Medicinal Plants for Mitigating Pain and Inflammatory-Related Conditions: An Appraisal of Ethnobotanical Uses and Patterns in South Africa.

In South Africa, traditional medicine remains the first point of call for a significant proportion of the population seeking primary healthcare needs. This is particularly important for treating common conditions including pain and inflammation which are often associated with many disease conditions. This review focuses on the analysis of the trend and pattern of plants used for mitigating pain and inflammatory-related conditions in South African folk medicine. An extensive search was conducted using various scientific databases and popular ethnobotanical literature focusing on South African ethnobotany. Based on the systematic analysis, 38 sources were selected to generate the inventory of 495 plants from 99 families that are considered as remedies for pain and inflammatory-related conditions (e.g., headache, toothache, backache, menstrual pain, and rheumatism) among different ethnic groups in South Africa. The majority (55%) of the 38 studies were recorded in three provinces, namely, KwaZulu-Natal, Limpopo, and Western Cape. In terms of the number of mentions, the most popular plants used for pain and inflammatory-related conditions in South Africa were Ricinus communis L. (10), Aloe ferox Mill. (8), Pentanisia prunelloides subsp. latifolia (Hochst.) Verdc. (8), Dodonaea viscosa Jacq var. angustifolia (L.f) Benth. (8), (L.) W.T.Aiton. (7) Ruta graveolens L. (7), and Solanum aculeastrum Dunal. (7). The top five plant families represented were Asteraceae (13%), Fabaceae (8%), Apocynaceae (4.3%), Asparagaceae (4%), and Lamiaceae (4%). An estimated 54% of the recorded plants were woody (trees and shrubs) in nature, while the leaves (27%) and roots (25%) were the most dominant plant parts. The use of plants for alleviating pain and inflammatory-related conditions remains popular in South African folk medicine. The lagging ethnobotanical information from provinces such as North West, Gauteng, and Free State remains a gap that needs to be pursued meticulously in order to have a complete country-wide database.

Bioactive molecules derived from smoke and seaweed Ecklonia maxima showing phytohormone-like activity in Spinacia oleracea L.

Bioactive compounds such as karrikinolide (KAR1 from smoke) and eckol (from the seaweed Ecklonia maxima) show promising effects on several important crop plants. These plant growth-stimulating organic biomolecules, along with crude extracts (smoke-water and Kelpak® product prepared from Ecklonia maxima), were tested on spinach plants. Eckol sprayed at 10-6 M significantly increased all the growth and biochemical parameters examined compared to control spinach plants. All tested plant growth biostimulants significantly increased total chlorophyll, carotenoids and protein content of spinach leaves. The cytokinin profile of spinach plants was also determined. Cis-zeatin, dihydrozeatin and isopentenyladenine types of cytokinins were promoted by both smoke- and seaweed-based biostimulants. In comparison to the control plants, the level of free sinapic acid was greater in all spinach plants treated with these biostimulants. The application of these biostimulants can help spinach crop by improving growth, yield and nutritional quality; moreover, they are organic and cost-effective.

Identification and characterization of potential bioactive compounds from the leaves of Leucosidea sericea.

ETHNOPHARMACOLOGICAL RELEVANCE: Leucosidea sericea is a southern African tree used for treating different diseases including microbial infections and inflammatory-related conditions. AIM OF THE STUDY: To isolate and identify the chemicals in Leucosidea sericea which possibly account for the diverse therapeutic effects of the species. MATERIALS AND METHODS: Leaf material was extracted using 20% methanol and subsequently partitioned with different solvents (hexane, dichloromethane, ethyl acetate and butanol). Resultant fractions were subjected to bioactive (antimicrobial)-guided isolation and the structural elucidation was conducted using NMR (1D and 2D) spectroscopic methods. Given the broad uses of Leucosidea sericea in traditional medicine, the extract, fractions and isolated compounds were evaluated in five (5) biological assays in vitro (antimicrobial, antioxidant, acetylcholinesterase (AChE) and anti-inflammatory inhibition as well as cytotoxicity effect). RESULTS: As the most active fractions, from ethyl acetate yielded 5,7-dihydroxychromone (1); 1-hydroxy-2-oxopomolic acid (2); 3,5,7,3´,4´-pentahydroxyflavone (3) and Tiliroside (4). For the first time, these four (4) compounds were isolated from leaves of Leucosidea sericea. These aforementioned compounds demonstrated broad-spectrum antibacterial activity (1.95-125 µg/mL) and noteworthy antifungal (3.9-250 µg/mL) potential. In addition to its noteworthy antimicrobial activity, compound 3 also demonstrated significant antioxidant (EC50 = 14 µg/mL in DPPH assay) and anti-inflammatory (inhibited the level of ELAM by approximately 36% and decreased also the viability of endothelial cells) activities in vitro. Overall, AChE inhibition activity and cytotoxic response was generally weak for the extracts, fractions and isolated compounds. CONCLUSION: The pool of chemicals in Leucosidea sericea were enriched with the isolation and identification of four (4) compounds obtained from the leaf extract. Among these compounds, the significant antimicrobial activity of compound 3 provides strong evidence that support the use of Leucosidea sericea for microbial-related infections in folk medicine.

Enhancing growth, phytochemical constituents and aphid resistance capacity in cabbage with foliar application of eckol--a biologically active phenolic molecule from brown seaweed.

Although foliar application of seaweed extracts on plant growth and development has and is extensively studied, reliable knowledge and understanding of the mode of action of particular compound(s) responsible for enhancing plant growth is lacking. A brown seaweed Ecklonia maxima is widely used commercially as a biostimulant to improve plant growth and crop protection. Eckol, a phenolic compound isolated from E. maxima has recently shown stimulatory effects in maize, indicating its potential use as a plant biostimulant. Cabbage is a widely cultivated vegetable crop throughout the world, which requires high input of fertilizers and is susceptible to several aphid borne diseases. This study was conducted to evaluate the effect of foliar application of eckol on the growth, phytochemical constituents and myrosinase activity (aphid resistance capacity) of commercially cultivated cabbage. Foliar application of eckol (10(-6) M) significantly enhanced shoot and root length, shoot and root fresh and dry weight, leaf area and leaf number. This treatment also showed a significant increase in photosynthetic pigments (chlorophyll 'a', chlorophyll 'b', total chlorophyll and carotenoid) compared to the untreated plants. The levels of protein, proline and iridoid glycosides were significantly higher in cabbage leaves with eckol treatment. All the control plants were severely infested with cabbage aphid (Brevicoryne brassicae) but no infestation was observed on the eckol-sprayed plants, which can be attributed to an increase in myrosinase activity. This study reveals dual effects (plant growth promoting and insect repelling) of eckol on cabbage plants that need further investigations both under field conditions and in other brassicaceous species.