African Plants Research Articles

Elucidating the antidiabetic potential of Chrysophyllum albidum: An integrative approach combining in vitro and in silico studies on dipeptidyl peptidase IV and adenosine deaminase inhibition

Diabetes mellitus remains a significant global health challenge, necessitating the discovery of novel therapeutic interventions. This study elucidated the inhibitory potential of phytochemicals derived from the African star apple (Chrysophyllum albidum (C. albidum)) against two critical enzymes implicated in diabetes pathogenesis: dipeptidyl peptidase IV (DPP-IV) and adenosine deaminase (ADA). A multi-pronged approach integrating in vitro enzyme inhibition assays and in silico molecular docking simulations was employed. Aqueous extracts from various C. albidum fruit parts were evaluated for enzyme inhibition using colorimetric assays. Molecular docking studies were performed using the crystal structures of DPP-IV (PDB ID: 2ONC) and ADA (PDB ID: 3IAR) to investigate binding interactions and identify potential hit compounds using autodock-vina. In vitro assays revealed potent, dose-dependent inhibition of both DPP-IV and ADA by the aqueous extracts, with the fruit's seed coat extract exhibiting the most promising activity (IC50 = 4.88 μg/mL and 18.25 μg/mL against DPP-IV and ADA, respectively). Molecular docking unveiled several C. albidum hits, including CIDs 562,128 (-9.569), 6,430,793 (-9.501), and 23,647,311 (-8.286), and 73,530 (-6.936) exhibiting favorable drug-like properties and binding geometries. This integrative study unveiled the inhibitory potential of C. albidum phytochemicals against DPP-IV and ADA, with a notable correlation between in vitro and in silico data, underscoring the therapeutic promise of this indigenous African plant source for developing novel antidiabetic agents, most importantly the seedcoat.

3-Hydroxyneocryptolepine, a new indoloquinoline alkaloid from the roots of Cryptolepis sanguinolenta (Lindl.) Schltr

Phytochemical investigations of the African ethnomedicinal plant Cryptolepis sanguinolenta (Lindl.) Schltr. (Apocynaceae) have yielded only a small number of rare naturally occurring indoloquinoline alkaloids. Our recent work has resulted in the isolation of a new indoloquinoline named 3-hydroxyneocryptolepine, which was obtained from an ethanolic extract of the roots. The structure of the compound was elucidated based on 1D and 2D NMR as well as HRESIMS spectral evidence. LDL uptake promotion activity of the compound in HepG2 cells was not significant.

Fundamental overview and applicability of thaumatin

There are currently worldwide efforts to reduce sugar intake due to various adverse health effects linked with the overconsumption of sugar. Natural sweeteners have been used as an alternative to artificial sweeteners, nutritive sugar for numerous applications. However, their long-term effects on human health remain. Thaumatin is a class of sweet proteins found in West African plants from the arils of Thaumatococcus daniellii. The article reviews the Thaumatin Morphology, Collection time, Extraction, Bio-production, Bio-transformation, Properties like sensory properties, Characteristics of plants ie Sweetness, Composition, Isolation process, Mode of action, Binding site of the receptor, Applications, Uses and overall safety aspects of Thaumatin is known as sweetest compound till the date.

Evaluating local plant species for effective fall armyworm management strategies in Taiwan

BackgroundThe emergence of Spodoptera frugiperda (fall armyworm; FAW) in the world has raised concerns regarding its impact on crop production, particularly on corn and sorghum. While chemical control and Bt crops have been effective in managing FAW damage, the development of pesticide-resistant and Bt-resistant strains necessitates alternative control methods. The push-pull farming system has gained attention, but direct utilization of African plant species in Taiwan faces challenges due to invasive potential and climatic disparities. Therefore, identifying and evaluating suitable local plant species, such as Napier grass (Pennisetum purpureum), Desmodium species, and signal grass (Brachiaria brizantha), is crucial for implementing effective FAW management strategies in Taiwan.ResultsIn screening fifty Napier grass germplasms, all demonstrated an antibiotic effect, reducing leaf consumption compared to corn. Notably, thirty-five germplasms exhibited robust antibiotic traits, decreasing FAW consumption and increasing mortality rates. Three Napier grass germplasms also attracted more female moths for oviposition. Further evaluation of selected Napier grass germplasms and signal grass demonstrated efficacy in reducing FAW larval weight and survival duration. Additionally, Desmodium species, particularly D. uncinatum, showed promising toxicity against FAW larvae.ConclusionOur findings support the effectiveness of selected Napier grass germplasms and signal grass as pull plants, and highlight the potential of D. uncinatum as a push plant in FAW management strategies in Taiwan.

Indigenous Medicinal Plants Used in the Management of Diabetes in Africa: 5 Years (2019-2024) in Perspective.

(1) Background: The utilization of medicinal plants in the management of diabetes is of great importance to the health of the indigenous population on the African continent. The high cost of orthodox conventional medicines coupled with the perceived side effects encourages the high patronage of indigenous medicinal plants in the management of this metabolic disorder. We conducted a review on the indigenous African medicinal plants that could be useful in preclinical and clinical trials in the field of diabetes mellitus research. (2) Methods: Data were mined from research articles published and associated with the use of medicinal plants in the management of diabetes on the African continent (from January 2019 to March 2024). Literature from ethnobotanical studies on the African continent was searched from the Google Scholar, SCOPUS, Medline, Web of Science and PubMed databases. We employed the following keywords: "indigenous plants", "diabetes in Africa" and "antidiabetic effect of medicinal plants". (3) Results: A total of 52 medicinal plants belonging to 31 families were recorded in this study. Amaryllidaceae (14.28%), Fabaceae (9.52%) and Asteraceae (9.52%) were the most cited plant families. The frequently used indigenous medicinal plants on the African continent were Allium sativum L. (n = 6), Olea europaea L. (n = 6), Azadirachta indica A. Juss (n = 5), Allium cepa L. (n = 5) and Moringa oleifera Lam. (n = 5). The highly cited parts of the plant used in the management of diabetes were the leaves (45.55%), bark (14.44%) and bulbs (12.22%). The preferred methods of the preparation of herbal medicines were decoction (45.23%) and infusion (25%). Oral (52.32%) was the preferred route of the administration of herbal medicine on the African continent. (4) Conclusions: The data revealed some similarities in the way countries on the African continent manage diabetes. This interesting observation will assist in our quest towards obtaining a standardized protocol using indigenous medicinal plants to combat diseases on the African continent.

New Members of the Centrapalus Coumarin and Pauciflorin Series from Centrapalus pauciflorus.

Monoterpene and 5-methylcoumarin- or 5-methylchromone-coupled meroterpenoids occurring mainly in the Asteraceae species proved to have high potency against protozoans, worms, and various tumor cells, which make them interesting targets for searching for new bioactive compounds. The African plant Centrapalus pauciflorus was applied in traditional medicine for healing chest pain and stomach aches. Three new meroterpenoids named centrapalus coumarin N (2), pauciflorins P (3), and Q (4), and the already known cyclohoehnelia coumarin (1), were isolated from the chloroform extract of C. pauciflorus, together with centrapalus coumarin O (5), which was obtained for the first time from a natural source. The structures were established from HRESIMS, 1D (1H NMR, 13C NMR JMOD) and 2D NMR (HSQC, HMBC, 1H-1H COSY, NOESY) spectroscopies, and the absolute stereochemistry of 5 was determined by single-crystal X-ray diffraction. Compounds 1, 2, and 5 are hybrid molecules of 5-methylcoumarin-monoterpene origin. Centrapalus coumarin N is the first example of meroterpenoids, where a monoterpene is fused with a coumarin and an acetophenone unit. Pauciflorins P and Q are dimeric meroterpenoid isomers. Centrapalus coumarins N and O were tested for antiproliferative activity against human adherent breast (MCF-7, MDA-MB-231), cervical (HeLa, SiHa), and ovarian (A2780) cancer cell lines, and were additionally included to obtain data concerning cancer selectivity. Both compounds exhibited moderate (IC50 > 10 µM) but selective activity against A2780 cells.

Ethnopharmaceutical Study of Plants as an Alternative Treatment Gastritis Baluwarti Society

The Baluwarti community is a community that lives around the Surakarta Hadiningrat Palace with consist of princes relatives, courtiers, and ordinary people. Baluwarti community to currently still carrying out traditional medicine traditions by utilizing medicinal plants as a treatment in Baluwarti village, gastritis is included in the category of 15 diseases frequent highs. This research is an ethnopharmaceutical research aimed at to find out the local name of the plant, the part used, the way of processing, the rules usage, and treatment methods used as an alternative treatment of gastritis carried out by the community around the Surakarta Hadiningrat Palace. This research is descriptive research that uses quantitative methods. The analysis parameters used are: Use Value (UV), Informant Consensus Factor (ICF), Fidelity Level (FL), and Plant Part Value (PPV). Sampling technique using snowball sampling through open ended interview with the community around the Surakarta Hadiningrat Palace. Based on results interviews with 17 informants found 13 types of medicinal plants used as alternatives treatment of gastritis includes African plants, neem plants, cassava genderuwo, white turmeric, temulawak, cassava, and ginger are processed by boiling. In addition, breadfruit pace and white duwet that can be eaten immediately. Turmeric by processing is ground and grated, as well as aloe vera that is taken mucus using a spoon. The result of the ICF value obtained disease gastritis with a value of 0.25. Plant species that have the highest UV value with a value 0.647 and the highest FL yield of 64.70% is turmeric (Curcuma longa L.) while the PPV value obtained the use of plant parts that are most often used as medicinal materials traditional is 30% rhizome, 18% leaf, 12% fruit, 12% tuber, and 6% mucus.

Investigation of the antimycobacterial activity of African medicinal plants combined with chemometric analysis to identify potential leads

The emergence of drug-resistant Mycobacterium tuberculosis strains is a threat to global health necessitating the discovery of novel chemotherapeutic agents. Natural products drug discovery, which previously led to the discovery of rifamycins, is a valuable approach in this endeavor. Against this backdrop, we set out to investigate the in vitro antimycobacterial properties of medicinal plants from Ghana and South Africa, evaluating 36 extracts and their 252 corresponding solid phase extraction (SPE) generated fractions primarily against the non-pathogenic Mycobacterium smegmatis and Mycobacterium aurum species. The most potent fraction was further evaluated in vitro against infectious M. tuberculosis strain. Crinum asiaticum (bulb) (Amaryllidaceae) emerged as the most potent plant species with specific fractions showing exceptional, near equipotent activity against the non-pathogenic Mycobacterium species (0.39 µg/ml ≤ MIC ≤ 25 µg/ml) with one fraction being moderately active (MIC = 32.6 µg/ml) against M. tuberculosis. Metabolomic analysis led to the identification of eight compounds predicted to be active against M. smegmatis and M. aurum. In conclusion, from our comprehensive study, we generated data which provided an insight into the antimycobacterial properties of Ghanaian and South African plants. Future work will be focused on the isolation and evaluation of the compounds predicted to be active.

Identification of South African Plant-Based Bioactive Compounds as Potential Inhibitors against the SARS-CoV-2 Receptor.

The expected progress in SARS-CoV-2 vaccinations, as anticipated in 2020 and 2021, has fallen short, exacerbating global disparities due to a lack of universally recognized "safe and effective" vaccines. This study focuses on extracts of South African medicinal plants, Artemisia annua and Artemisia afra, to identify metabolomic bioactive compounds inhibiting the binding of the SARS-CoV-2 spike protein to ACE2 receptors. The extracts were monitored for cytotoxicity using a resazurin cell viability assay and xCELLigence real-time cell analyzer. Chemical profiling was performed using UPLC-MS/MS, orthogonal projection to latent structures (OPLS), and evaluated using principle component analysis (PCA) models. Identified bioactive compounds were subjected to in vitro SARS-CoV-2 enzyme inhibition assay using standard methods and docked into the spike (S) glycoprotein of SARS-CoV-2 using Schrodinger® suite followed by molecular dynamics simulation studies. Cell viability assays revealed non-toxic effects of extracts on HEK293T cells at lower concentrations. Chemical profiling identified 81 bioactive compounds, with compounds like 6″-O-acetylglycitin, 25-hydroxyvitamin D3-26,23-lactone, and sesaminol glucoside showing promising binding affinity. Molecular dynamics simulations suggested less stable binding, but in vitro studies demonstrated the ability of these compounds to interfere with SARS-CoV-2 spike protein's binding to the human ACE2 receptor. Sesaminol glucoside emerged as the most effective inhibitor against this interaction. This study emphasizes the importance of multiplatform metabolite profiling and chemometrics to understand plant extract composition. This finding is of immense significance in terms of unravelling metabolomics bioactive compounds inhibiting the binding of the SARS-CoV-2 spike protein to ACE2 receptors and holds promise for phytotherapeutics against SARS-CoV-2.

Green synthesis and characterization of AgNPs, liposomal loaded AgNPs and ZnPcS4 photosensitizer for enhanced photodynamic therapy effects in MCF-7 breast cancer cells

Breast cancer remains a formidable challenge in oncology despite significant advancements in treatment modalities. Conventional therapies such as surgery, chemotherapy, radiation therapy, and hormonal therapy have been the mainstay in managing breast cancer for decades. However, a subset of patient's experiences treatment failure, leading to disease recurrence and progression. Therefore, this study investigates the therapeutic potential of green-synthesized silver nanoparticles (AgNPs) using an African medicinal plant (Dicoma anomala methanol root extract) as a reducing agent for combating breast cancer. AgNPs were synthesized using the bottom-up approach and later modified with liposomes (Lip) loaded with photosensitizer (PS) zinc phthalocyanine tetrasulfonate (Lip@ZnPcS4) using thin film hydration method. The successful formation and Lip modification of AgNPs, alongside ZnPcS4, were confirmed through various analytical techniques including UV–Vis spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), high-resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Following a 24 h treatment period, MCF-7 cells were assessed for viability using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT viability assay), cell death analysis using mitochondrial membrane potential (MMP) (ΔΨm), Annexin V-fluorescein isothiocyanate (FITC)-propidium iodide (PI) kit, and caspase- 3, 8 and 9 activities. The experiments were repeated four times (n = 4), and the results were analyzed using SPSS statistical software version 27, with a confidence interval set at 0.95. The synthesized nanoparticles and nanocomplex, including AgNPs, AgNPs-Lip, Lip@ZnPcS4, and AgNPs-Lip@ZnPcS4, exhibited notable cytotoxicity and therapeutic efficacy against MCF-7 breast cancer cells. Notably, the induction of apoptosis, governed by the upregulation of apoptotic proteins i.e., caspase 8 and 9 activities. In addition, caspase 3 was not expressed by MCF-7 cells in both control and experimental groups. Given the challenging prognosis associated with breast cancer, the findings underscore the promise of liposomal nanoformulations in cancer photodynamic therapy (PDT), thus warranting further exploration in clinical settings.

Dose-dependent regulation of morphological, physio-biochemical, nutritional, and metabolic responses by cobalt in Tagestes erecta L. plants exposed to salinity stress

Salinity is a major concern globally and causing reduction in crop growth and development thereby lowering food production. Interestingly, cobalt (Co), a multifunctional non-essential micro-element, has an important role in improving growth and development under salinity stress. In the current study, the effects of Co on the morphological, biochemical, nutritional, and metabolic changes of African marigold plants at two salinity levels were assessed. Two concentrations of Co (C1; 10 mg/L and C2; 20 mg/L) were applied as foliar application to the marigold plants under salinity (S1; 300 mM and S2; 600 mM) stress. The results indicated that salinity substantially reduced the growth by negatively affecting the nutritional and metabolic profile. Interestingly, the C1 application mitigated the salinity effects and improved all the studied parameters including vegetative, nutritional, biochemical and metabolites (amino acids, fatty acids, organic acids, sugars, carotenoids, flavonoids, and terpenoids) by reducing the reactive oxygen species (ROS) and methylglyoxal (MG)-induced oxidative stress, at two salinity levels. The overall results revealed that C1was an ideal dose for marigold plants undergoing salinity stress since C2 application showed some toxicity symptoms under both the salinity levels; with reduced growth and impaired development. Based on the observations, the two different oxidative stress scavenging pathways in marigold are discussed i.e. ROS-scavenging by ascorbate-glutathione (AsA-GSH) cycle and the MG-detoxification by glyoxalase. With the limitations imposed upon the glutathione (GSH) pool size and redox homeostasis, the study indicated that GSH played a critical role in both ROS- and MG-detoxification in marigold plants at both salinity levels.

Multi-stakeholder value creation and appropriation from food-related health claims

Health claims are considered a means to add value to food and beverages; however, it is not always evident which stakeholders benefit and to what extent they benefit. In this paper, we extend the investigation of value creation and appropriation into the domain of food, specifically food labels. Using a qualitative approach, we aimed to elucidate which forms of value can be created by legislating health claims (including those for bioactive compounds found in South African indigenous plants) on food labels. The findings reveal that health claims have the potential to advance the sustainable development agenda in South Africa, but only if structures can be put in place to appropriate human and intellectual (HI) value, as well as environmental value. Currently, there is strong evidence for economic value creation and appropriation potential, but little clear evidence that HI or environmental value will be appropriated from health claims, especially if these health claims exclude benefits from bioactive compounds found in indigenous South African plants. If we could find a means to measure the HI and environmental value creation potential of health claims, using metrics that people understand, we may be able to develop strategies to ensure that such products can benefit stakeholders beyond economic value alone (i.e. more sustainable value creation). The findings could directly impact food labelling policy formulation, considering current draft regulations to implement health claims in South Africa.

Apoptotic efficiency of Dicoma anomala biosynthesized silver nanoparticles against A549 lung cancer cells

Lung cancer is one of the common forms of cancer that affects both men and women and is regarded as the leading cause of cancer related deaths. It is characterized by unregulated cell division of altered cells within the lung tissues. Green nanotechnology is a promising therapeutic option that is adopted in cancer research. Dicoma anomala (D. anomala) is one of the commonly used African medicinal plant in the treatment of different medical conditions including cancer. In the present study, silver nanoparticles (AgNPs) were synthesized using D. anomala MeOH root extract. We evaluated the anticancer efficacy of the synthesized AgNPs as an individual treatment as well as in combination with pheophorbide a (PPBa) mediated photodynamic therapy (PDT) in vitro. UV–VIS spectroscopy, high-resolution transmission electron microscopy (HR-TEM), Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) was used to confirm the formation of D.A AgNPs. Post 24 h treatment, A549 cells were evaluated for ATP proliferation, morphological changes supported by LIVE/DEAD assay, and caspase activities. All experiments were repeated four times (n=4), with findings being analysed using SPSS statistical software version 27 set at 0.95 confidence interval. The results from the present study revealed a dose-dependent decrease in cell proliferation in both individual and combination therapy of PPBa mediated PDT and D.A AgNPs on A549 lung cancer cells with significant morphological changes. Additionally, LIVE/DEAD assay displayed a significant increase in the number of dead cell population in individual treatments (i.e., IC50’s treated A549 cells) as well as in combination therapy. In conclusion, the findings from this study demonstrated the anticancer efficacy of green synthesized AgNPs as a mono-therapeutic drug as well as in combination with a chlorophyll derivative PPBa in PDT. Taken together, the findings highlight the therapeutic potential of green nanotechnology in medicine.

Evaluation of cytotoxic effect of siphonochilone from African ginger: an in vitro analysis.

Plants provide a wide array of compounds that can be explored for potential anticancer properties. Siphonochilone, a furanoterpene that represents one of the main components of the African plant Siphonochilus aethiopicus, shows numerous health benefits. However, to date, its antiproliferative properties have not been tested. The aim of this study was to analyze the cytotoxic effects of siphonochilone on a panel of cancer cell lines and its underlying mechanism of action. Our results demonstrated that siphonochilone exhibited significant cytotoxic effects on pancreatic, breast, lung, colon, and liver cancer cell lines showing a IC50 ranging from 22 to 124 μM at 72 h of treatment and highlighting its cytotoxic effect against MCF7 and PANC1 breast and pancreas cancer cell lines (22.03 and 39.03 μM, respectively). Cell death in these tumor lines was mediated by apoptosis by the mitochondrial pathway, as evidenced by siphonochilone-induced depolarization of the mitochondrial membrane potential. In addition, siphonochilone treatment involves the generation of reactive oxygen species that may contribute to apoptosis induction. In this work, we described for the first time the cytotoxic properties of siphonochilone and provided data about the molecular processes of cell death. Although future studies will be necessary, our results support the interest in this molecule in relation to their clinical application in cancer, and especially in breast and pancreatic cancer.

The best African plant-derived antibacterial products for clinical perspectives: The state-of-the-art

Background: The global burden of bacterial infections remains a serious health concern. In the present review, we have summarized the best botanicals and phytochemicals from the flora of Africa that deserve clinical studies to develop novel antibacterial drugs to combat enterobacteria, Pseudomonas aeruginosa, Gram-positive bacteria, and mycobacteria. Methods: Data were retrieved from scientific databases such as PubMed, Scopus, ScienceDirect, Google Scholar, and Web of Science using the keywords “African country and plant and antibacterial” and plants or phytochemicals with outstanding antibacterial activities following established cutoff point standards were selected. Results: The identified botanicals were from Acacia polyacantha, Alchornea floribunda, Artemisia abyssinica, Beilschmiedia acuta, Eriosema glomeratum, Harungana madagascariensis, Macaranga capensis, Macaranga conglomerata, Macaranga kilimandscharica, Mangifera indica, Piper nigrum, Piptadeniastrum africanum, and Uapaca togoensis. The phytochemicals identified included 2-(4-hydroxyphenyl)-ethyltriacontanoate (1), 1,3,5,6-tetrahydroxyxanthone (2), 1,3,5,7-tetrahydroxyxanthone (3), 8,8-bis-(dihydroconiferyl) diferulate (4), 2-hydroxy-3-methoxy-9,10-dioxo-9,10-dihydroanthracene-1-carbaldehyde (5), allanxanthone D (6), angusticornin B (7), bartericin A (8), diospyrone (9), dorsmanin C (10), gancaonin Q (11), isobavachalcone (12), isoliquiritigenin (13), laburnetin (14), O1-demethyl-3',4'-deoxy-psorospermi-3',4' diol (15), plumbagin (16), and vismiaquinone (17). Conclusion: These plant-derived products deserve clinical investigations to develop novel antibacterial agents to combat bacterial infections.

Phytochemical screening and GC-FID identification of bioactive compounds in n-hexane, ethylacetate and methanol fractions of methanolic leaves extract of Azanza garckeana

Azanza garckeana is a tropical African plant commonly used for food and medicine. This study was aimed at evaluating the antioxidant, phytochemicals and the bioactive compounds present in n-hexane, ethylacetate and methanol fractions of the methanolic extract of Azanza garckeana leaves. Phytochemical screening and antioxidant assayed were carried out using standard methods, while bioactive compounds were analyzed using gas chromatography-flame ionization detector (GC-FID). The phytochemical compositions revealed considerable level of tannins and saponins with moderate concentration of flavonoids and steroids in the methanol fraction; whereas n-hexane fraction also showed considerable amount of tannins followed by saponins and a low concentration of steroids. However, ethylacetate fraction had the highest yield of tannins, steroids, and terpenoids which were significantly (p < 0.05) higher than methanolic fraction and n-hexane fraction respectively. The antioxidant activity of the methanolic crude extract of A. garckeana leaves showed that the % DPPH radical scavenging activity of the crude extract increased with decreased in concentration when compared with the standard antioxidant (ascorbic acid). The result of GC-FID analysis revealed the presence of nineteen constituents in n-hexane fraction, while ethylacetate and methanol fractions each have twenty constituents. This result showed that Azanza garckeana leaves contain health-promoting bioactive compounds with potent antioxidants.

Systematic Review of Chemical Compounds with Immunomodulatory Action Isolated from African Medicinal Plants.

A robust, well-functioning immune system is the cornerstone of good health. Various factors may influence the immune system's effectiveness, potentially leading to immune system failure. This review aims to provide an overview of the structure and action of immunomodulators isolated from African medicinal plants. The research was conducted according to PRISMA guidelines. Full-text access research articles published in English up to December 2023, including plant characteristics, isolated phytochemicals, and immuno-modulatory activities, were screened. The chemical structures of the isolated compounds were generated using ChemDraw® (version 12.0.1076), and convergent and distinctive signaling pathways were highlighted. These phytochemicals with demonstrated immunostimulatory activity include alkaloids (berberine, piperine, magnoflorine), polysaccharides (pectin, glucan, acemannan, CALB-4, GMP90-1), glycosides (syringin, cordifolioside, tinocordiside, aucubin), phenolic compounds (ferulic acid, vanillic acid, eupalitin), flavonoids (curcumin, centaurein, kaempferin, luteolin, guajaverin, etc.), terpenoids (oleanolic acid, ursolic acid, betulinic acid, boswellic acids, corosolic acid, nimbidin, andrographolides). These discussed compounds exert their effects through various mechanisms, targeting the modulation of MAPKs, PI3K-Akt, and NF-kB. These mechanisms can support the traditional use of medicinal plants to treat immune-related diseases. The outcomes of this overview are to provoke structural action optimization, to orient research on particular natural chemicals for managing inflammatory, infectious diseases and cancers, or to boost vaccine immunogenicity.

Antimicrobial activity of Southern African medicinal plants on Helicobacter pylori and Lactobacillus species

Ethnopharmacological relevanceNumerous medicinal plants have been used traditionally in South Africa for gastric ulcer treatment. Helicobacter pylori is known for causing inflammation and the onset of gastric ulcers. While several studies explored medicinal plants against H. pylori, investigation of medicinal plants used for gastric ulcers has been neglected, as well as the effects these plants would have on bacteria occurring naturally in the gut microbiome. Aim of the studyThis study aimed to investigate Southern African medicinal plants used traditionally for treating gastric ulcers against H. pylori , as well as the effects that these plants have when combined with Lactobacillus species and tested against H. pylori. MethodologyBased on evidence from the ethnobotanical literature, 21 plants were collected. Their antimicrobial activity was assessed against five clinical H. pylori strains, and in combination with each of three Lactobacillus species, using the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) broth microdilution assays. Toxicity was assessed using the brine shrimp lethality assay. ResultsNoteworthy activity was observed against at least one H. pylori strain for 12 plant species. The lowest mean MICs were from organic extracts of Carissa edulis Vahl (0.18 mg/mL) and Chironia baccifera L. (0.20 mg/mL), and aqueous extracts of Sansevieria hyacinthoides (L.) Druce (0.26 mg/mL) and Dodonaea viscosa Jacq. (0.30 mg/mL). Aqueous extracts of the investigated plants were combined with Lactobacillus species, and the majority of combinations showed increased antimicrobial activity compared with the extracts alone. Combinations of Lactobacillus rhamnosus with 18 of the 21 aqueous plant extracts showed at least a two-fold decrease in the mean MBC against all H. pylori strains tested. Lactobacillus acidophilus combined with either Protea repens L., Carpobrotus edulis (L.) L. Bolus or Warburgia salutaris (Bertol.f.) Chiov. aqueous extracts had the best anti-H. pylori activity (mean MBCs of 0.10 mg/mL for each combination). Only four organic and one aqueous extract(s) were considered toxic. ConclusionThese results highlight the potential of medicinal plants to inhibit H. pylori growth and their role in traditional treatments for the management of ulcers. The results also indicate that aqueous extracts of these plants do not hinder the growth of bacteria that occur naturally in the gut microbiome and play a role in maintaining gut health, as well as show the potential benefit of including Lactobacillus species as potentiators of H. pylori activity.

Analysing the Techno-Economic Viability of Different Solar Heating Systems in South African Beverage Plants

With ongoing real-term reductions in the cost of renewable energy technologies, opportunities to reduce carbon emissions within industry have improved. While the South African industrial sector has been investing in photovoltaics to meet electricity requirements, little has been done to replace fossil fuels used for the generation of process heat, representing two-thirds of the energy consumed. While previous studies have demonstrated the benefits and limitations of solar thermal (ST) energy solutions for industrial applications, recent developments in high-temperature heat pumps (HTHP) offer opportunities for novel configurations, including the use of renewable energy like photovoltaics (PV). This study compares the techno-economic benefits of solar thermal energy systems with PV-supported HTHP systems within the South African beverage sector. After a general consideration, simulation calculations are presented for selected applications. The cost of heat is determined for PV-heat pump systems operating on a stand-alone basis and with heat storage. The study finds that the levelised cost of heat of US$0.050-0.073/kWhth is at least twice that of coal-fired steam boilers. The study, therefore, calls for further work on optimising systems minimising steam requirements, and thereby improving the economics of heat pumps and for a coordinated effort to support the development and financing of high-temperature heat pumps for industrial applications.

Exploring Phytotherapy's Preventive and Therapeutic Impact on Global COVID-19 Management: A Narrative Review

Introduction:: The WHO Emergency Committee advocates preventive strategies for COVID-19 management, emphasising vaccines as highly effective but acknowledging their limitations. Chloroquine and hydroxychloroquine, initially effective against COVID-19, were discontinued due to severe side effects. Further clinical trials are imperative to establish the safety and efficacy of new antiviral agents, some of which may have harmful effects on human development. Objectives:: The shortcomings of various conventional treatments have prompted urgent efforts to discover safe, natural compounds that may be useful in combating COVID-19. This study aims to review research that has investigated the potential of traditional phytotherapies used by different populations for the prevention and symptomatic treatment of COVID-19 infection. Methods:: This paper reviewed scientific studies published through searching on search engines such as PubMed, Scopus, Google Scholar, ScienceDirect and Elsevier from May until October 2023. Results:: The preventive and anti-COVID-19 attributes of Traditional Chinese Medicine, Ayurvedic formulations and African medicinal plants have been substantiated in research. In Nepal, recommendations endorse the utilisation of medicinal plants for herbal teas and homemade sanitizers. Zingiber officinale, Curcuma longa L. and Curcuma xanthorriza Roxb., along with Camellia sinensis are crucial Indonesian medicinal plants with potential for treating COVID-19. Z. officinale was predominantly chosen for relieving coughs and sore throats associated with COVID-19 in Saudi Arabia. Discussion:: The immunomodulatory properties of medicinal plants, which may prove useful in combating COVID-19, have been verified via elevation of the level of peripheral WBCs, IgM, IgG; inhibition of leukotrienes and prostaglandins, maintenance of the integrity of intestinal mucosal barrier and regulation of HMGB1. The antiviral effects of herbs, including the inhibition of viral DNA and RNA replication, down-regulation of oxidative stress, and the impediment of SARS-CoV-2 access to vascular endothelial cells, suggest their potential to facilitate earlier recovery from COVID-19 infection. Conclusion:: Advancing scientific research in phytotherapy promises the possibility of novel approaches for effectively managing future infectious diseases and pandemics.