The indications are that the greatest potential for change is in Africa. It is also the place where the greatest potential to make more people’s lives better can be realized. This is an issue of architecture and the built environment. This continent has long been synonymous with failed investment and corruption. It is the place where people with good intentions went to see their hopes and dreams quashed, for any number of reasons, including the two mentioned above. Yet, there are places with stable governments and stable growth, and a growing middle class looking to invest its new wealth. Inevitably, investment means construction. So there is a real need for excellent architecture and planning that can ensure the retention of value.

A is for Africa

Free radicals are highly reactive molecules generated during oxidation reactions which in turn initiate chain reactions resulting to cellular damage. There is substantial evidence implicating free radicals especially reactive oxygen species (ROS) in the etiology of more than one hundred degenerative disorders in humans including, arthritis, atherosclerosis, ischemia and reperfusion injury of many tissues, gastritis, diabetics, central nervous system injury, acquired immunodeficiency syndrome (AIDS) and cancer. Scientific evidence postulates that bioactive compounds especially from natural products are capable of providing protection against free radicals. Consequently, few decades have witnessed a surfeit of research geared towards validating the antioxidant and hepatoprotective potential of the natural products. In this review, African natural products whose antioxidants activities were scientifically validated either in their crude extracts and/or derived products have been discussed. A total 1076 plants species representing 287 family, 132 isolated compounds and 7 insect/mollusk secreation were found. The plant species from the following families; Fababceae, Asteraceae, Lamiaceae, Moraceae, Euphorbiaceae, Combretaceae and Malvaceae have received more scientific attention than others. Analysis of the reports revealed that Combretum apiculatum, Telfaria occidentalis, Acalypha racemosa, Garcinia lucida were the most active plant extracts from African flora. The most active ROS-detoxifying phytochemicals were moracin T, U, S and R (84–87), oleanolic acid (54), 5,7,4′–trihydroxy–3,8,3′,5′–tetramethoxyflavone (89), 5,7,3′–trihydroxy-3,8,4′,5′–trimethoxyflavone (88), luteolin (3′,4′,5,7–tetrahydroxy flavone) (117) and genistein (4′,5,7–trihydroxyisoflavone) (116). The significant antioxidant potential demonstrated by some crude extracts and their constituent compounds render them good candidates for the development of new drugs. Although, the study of the mechanisms of actions as well as clinical validation of some of these isolated compounds is lacking. It is hoped that pertinent scientist and stakeholders will look further into some of these compounds for detailed authentification and subsequent commercialization.

https://link.springer.com/content/pdf/10.1186%2Fs40816-016-0037-0.pdf

African natural products with potential antioxidants and hepatoprotectives properties: a review

In view of the great importance bestowed on amino acids as antioxidants in oxidation resistance, we attempted two common redox titration methods in this report, including micro-potassium permanganate titration and iodometric titration, to measure the antioxidative capacity of 20 amino acids, which are the construction units of proteins in living organisms. Based on the relative intensities of the antioxidative capacity, we further conducted a quantitative comparison and found out that the product of experimental values obtained from the two methods was proven to be a better indicator for evaluating the relative antioxidative capacity of amino acids. The experimental results were largely in accordance with structural analysis made on amino acids. On the whole, the 20 amino acids concerned could be divided into two categories according to their antioxidative capacity. Seven amino acids, including tryptophan, methionine, histidine, lysine, cysteine, arginine and tyrosine, were greater in total antioxidative capacity compared with the other 13 amino acids.

https://www.mdpi.com/1420-3049/22/12/2066/pdf

Antioxidative Categorization of Twenty Amino Acids Based on Experimental Evaluation.

Plant medicine is the oldest form of health care known to mankind. Syzygium guineense is one of the many species of Ethiopian medicinal plants which has a long history of use as remedies for various ailments such as dysentery, diarrhea, and hypertension. In many countries, herbal medicines and related products are introduced into the market without safety or toxicological evaluation. The aim of this study was to investigate the histopathological effect of 80% methanol extract of S. guineense on liver and kidney and blood parameters of rats. For acute toxicity study, rats were randomly divided into three groups (n=4). The control group received distilled water, while the experimental groups received a single dose of 2000 mg/kg and 5000 mg/kg 80% methanolic extract of S. guineense leaves per oral. For subacute toxicity study, the rats were randomly divided into three groups (n=6). The control group received distilled water, while the experimental groups received 500 mg/kg and 1500 mg/kg 80% methanol extract of S. guineense leaves orally for 28 days. At the end of the experiment, blood samples were collected for hematology and clinical chemistry evaluations. Gross pathology and histopathology of liver and kidneys were assessed. In the acute toxicity study, rats treated with 2000 mg/kg and 5000 mg/kg showed no toxicological signs observed on behavior, gross pathology, and body weight of rats. In the subacute toxicity study rats have showed no significant changes on behavior, gross pathology, body weight, and hematological and biochemical parameters, whereas both experimental groups had a lower blood glucose level compared with the control group (p < 0.05). There were no significant differences in the gross and histopathology of the liver and kidneys of experimental animals in extract exposed groups and their counterpart control. The 80% methanol extract of S. guineense does not produce adverse effects in rats after acute and subacute treatment. Before marketing a S. guineense leaf based remedy, subchronic and chronic toxicity evaluations need to be done.

/pdf/acute-and-subacute-toxicity-of-methanol-extract-of-syzygium-1cqhfbyfua.pdf

Acute and Subacute Toxicity of Methanol Extract of Syzygium guineense Leaves on the Histology of the Liver and Kidney and Biochemical Compositions of Blood in Rats.

Background: The phenotypic expression of sickle cell disease (SCD) is a complex pathophysiologic condition. However, sickle erythrocytes might be the cause for multiple sources of pro-oxidant proce...

https://tandfonline.com/doi/pdf/10.1080/10245332.2018.1498441

Oxidative stress, antioxidant capacity, biomolecule damage, and inflammation symptoms of sickle cell disease in children.

Studies demonstrate that free radicals are involved in the pathogenesis of diabetic complications. The aim of this study was to determine the implication of total antioxidant capacity (TAC) and some enzymatic and non-enzymatic antioxidants as suitable biomarkers of diabetic complications risk factors. A total of 90 patients (70 patients with or without diabetic complications +20 normal healthy) were examined by evaluating the level of lipid peroxidation, nitrogen monoxide (NO), fasting blood glucose, glycated haemoglobin (HbA1c), enzymatic and non-enzymatic antioxidants using standard spectrophotometric methods. The fasting blood glucose and HbA1c levels were respectively 2.05 and 2.32 times higher in the group of patients with diabetes and complications (DPWC) compared to those of healthy persons. A statistically higher level of malondialdehyde (MDA), NO and TAC was observed in a group of patients with diabetes and complications compared to those without complications (DPNC). A significant positive correlation was found between catalase (CAT) and fasting blood glucose while a significant and negative correlation was noted between reduced glutathione (GSH) and fasting blood glucose. Also was noted a significant relationship between HbA1c and other markers of oxidative stress. The results suggest that the plasma levels of CAT, TAC and reduced glutathione could give information on the risk of developing complications of diabetes, considering that the modification of these biomarkers levels were associated with oxidative stress.

/pdf/relationship-between-hyperglycemia-antioxidant-capacity-and-4fj3ql4l7i.pdf

Relationship between hyperglycemia, antioxidant capacity and some enzymatic and non-enzymatic antioxidants in African patients with type 2 diabetes

The aim of this study was to determine the in vitro antioxidant activity, free radical scavenging property and the beneficial effects of extracts of various parts of Syzygium guineense in reducing oxidative stress damage in the liver. The effects of extracts on free radicals were determined on radicals DPPH, ABTS, NO and OH followed by the antioxidant properties using Ferric Reducing Antioxidant Power assay (FRAP) and hosphomolybdenum (PPMB). The phytochemical screening of these extracts was performed by determination of the phenolic content. The oxidative damage inhibition in the liver was determined by measuring malondialdehyde (MDA) as well as the activity of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and peroxidase. Overall, the bark extract of the ethanol/water or methanol showed the highest radical scavenging activities against DPPH, ABTS and OH radicals compared to the other extracts. This extract also contained the highest phenolic content implying the potential contribution of phenolic compounds towards the antioxidant activities. However, the methanol extract of the root demonstrated the highest protective effects of SOD and CAT against ferric chloride while the hydro-ethanol extract of the leaves exhibited the highest inhibitory effects on lipid peroxidation. These findings suggest that antioxidant properties of S. guineense extracts could be attributed to phenolic compounds revealed by phytochemical studies. Thus, the present results indicate clearly that the extracts of S. guineense possess antioxidant properties and could serve as free radical inhibitors or scavengers, acting possibly as primary antioxidants. The antioxidant properties of the bark extract may thus sustain its various biological activities.

Syzyguim guineense Extracts Show Antioxidant Activities and Beneficial Activities on Oxidative Stress Induced by Ferric Chloride in the Liver Homogenate

Sickle cell disease (SCD) is a class of hemoglobinopathy resulting from a single mutation in the s-globin chain inducing the substitution of valine for glutamic acid at the sixth amino acid position which leads to the production of abnormal haemoglobin (haemoglobin S [HbS]). Studies demonstrated the implication of oxidative stress in the development of the sickle cell disease. The study aim was to determine the level of oxidative stress markers in a group of sickle cell homozygous patients (SS) in the Yaounde Central Hospital above 15 years of age. Hemolysates obtained from patients were used to investigate some oxidative stress markers including malondialdehyde (MDA), nitric oxide (NO), catalase (CAT), superoxide dismutase (SOD), peroxidase, total antioxidant capacity (TAC) and total protein concentration. Eighty four individuals, 42 males and 42 females participated (50 % each) with an age range of 15 to 55 years. The levels of markers were significantly higher in the healthy AA group than sickle (SS) (p < 0.05), with the exception of MDA which was significantly high in sickle cell (SS) patients than healthy (p = 0.037). With respect to the gender, both healthy and SS females showed a greater Total anti-oxidant capacity (65 μM) compared to the males (55 μM). The increase in the oxidative stress level especially MDA in sickle cell homozygous patients compared to healthy AA individuals confirms that oxidative stress is involved in the pathogenesis of the sickle cell disease.

/pdf/oxidative-profile-of-sickle-cell-patients-in-a-cameroonian-i9jrf747e0.pdf

Borgia Legrand Njinkio Nono

Papers

Relationship between hyperglycemia, antioxidant capacity and some enzymatic and non-enzymatic antioxidants in African patients with type 2 diabetes

Syzyguim guineense Extracts Show Antioxidant Activities and Beneficial Activities on Oxidative Stress Induced by Ferric Chloride in the Liver Homogenate

Oxidative profile of sickle cell patients in a Cameroonian urban hospital.