An Investigation of Potential Sources of Nutraceuticals from the Niger Delta Areas, Nigeria for Attenuating Oxidative Stress

The Genus Dacryodes Vahl.: Ethnobotany, Phytochemistry and Biological Activities

Dacryodes Vahl. species, belonging to the Burseraceae family, are widely used in traditional medicine in tropical regions to treat a range of ailments including malaria, wounds, tonsillitis, and ringworms. This review discusses the distribution, ethnobotanical uses, phytochemistry, and bioactivities of Dacryodes species. The intent is to spur future research into isolating and identifying key active principles, secondary metabolites, and crude extracts, and evaluating their pharmacological and toxicological effects, as well as the mechanism of actions to understand their medicinal benefits. A systematic review of scientific electronic databases from 1963 to 2022 including Scifinder, Scopus, Pubmed, Springer Link, ResearchGate, Ethnobotany Research and Applications, Google Scholar, and ScienceDirect was conducted with a focus on Dacryodes edulis (G.Don) H.J. Lam and Dacryodes rostrata (Blume) H.J. Lam. Pharmacological data revealed that D. edulis isolates contain secondary metabolites and other phytochemical groups belonging to the terpenoids class with anti-microbial, anticancer, antidiabetic, antiinflammatory and hepatoprotective activities, highlighting its pharmacological potential in the therapy or management of diverse cancers, cardiovascular, and neurological diseases. Thus, phytochemicals and standardized extracts from D. edulis could offer safer and cost-effective chemopreventive and chemotherapeutic health benefits/regimen, or as alternative therapeutic remedy for several human diseases. Nevertheless, the therapeutic potential of most of the plants in the genus have not been exhaustively explored with regard to phytochemistry and pharmacology, but mostly complementary approaches lacking rigorous, scientific research-based knowledge. Therefore, the therapeutic potentials of the Dacryodes genus remain largely untapped, and comprehensive research is necessary to fully harness their medicinal properties.

The Future of Food: Domestication and Commercialization of Indigenous Food Crops in Africa over the Third Decade (2012–2021)

This paper follows the transition from ethnobotany to a deeper scientific understanding of the food and medicinal properties of African agroforestry tree products as inputs into the start of domestication activities. It progresses on to the integration of these indigenous trees as new crops within diversified farming systems for multiple social, economic and environmental benefits. From its advent in the 1990s, the domestication of indigenous food and non-food tree species has become a global programme with a strong African focus. This review of progress in the third decade is restricted to progress in Africa, where multi-disciplinary research on over 59 species has been reported in 759 research papers in 318 science publications by scientists from over 833 research teams in 70 countries around the world (532 in Africa). The review spans 23 research topics presenting the recent research literature for tree species of high priority across the continent, as well as that in each of the four main ecological regions: the humid zone of West and Central Africa; the Sahel and North Africa; the East African highlands and drylands; and the woody savannas of Southern Africa. The main areas of growth have been the nutritional/medicinal value of non-timber forest products; the evaluation of the state of natural resources and their importance to local people; and the characterization of useful traits. However, the testing of putative cultivars; the implementation of participatory principles; the protection of traditional knowledge and intellectual property rights; and the selection of elite trees and ideotypes remain under-researched. To the probable detriment of the upscaling and impact in tropical agriculture, there has been, at the international level, a move away from decentralized, community-based tree domestication towards a laboratory-based, centralized approach. However, the rapid uptake of research by university departments and national agricultural research centres in Africa indicates a recognition of the importance of the indigenous crops for both the livelihoods of rural communities and the revitalization and enhanced outputs from agriculture in Africa, especially in West Africa. Thus, on a continental scale, there has been an uptake of research with policy relevance for the integration of indigenous trees in agroecosystems and their importance for the attainment of the UN Sustainable Development Goals. To progress this in the fourth decade, there will need to be a dedicated Centre in Africa to test and develop cultivars of indigenous crops. Finally, this review underpins a holistic approach to mitigating climate change, as well as other big global issues such as hunger, poverty and loss of wildlife habitat by reaping the benefits, or ‘profits’, from investment in the five forms of Capital, described as ‘land maxing’. However, policy and decision makers are not yet recognizing the potential for holistic and transformational adoption of these new indigenous food crop opportunities for African agriculture. Is ‘political will’ the missing sixth capital for sustainable development?

Anti-Cholinesterase Combination Drug Therapy as a Potential Treatment for Alzheimer's Disease

Alzheimer’s disease (AD) is a burgeoning social and healthcare problem. Cholinesterase inhibitors (ChEIs) are employed for symptomatic treatment of AD, but often elicit adverse drug reactions (ADRs). Herein, the potency of the ChEIs, donepezil, tacrine, berberine, and galantamine to inhibit human or Torpedo californica acetylcholinesterase (tcAChE) proteins were evaluated. The efficacy of dual-drug combinations to inhibit human AChE directly and within differentiated neurons was also quantified. ChEI potency was in the order: donepezil > tacrine > berberine > galantamine for both AChEs. Dual-drug combinations of berberine and tacrine (BerTac), berberine and galantamine (BerGal), and tacrine and donepezil (TacDon) all produced synergistic outcomes for AChE inhibition. Donepezil and berberine (DonBer) and tacrine and galantamine (TacGal) elicited antagonistic responses. Donepezil and galantamine (DonGal) was synergistic for human AChE but antagonistic for tcAChE. After application of dual-drug combinations to neuronal cells, BerTac, BerGal, DonGal, and DonBer all showed synergistic inhibition of AChE, TacDon additive, and TacGal antagonistic effects. BerGal produced the most potent synergism and reduced total drug dose by 72%. Individual ChEIs or dual-drug combinations were relatively non-toxic to neuronal cells, and only reduced cell viability at concentrations two–three orders of magnitude greater than that required to inhibit AChE. In summary, dual-drug combinations of ChEIs potentially represent a novel means of AD patient treatment, with reduced and more cost-effective drug dosing, and lowered likelihood of ADRs.

Potential Nutraceutical Properties of Leaves from Several Commonly Cultivated Plants

Chronic dietary ingestion of suitable phytochemicals may assist with limiting or negating neurodegenerative decline. Current therapeutics used to treat Alzheimer disease elicit broad adverse drug reactions, and alternative sources of cholinesterase inhibitors (ChEIs) are required. Herein, we screened methanolic extracts from seven commonly cultivated plants for their nutraceutical potential; ability to inhibit acetylcholinesterase (AChE) and butyryl-cholinesterase (BuChE), and provision of antioxidant activity through their 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) free radical scavenging capabilities. Potential neurotoxicity of plant extracts was examined via application to SHSY-5Y neuroblastoma cells and quantitation of cell viability. Methanolic extracts of Citrus limon (Lemon), Bombax ceiba (Red silk-cotton), Lawsonia inermis (Henna), Eucalyptus globulus (Eucalyptus), Ocimum basilicum (Basil), Citrus reticulata (Mandarin orange), and Mentha spicata (Spearmint) all displayed concentration-dependent inhibition of AChE and BuChE. The majority of extracts inhibited AChE and BuChE to near equipotency, with Henna and Eucalyptus extracts the two most potent ChEIs. All plant extracts were able to scavenge free radicals in a concentration-dependent manner, with Eucalyptus the most potent antioxidant. Toxicity of plant extracts to neuronal cells was concentration dependent, with Eucalyptus also the most toxic extract. Fractionation of plant extracts and analysis by mass spectrometry identified a number of plant polyphenols that might have contributed to the cholinesterase inhibition: 3-caffeoylquinic acid, methyl 4-caffeoylquinate, kaempferol-acetyl-glycoside, quercetin 3-rutinoside, quercetin-acetyl-glycoside, kaempferol 3-O-glucoside, and quercetin 3-O-glucoside. In silico molecular modeling of these polyphenols demonstrated their improved AChE and BuChE binding affinities compared to the current FDA-approved dual ChEI, galantamine. Collectively, all the plant extracts contained nutraceutical agents as antioxidants and ChEIs and, therefore, their chronic consumption may prove beneficial to combat the pathological deficits that accrue in Alzheimer disease.

Characterization of the Phenolic Compounds in Different Plant Parts of Amaranthus cruentus Grown under Cultivated Conditions

Phenolic compounds that are present in amaranth crops have gained a lot of interest from researchers due to their health benefits potential. Therefore, the aim of this study was to investigate phenolic compounds present in different plant parts of Amaranthuscruentus using liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry. Moreover, data were analyzed by one-way analysis of variance of the statistical analysis software, whereas commercial statistical package version 4.02 was used for principal component analysis. A total of 21 phenolic compounds were detected and eight were not identified. Caffeoylsaccharic acid isomer, coumaoryl saccharic acid, tryptophan, feruloyl-d-saccharic acid isomer a, b, and c, caffeoyl isocitrate, quercetin 3-O-rhamnosyl-rhamnosyl-glucoside, feruloyl isocitrate, hyperoside, kaempferol rutinoside, and alkaloid compounds were mostly detected in tender and mature leaves. Generally, rutin content was higher (p < 0.05) in most vegetative parts of the amaranth plant, thus, late maturity leaves, tender leaves, and mature leaves, respectively. Lower quantities of rutin were observed in tender grains, flowers, and mature grains. It can be concluded that amaranth contains phenolic compounds, predominantly in the vegetative parts, which makes it to be a promising source of phenolic compounds beneficial to human health.

Plant Polyphenols, More than Just Simple Natural Antioxidants: Oxidative Stress, Aging and Age-Related Diseases

The present editorial serves as an introduction to the Special Issue "Antioxidant and Anti-aging Action of Plant Polyphenols". It also provides a summary of the polyphenols, their biological properties and possible functions as medicines, the importance of traditional medicines as a source of inspiration, the rationalization of new uses of plant extracts which lead to applications in modern medicine, the status of modern green-chemistry extraction methods, and some reflections on future prospects. Here, the articles from this Special Issue, and the main aspects of the antioxidant and anti-aging effects of plant polyphenols are discussed in the form of seven questions.

Potential Application of Tetrapleura tetraptera and Hibiscus sabdariffa (Malvaceae) in Designing Highly Flavoured and Bioactive Pito with Functional Properties

Sorghum beer (pito) is an indigenous alcoholic beverage peculiar to northern Ghana and parts of other West African countries. It is overwhelmed with calories, essential amino acids (such as lysine, etc.), B-group vitamins, and minerals. In recent years, there has been a growing demand for highly flavoured yet functional pito in Ghana; however, the local producers lack the prerequisite scientific expertise in designing such products. We propose the utilization of Tetrapleura tetraptera (TT) and Hibiscus sabdariffa (HS) as cheap and readily available materials in designing functional flavoured pito. The addition of TT and HS would not alter the fermentation profile but rather augment the starter with nutrients, thus improving the fermentation performance and shelf life of the final pito. In vitro and in vivo studies provide substantive evidence of antioxidant, nephro- and hepato-protective, renal/diuretic effect, anticholesterol, antidiabetic, and antihypertensive effects among others of the TT and HS, hence enriching the pito with health-promoting factors and consequently boosting the health of the consumer. Herein, we summarise the phytochemical, biological, pharmacological, and toxicological aspects of TT and HS as well as the technology involved in brewing the novel bioactive-flavoured pito. In addition, we also report the incidence of heavy metal in conventional pito.