Exploring a Simple Method of Thaumatin Extraction from Thaumatococcus daniellii

Thaumatin is a naturally occurring protein sweetener found in the arils of Thaumatococcus daniellii fruits. In spite of its high market value as a safe flavour enhancer and high-intensity sweetener, challenges associated with the extraction and purification process have limited the economic exploitation of T. daniellii for thaumatin production in the West and Central Africa. This study examined a simple extraction technique that could be adapted locally. The arils of T. daniellii fruits were homogenized (in water), and filtered through a double-folded muslin cloth to obtain a crude protein extract. The extract was precipitated with 80% ammonium sulphate, dialysed and purified by gel filtration (Sephadex G-75). The crude protein extract and proteins from dialysed and gel chromatographic fractions were separately freeze-dried and run through SDS-PAGE. The extract of T. daniellii arils contained sweet-tasting proteins (thaumatin) with average molecular weight of about 22 kDa. The proteins were extremely sweet at 20 – 40oC; the sweetness decreased as temperature increased and became faint at 70oC. Protein recovery from ammonium sulphate precipitation and gel filtration was 76.14% and 63.0%, respectively. The crude extract was light brown whereas the purified protein was cream coloured. The simple process of homogenisation and filtration through muslin cloth can be adapted for extraction and initial processing of thaumatin in West Africa. Enzymatic hydrolysis of the sticky substances (polysaccharides) in the arils can enhance the extraction process

Stage 2 Hypertension and Electrocardiogram Abnormality: Evaluating the Risk Factors of Cardiovascular Diseases in Nigeria. High Blood Press Cardiovasc

Abstract Introduction This study evaluated the status of stage 2 hypertension, abnormal ECG and their co-occurrence as possible risk factors of cardiovascular disease and their predictors in a Nigerian University population. Methods A total of 717 subjects participated in this study. Blood pressure (BP), resting electrocardiogram (ECG) and other clinical parameters were measured and categorised according to standard organisational guidelines. Bivariate correlation and multivariate logistic regression model were used to determine covariates and clinical parameter association at a 95 % significant level. Results Stage 2 hypertension and abnormal ECG respectively occurred in 264 (37 %) and 217 (39.2 %) subjects, with co-occurrence and abnormal BMI in 85 (11.8 %) and 459 (64.8%) subjects, respectively. Sex (p = 0.001) and occupation (p = 0.022) were independently associated with abnormal BP and ECG, respectively, while age was independently associated (p < 0.001) with abnormal BP, ECG and co-occurrence of these conditions. Predictors of stage 2 hypertension and abnormal ECG were sex (adjusted odds ratio [aOR] = 1.652, 95 % CI 1.097–2.488) and occupation (aOR = 0.411, 95 % CI 0.217–0.779), respectively, while age was a predictor for stage 2 hypertension (aOR = 0.065, 95 % CI 0.015–0.283), abnormal ECG (aOR = 0.137, 95 % CI 0.053–0.351) and their co-occurrence (aOR = 0.039, 95 % CI 0.014–0.113). Conclusions This study shows prevalence rates of these risk factors are on the increase. It also suggests that ECG abnormality is a public health issue among stage 2 hypertensive patients that must be monitored. Therefore, appropriate interventions that prevent and control hypertension and identified risk factors should be put in place in addition to lifestyle changes, regular screening and surveillance

Synthesis of low toxic silver-cobalt nanoparticles using Annona muricata leaf extract: Antimicrobial evaluation

In a bid for green chemistry, a sustainable approach using Annona muricata aqueous extract was engaged as a reducing agent to synthesise bimetallic silver-cobalt nanoparticles (Ag-Co NPS). Hot extraction using distilled water was done on the locally sourced plant (leaf part). It was then screened for biomolecules present as geographical location affects phytochemical compositions. Phytoreduction reaction with nanoparticle formation rate was monitored with a UV–Vis spectrophotometer. Then, further characterisations were achieved by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), Fourier-transform infrared (FTIR), and X-ray diffraction (XRD). The average particle size of 39.34 nm 9.21 nm was obtained. This study shows an interesting result, as the increase in Ag-Co NPs concentration did not significantly affect the flies’ survival compared to the control. At P < 0.05, similar behaviour was observed in the locomotive assay of the model used. An antibacterial agent can also be developed, as revealed in the antimicrobial assay on Staphylococcus aureus (ATCC25923), Streptococcus pneumoniae, Escherichia coli (ATCC 25922), Klebsiella sp., and Salmonella sp. and a fungus strain: Candida albicans

Synthesis of low toxic silver-cobalt nanoparticles using Annona muricata leaf extract: Antimicrobial evaluation

In a bid for green chemistry, a sustainable approach using Annona muricata aqueous extract was engaged as a reducing agent to synthesise bimetallic silver-cobalt nanoparticles (Ag-Co NPS). Hot extraction using distilled water was done on the locally sourced plant (leaf part). It was then screened for biomolecules present as geographical location affects phytochemical compositions. Phytoreduction reaction with nanoparticle formation rate was monitored with a UV–Vis spectrophotometer. Then, further characterisations were achieved by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), Fourier-transform infrared (FTIR), and X-ray diffraction (XRD). The average particle size of 39.34 nm ± 9.21 nm was obtained. This study shows an interesting result, as the increase in Ag-Co NPs concentration did not significantly affect the flies’ survival compared to the control. At P < 0.05, similar behaviour was observed in the locomotive assay of the model used. An antibacterial agent can also be developed, as revealed in the antimicrobial assay on Staphylococcus aureus (ATCC25923), Streptococcus pneumoniae, Escherichia coli (ATCC 25922), Klebsiella sp., and Salmonella sp. and a fungus strain: Candida albicans

Mitochondrial toxicity of aflatoxin B1

This chapter discusses the toxicity of aflatoxin B1 (AFB1) on mitochondrial function. It starts with an overview of aflatoxins: what they are, where they are found, and the types that exist. The introduction also describes the routes of AFB1 exposure, biotransformation, metabolism, and excretion. Thereafter, the chapter explains the major toxic effects of AFB1 on the mitochondria. First, it discusses how AFB1 disrupts the levels of lipids, particularly cholesterol and phospholipids, which are the major lipid component of the mitochondrial membrane. The changes in the lipids can affect the mitochondrial membrane carriers, thereby affecting membrane transport. Second, it discusses how AFB1 affects the mitochondria membrane potential and permeability. Specifically, AFB1 reduces mitochondrial membrane potential and promotes mitochondrial permeability transition. Third, it discusses how AFB1 induced oxidative stress and apoptosis in mitochondria leading to mitochondrial damage. Lastly, it examines the effects of AFB1 on enzymes of the electron transport chain

Early-life AFB1 exposure: DNA methylation and hormone alterations.

Aflatoxins are secondary metabolites of mold that contaminate food and feedstuff. They are found in various food including grains, nuts, milk and eggs. Aflatoxin B1 (AFB1) is the most poisonous and commonly found of the various types of aflatoxins. Exposures to AFB1 start early in life viz. in utero, during breastfeeding, and during weaning through the waning foods which are mainly grain based. Several studies have shown that early-life exposures to various contaminants may have various biological effects. In this chapter, we reviewed the effects of early-life AFB1 exposures on changes in hormone and DNA methylation. In utero AFB1 exposure results in alterations in steroid and growth hormones. Specifically, the exposure results in a reduction in testosterone levels later in life. The exposure also affects the methylation of various genes that are significant in growth, immune, inflammation, and signaling pathways

Breast Cancer Phenotypes in Africa: A Scoping Review and Meta-Analysis

PURPOSE Africans have been associated with more aggressive forms of breast cancer (BC).However, there is a lack of data regarding the incidence and distribution of different subtypes on the basis of phenotypic classification. This scoping review and meta-analysis was undertaken to determine the distribution pattern of BC phenotypes (luminal, human epidermal growth factor receptor 2 [HER2]1, and triple-negative breast cancer [TNBC]) across the African region. METHODS Four online databases (PubMed, Scopus, ProQuest, and EBSCOhost) were accessed to identify studies published between 2000 and 2022 reporting the representation of receptor status (estrogen receptor, progesterone receptor, and HER2) in African patients with BC. Furthermore, the meta-analysis was carried out using a random-effects model and pooled using the inverse variance method and logit transformation. 95% CI and I2 statistics were calculated using the Clopper-Pearson method to estimate between-study heterogeneity. RESULTS A total of 2,734 records were retrieved, of which 2,133 were retained for further screening. After the screening, 63 studies were finally selected for the scoping review and meta-analysis. The pooled frequency of luminal, HER2-positive (HER21), and TNBC was estimated at 56.30%, 12.61%, and 28.10%, respectively.Northern Africa had the highest frequency of the luminal subtype, while West Africa showed higher frequencies of HER21 and TNBC subtypes. The review also had a representation of only 24 countries in Africa. CONCLUSION Our results highlight the disparity in the representation of molecular subtypes among the people in different regions of Africa. There is a need to incorporate routine molecular subtyping into the management of African patients with BC

GC-MS Analysis and Inhibitory Evaluation of Leaf Extracts on Major Enzymes Linked to Diabetes.

leaves are used in managing both diabetes mellitus and its complications in Southwest Nigeria. However, its inhibitory activity on enzymes implicated in diabetes is not very clear. This study investigated the inhibitory properties and mode of inhibition of leaf extracts on enzymes associated with diabetes. The study also identified some bioactive compounds as well as their molecular interaction in the binding pocket of these enzymes. Standard enzyme inhibition and kinetics assays were performed to determine the inhibitory effects of aqueous extract (TCA) and ethanol extract (TCE) of leaves on -glucosidase and -amylase activities. The phytoconstituents of TCA and TCE were determined using GC-MS. Molecular docking of the phytocompounds was performed using Autodock Vina. TCA and TCE were the most potent inhibitors of -glucosidase (IC = 3.28 ± 0.47 mg/mL) and -amylase (IC = 0.24 ± 0.08 mg/mL), respectively. Both extracts displayed a mixed mode of inhibition on -amylase activity, while mixed and noncompetitive modes of inhibition were demonstrated by TCA and TCE, respectively, on -glucosidase activity. The GC-MS analytic chromatogram revealed the presence of 24 and 22 compounds in TCE and TCA, respectively, which were identified mainly as phenolic compounds, terpenes/terpenoids, fatty acids, and other phytochemicals. The selected compounds exhibited favourable interactions with the enzymes compared with acarbose. Overall, the inhibitory effect of on -amylase and -glucosidase may be ascribed to the synergistic action of its rich phenolic and terpene composition giving credence to the hypoglycaemic nature of leaves

Protective Role of Picralima nitida Seed Extract in High-Fat High-Fructose-Fed Rats

Picralima nitida is a therapeutic herb used in ethnomedicine for the management of several disease conditions including diabetes. This study examined the potential palliative effect of aqueous seed extract of Picralima nitida (APN) on dyslipidemia, hyperglycemia, oxidative stress, insulin resistance, and the expression of some metabolic genes in high-fat high-fructose-fed rats. Experimental rats (2 months old) were fed a control diet or a high-fat diet with 25% fructose (HFHF diet) in their drinking water for nine weeks. APN was administered orally during the last four weeks. Anthropometric and antioxidant parameters, lipid profile, plasma glucose, and insulin levels and the relative expression of some metabolic genes were assessed. APN caused a significant decrease (P<0.05) in weight gained, body mass index, insulin resistance, plasma glucose, and insulin levels. High-density lipoprotein cholesterol level was significantly increased (P<0.05), while triacylglycerol, cholesterol, low-density lipoprotein, cardiac index, atherogenic index, coronary artery index, and malondialdehyde levels in plasma and liver samples were also significantly decreased (P<0.05) by APN at all experimental doses when compared to the group fed with an HFHF diet only. APN also significantly (P<0.05) upregulated the relative expression of glucokinase, carnitine palmitoyltransferase-1 (CPT-1), and leptin at 400 mg/kg body weight when compared to the group fed with an HFHF diet only. This study showed that APN alleviated dyslipidemia, hyperglycemia, and oxidant effect associated with the intake of a high-fat high-fructose diet