H.A. Abdelgadir

Antioxidant, Antimicrobial and Phytochemical Variations in Thirteen Moringa oleifera Lam. Cultivars

A study was undertaken to assess variation in antioxidant, antimicrobial and phytochemical properties of thirteen Moringa oleifera cultivars obtained from different locations across the globe. Standard antioxidant methods including the DPPH scavenging, ferric reducing power (FRAP) and β-carotene-linoleic acid model were used to evaluate the activity. Variation in the antioxidant activity was observed, with TOT4951 from Thailand being the most active, with activity five times higher than that of ascorbic acid (reference compound). A different trend was observed for the activity in the FRAP and β-carotene-linoleic acid assays. Antimicrobial activity was tested against Gram-positive (Staphylococcus aureus) and Gram-negative (Klebsiella pneumoniae) strains using the microdilution method. Acetone extracts of all cultivars exhibited good antibacterial activity against K. pneumoniae (MIC values of 0.78 mg/mL). The remaining extracts exhibited weak activity against the two microorganisms. For the antifungal activity, all the extracts exhibited low activity. Variations were observed in the total phenolic and flavonoid contents. Cultivars TOT5169 (Thailand) and SH (South Africa) exhibited highest amounts of total phenolic compounds while TOT5028 (Thailand) exhibited the lowest amounts of five times lower than the highest. The information offer an understanding on variations between cultivars from different geographical locations and is important in the search for antioxidant supplementation and anti-ageing products.

Pollinator effectiveness, breeding system, and tests for inbreeding depression in the biofuel seed crop, Jatropha curcas.

Summary Experiments were conducted to determine factors that could influence seed production in the potential biofuel seed crop, Jatropha curcas. Controlled pollination experiments in a South African plantation of J. curcas showed that plants required pollinator visits for seed production and were genetically self-compatible. Pollen-supplementation did not lead to increased fruit set, suggesting that seed production in the study population was not pollen-limited. Both male and female flowers produced nectar and were highly attractive to honeybees. These insects were effective pollinators of J. curcas, as shown by experiments in which flowers exposed to single or multiple visits by honeybees set significantly more fruit than those from which visits had been prevented. Self-pollination led to marginally lower levels of fruit set relative to cross-pollination. However, fruits arising from self-pollination were almost as numerous and as large as those arising from cross-pollination. Progeny from selfed plants had significantly shorter roots than the progeny of out-crossed plants. However, in general, there was little evidence of inbreeding depression. These results provide empirical evidence that honeybees are effective pollinators of J. curcas and indicate that promotion of cross-pollination does not have to be a priority in orchard management for fruit yield.

Antimicrobial, Anthelmintic Activities and Characterisation of Functional Phenolic Acids of Achyranthes aspera Linn.: A Medicinal Plant Used for the Treatment of Wounds and Ringworm in East Africa

Achyranthes aspera Linn. (Amaranthaceae) commonly known as Prickly Chaff flower (English) is traditionally used for treating a number of ailments. Different parts of the plant are used in treating wounds and ringworm in East Africa and elsewhere for a number of ailments. In this study, leaf extracts of A. aspera collected from two different geographical locations (Ciaat, Eritrea and Ukulinga, South Africa) were evaluated for antibacterial, antifungal, anthelmintic activities and the plant characterized for functional phenolic acids as well as protein binding capacity. The pathogens used in the tests were, two Gram-negative (Escherichia coli and Klebsiella pneumoniae), two Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus), a filamentus yeast-like fungus (Candida albicans) and a free-living nematode (Caenorhabditis elegans). The water and acetone extracts of the samples collected from Ciaat exhibited good antibacterial, antifungal and anthelmintic activity (MIC < 1 mg/ml) except the water extract against E. coli which showed moderate activity. In contrast, the extracts collected from Ukulinga exhibited moderate to weak activities except for the acetone (aq.) extracts which had good activity against some of the tested organisms. UHPLC-MS/MS revealed variation in the levels of some functional phenolic compounds, with rutin, chlorogenic acid and genistein not being detected in the extracts from Ukulinga. The variation was also observed in the protein binding capacity, which could offer a predictive wound healing model. All extracts from plant samples collected at Ciaat expressed significant dominant potency compared to similar extracts from Ukulinga.

Acceptability of a moringa-added complementary soft porridge to caregivers in Hammanskraal, Gauteng province and Lebowakgomo, Limpopo province, South Africa

Objectives: This study determined caregivers’ (mothers’) acceptability and perceptions of a soft, white maize porridge (traditional complementary food (TCF)) that was modified by substituting maize meal with Moringa oleifera Lam. leaf powder at different levels, 1%, 2% and 3% weight for weight (w/w). Design: A cross-sectional study was conducted. Setting: The study was conducted in Stinkwater, Hammanskraal, Gauteng province (25° 23’ 59.99” S: 28° 16’ 60.00” E) and Ga-Mphahlele village, Lebowakgomo, Limpopo province (24°18’0.83”S: 29°32’33.61”E), South Africa. Subjects: Sixty mothers were sampled, separately, from Hammanskraal and Lebowakgomo communities. Outcome measures: The sensory acceptability of the complementary soft porridges was evaluated by caregivers from Hammanskraal and Lebowakgomo communities using a five-point facial hedonic scale (n = 60 per study area). A series of three focus-group discussions were conducted per study area (n = 12 persons per group) to assess caregivers’ perceptions on the inclusion of moringa in complementary foods. Results: Sensory evaluation results showed that the acceptability of the two traditional complementary foods decreased as the level of moringa leaf powder increased. Caregivers indicated in the focus-group discussions that moringa-based soft porridges had a bitter taste, which would not be suitable for children. Only the Lebowakgomo modified traditional complementary food (MTCF) containing 1% of moringa was rated similar in overall acceptability to the corresponding TCF (control). Nevertheless, all caregivers expressed willingness to use moringa in complementary foods provided they would be trained on how to process it. Conclusions: Varying product formulation and processing methods may contribute to increased acceptability of moringa-based foods. Overall, moringa appears to have the potential for use in complementary foods.

An Assessment of the Food and Nutrition Security Status of Weaned 7–12 Months Old Children in Rural and Peri-Urban Communities of Gauteng and Limpopo Provinces, South Africa

This study assessed the food and nutrition security status of children receiving complementary food in rural and peri-urban communities. A group of 106 mothers from Lebowakgomo village and Hammanskraal Township, respectively, participated in the survey. Additionally, six focus group discussions were conducted per study area to assess the mothers’ perceptions about children’s food access. The Children’s Food Insecurity Access Scale (CFIAS) was used to assess the food security status (access) of the children. The Individual Dietary Diversity Score (IDDS) together with the unquantified food consumption frequency survey were used as a proxy measure of the nutritional quality of the children’s diets. The age and weight of the children obtained from the children’s clinic health cards were used to calculate Weight-for-Age Z scores (WAZ) in order to determine the prevalence of underweight children. The findings showed that a large percentage of children were severely food-insecure, 87% and 78%, in rural and peri-urban areas, respectively. Additionally, Lebowakgomo children (23.6%) and Hammanskraal children (17.9%) were severely underweight. Overall, children’s diets in both study areas was characterized by nutrient-deficient complementary foods. Cheaper foods with a longer stomach-filling effect such as white maize meal and sugar were the most commonly purchased and used. Hence, the children consumed very limited amounts of foods rich in proteins, minerals, and vitamins, which significantly increased the risk of their being malnourished.

Antioxidant Potential of African Medicinal Plants

In Africa, the use of medicinal plants to combat diseases forms an integral component of the culture and is thus practised widely. To this extent, several important plant species have been subjected to different pharmacological screening techniques to give scientific credence to the claimed uses. Among those that have been screened are those used to combat oxidative stress. We present here a review of the important plants used in African traditional medicine with antioxidant potential. The plants listed here are habitats of North Africa, covering the vast Sahara, West Africa, East Africa and the Palaeotropical kingdom of Central Africa as well as Southern Africa including the Capensis kingdom of the Western Cape province of South Africa, Madagascar, Mauritius and the Mascarenes. Oxidative stress has been implicated as one of the key factors in accelerated pathogenesis of a number of human diseases including cardiovascular, inflammatory, cancer, autoimmune and neurodegenerative diseases. Plants listed here have been utilised directly or indirectly in managements of some of these conditions.