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Baby spinach is a relatively new crop of commercial significance in South Africa with considerable health attributes. Three parallel trials to investigate its response to nitrogen (N), phosphorus (P), and potassium (K) were conducted. N and P (0, 45, 75, 105, and 120 kg·ha−1) and K (0, 63, 85, 127, and 148 kg·ha−1) treatments were applied to baby spinach in a randomized block design with four replications. After the parallel trial, NPK combination trial was also done. The biomass yield, chlorophyll content, and leaf area index increased significantly with increase in N and P rates; K had no effect on the yield, chlorophyll content, stomatal conductance, and leaf area index. Yield and chlorophyll content peaked at 75 kg·ha−1 of N/P but growth was best optimized at the NPK combination of 45:45:60 kg·ha−1.

Baby spinach is a nutritious vegetable rich in phytochemicals and minerals. Cultural practices such as fertilisation have an impact on the nutritional composition of vegetables. Hence, the current study investigated the responses of the chemical composition of baby spinach to nitrogen (N), phosphorus (P) and potassium (K) fertilisation. Three parallel trials for N and P treatments (0, 45, 75, 105 and 120 kg N and P ha−1) and K (0, 60, 85, 100, 125 and 145 kg K ha−1) arranged in a randomised complete block design with four replicates were conducted. Thereafter, a NPK combination trial was also carried out. Nitrogen, P and K increased the concentrations of total phenols, total antioxidants activity, total flavonoids and vitamin C with maximum concentrations observed at 45 kg N ha−1, 45 kg P ha−1 and 85 kg K ha−1. Interactive effects of NPK fertilisers improved the total phenolic content, total antioxidants activity, total flavonoids and vitamin C content at 35 + 35 + 60 kg ha−1 of NPK. Thus, varying fertili...

The use of complementary and alternative medicine from plants in South Africa, as in the rest of the world, continues to increase. Heteropyxis natalensis, known as the Lavender tree, is indigenous to South Africa and is traditionally used for oral care. The ethanolic extract, of the leaves and twigs, of H. natalensis was investigated for antimicrobial activity against selected oral microorganisms. Actinomyces israelii was found to be the most sensitive oral microorganism to the extract, with a minimum inhibitory concentration (MIC) of 0.88 mg/ml and an MIC of 2.6 mg/ml against Streptococcus mutans. Five known compounds were identified from the ethanolic extract of H. natalensis. The compounds were identified as aurentiacin A (1), cardamomin (2), 5-hydroxy-7-methoxy-6-methylflavanone (3), quercetin (4) and 3,5,7-trihydroxyflavan (5). The MICs of the compounds 1 and 4 were found to be 0.06 mg/ml and 1 mg/ml, respectively, against A. israelii. The cytotoxicity, acute and sub-acute toxicity in pre-clinical studies were also determined for H. natalensis. The extract showed moderate cytotoxicity (35.56 ± 0.16 μg/ml) on human monocyte cells. The acute and sub-acute toxicity analysis of H. natalensis indicated the NOEL (no-observed-effect level) at 200 mg/kg. Interleukin-8 (IL-8) is a chemokine that stimulates the recruitment of leukocytes. A significant reduction of IL-8 production by macrophage cells was observed when exposed to the extract of H. natalensis. It is possible that H. natalensis can prevent excessive tissue damage in periodontal diseases through its reduction of inflammation. Enzymatic bioanalysis of lactic and acetic acid production from Streptococcus mutans and Lactobacillus paracasei was done. A reduction in the acid production from each bacterium was observed on exposure to the extract of H. natalensis. Consequently, this increased the pH, which could possibly reduce the demineralization of enamel which may help prevent the formation of dental caries. In addition the extract may be considered for preventing periodontal diseases.

B spinach (Spinacia oleracea L) is a member of the Amaranthaceae family. Its leaves have a very high respiration rate thus post-harvest quality is affected mostly by tissue decay and the development of off-odours. Thus, this study was conducted to investigate the influence of storage temperature and time on the post-harvest quality of baby spinach. Baby spinach leaves were harvested at 36 days after planting and subsequently stored at 4 C or 22 C for 0, 2, 4, 6, 8, 10 and 12 days. Thereafter the leaves were incubated for 72 hours at 40 C to dry. Minerals, trace elements, total phenols, total carotenoids, flavonoids and antioxidant activities were measured. Composition of magnesium, zinc and iron declined after 8 days of storage at 4 C whilst at 22 C, they declined after 2 days of storage. Magnesium, zinc and iron revealed a similar trend with significantly higher carotenoids found up to 6 days in storage at 4 C whilst at 22 C the carotenoid levels declined after only 2 days. Total phenolic compounds gradually decreased in samples stored at 4 C. However, samples stored at 22 C showed a rapid decrease after 4 days. Both total antioxidant activities and Vitamin C content showed a similar trend with the content remaining constant at 4 C and decreasing after 6 days, whereas the total antioxidant activities and vitamin C for leaves stored at 22 C decreased immediately after 2 days. However, storage time and temperature did not exhibit significant effects on selenium. Results demonstrated that quality of baby spinach deteriorates as storage time and temperature increase.

Objective: The objective of this research was to evaluate the significance of the plant's origin and to assess the essential oil composition of Artemisia vulgaris grown in Egypt simultaneously evaluating the effect of environmental conditions on essential oil composition.Methods: Seeds were planted and the essential oils extracted, using hydrodistillation, from the plants that grew. The resulting essential oils were examined, using gas chromatography linked to mass spectrometry (GC-MS). Thus also evaluating the essential oil chemotype “fingerprint” in A. vulgarisResults: The study identified: the most abundant compounds being camphor, 3, 5-dimethylcyclohexane, germacrene D, cubebene, yomogi alcohol, artemisia alcohol, caryophyllene, while is lower concentrations thujopsene, muurolene, borneol, terpinen-4-ol, valencene, elemene and humulene. Despite the origins of the seeds, the chemical profile was very similar to those of plants grown in Egypt, thus suggesting essential oil composition was significantly influenced by the environmental conditions.Conclusion: Based on the present study, It is suggested that seed origin may play a less significant part if the seed is planted in an environment different to that of its origin, this study proved that and favors the plant-environment interaction to influence the secondary metabolite composition. This supports that plant metabolite profiles are greatly affected by the environment they are grown in.

Heteromorpha arborescens belongs to the family Apiaceae. It is commonly known as the parsley tree. One of its uses in the Eastern Cape Province of South Africa is for the treatment of abdominal pains. The therapeutic effects of the methanolic and aqueous root extracts of H. arborescens were investigated at two dose levels respectively on experimental models of pain and inflammation in rodents. The antinociceptive activity was evaluated using the hot-plate, abdominal constriction and formalin tests. The anti-inflammatory properties of these extracts were assessed using albumin and carrageenan as phlogistic agents. Both extracts produced significant (P

Background Salvia africana-lutea L., an important medicinal sage used in the Western Cape (South Africa), can be termed a ‘broad-spectrum remedy’ suggesting the presence of a multiplicity of bioactive metabolites. This study aimed at assessing wild S. africana-lutea populations for chemotypic variation and anti-Fusarium properties. Methods Samples were collected from four wild growing population sites (Yzerfontein, Silwerstroomstrand, Koeberg and Brackenfell) and one garden growing location in Stellenbosch. Their antifungal activities against Fusarium verticillioides (strains: MRC 826 and MRC 8267) and F. proliferatum (strains: MRC 6908 and MRC 7140) that are aggressive mycotoxigenic phytopathogens were compared using an in vitro microdilution assay. To correlate antifungal activity to chemical profiles, three techniques viz. Gas chromatography-mass spectrometry (GC-MS); Liquid chromatography-mass spectrometry (LC-MS) and 1H Nuclear Magnetic Resonance (NMR) were employed. Principal Component Analysis (PCA) was applied to the NMR data. The partial least squares-discriminant analysis (PLS-DA) was used to integrate LC-MS and NMR data sets. All statistics were performed with the SIMCA-P + 12.0 software. Results The dichloromethane:methanol (1:1; v/v) extracts of the plant species collected from Stellenbosch demonstrated the strongest inhibition of F. verticillioides and F. proliferatum with minimum inhibitory concentration (MIC) values of 0.031 mg ml-1 and 0.063 mg ml-1 respectively. GC-MS showed four compounds which were unique to the Stellenbosch extracts. By integrating LC-MS and 1H NMR analyses, large chemotype differences leading to samples grouping by site when a multivariate analysis was performed, suggested strong plant-environment interactions as factors influencing metabolite composition. Signals distinguishing the Stellenbosch profile were in the aromatic part of the 1H NMR spectra. Conclusions This study shows the potential of chemotypes of Salvia africana-lutea in controlling fungal growth and consequently mycotoxin production. Products for use in the agricultural sector may be developed from such chemotypes.