A Review of African Medicinal Plants and Functional Foods for the Management of Alzheimer's Disease-related Phenotypes, Treatment of HSV-1 Infection and/or Improvement of Gut Microbiota.

Alzheimer's disease (AD), which is a progressive neurodegenerative disorder is the most common form of dementia globally. Several studies have suggested alteration in the gut microbiota and HSV-1 infection as contributing factors to the development of the disease. As at now, there are no AD attenuating agents and AD pharmacotherapy is focused on managing symptoms while plants used in ethnomedicine remain potential sources of drugs for the treatment of the condition. Here, we reviewed published databases for African ethnomedicinal plants and functional foods of African origin that are used in the management of AD-related phenotypes, treatment of herpes simplex virus -1 (HSV-1) and/or improvement of gut microbiota. A total of 101 unique plant species and 24 different types of traditionally prepared African functional foodstuff were identified. Of the 101 identified plant species, 50 species serve as functional foodstuffs. Twenty-three (23) of the ethnomedicinal plant families were successfully identified for the treatment and management of AD-related phenotypes and age-related dementia. Eighteen (18) African plant species from 15 families were also identified as potent remedies for HSV-1; while many African wild fruits (3 species), roots and tubers (7 species), leafy vegetables (14 species), and seaweeds (26 species) were functional foods for modifying AD-related phenotypes. It was concluded that African medicinal plants are potential sources of both AD attenuating agents and phytocompounds that may be used against HSV-1 infection and alteration of gut microbiota. Additionally, a number of African functional foods are important sources of prebiotics and probiotics.

Hydro-ethanol extract of Holarrhena floribunda stem bark exhibits anti-anaphylactic and anti-oedematogenic effects in murine models of acute inflammation.

BACKGROUND: Holarrhena floribunda (G.Don) T.Durand & Schinz stem bark has anecdotal use in Ghanaian folk medicine for the management of inflammatory conditions. This study was conducted to investigate the in vivo anti-inflammatory activity of the bark extract using models of acute inflammation in male Sprague Dawley rats, C57BL/6 mice and ICR mice. METHODS: A 70% hydro-ethanol extract of the stem bark (HFE) was evaluated at doses of 5-500 mg/kg bw. Local anaphylaxis was modelled by the pinnal cutaneous anaphylactic test. Systemic anaphylaxis or sepsis were modeled by compound 48/80 or lipopolysaccharide, respectively. Clonidine-induced catalepsy was used to investigate the effect on histamine signaling. Anti-oedematogenic effect was assessed by induction with carrageenan. Effects on mediators of biphasic acute inflammation were studied using histamine and serotonin (early phase) or prostaglandin E2 (late phase). RESULTS: HFE demonstrated anti-inflammatory and/or anti-oedematogenic activity comparable to standard doses of aspirin and diclofenac (inhibitors of cyclooxygenases-1 and -2), chlorpheniramine (histamine H1-receptor antagonist), dexamethasone (glucocorticoid receptor agonist), granisetron (serotonin receptor antagonist) and sodium cromoglycate (inhibitor of mast cell degranulation). All observed HFE bioactivities increased with dose. CONCLUSIONS: The data provide evidence that the extract of H. floribunda stem bark has anti-anaphylactic and anti-oedematogenic effects; by interfering with signalling or metabolism of histamine, serotonin and prostaglandin E2 which mediate the progression of inflammation. The anti-inflammatory and antihistaminic activities of HFE may be relevant in the context of the management of COVID-19.

Nutritional value and safety of animal feed supplemented with Talaromyces verruculosus-treated cocoa pod husks.

Theobromine exerts deleterious effects on animal physiology. Removal of theobromine from the millions of metric tons of cocoa pod husks (CPH) discarded annually could allow for the production of cheap, CPH-based animal feed. The aim of this study was to evaluate safety and nutritional value of bio-detheobrominated CPH in Sprague-Dawley rats. Theobromine was removed from CPH by treatment with an isolate of Talaromyces verruculosus (TvTD). Substituted feeds containing CPH were formulated by replacing 30% or 50% of the maize content of regular rat feed with TvTD-treated or inactivated TvTD-treated CPH. Feeding groups included control groups without or with theobromine administration. Effects of the feed formulations on water and feed intake, weight gain, blood biochemistry and organ-specific toxicity were assessed. Rats ingesting theobromine in inactivated TvTD-treated CPH-based diet or by oral gavage variably exhibited marked deleterious effects, mainly evident in body weight, thymus wet weight and tissue histology. In contrast, substitution with TvTD-treated CPH caused significant increase in body weight. Substitution at 30% did not cause mortality or organ-specific toxicity with reference to the testes, kidneys, spleen or liver, unlike substitution at 50%. The data demonstrate that detheobrominated CPH may safely replace up to 30% of maize in animal feed formulations.

Establishment of a quantitative and qualitative analysis and isolation method for tetracyclic iridoids from Morinda lucida Bentham leaves.

A new high performance liquid chromatography (HPLC) method has been established for quantitative and qualitative analysis of three tetracyclic iridoids: ML-2-3 (1), molucidin (2), and ML-F52 (3), which are responsible for anti-trypanosomal and anti-leishmanial activities of Morinda lucida Bentham leaves. Separation of 1-3 from dried 80% aqueous (aq.) ethanol extract was achieved on a reversed-phase cholester column packed with cholesteryl-bonded silica using an acetonitrile-0.1% aq. formic acid mobile phase system. Ultraviolet-visible (UV-VIS) spectroscopy was employed for detection of compounds, and their contents were determined by measuring absorbance at 254 nm. Depending on the above system, several factors potentially affecting the concentration of tetracyclic iridoids were evaluated resulting in several variation on plant organs, seasonality, variation between individual trees, and branch positions within the trees. Moreover, we developed a simple, quick, and effective method for tetracyclic iridoid isolation from M. lucida leaves that consisted of extraction by sonication into 80% aq. ethanol, basic hydrolysis, acid neutralization, liquid-liquid extraction into an organic solvent, and reverse phase open column chromatography. Employing this method, we have succeeded to obtain 1 as a colorless crystal yielding of 0.23%, which was 28 times higher than that of previous isolation method. Setting up methodology in this paper may be important for future in vitro and in vivo studies of tetracyclic iridoids and moreover for their applications in new drug design and development.

Mitochondria as pharmacological targets: the discovery of novel anti-obesity mitochondrial uncouplers from Africa's medicinal plants.

Obesity results from prolonged positive imbalance between energy in take and expenditure. When food intake chronically exceeds the body's energy need, an efficient metabolism results in the storage of the excess energy as fat. Mitochondria are the main centre for energy production in eukaryotic cells. Mitochondrial proton cycling is responsible for a significant proportion of basal or standard metabolic rate, therefore, further uncoupling of mitochondria may be a good way to increase energy expenditure and hence represent a good pharmacological target for the treatment of obesity. This implies that, any chemical agent or photochemical compound that further uncouples the mitochondria in vivo without having any effect on mitochondria activity could be a potential target in finding treatment for obesity. In the past, uncoupling by 2, 4-dinitrophenol has been used this way with notable success. This paper discusses the mitochondria as targets in the discovery of potential plant natural anti-obesity products from Africa's rich rainforests.