Evaluation of the polyphenolic contents and antioxidant properties of aqueous extracts of garlic, ginger, cayenne pepper and their mixture

Garlic (Allium sativum), Ginger (Zingiber officinale), and Cayenne Pepper (Capsicum fructences) are common culinary spices that are used singly or combined in the diet of many populations of the world and there is a long-held belief of their health-enhancing properties.  This study investigated the aqueous extracts each of garlic, ginger, cayenne pepper and a combination of the three for polyphenolic and antioxidant properties that might justify such claims. Aqueous extracts of garlic, ginger, pepper and a combination of the three was evaluated for polyphenolic and antioxidant activities using DPPH, ABTS, nitric oxide radical scavenging activities and reducing power assay. Each of the spice extracts showed high content of phenolics, flavonoids, flavonols and proanthocyanidin, with the pepper extract exhibiting the highest concentration of each polyphenol investigated. The antioxidant activities of the spices and their mixture was concentration dependent, though positively comparable with the standards used. Among the extracts, the mixture exhibited the highest antioxidant activity compared to the individual spices and standards probably due to a synergistic effect of combining the spices. The present study confirmed that the aqueous extracts of garlic, ginger and pepper exhibited significant polyphenolic content and antioxidant potentials. Also, that a mixture of the three spices potentially exhibits more powerful synergistic antioxidant activity than the individual spices, making a strong case for their combined use

Evaluation of Antidiabetic Activity and Associated Toxicity of Artemisia afra

Artemisia afra Jacq. ex Willd. is a widely used medicinal plant in South Africa for the treatment of diabetes. This study aimed to evaluate the hypoglycemic activity and possible toxicity effect of aqueous leaf extract of the herb administered at different dosages for 15 days in streptozotocin-induced diabetic rats. Administration of the extract at 50, 100, and 200 mg/kg body weight significantly (P<0.05) increased body weight, decreased blood glucose levels, increased glucose tolerance, and improved imbalance in lipid metabolism in diabetic rats. These are indications of antidiabetic property of A. afra with 200 mg/kg body weight of the extract showing the best hypoglycemic action by comparing favourably well with glibenclamide, a standard hypoglycemic drug. The extract at all dosages tested also restored liver function indices and haematological parameters to normal control levels in the diabetic rats, whereas the kidney function indices were only normalized in the diabetic animals administered with 50 mg/kg body weight of the extract. This investigation clearly showed that in addition to its hypoglycemic activity, A. afra may also protect the liver and blood against impairment due to diabetes. However, some kidney functions may be compromised at high dosages of the extract

In vivo Studies on Antidiabetic Plants Used in South African Herbal Medicine

Diabetes is one of the most common metabolic disorders worldwide. It is a major health problem with its frequency increasing every day in most countries. The disease is generally believed to be incurable; and the few orthodox drugs available to manage the disease are not readily affordable to the poor. Based on the historical success of natural products as antidiabetic agents and the ever increasing need for new antidiabetics, a number of South African medicinal plants have been evaluated for their antidiabetic properties. In this article, we review the major studies conducted based on ethnobotanical surveys carried out between 2005 and 2008 in South Africa on plants that are traditionally used for the treatment of diabetes. Overall, the results of the studies conducted confirmed the potential of South African medicinal plants in antidiabetic drug discovery and identified a number of promising taxa for further in vivo investigation as plant-based antidiabetic agents

Antioxidant and phytochemical properties of Carpobrotus edulis (L.) bolus leaf used for the management of common infections in HIV/AIDS patients in Eastern Cape Province

BACKGROUND: Carpobrotus edulis (Mesembryanthemaceae), also known as igcukuma in Xhosa language is a medicinal plant used by the traditional healers to treat common infections in HIV/AIDS patients. Based on this information, we researched on the plant phytoconstituents, as well as its inhibitory effect using aqueous and three different organic solvent extracts in order to justify its therapeutic usage. METHODS: Antioxidant activity of the extracts were investigated spectrophotometrically against 1,1- diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) diammonium salt, hydrogen peroxide (H(2)O(2)), nitric oxide (NO), and ferric reducing power, Total phenols, flavonoids, flavonols, proanthocyanidins, tannins, alkaloids and saponins were also determined using the standard methods. RESULTS: Quantitative phytochemical analysis of the four solvent extracts revealed a high percentage of phenolics (55.7 ± 0.404%) in the acetone extract, with appreciable amount of proanthocyanidins (86.9 ± 0.005%) and alkaloids (4.5 ± 0.057%) in the aqueous extract, while tannin (48.9 ± 0.28%) and saponin (4.5 ± 0.262%) were major constituents of the ethanol extract. Flavonoids (0.12 ± 0.05%) and flavonols (0.12 ± 0.05%) were found at higher level in the hexane extract in comparison with the other extracts. The leaf extracts demonstrated strong hydrogen peroxide scavenging activity, with the exception of water and ethanol extracts. IC(50) values of the aqueous and ethanolic extract against DPPH, ABTS, and NO were 0.018 and 0.016; 0.020 and 0.022; 0.05 and 0.023 mg/ml, respectively. The reducing power of the extract was found to be concentration dependent. CONCLUSION: The inhibitory effect of the extracts on free radicals may justify the traditional use of this plant in the management of common diseases in HIV/AIDs patients in Eastern Cape Province. Overall, both aqueous and ethanol were found to be the best solvents for antioxidant activity in C. edulis leaves

Mineral uptake in Solanum nigrum L. cultivated on fertiliser amended soils of the Eastern Cape, South Africa

A considerable interest has been manifested in the cultivation of wild vegetables to combat the ever increasing hunger and micronutrient deficiencies especially in children from the developing world. Solanum nigrum, one of the popular wild vegetables consumed in the Eastern Cape was cultivated on sandy loam soils to determine the effect of fertilisers on Cu, Fe, Mn and Zn uptake in relation to its growth stages. Five treatments (control; 100 kg N/ha; 8.13 t manure/ha; 100 kg N/ha + 8.13 t manure/ha and 50 kg N/ha + 4.07 t manure/ha) were arranged in plots in a Randomised Complete Block Design with five replicates. Cu (mg/kg) remained variably high throughout the trial, ranging between 7.20-23.50 on the field and 5.30-21.40 in the glasshouse. Fe (mg/kg) also remained variably high, ranging between 213- 766 on the field and 178-523 in the glasshouse. Mn (mg/kg) increased with increasing plant maturity and ranged between 85-222 on the field and 64-215 in the glasshouse, but Zn (mg/kg) decreased with plant maturity and ranged between 33-78 on the field and 16-74 in the glasshouse. The results indicate that Solanum nigrum has the potential to supply the recommended daily micronutrient intake values throughout all its growth stages

Growth and physiological response of Solanum nigrum L. to organic and/or inorganic fertilisers

A pot experiment was conducted to determine the effect of organic and/or inorganic fertilisers on the growth and physiological response of Solanum nigrum L. The experiment was laid out in a Randomised Complete Block Design with five treatments and fifty replicates. The treatments were: Control (T1); 100 kg N/ha (T2); 8.13 t manure/ha (T3); 100 kg N/ha + 8.13 t manure/ ha (T4) and 50 kg N/ha + 4.07 t manure/ ha (T5). Plant height, total number of leaves, chlorophyll, moisture, root: shoot ratio, leaf area and stem diameter were measured using standard growth indicator methods. Application of 100 kg N/ ha produced the best root: shoot ratio and stem diameter values; 100 kg N/ha + 8.13 t manure/ ha produced the best chlorophyll and total leaf count values and 50 kg N/ha + 4.07 t manure/ ha boosted leaf area and plant height. The control showed signs of nutrient stress and inorganic fertiliser applied independently did not significantly affect the growth parameters. Although parameters responded differently to each fertiliser treatment, applying a combination of organic and inorganic fertiliser may be a good option to poor resource farmers who may not be able to afford inorganic fertilisers

In vitro inhibitory effects of the ethanol extract of Tetrapleura tetraptera (Schum and thonn.) taub. against multidrug resistant staphylococcus aureus

In this study, the antibacterial effect of ethanol extract of Tetrapleura tetraptera was investigated in vitro against methicillin-resistant Staphylococcus aureus by agar diffusion and macrobroth dilution methods. At the lowest concentration of 20 mg/ml of the ethanol extract, 100 µl produced inhibition zones that ranged between 06 and 15 ± 1.0 mm while the inhibition zones ranged between 16 ± 1.0 mm and 22 ± 1.0 mm when the isolates were tested with 100 µl of the highest concentration (100 mg/ml) of ethanol extract. The minimum inhibitory concentrations (MICs) of the ethanol extract were between 0.019 mg/ml and 5.0 mg/ml while its minimum bactericidal concentrations (MBCs) ranged between 0.078 and 10.0 mg/ml. Ten strains had their MICs less than 1.0 mg/ml while the remaining S. aureus strains had their MICs at concentrations ranging between 1.25 mg/ml and 5.0 mg/ml. The degree of antibacterial activity exhibited by the extract of T. tetraptera demonstrated that its herbal medicine could be as effective as modern medicine in treating diseases associated with the test pathogenic organism and justifying its traditional use in the treatment of bacterial infections

ULTRASTRUCTURE AND ELEMENTAL ANALYSIS OF HYPOXIS HEMEROCALLIDEA: A MULTIPURPOSE MEDICINAL PLANT

Background: Herbal medicine is a popular means of medical management in some parts of the world especially in Africa. Hypoxis hemerocallidea Fisch.C.A.Mey. & Avé-Lall, also known as African potato of the Hypoxidaecae family, is one of the medicinal plants that have enjoyed long usage as an herbal medicine in South Africa. In this study, the morphology and elemental constituents of H. hemerocallidea leaf was investigated to correlate the functional role of the ultrastructure in the production of therapeutic compounds. Materials and Methods: Fresh leaves of H. hemerocallidea were prepared for analysis using standard methods. The ultrastructure and crystal deposits of the plant were assessed using scanning electron microscopy (SEM), and energy dispersive x-ray (EDX). Results: It was observed that the leaves were characterised by multicelullar glandular and non glandular trichomes which are sparsely distributed over the entire surfaces. The glandular trichomes (GTs) in H. hemerocallidea leaf have boulbous heads which are probably filled with secretions, while the non glandular trichomes were long, fibrous and sparse. EDX-SEM of Hypoxis hemerocallidea leaf revealed that carbon, oxygen, nitrogen and silicon are the major components of the deposits, while other elements such as iron, sulphur, sodium, calcium, magnesium, potassium, manganese, iodine, chromium and iodine were present in small but variable amounts. Conclusion: The presence of these elements which are crucial to maintaining good health, in addition to other bioactive constituents might be accountable for the multipurpose therapeutic uses of Hypoxis hemerocallidea in the treatment of cancers, HIV/AIDS related diseases, urinary tract infections, cardiovascular disorders, diabetes and other chronic ailments of human

AN INVENTORY OF INDIGENOUS PLANTS USED AS ANTHELMINTICS IN AMATHOLE DISTRICT MUNICIPALITY OF THE EASTERN CAPE PROVINCE, SOUTH AFRICA

Background: Intestinal parasitic infections are among the most common chronic human infections in developing countries; particularly within the tropical and subtropical regions. An ethno-botanical survey was carried out to document medicinal plants used for the treatment of intestinal worms in Amathole District Municipality of the Eastern Cape Province (ECP), South Africa Materials and methods: A questionnaire-guided interview of the indigenous people by random sampling was done with the help of an interpreter during the survey of the district. Results: Medicinal plants mostly used for traditional management of intestinal worms were selected from 13 plant families: Alliaceae, Anacardiaceae, Asphodelaceae, Asteraceae, Crassulaceae, Dracaenaceae, Fabaceae, Hypoxidaceae, Lamiaceae, Longaniaceae, Punicaceae, Polygonaceae, and Verbenaceae. Out of these, Hypoxis hererocallidea (17%), Strychonos henningsii (14%), Rumex lanceolatus (12%), Ozoroa mucronata (9%) and Acacia karoo (9%) belonging to the families Hypoxidaceae, Longaniaceae, Polygonaceae, Anacardiaceae and Fabaceae respectively were found as the most cited, the least cited plant was Cotyledon orbiculata (2%). Leaves and roots from these plants were found to commonly used (36%), followed by the root (27%), bark (14%), the bulb and stem (9%), and rhizome collectively constitute (5%). Oral method administration by decoction (50%) and infusion (39%) was however found to be a common method by respondents. Conclusion: The current study however showed that ethno-pharmacological knowledge of the traditional healers in ECP largely depends on naturally growing species, documentation of which will go a long way in validating the therapeutic uses and safety of these plants as anthelmintic plants