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

A Review of the Antidiabetic Activities of Ginger

Diabetes mellitus, a chronic metabolic disorder with major health care burden worldwide, is increasing, with 173 million adults being diabetic and over 8 million deaths recorded annually. Undesirable pathological conditions and high rates of secondary failure limit the use of current antidiabetic agents, thus, the need for more effective antidiabetic agents. Medicinal plants such as spices, rich in bioactive components that promote prevention and treatment of chronic conditions such as heart disease, cancer and Type-2 diabetes, are inexpensive with no side effects. The Zingiberaceae family, of which ginger is a member, consists of many species frequently cited for their antidiabetic and hypoglycemic properties. All important scientific literatures from 2000 to 2018 on the antidiabetic potentials of Zingiber officinale were evaluated. According to these studies, ginger exerts its antidiabetic effects through restorative effects on pancreatic β-cells, increasing insulin sensitivity, action and peripheral utilization of glucose. Other mechanisms include increased synthesis of hepatic glycogen through the enhancement of glycogen regulatory enzyme expression in the liver, inhibition of carbohydrate metabolizing enzymes, stimulation of pancreatic insulin release and inhibition of hepatic glucose production. Further studies, especially in humans are needed, more so, since ginger is one of the spices generally regarded as safe

Foliar Micromorphology and Histochemical Localization of Specific Metabolites in the Leaves of Celosia argentea L.

Celosia argentea is an essential vegetable that is cultivated in the western part of Africa. This species has a growing reputation for its role in alleviating nutritional challenges and has found great application as herb of therapeutic importance in many regions of the world. This study investigated the foliar micromorphology and the histochemistry of Celosia argentea. Scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectrometry and staining agents were used to evaluate the micromorphology of the plant. The result revealed sunken amphistomatic stomata distribution on both surfaces of the leaf. Anomocytic and anisocytic stomata complexes were also observed on both epidermal surfaces. A definitive protuberance was observed on the polar end of the adaxial stomata. Stomata apparatus was ellipsoidal with a mean length of 19.60 ± 0.56 µm, while the mean stomata densities on the adaxial and abaxial surfaces were 83.5 ± 2.12 mm‑2 and 194.18 ± 3.70 mm‑2 respectively. Trichomes (with a length of 100.94 ± 9.44 µm) were sparsely distributed on both surfaces; glandular trichomes were observed only on the abaxial surface. The EDX spectrometry revealed the presence of iron, oxygen, sodium, calcium, potassium and sulphur as the major elements on the leaf, while histochemical tests revealed the presence of polyphenols, starch and lipids. Our results could be used to support and validate the information database on the anatomy of Celosia argentea

Foliar micromorphology of Lippia javanica (Burm.F) Spreng

Background: Lippia javanica (Burm.F.) Spreng is an aromatic indigenous South African plant with culinary and medicinal values. This study investigated the foliar morphology and elemental composition of the plant because not much data concerning the anatomical and micro-morphological features can be found in literatureMaterials and Methods: Fresh leaves of the plant were investigated using light and scanning electron microscopy (SEM). The elemental composition of the leaf was determined by energy dispersive X-ray spectroscopy.Results: The leaves of L. javanica were amphitrichomic while the stomata distribution was amphistomatic. These stomata were more or less randomly distributed over the epidermis lying almost close to each other and were fewer in number in between the veins and over the finer veins. The major constituents of crystals found in the plant were Ca, Na, S, Al, P, Cl, K, Mg and Fe. The presence of long glandular trichomes on the leaf surfaces of the plant could indicate secretory sites where secondary metabolites are produced.Conclusion: Secretions from the glandular trichomes and the presence of these elements, which are vital in maintaining good health, are probably responsible for the culinary and medicinal properties of L. javanica.Key words: Lippia javanica, electron dispersive x-ray, scanning electron microscope, amphitrichomic lea

Unraveling the genetic complexity underlying sorghum response to water availability

Understanding the adaptation mechanisms of sorghum to drought and the underlying genetic architecture may help to improve its production in a wide range of environments. By crossing a high yielding parent (HYP) and a drought tolerant parent (DTP), we obtained 140 recombinant inbred lines (RILs), which were genotyped with 120 DArT and SSR markers covering 14 linkage groups (LGs). A subset of 100 RILs was evaluated three times in control and drought treatments to genetically dissect their response to water availability. Plants with early heading date (HD) in the drought treatment maintained yield (YLD) level by reducing seed number SN and increasing hundred seed weight (HSW). In contrast, early HD in the control treatment increased SN, HSW and YLD. In total, 133 significant QTL associated with the measured traits were detected in ten hotspot regions. Antagonistic, pleiotropic effects of a QTL cluster mapped on LG-6 may explain the observed trade-offs between SN and HSW: Alleles from DTP reduced SN and the alleles from HYP increased HSW under drought stress, but not in the control treatment. Our results illustrate the importance of considering genetic and environmental factors in QTL mapping to better understand plant responses to drought and to improve breeding programs

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

Comparative analysis of the chemical composition of three spices – Allium sativum L. Zingiber officinale Rosc. and Capsicum frutescens L. commonly consumed in Nigeria

The beneficial health effects of spices against common chronic systemic diseases have been well documented. Comparative study of the proximate, mineral and phytochemical components of three spices namely garlic (Allium sativum L.), ginger (Zingiber officinale Rosc.) and pepper (Capsicum frutescens L.) were investigated. Analysis of the proximate composition revealed that the spices had considerable carbohydrate and crude protein content, but low ash, fibre, moisture and fat except pepper which has high crude fat content. The spices were also characterized by the presence of mineral elements such as calcium, iron, potassium, phosphorus, sodium, magnesium, copper and zinc which are very important to human nutrition. Phytochemical screening indicated that these spices are also rich in phytonutrients including alkaloid, tannin, carotenoids, saponin and flavonoids. The spices had low concentrations of steroids and cardenolides. Overall, the findings indicate that the spices are good sources of nutrients, mineral elements and phytochemicals which could be exploited as great potentials for drugs and/or nutritional supplements.Key words: Comparative, nutritional, supplements, spices

Suitability of Fruits and Vegetables for Provision of Daily Requirement of Dietary Fiber Targets

The risk factors associated with low dietary fiber intake and the synergy with its role in colon prebiotic activity has stimulated a re-awakening in the scientific research. Dietary fiber intake has reduced all over the world, and so it has been labelled as a major shortfall nutrient of important in public health. Changes in lifestyle and improved standard of living have affected the diet of consumers in so many ways. Observation of these facts have spurred a special interest in the search for functional foods that contains essential nutrients like dietary fiber whose nutritional value improves the health of the consumer, enhances their physical and mental state and prevent lifestyle diseases. Fruits and vegetables are a modest source of total dietary fiber with nutrients such as vitamins, minerals, and phytochemicals, including polyphenols, which provide support for their biological plausibility and enhance their health benefits. This chapter therefore reviews existing literature on the utilization of fruits and vegetables as rich sources of fiber; their fiber concentration, their appropriateness in meeting the adequate fiber intake for daily consumption and their overlapping roles as a fiber source and as nutraceuticals

Lifestyle factors and co-morbidities associated with obesity and overweight in Nkonkobe Municipality of the Eastern Cape, South Africa

Background: Obesity is a global epidemic that affects 500 million people worldwide and is predicted to increase to one billion people by 2030. The prevalence of obesity is increasing across populations in South Africa. However, questions still remain surrounding the predisposing factors and obesity-related health problems especially in the rural areas. This study evaluated several lifestyle factors such as dietary habits, physical activity, smoking, alcohol intake, co-morbidities and their association with the prevalence of obesity and overweight in Nkonkobe Municipality of the Eastern Cape. Methods: A cross-sectional, population-based survey was conducted among 118 residents in four rural/sub-urban townships of the study area. Measurements including weight, height, body mass index (BMI), physical activity and dietary habits were determined using a validated questionnaire. Results: The overall prevalence of obesity and overweight was 38 and 19%, respectively. The highest prevalence of obesity (70%) was observed among those who do not undertake any physical activity. Close to half (48.48%) of the respondents who eat fast foods always were obese, and 30.30% were overweight; when combined, the prevalence for obesity is 78.78%. A negative association with obesity was observed among regular smokers (26.92%) and consumers of alcohol (4.00%). Arthritis, hypertension and tuberculosis were co-morbidities significantly (P < 0.05) associated with obesity in the study area. Conclusions: The findings of this study reveal that lack of physical activity, overindulgence on fast and fried foods, low fruit and vegetable consumption as well as arthritis, hypertension and tuberculosis were significant risk factors of obesity in Nkonkobe Municipality

FOLIAR MICROMORPHOLOGY OF LIPPIA JAVANICA (BURM.F) SPRENG

Background: Lippia javanica (Burm.F.) Spreng is an aromatic indigenous South African plant with culinary and medicinal values. This study investigated the foliar morphology and elemental composition of the plant because not much data concerning the anatomical and micro-morphological features can be found in literature Materials and Methods: Fresh leaves of the plant were investigated using light and scanning electron microscopy (SEM). The elemental composition of the leaf was determined by energy dispersive X-ray spectroscopy. Results: The leaves of L. javanica were amphitrichomic while the stomata distribution was amphistomatic. These stomata were more or less randomly distributed over the epidermis lying almost close to each other and were fewer in number in between the veins and over the finer veins. The major constituents of crystals found in the plant were Ca, Na, S, Al, P, Cl, K, Mg and Fe. The presence of long glandular trichomes on the leaf surfaces of the plant could indicate secretory sites where secondary metabolites are produced. Conclusion: Secretions from the glandular trichomes and the presence of these elements, which are vital in maintaining good health, are probably responsible for the culinary and medicinal properties of L. javanica