Abstract

Tuberculosis (TB) is the most prevalent infectious disease after COVID-19. Medicinal plants havereportedly been used to treat TB and Multidrug-resistant TB (MDR-TB) in East Africa. However, they have not been evaluated for antimycobacterial activity. The present study examines antimycobacterial activity, cytotoxicity, synergistic interactions, and phytochemical profiles of the root bark of Albizia zygia (Dc.) J.F. Macrb. The CC50 of the tested extracts was >1000 μg/mL (non-cytotoxic) except for dichloromethane extract with 82.59±00 μg/mL (moderately cytotoxic). The MIC99 of methanolic and aqueous extracts was 625±0 μg/mLand 2500±0 μg/mL, respectively. Hexane, dichloromethane, and ethyl acetate extracts were inactive. The methanolic and aqueous extracts exhibited synergistic (FICI of 0.5) and additive (FICI of 0.75) interactions, respectively. GC-MS revealed 7-ethyl-quinoline and acetyl-hydroquinone with reported antimycobacterial activity and numerous phytochemicals with reported antibacterial activity were identified in A. zygia.

Keywords: TB, Antimycobacterial, Cytotoxicity, Synergistic, Albizia zygia.

Abstract

The present study, aim to isolate, the phytochemical constituents of the leaves and root bark of S.latifolius and investigate their in vitro enzymes inhibitory actions, in silico molecular docking and ADME/T properties. The purified compounds were identified by means of NMR spectroscopy and mass spectrometry.  Four phytochemicals, 3-O-caffoylquinic acid, 10-Hydroxylstrictosamide, Quercetin-3-O-β-D-glucopyranoside and 4,5-O-dicaffoyl quinic acid were identified from the leaves while β-sistosterol, Clethric acid,  Quinovic acid-3-O-β-D-fucopyranoside,  Quinovic acid-3-O-α-L-rhamnosyl-28-O-β-D-glucopyranosyl ester, Quinovic acid-3-O-β-D-fucopyranosyl-28-O-β-D-glucopyranosyl ester, Quinovic acid-3-O-β-D-glucopyranoside, Strictosamide,  Ethyl-O-β-D-glucopyranside  and Strictosidine from the root bark. These compounds were docked against 3MNG and 2RGU proteins using PyRx (version 0.9.3 software) to identify the binding affinities of the compounds. ADME/T properties were analysed using SwissADME webserver. The in vitro enzyme inhibitory actions were investigated against α-amylase and α-glucosidase.  The results demonstrated that majority of the compounds showed good binding potential against proteins and good inhibitory potential against α-amylase and α-glucosidase.  The result of ADMET analysis suggested that the compounds might be safe for human.  In conclusion, the isolated compounds displayed excellent antihyperglycemic potential when compared to the standard drug, and the result of molecular docking study was used to better rationalize the action and prediction of the binding modes of these compounds.

Keywords: Phytochemicals, Molecular docking, ADME/T, Sarcocephalus latifolius

Abstract

Sesame oil, an edible essential oil, is known to be rich in unsaturated fatty acids, vitamins and lignans with several reported health-promoting benefits. In this study, we investigated the protective effect of sesame seed oil (SSO) against genotoxicity, hepatotoxicity and colonic toxicity induced by sodium arsenite (SA) in Wistar rats. Liver function and morphology, bone marrow micronuclei induction, colonic histopathology, mucus production and immune expression of Bcl-2, carcinoembryonic antigen (CEA), MUC1 and cytokeratins AE1/AE3 were evaluated. SA provoked increased serum activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and caused severely altered morphology of hepatic and colonic tissues with increased frequency of micronucleated polychromatic erythrocytes (MnPCEs/1000PCE) in the bone marrow. In addition, SA triggered increased expression of colonic CEA and MUC1 but weak Bcl-2 immunoexpression. However, cotreatment with SSO demonstrated protective activities against SA-induced damage, as indicated by significantly reduced serum ALT and AST, fewer micronucleated bone marrow erythrocytes and well-preserved hepatic and colonic morphologies compared to the SA-treated rats. Furthermore, SSO protected the colonic mucosa by boosting mucus production, elevating anti-apoptotic Bcl-2 expression and reducing CEA expression. GC‒MS analysis of SSO revealed that it was predominated by linoleic acid, an omega-3 fatty acid, and tocopherols.

Abstract

Hydroxy-substituted anthraquinones are among the most important derivatives in organic synthesis. The attractive biological properties of these compounds are relevant to many therapeutic areas that are of use in clinical applications. In this study we synthesized 3-ethoxyphthalic acid from anacardic acid obtained from cashew nut shells. We further synthesized several amino-substituted anthraquinones from 1,4-dihydroxyanthraquinone using a modified Marschalk reaction. The in-vitro screening of the compounds against Trypanosoma brucei parasites revealed noteworthy activity with reasonable selectivity against human cell lines. A molecular docking study was performed to analyze the synthesized compounds' modes of interaction to the trypanothione reductase's active site. Visual inspections examined the docked poses, and test compounds displayed a good binding affinity with the receptor protein. This in vitro/ molecular docking evaluation suggests that substituted 1,4-dihydroxyanthraquinone derivative can be promising starting structures in the search for active drugs against trypanosomiasis.

Abstract

Hydroxy-substituted anthraquinones are among the most important derivatives in organic synthesis. The attractive biological properties of these compounds are relevant to many therapeutic areas that are of use in clinical applications. In this study we synthesized 3-ethoxyphthalic acid from anacardic acid obtained from cashew nut shells. We further synthesized several amino-substituted anthraquinones from 1,4-dihydroxyanthraquinone using a modified Marschalk reaction. The in-vitro screening of the compounds against Trypanosoma brucei parasites revealed noteworthy activity with reasonable selectivity against human cell lines. A molecular docking study was performed to analyze the synthesized compounds' modes of interaction to the trypanothione reductase's active site. Visual inspections examined the docked poses, and test compounds displayed a good binding affinity with the receptor protein. This in vitro/ molecular docking evaluation suggests that substituted 1,4-dihydroxyanthraquinone derivative can be promising starting structures in the search for active drugs against trypanosomiasis.

Abstract

Nature has contributed tremendously to drug discovery with a significant percentage of approved drugs originating from either natural products or their derivatives. Natural products have gotten much attention from researchers who are seeking prospective therapeutics for the treatment of various disease conditions including cancer.

In the course of my research career, I have isolated, identified and characterized phytochemicals from a medicinal plant with anticancer potential via on-silica bioassay-guided fractionation. Lead compounds with antiproliferative activity on cancer cell lines were demonstrated. My team and I established lead compounds with drug-likeness properties from phytoconstituents of the bioactive plant using a computational molecular modeling (in-silico) approach. Data obtained from the in-silico study revealed potential herb-drug interactions via induction or inhibition of transporters and metabolic enzymes by the phytoconstituents.

There is a need for research grants, training, collaboration and access to necessary laboratory facilities to further develop identified natural products lead molecules into herbal drug products for consumption by end users.

Several lead compounds from plants with proven anticancer potential have been established via on-silica and in-silico assays. These anticancer leads can be delivered to the targeted site of action via the development of a formulated anticancer herbal drug product for human consumption.

Abstract

Studies examining the role of abiotic variables on fructification sequences of ectomycorrhizal symbionts (boletes), the extent and direction of these effects are quite rare in Africa. In the current study, we assessed the effects of microclimate on the distribution and productivity of boletes in Benin. Nine permanent plots of 2,500 m2 each split into 25 sub-plots of 100 m2 were installed in three different vegetation types. The first vegetation type is dominated by Isoberlinia doka, the second by Isoberlinia tomentosa and the third by Uapaca togoensis. Abiotic variables including soil temperature, air temperature, air relative humidity and soil moisture, were recorded every 30 minutes from June to October. Each plot was surveyed twice a week during the mushroom season over three years (2015, 2016 and 2017) to record the abundance and the fresh biomass. The effects of microclimate on boletes productivity were evaluated using generalized linear mixed models in R. Boletes give the largest natural production in July and the lowest in October. Only soil moisture has a significant negative influence on the abundance (Prob. < 0.05). The favorable interval of soil moisture for the optimal natural production of boletes is ''0.05 - 0.25 m3/m3''. Key words: Boletes, fresh biomass, microclimate, vegetation, Benin.

Abstract

Ectomycorrhizal fungi (EcM) play a key role in the structure and functioning of forest ecosystems. They have a paramount importance in nutrient cycling, plant protection against pathogens and abiotic stress. There are more than 20 000 fungal species involved in EcM symbiosis, of which a large proportion are edible, and have enormous relevance either as a source of subsistence in low- income human groups or as an important economic component of local population. They contribute to the diversification of the diet, which often predominantly consists of micronutrient-poor cereal and root crops, such as maize, yam, and cassava in sub-Saharan Africa. Despite the crucial ecological and social role of EcM fungi, their current diversity is not yet adequately assessed. During the last few years, 8806 EcM specimens have been sampled in different vegetation in Forest Reserve of “Ouémé Supérieur” of which 74 edible species have been identified as edible by local people in the project context ‘’ The diversity and natural productions of locally harvested mushrooms in light of climatic change in West Africa”. In our collections, many unrecognized and cryptic edible species have been harvested. In addition, no documentation has been done on the nutritional and medicinal value of edible EcM species collected to assure nutritional security in Benin. Thus, my current work focuses on how to identify these species with molecular and taxonomic analyzes and document the nutrional and medicinal compounds they contain either using the AOAC method (AOAC, 1995. Official methods of analysis (16th Ed.). Arlington VA, USA: Association of Official Analytical Chemists) or through new molecular methods.

Abstract

The essential oil of air-dried leaves of Pinus sylvestris obtained through hydrodistillation was characterized by gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry analyses (GC-MS).  The oil yielded 0.78 % per dry weight of sample. The oil was composed majorly of mono and sesquiterpenoids. The major components of the essential oil of P sylvestris were humulene (13.24 %), α-guaiene (11.57 %), allo-ocimene (9.40 %), terpinolene (8.84 %), caryophyllene (8.84 %) and terpineol (5.02 %). The air-dried leaf oil showed strong activity against Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae, as well as a promising antioxidant potency. To our knowledge, this is the first report concerning chemical composition and antimicrobial activities of the essential oil from Pinus sylvestris

 Keywords: Essential oil, Pinus sylvestris, GC-MS, antibacterial, humulene, antioxidants.

Abstract

Introduction: Microbial infections are very common in developing countries like Nigeria. It is the cause of poverty as well as many deaths in developing countries. However, natural products can help to overcome the problems associated with pathogenic diseases.

Method: Ethanolic extract was fractionated by column and pooled into four fractions (A–D), these were evaluated for their antimicrobial activity against E. coli, S. typhi, S. aureus and K. pneumonia at different concentrations. Fraction A with the characteristic single spot and broader spectrum was subjected to 1D and 2D NMR analysis to elucidate the structure. 

Results: The H-NMR, 13C NMR, HSQC and HMBC spectra’s of the isolated compound FA showed the presence lupeol acetate.

Conclusion: The low MIC values of the crude extract against S. aureus and K. pneumonia holds potential for use as antimicrobial drug leads.

Reccommendation: Toxicity studies of the plant should be done to determine the safety indices of the extract

Acknowledgment: This study was funded by TETFUND-IBR 2022 grant

Abstract

This work aimed to determine the anti-proliferative activity of Euphorbia ingens and Aspilia pluriseta against prostate cancer cells. The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay was used to assess the anti-proliferative activity on DU-145 human prostate cancer cell and vero E6 cell lines. Qualitative phytochemical screening and Gas Chromatography-Mass Spectrometry (GC-MS) analysis was carried out to identify plants’ bioactive compounds. Quantitative real-time polymerase chain reaction was used to assess the gene expression profiles of AR, BCL2, CDK1, Caspase 3 and p53. Euphorbia ingens ethyl acetate and Aspilia pluriseta’s crude dichloromethane:methanol, hexane and ethyl acetate significantly inhibited the growth of DU-145 in a concentration dependent manner while being highly selective on the vero cells (with selectivity index of 8.26, 6.04, 3.62 and 6.68 respectively) compared to a reference drug, doxorubicin (33.23). Phytochemical screening revealed the presence of phenols, terpenoids, flavonoids, tannins, sterols and saponins in both plants. Additionally, 141 phytocompounds were identified through GC-MS analysis. There was downregulation of AR, BCL2, CDK1 and upregulation of Caspase 3 and p53 genes compared to untreated cells. The plants demonstrated safe anti-proliferative activity; further in vivo studies need to be undertaken as a step towards their clinical utilization as anti-prostate cancer drugs.

Abstract

Diabetes mellitus is a group of chronic metabolic diseases which diminishes the quality of life due to the numerous complications associated with it. Nymphaea lotus is used traditionally for the treatment of diabetes and its complications. Acute and gene toxicity, and anti-hepatic effect of N. lotus was investigated. It was also subjected to in silico docking to gain insight into its antidiabetic effect. Its effect on insulin resistance, glucose metabolism, nephropathy and cardiomyopathy in diabetes will be further investigated. The extract was safe and inhibited hepatic fibrosis – a co-morbidity of diabetes. In silico docking predicted that the extract inhibited key molecular targets of diabetes. The progress of the work is however impeded by lack of some needed facilities and grant to fund the study. I therefore look forward to getting grant to fund the study and buy needed facilities, and international collaboration to access equipment not currently available in my institute and learn the technical know-how. Access to funding, international collaboration and availabity of needed equipment will position me and my research team to identify and isolate novel compounds that can serve as leads for a safe and efficient diabetes drug. 

Abstract

In our previous study, extracts from four Togolese plants, namely, Cochlospermumplanchonii (CP), Piliostigma thonningii (PT), Paullinia pinnata (PP), and Securidaca longipedunculata (SL), actually used in traditional medicine for cancer treatment, showed beneficial health effects against oxidative stress, inflammation, and angiogenesis. In the present study, we aimed to investigate their cytotoxicity and antitumor activities. Cytotoxicity tests revealed that SL, PP, and CP extracts have more than 50% cytotoxicity at 150 μg/mL. At therapeutic doses of 100 mg/kg, 200 mg/kg and 400 mg/kg of PP and 40 mg/kg, 80 mg/kg, and 160 mg/kg of SL, extracts showed beneficial health effects by modulating several biological parameters. SL extract significantlyreduced tumor volume (P<0.001), cell viability, and normalized hematological parameters. SL also demonstrated a strong anti-inflammatory activity similar to the standard drug. The SL extract also revealed a significant increase of the life span of treated mice. PP extract reduced the tumor volume and significantly improved the values of endogenous antioxidants. Both PP and SL extracts also exerted significant anti-angiogenic potency. The study indicated that polytherapy would be a panacea for the efficient use of medicinal plant extracts against cancer. Molecular studies of both extracts targeting key cancer genes are currently underway.

Keywords: cancer, cytotoxicity, antitumor, EAC cells, anti-inflammatory, anti-angiogenic.

Abstract

The development of antimalarial drug with dual actions; having both antiplasmodial and immunomodulatory effects, would be a better way of combating Plasmodium parasite resistance. Thus,  n-Hexadecanoic acid, a compound present in acetone leaf and stem bark extracts of Anogeissus leiocarpus was identified by Gas Chromatography-Mass Spectrometry (GC-MS). Antimalarial and anti-inflammatory effects of n-Hexadecanoic acid were determined using in silico method. The compound was docked against Plasmodium falciparum dihydrofolate reductase (PfDHFR) and enoyl acyl carrier protein reductase (PfENR), and human inflammatory cytokines; interferon gamma (IFN-γ), tumor necrosis factor-α (TNF-α) and interleukin-12 (IL-12). The in vivo immunomodulatory activity of the compound was done using heamaglutination (HG) and delayed-type hypersensitivity (DTH) assay, while Peters' 4-day suppressive test was used to determine the antiplasmodial effect on Plasmodium berghei Anka infected mice. The binding energies of the compound against PfDHFR,  and PfENR are -8.73 and -8.62 kcal/mol, while IFN-γ, TNF-α, IL-12 are -8.07, -7.55 and -7.60 kcal/mol, respectively. The in vivo antiplasmodial activity revealed a highest percentage chemosuppression of 89.74% at 100 mg/kg. The HG and DTH showed that the compound boosted immune responses. The n-Hexadecanoic acid is a potential antimalarial drug candidate, therefore further assays to establish its efficacy are needed.

Abstract

Insects are commonly found to be involved in a vast array of symbiotic interactions with microorganisms (insect-microbe interactions), which range from parasitic to mutualistic relationships. However, certain symbiotic interactions between insects and several microbes have proven to be a reliable source of pharmacological innovations, because these microbial symbionts are known to produce small molecules in prolific amounts that help defend against pathogens, parasites, and predators in their hosts. These symbiotic microorganisms offer promising applications in human medicine and several industrial processes, therefore new knowledge on host-microbe interactions arising from my study can be exploited for biotechnological use in the long run. My main objective is to isolate novel molecules from African meliponine stingless bees and long horned beetles which exhibit anti-microbial activity or targeting specific fungal antagonists for future biotechnological applications. Several of these antimicrobial secondary metabolites can help find lasting solutions to drug resistance affecting human health. In particular, I will be targeting defensive insect-bacteria/ insect-fungal symbiont-produced defensive compounds in hymenopteran and coleopteran orders which are known to confer protection on the host or its offspring (egg/larvae) against antagonistic micro- or macroorganisms such as mold fungi. Even though current exploitation is hampered by the unculturability of some endosymbionts, advances in culturing techniques as well as genomic tools will help with identification and heterologous expression of genes of interest.

Abstract

The fall armyworm (FAW) is an invasive agricultural pest in Africa, which causes major economic damage. Although five sex pheromone components, E7-12:OAc, Z7-12:OAc, Z9-12:OAc, Z9-14:OAc, Z11-16:OAc, have been identified from calling females, it is unclear whether males from different geographic regions respond differently. Therefore, male antennal responses of Kenya and Benin populations towards these sex pheromone compounds are determined. Antennal responses of each of the above components were tested in coupled GC-EAD setup, in concentrations of 1, 3 10 and 20 ng/µl. Male FAW responded similarly to most compounds, although Kenyan males showed lower responses. Furthermore, both populations already showed EAG responses to Z7-12:OAc at 1 ng/µl, while all males were only responsive to E7-12:OAc at concentrations ≥ 10 ng/µl. In addition to testing the synthetic sex pheromone compounds, we also tested female gland extracts to determine whether male antennae respond to other yet unidentified compounds. So far, both populations only responded to Z9-14:OAc in gland extracts containing 5 females. We are also investigating whether lures with host plant volatiles can be used as attractants/repellents against FAW, using behavioural assays and further chemical analyses as well as fieldwork in African countries.