Fhatuwani N. Mudau

The synergistic potential of various teas, herbs and therapeutic drugs in health improvement: a review

Tea is one of the most widely consumed non-alcoholic beverages in the world next to water. It is classified as Camellia sinensis and non-Camellia sinensis (herbal teas). The common bioactive compounds found mainly in green teas are flavan-3-ols (catechins) (also called flavanols), proanthocyanidins (tannins) and flavonols. Black tea contains theaflavins and thearubigins and white tea contains l-theanine and gamma-aminobutyric acid (GABA), while herbal teas contain diverse polyphenols. Phytochemicals in tea exhibit antimicrobial, anti-diabetic and anti-cancer activities that are perceived to be helpful in managing chronic diseases linked to lifestyle. Many of these phytochemicals are reported to be biologically active when combined. Knowledge of the synergistic interactions of tea with other teas or herbs in terms of biological activities will be of benefit for therapeutic enhancement. There is evidence that various types of teas act synergistically in exhibiting health benefits to humans, improving consumer acceptance and economic value. Similar observations have been made when teas and herbs or medicinal drugs were combined. The aim of this review is to highlight potential beneficial synergies between combinations of different types of teas, tea and herbs, and tea and medicinal drugs.

Chemical compositions and antimicrobial activities of Athrixia phylicoides DC. (bush tea), Monsonia burkeana (special tea) and synergistic effects of both combined herbal teas

OBJECTIVEnTo determine the chemical compositions and evaluate the antimicrobial activity of bush tea (Athrixia phylicoides DC.), special tea (Monsonia burkeana) and synergy (combination of bush tea and special tea).nnnMETHODSnTotal polyphenols were determined using the methods reported by Singleton and Rossi (1965) and modified by Waterman and Mole (1994). Tannins were determined using vanillin HCL methods described by Prince et al. (1978). Total antioxidants were determined using the methods described by Awika et al. (2004). The micro dilution technique using 96-well micro-plates, as described by Eloff (1998) was used to obtain the minimum inhibition concentration (MIC) and minimum microbicidal concentration (MMC) values of the ethanol extracts against the microorganisms under study. The microbes strain used was Gram negative bacteria such as Escherichia coli, Klebsiella oxytoca, Proteus vulgaris, Serratia marcescens, Salmonella typhi, Klebsiella pneumonia; Gram positive bacteria such as Bacillus cereus, Staphylococcus aureus and a fungus Candida albicans.nnnRESULTSnThe results demonstrated that special tea contains significantly higher content of total polyphenols (8.34 mg/100 g) and total antioxidant (0.83 mg/100 g) as compared to bush tea [total polyphenols (6.41 mg/100g) and total antioxidant (0.63 mg/100g)] and combination of bush tea and special tea [total polyphenols (6.42 mg/100 g) and total antioxidant (0.64 mg/100 g)]. There was no significant difference in tannins between bush tea, special tea and synergy. The results of antimicrobial activity (MIC and MMC) demonstrated that the ethanol extracts of bush tea, special tea and synergy possessed antimicrobial activity against all microorganisms at different zones. The MIC of bush tea ranged from 1.56 to 12.50 mg/mL while the MMC ranged from 0.78 to 12.50 mg/mL. Special teas MIC ranged from 0.39 to 12.50 mg/mL while the MMC ranged from 0.01 to 12.50 mg/mL. The MIC of synergy ranged from 3.13 to 12.50 mg/mL while the MMC ranged from 3.13 to 12.50 mg/mL without positive synergistic effect recorded.nnnCONCLUSIONSnBoth bush and special tea contain total polyphenols, total antioxidants and tannins with special tea containing a significantly higher total polyphenols and total antioxidant as compared to bush tea and synergy. Bush tea, special tea and synergy possess antimicrobial activity at various degrees.

Yield and Essential Oil Response in Coriander to Water Stress and Phosphorus Fertilizer Application

Abstract Coriander (Coriandrum sativum L.) contains essential oil, and various extracts from the seeds possess anti-bacterial, antioxidant, anti-diabetic, anti-cancerous and anti-mutagenic activities. Field experiments were carried out to study the effect of phosphorus (P) fertilization (0, 12 and 24u2005kg-ha−1 P) on the seed yield, and volatile oil of Egyptian cultivar of coriander under water stress conditions. The oil was obtained by hydrodistillation extraction method using Clevenger apparatus. Chemical analysis of the oil was done by using gas chromatography and mass spectrometry (GC-MS). Increasing water amounts and P fertilization rates increased plant height, number of branches, number of umbels and seed yield. Essential oil yields increased significantly with increasing water regimes from 50 % to 100 % of ET crop. Irrigation applied at 100 % of crop water need, combined with 24u2005kg-ha−1 P, gave the best seed and oil yields results. Coriander plants have high water use efficiency (WUE) at 50 % ET crop, and 24u2005kg-ha−1 P whilst irrigation at 100 % ET crop without any phosphorus application gave the lowest WUE. Concerning essential oil constituents, linalool was the major compound in coriander fruits.

Influence of Postharvest Storage Temperature and Duration on Quality of Baby Spinach

S agriculture in most developing countries world-wide including South Africa is largely rain-fed. Changes occurring in the Extension environment include the climate, globalisation and technological improvements. Broad political and scientific consensus exist that climate change and variability is happening and will continue well into the future with negative effects on food production and food security. Extension professionals, therefore, need to constantly develop and improve their capabilities to remain useful and relevant to farming communities. The purpose of the paper is to determine the extension agents’ competencies regarding coping strategies they promote and their effectiveness in contributing tosmallholder crop farmers’ food production in light of climate variability. The study adopted a multi-stage random sampling approach to select districts, municipalities and respondents. Semistructured questionnaires were used to collect data from 194 smallholder crop farmersin 20 villages from four municipalities of Limpopo province, South Africa in January of 2014. Extension managers and field-level extension agents of the Limpopo Department of Agriculture Extension service took part in the survey. Findings show that only one-third of survey respondents receive public extension services including information on climate variability coping assistance; this group finds the information useful for farm production. The most popular climate variability coping strategies promoted by most extension agents were conservation agricultural practices. Small yield differences between extension service and non-extension service recipients indicate agents need new competencies in how to apply coping strategies with producers. Study recommends involvement of extension agents, scientists and farmers in adaptive, municipality-specific trials on the effective implementation of conservation agricultural practices to enhance crop yields. There is need for agents to use multiple channels for effective communication to improve adoption of climate variability coping innovations which have the potential to improve crop yields.Groundnut is one of the most important oilseed crops grown in Andhra Pradesh. The crop is affected by variety of diseases, of which stem rot caused by Sclerotium rolfsii is very important and has become one of the major constraints causing damage to the crop. Management of stem rot is difficult because of soil borne nature of the pathogen and its wide host range and the chemical methods are very expensive and will not provide complete protection from the pathogen. There is worldwide acceptance to the use of ecologically safe, environment friendly methods of protecting crops from the plant pathogens. Using plant produced allelochemicals in agricultural and horticultural practices could minimize synthetic pesticide use, reduce the associated potential for environmental contamination and contribute to a sustainable agricultural system. In vitro studies conducted to reduce the growth of S. rolfsii against mustard leaf discs (8 mm size) inoculated with S. rolfsii (5 mm size), un-inoculated leaf discs revealed at the end of the experiment i. e. at 72 hours, the growth of the pathogen exposed to S. rolfsii inoculated leaf discs was reduced by 15.68 per cent over control and in un-inoculated leaf discs it recorded 11.48 per cent over control. Similarly, the S. rolfsii exposed to mustard powder 2 mg, 5 mg, 10 mg and 20 mg after 24 hours of exposure to mustard powder, the growth of S. rolfsii was completely inhibited in all the concentrations. At the end of the experiment at 96 hours of exposure, mustard powder of 20 mg was found 63.2% inhibitory to the growth of S. rolfsii, while 2 mg of mustard powder did not show any effect on S. rolfsii, suggesting that the fungus may have the ability to adapt to volatiles at lower concentrations. In green house experiment, incorporation of the mustard plant parts into the soil reduced the infectivity of S. rolfsii at every date at which inoculum was added to soil over the 13 day period. The disease incidence was minimum 37.44% at 0 day application of S. rolfsii immediately after incorporation of mustard. The present results also showed that the persistence of Brassica residues was significantly shorter than the persistence of residue action. The results on the effect of incorporation of Brassica sp residues with other treatments on stem and pod rot of groundnut, indicated that the incorporation of mustard plant parts with conventional and non-conventional treatments highly influenced the incidence of stem rot and plant growth. Treatment FYM application @ 6 kg per plot + in situ application of Brassica residues + rhizobium seed treatment @ 20 g per kg seed (T9) showed highest plant height (25.63, 36.93, 42.50 cm), leaf area (272, 1040, 1348.58 cm) at 30, 60 and 90 DAS respectively, fresh weight and dry weight (70.91, 26.66 g plant) and pod yield (2.16 kg plot) at the time of harvest. Soil drenching with propiconazole @ 0.1% + in situ application of Brassica residues @ 4 kg per plot + rhizobium seed treatment @ 20 g per kg seed (62.55%, 67.95%) followed by soil solarization + in situ application of Brassica residues @ 4 kg per plot + rhizobium seed treatment @ 20 g per kg seed (57.10%, 66.70%) resulted in maximum reduction in stem rot and pod rot disease severity per cent over inoculated control respectively. Among all the treatments lowest fungal and bacterial population were recorded in soil drenching with propiconazole @ 0.1% + in situ application of Brassica residues @ 4 kg per plot + rhizobium seed treatment @ 20 g per kg seed (before sowing of groundnut as well as after harvest of groundnut (4.66 x 10, 5.00 x 10; 21.33 x10, 24.00 x 10 cfu g of soil) respectively. In vitro studies on the effect of dried leaf residues of mustard, cabbage and onion on soil microbial population showed that the population of bacteria was revealed more over the fungi in all the treatments. Minimum microbial population was noticed in the soil exposed to dried mustard leaf volatiles followed by onion and cabbage dried leaf residues.D from national typical matter spectral library of China, the featured crop spectral library in south China was built including litchi, banana, winter crop (potato, chili, etc). Spectral and remote sensing models and Applications were developed for inversion of land surface temperature, surface soil moisture. We built the spectral models (350-2500nm) of leave chlorophyll a, soil organic matter, N and P for precision fertilizing in litchi orchard. Besides, a new remote sensing method was developed for estimating the planting area of winter potato, combining the NDVI spectra and spectral angle method. The research achievements had been widely applied in crop planting area estimation, drought & cold disaster monitoring and litchi fertilizer application with notable economic and social benefits.Conservation of biodiversity on dryland agricultural farms, forests, and protected areas is likely to backup future livelihood options. The main objective of this research was to investigate the ethnobotanical importance of indigenous trees protected within agricultural farming system of Mutale local municipality. Tree layer of indigenous species were recorded and classified into families, parts used and their utilization purposes. Twenty two agricultural fields were visited and nineteen species were recorded. The 19 species were classified into sixteen families with Fabaceae, Combretaceae, Capparaceae being the dominating families. Sclerecarya birrea belonging to Anacardiaceae family was the plant species which was well represented in the agricultural farming fields, occurring in 21 farms, followed by Adansonia digitata (19 farms) which belongs to Malvaceae family, and Boscia albitrunca (16 farms), Maerua angolensis (15 farms) which both belong to the Capparaceae family. Shade use category amongst tree species protected within agricultural fields was the dominant category followed by medicine, food, demarcation fence, fodder, and firewood. Protection of these indigenous trees within agricultural fields will go a long way towards conservation of declared protected and endangered species.

Influence of temperature, aluminium chloride toxicity and exposure to Bacillus subtilis on the germination of okra

Influences of heat, aluminium chloride concentration and exposure to Bacillus subtilis on germination of okra seed were investigated. A factorial experiment was conducted using Petri dish assays, and seed germination percentage and coleoptile length were recorded for the different treatments. Secondary metabolite shifts of five-day-old germinated seed were assessed using 1H nuclear magnetic resonance and ultra-high resolution mass analyses. Analysis of the experimental data indicated that, individually, temperature, aluminium chloride concentration and exposure of the germinating seed to B. subtilis influenced germination of okra. Germination phenotype was also influenced by the interactions of the treatments. No clear-cut spectral shifts were observed in the secondary metabolome of the germinated seeds.

The quality of baby spinach as affected by developmental stage as well as postharvest storage conditions

ABSTRACT Baby spinach is rich in phytochemicals that provide great benefits to consumers’ health. The study aim was to investigate the effect of the growth harvest stage, postharvest storage duration and temperature on quality of baby spinach leaves. A 3u2009×u20095u2009×u20093 factorial experiment was laid out in a randomised complete block design with four replicates per treatment. The treatments were arranged as follows namely: stage I [28 days after sowing (DAS)], stage II (35 DAS)and stage III (42 DAS), and leaves were kept up to 12 d at three different temperatures – 4, 10 and 20°C. The study demonstrated that the overall appearance and odour were both well maintained in the leaves of baby spinach harvested at stage II. The baby spinach harvested 28 DAS led to higher content of iron [1.13u2005mgu2005g−1 dry weight (DW)], magnesium (14.4u2005mgu2005g−1 DW), and zinc (0.17u2005mgu2005g−1 DW). The highest level of total antioxidant activity (0.43u2005mgu2005g−1 DW) and flavonoids (12u2005mgu2005g−1 DW) after 12 d of storage was observed in baby spinach leaves at stage I when stored at 4°C. Therefore, baby spinach leaves harvested 28 DAS and store at 4°C for 6 d improved shelf life and nutraceutical quality. Thus, early harvest of fresh produced baby spinach harvested in order to attain high phytochemical and mineral content when stored at low temperature (4°C) without exceeding 6 days is recommended.

Effect of Timing and Rates of Nitrogen Application on Yield, Chemical Compositions, Pharmacologic Activities, and Cytotoxicity of Herbal Bush Tea (Athrixia phylicoides DC.)

Bush tea is a popular South African herbal and medicinal tea with the potential for commercialization. The objective of the study was to investigate the effects of different rates of applied nitrogen (N) and timing (early and late) of N application on yield, chemical composition, pharmacologic activity, and cytotoxicity of bush tea. Factorial treatments consisted of timed N application rates (0, 75, 150, and 225 kg·ha) for both early and late N application. The treatments were arranged in a randomized complete block designwith five replicates. The results show a significant positive response of bush tea fresh and dry leaf and twig weight, chlorophyll, leaf tissue N, total polyphenols, and total flavonoids in response to applied N rates, regardless of the timing of N application, reaching a maximum at 225 kg·ha of N. Later, regardless of the timing of N application, total tannins and total antioxidant activity increased with increasing applied N from 0 to 225 kg·ha, reaching a maximum of 150 kg·ha N. The results of this study suggest that, with the exception of antimicrobial activity, most of the parameters recorded increased with increasing rates of N applied. The results further denote that parameters recorded were consistently greater on early applied N compared with late applied N. However, there was no significant difference between the minimum inhibition concentration (MIC) and minimum microbicide concentration (MMC) of early and late appliedN. Bush tea appliedwith 75 N and 150 N had a significantMIC value (3.1mg·mL) for Escherichia coli and Klebsiella pneumonia compared with 6.3 mg·mL reached at 225 kg·ha N. Among N rates applied, the MIC for Klebsiella oxytoca, Proteus vulgaris, Salmonella typhi, Serratia marcescence, and Staphylococcus aureus were not significantly different. Hence, N rates applied did not have a significant effect on bush tea MMC values of all microbial species tested. The cytotoxicity of bush tea leaf and twigs harvested from early and late N application were significantly reduced with increasing nitrogen levels reaching a maximum at 225 kg·ha. There was a wide variation of compounds despite rates of N applied as well as timing of application, with most compounds such as norfenfluramine, phytol, caryophyllene, propylene glycol, a-copaene, and squalene detected in greater quantities. Bush tea is a South African herbal tea with the potential for commercialization. The commercialization of bush tea is supported by a report of the toxicologic assessment of bush tea conducted by Chellan et al. (2008). They have reported widespread consumption of bush tea in South Africa. Mudau et al. (2007) also reported that commercialization of bush tea can provide a healthy beverage alternative to caffeine-containing teas. The plant is used popularly as an herbal tea and a medicinal plant for the treatment of different ailments (Nchabeleng et al., 2013). Naturally, bush tea grows at different altitudes with different rainfall regimes and soil characteristics (Nchabeleng et al., 2012). Therefore, to achieve good-quality bush tea, it is important to study the nutritional requirement of field-grown bush tea plants. Fertilizers play a critical role in determining horticultural crop yield, quality, and nutritional content (Martinez-Ballestra et al., 2008). In general, all major quality attributes in horticultural crops, including visual quality and taste, are influenced directly by N availability (Locascio et al., 1984). In green tea production, fertilizer is a major agro-input for the production of high-yield and high-quality tea (Woldegebriel, 2007). Fertilizers improve the nutritional status of both soil and plants (Njogu et al., 2014). Because tea production is a perennial monoculture, a well-balanced fertilizer is necessary throughout the year (Hamid et al., 2014). The production of secondary metabolites in medicinal plants has been reported to be influenced by genetics and cultivation conditions, such as climate, plant density, and the use of fertilizers (Baranauskiene et al., 2003). Among fertilizers, N is the most important nutrient for crop production because it promotes both yield and quality of plant secondary metabolites (Sifola and Barbieri, 2006). The reason for extensive N application is that the quality of green tea is known to correlate directly with the concentration of primary compounds related to N application (Watanabe, 1995). In addition, N is a wellknown essential element for plant growth and it plays a regulatory role in the synthesis of secondary metabolites, such as phenolic compounds (Ruan et al., 2010). Conversely, Bryant et al. (1983) hypothesized that high N levels in plant tissues contribute to the formation of more amino acids and proteins for growth in relation to defense compounds such as secondary metabolites. Previous studies demonstrated that earlyapplied N levels ranging from 75 to 225 kg·ha improved growth and quality in cultivated bush tea (Tshivhandekano et al., 2017). However, data are lacking to demonstrate the effect of timing and rates of N application on bush tea. Thus, this study aimed at investigating the effect of applied N rates and timing of N application on yield, chemical compositions, pharmacologic activity, and cytotoxicity of bush tea. Materials and Methods Experimental site. The experiments were conducted at the Tshwane University of Technology (TUT) experimental farm, which is situated north of Pretoria (lat. 25 36#03.2

Metabolic profiling of four South African herbal teas using high resolution liquid chromatography-mass spectrometry and nuclear magnetic resonance

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Nitrogen application influences quality, pharmacological activities and metabolite profiles of Athrixia phylicoides DC. (Bush tea) cultivated under greenhouse and field conditions

E). The trials were conducted beginning in spring (Sept. 2016) to the end of Nov. 2016. The plants were allowed to resprout and the trial was repeated beginning in the summer (Dec. 2016) until the end of the summer season (Feb. 2017). The resprouted shoots were fertilized in the same manner as the initial plants. Weather data are presented in Table 1; this was the best time to cultivate bush tea in South Africa (Mudau et al., 2006, 2007). Five soil samples were collected per horizon (A and B) from different spots on the plot the trial was conducted. Each soil sample collected was packed separately in different marked brown paper bags. The initial soil chemical analyses were conducted using the procedure described by Hanlon et al. (1994). The soil contained 0.001 mg·kg nitrate-N. Received for publication 2 Mar. 2018. Accepted for publication 10 July 2018. We gratefully acknowledge the financial support of the National Research Foundation, the Gauteng Department of Agriculture and Rural Development, and Stellenbosch University’s Division of Research Development. Corresponding author. E-mail: mudaufn@unisa. ac.za. 1332 HORTSCIENCE VOL. 53(9) SEPTEMBER 2018 Other soil chemical characteristics are presented in Table 2. Experimental design and treatment details. Factorial treatments consisted of timed N application rates (0, 75, 150, and 225 kg·ha) for both early and late N application. Applied N rates were 0, 75, 150, and 225 kg·ha per plot of 36 plants spaced at 0.5 · 0.5 m. The N rates were timely (early and late) manually broadcasted once off. Early (3 weeks after plant establishment) and late (6 weeks after plant establishment) N application was conducted in a randomized complete block design with five single plants per treatment replicated five times. Limestone ammonium nitrate (28% N) was used as an N fertilizer source. All plants received 75 kg·ha phosphorus (P) and 45 kg·ha potassium (K). The fertilizer source for P was single superphosphate (10.5%); for K, it was potassium chloride (50%) [Ocean Agriculture (PTY) LTD, Muldersdrift, South Africa]. Micronutrients were foliar applied as recommended by Maedza et al. (2017). Two liters of water per plant was applied every third day using a drip irrigation system. Plant material. The plant materials were collected from Haenerstburg (lat. 23 56# S; long. 29 54# E; 890 m a.s.l.) in Limpopo Province, South Africa. Plants were propagated by using cuttings as described byMudau et al. (2006). Bush tea cuttings 7 to 8 cm long were planted as described by Maudu et al. (2012), with sand used as the growth media. The cuttings were placed on the mist bed and allowed to sprout and root. The well-matured bush tea that hardened in the shade nets after propagation were later transplanted to the TUT experimental farm for the open field trial, using a plant spacing of 0.5 · 0.5 m. Parameters recorded. Biomass (fresh and dry weight of leaf and twigs), chlorophyll content, leaf tissue N, total polyphenols, total flavonoids, total tannins, antioxidant activity, antimicrobial activity, cytotoxicity, and detected compounds were documented. Determination of chlorophyll content. Chlorophyll was measured once every month during the growing seasons with a portable Minolta chlorophyll meter (SPAD-502; Spectrum Technologies, Inc., Plainfield, IL). Determination of fresh weight and dry weight. The average fresh and dry weights were determined used standard level precision balances. Fresh weight was measured immediately after harvest whereas dry weight was measured after 2 weeks of freeze drying. Harvest and extraction of bush tea leaf and twig samples. The bush tea leaves and twigs were harvested using the current traditional method of cutting the plant from the stem to allow resprouting. The bush tea leaves and twigs from both early and late applied N plots were all harvested at the end of spring (Nov. 2016) and the end of summer (end of Feb. 2017). During harvest, the leaves and twigs were packed in marked brown paper bags. After harvest, bush tea leaves and twigs were transported immediately to the science campus of the University of South Africa in Florida (lat. 5.26 9#501

Nutritional quality of baby spinach (Spinacia oleracea L.) as affected by nitrogen, phosphorus and potassium fertilisation

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