlets extracted by ethyl ...acetate (EA), 80% ethanol (Eth), and hot water (HW) sequentially were chemically characterized using high‐resolution accurate liquid chromatography‐mass spectrometry with the main compounds detected assigned as rosmarinic acid and derivatives of the flavones apigenin and luteolin, with the more diverse chemical composition observed with the Eth extract. All extracts showed dose‐dependent free‐radical scavenging activity, with the Eth extract the most potent (IC50 = 3.43 mg/ml for ABTS• scavenging and 0.27 mg/ml for DPPH• scavenging). The Eth extract also inhibited AAPH‐induced hemolysis (IC50 = 0.07 mg/ml) more potently than did the HW (IC50 = 0.38 mg/ml) and EA extracts (IC50 = 1.63 mg/ml). An MTT test revealed all the extracts were noncytotoxic at concentrations up to 200 μg/ml. Only the Eth and EA extracts showed protective effects against the generation of reactive oxygen species and lipid peroxidation in FeCl3‐induced HuH7 cells in a dose‐dependent manner. Our findings suggest the Eth extract of Thai perilla nutlets, containing rosmarinic acid and flavones and their derivatives, may have potential to provide protection against oxidative stress in hepatic disorders.
Globally 387 million people currently have diabetes and it is projected that this condition will be the 7th leading cause of death worldwide by 2030. As of 2012, its total prevalence in Central ...America (8.5%) was greater than the prevalence in most Latin American countries and the population of this region widely use herbal medicine. The aim of this study is to review the medicinal plants used to treat diabetes and its sequelae in seven Central American countries: Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua and Panama.
We conducted a literature review and extracted from primary sources the plant use reports in traditional remedies that matched one of the following disease categories: diabetes mellitus, kidney disease, urinary problems, skin diseases and infections, cardiovascular disease, sexual dysfunctions, visual loss, and nerve damage. Use reports were entered in a database and data were analysed in terms of the highest number of use reports for diabetes management and for the different sequelae. We also examined the scientific evidence that might support the local uses of the most reported species.
Out of 535 identified species used to manage diabetes and its sequelae, 104 species are used to manage diabetes and we found in vitro and in vivo preclinical experimental evidence of hypoglycaemic effect for 16 of the 20 species reported by at least two sources. However, only seven of these species are reported in more than 3 studies: Momordica charantia L., Neurolaena lobata (L.) R. Br. ex Cass., Tecoma stans (L.) Juss. ex Kunth, Persea americana Mill., Psidium guajava L., Anacardium occidentale L. and Hamelia patens Jacq. Several of the species that are used to manage diabetes in Central America are also used to treat conditions that may arise as its consequence such as kidney disease, urinary problems and skin conditions.
This review provides an overview of the medicinal plants used to manage diabetes and its sequelae in Central America and of the current scientific knowledge that might explain their traditional use. In Central America a large number of medicinal plants are used to treat this condition and its sequelae, although relatively few species are widely used across the region. For the species used to manage diabetes, there is variation in the availability and quality of pharmacological, chemical and clinical studies to explain traditional use.
Display omitted
Every year between 1.2 and 5.5 million people worldwide are victims of snakebites, with about 400,000 left permanently injured. In Central America an estimated 5500 snakebite cases are reported by ...health centres, but this is likely to be an underestimate due to unreported cases in rural regions. The aim of this study is to review the medicinal plants used traditionally to treat snakebites in seven Central American countries: Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua and Panama.
A literature search was performed on published primary data on medicinal plants of Central America and those specifically pertaining to use against snakebites. Plant use reports for traditional snakebite remedies identified in primary sources were extracted and entered in a database, with data analysed in terms of the most frequent numbers of use reports. The scientific evidence that might support the local uses of the most frequently reported species was also examined.
A total of 260 independent plant use reports were recorded in the 34 sources included in this review, encompassing 208 species used to treat snakebite in Central America. Only nine species were reported in at least three studies: Cissampelos pareira L., Piper amalago L., Aristolochia trilobata L., Sansevieria hyacinthoides (L.) Druce, Strychnos panamensis Seem., Dorstenia contrajerva L., Scoparia dulcis L., Hamelia patens Jacq., and Simaba cedron Planch. Genera with the highest number of species used to treat snakebite were Piper, Aristolochia, Hamelia, Ipomoea, Passiflora and Peperomia. The extent of the scientific evidence available to understand any pharmacological basis for their use against snakebites varied between different plant species.
At least 208 plant species are traditionally used to treat snakebite in Central America but there is a lack of clinical research to evaluate their efficacy and safety. Available pharmacological data suggest different plant species may target different symptoms of snakebites, such as pain or anxiety, although more studies are needed to further evaluate the scientific basis for their use.
Display omitted
Dementia pathologies such as Alzheimer’s disease (AD) are reaching epidemic proportions, yet they are not successfully managed by effective symptomatic treatments. Only five drugs have been developed ...to alleviate cognitive symptoms, and more effective and safe treatments are needed for both the cognitive symptoms and behavioural and psychological symptoms of dementia (BPSD). As two of these licensed drugs (cholinesterase inhibitors ChEIs) are naturally derived (galantamine and rivastigmine), the potential for plants to yield new therapeutic agents has stimulated extensive research to discover new ChEIs together with plant extracts, phytochemicals and their derivatives with other mechanistic effects relevant to dementia treatment. This review presents the potential and actual therapeutic strategies for dementia in relation to the known mechanisms of dementia pathology. Phytochemicals that have shown mechanistic effects relevant to the pathological targets in dementia are discussed, with an emphasis on those showing positive clinical trial evidence. Those phytochemicals discussed include the alkaloid physostigmine, a ChEI from the calabar bean (
Physostigma venenosum
), which has been used as a template for the development of synthetic derivatives that inhibit acetylcholinesterase, including the drug rivastigmine. Also discussed are other ChEI alkaloids including huperzine A, from
Huperzia serrata
, and galantamine, originally from the snowdrop (
Galanthus woronowii
); both alkaloids improve cognitive functions in AD patients. Other phytochemicals discussed include cannabinoids (e.g. cannabidiol) from
Cannabis sativa
, which are emerging as potential therapeutic agents for BPSD, and resveratrol (occurs in various plants) and curcumin (from turmeric
Curcuma longa
), which have been investigated for their pharmacological activities relevant to dementia and their potential effects on delaying dementia progression. The review also discusses plant extracts, and their known constituents, that have shown relevant mechanistic effects for dementia and promising clinical data, but require more evidence for their clinical efficacy and safety. Such plants include
Ginkgo biloba
, which has been extensively studied in numerous clinical trials, with most outcomes showing positive effects on cognitive functions in dementia patients; however, more reliable and consistent clinical data are needed to confirm efficacy. Other plants and their extracts that have produced promising clinical data in dementia patients, with respect to cognition, include saffron (
Crocus sativus
), ginseng (
Panax
species), sage (
Salvia
species) and lemon balm (
Melissa officinalis
), although more extensive and reliable clinical data are required. Other plants that are used in traditional practices of medicine have been suggested to improve cognitive functions (e.g.
Polygala tenuifolia
) or have been associated with alleviation of BPSD (e.g. the traditional prescription yokukansan); such remedies are often prescribed as complex mixtures of different plants, which complicates interpretation of pharmacological and clinical data and introduces additional challenges for quality control. Evidence for the role of natural products in disease prevention, the primary but considerably challenging aim with respect to dementia, is limited, but the available epidemiological and clinical evidence is discussed, with most studies focused on ChEIs, nicotine (from
Nicotiana
species), curcumin, wine polyphenols such as resveratrol and
G. biloba
. Challenges for the development of phytochemicals as drugs and for quality control of standardized plant extracts are also considered.
SUMMARY
An escalating "epidemic” of diseases like Alzheimer's has not yet been met by effective symptomatic treatments or preventative strategies. Among a few current prescription drugs are ...cholinesterase inhibitors including galantamine, originating from the snowdrop. Research into ethnobotanicals for memory or cognition has burgeoned in recent years. Based on a multi‐faceted review of medicinal plants or phytochemicals, including traditional uses, relevant bioactivities, psychological and clinical evidence on efficacy and safety, this overview focuses on those for which there is promising clinical trial evidence in people with dementia, together with at least one other of these lines of supporting evidence. With respect to cognitive function, such plants reviewed include sage, Ginkgo biloba, and complex mixtures of other traditional remedies. Behavioral and psychological symptoms of dementia (BPSD) challenge carers and lead to institutionalization. Symptoms can be alleviated by some plant species (e.g., lemon balm and lavender alleviate agitation in people with dementia; St John's wort treats depression in the normal population). The ultimate goal of disease prevention is considered from the perspective of limited epidemiological and clinical trial evidence to date. The potential value of numerous plant extracts or chemicals (e.g., curcumin) with neuroprotective but as yet no clinical data are reviewed. Given intense clinical need and carer concerns, which lead to exploration of such alternatives as herbal medicines, the following research priorities are indicated: investigating botanical agents which enhance cognition in populations with mild memory impairment or at earliest disease stages, and those for BPSD in people with dementia at more advanced stages; establishing an ongoing authoritative database on herbal medicine for dementia; and further epidemiological and follow up studies of promising phytopharmaceuticals or related nutraceuticals for disease prevention.
Alzheimer's disease (AD) is reaching epidemic proportions yet treatment strategies are limited and are restricted to providing symptomatic relief for the cognitive and behavioral and psychological ...symptoms of dementia (BPSD). Chinese herbal medicine (CHM) has been a valuable source of medicines for centuries and research has burgeoned in recent years to understand the scientific basis for their use. Some plants have been used in CHM for AD symptoms (e.g., Polygala tenuifolia), while others are CHMs for different conditions, but they show mechanistic effects relevant to AD (e.g., Salvia miltiorrhiza). Some CHMs (e.g., Ginkgo biloba extract, and huperzine A from Huperzia serrata) show pharmacological activities relevant to AD, and promising effects on cognitive functions in clinical trials. Other CHMs show effects relevant to BPSD (e.g., Crocus sativus). This chapter discusses available scientific evidence for CHM plants and formulae that have been used both traditionally for AD, and those that have been used traditionally but not specifically for AD symptoms, and encompasses chemical, pharmacological and clinical studies. The ethnopharmacological approach to understanding the use of CHMs for AD is also discussed.
Biodiversity is essential to food security and nutrition locally and globally. By reviewing the global state of edible plants and highlighting key neglected and underutilized species, we attempt to ...unlock plant food resources and explore the role of fungi, which along with the wealth of traditional knowledge about their uses and practices, could help support sustainable agriculture while ensuring better protection of the environment and the continued delivery of its ecosystem services. This work will inform a wide range of user communities, including scientists, conservation and development organizations, policymakers, and the public of the importance of biodiversity beyond mainstream crops.
Societal Impact Statement
Biodiversity is essential to food security and nutrition locally and globally. By reviewing the global state of edible plants and highlighting key neglected and underutilized species (NUS), we attempt to unlock plant food resources and explore the role of fungi, which along with the wealth of traditional knowledge about their uses and practices, could help support sustainable agriculture while ensuring better protection of the environment and the continued delivery of its ecosystem services. This work will inform a wide range of user communities, including scientists, conservation and development organizations, policymakers, and the public of the importance of biodiversity beyond mainstream crops.
Summary
As the world's population is increasing, humanity is facing both shortages (hunger) and excesses (obesity) of calorie and nutrient intakes. Biodiversity is fundamental to addressing this double challenge, which involves a far better understanding of the global state of food resources. Current estimates suggest that there are at least 7,039 edible plant species, in a broad taxonomic sense, which includes 7,014 vascular plants. This is in striking contrast to the small handful of food crops that provide the majority of humanity's calorie and nutrient intake. Most of these 7,039 edible species have additional uses, the most common being medicines (70%), materials (59%), and environmental uses (40%). Species of major food crops display centers of diversity, as previously proposed, while the rest of edible plants follow latitudinal distribution patterns similarly to the total plant diversity, with higher species richness at lower latitudes. The International Union for Conservation of Nature Red List includes global conservation assessments for at least 30% of edible plants, with ca. 86% of them conserved ex situ. However, at least 11% of those species recorded are threatened. We highlight multipurpose NUS of plants from different regions of the world, which could be key for a more resilient, sustainable, biodiverse, and community participation‐driven new “green revolution.” Furthermore, we explore how fungi could diversify and increase the nutritional value of our diets. NUS, along with the wealth of traditional knowledge about their uses and practices, offer a largely untapped resource to support food security and sustainable agriculture. However, for these natural resources to be unlocked, enhanced collaboration among stakeholders is vital.
PDF
