Nqobile A. Masondo

Pharmacological potential and conservation prospect of the genus Eucomis (Hyacinthaceae) endemic to southern Africa.

ETHNOPHARMACOLOGICAL RELEVANCE The genus Eucomis (Hyacinthaceae) consists of 10 species that are extensively used in African traditional medicine. This review is an appraisal of current information on the distribution and morphology, traditional uses, pharmacology, toxicology and approaches devised to enhance the conservation of the genus. METHODS A systematic and comprehensive literature search using electronic searches such as Scopus, Google Scholar, Web of Science and ethnobotanical books was conducted. RESULTS Evidence from traditional medicine usage shows wide utilization of this genus for ailments such as respiratory, venereal diseases, rheumatism as well as kidney and bladder infections. Pharmacological screening reported antimicrobial, antiplasmodial, antitumor, cytotoxic, phytotoxic and anti-inflammatory properties. CONCLUSIONS The potential of the genus Eucomis especially in terms of pharmacology cannot be overemphasized. Apart from the anti-inflammatory properties, the antifungal activity of Eucomis remains a valuable reservoir with potential application in the agriculture sector as a source of an affordable biocontrol agent. Based on the speculated toxic constituents in the genus Eucomis, it will be valuable to conduct detailed toxicological studies. Extensive utilization of members of the genus Eucomis is causing severe strain on wild populations. Although conventional propagation has been relatively effective in the alleviation of the declining status, micropropagation of members may be vital to guarantee the conservation of wild populations.

Nutritional and pharmacological potential of the genus Ceratotheca--An underutilized leafy vegetable of Africa.

ETHNOPHARMACOLOGICAL RELEVANCE Ceratotheca (Pedaliaceae) is an endemic African genus comprising of five species. The genus is commonly used as a leafy vegetable with medicinal properties. AIM OF THE REVIEW The review aims to highlight the unexplored nutritional and pharmacological potential of African indigenous leafy vegetables Ceratotheca sesamoides and triloba, in order to conserve and domesticate these species. METHODS The information was obtained from various search engines such as Scopus, Google Scholar and Web of Science as well as Ethnobotanical books. RESULTS Ceratotheca sesamoides and triloba have good nutritional potential. The species are high in energy levels, fat content, proteins and carbohydrate values. The species have also been reported to have good antibacterial, antidiarrhoeal, antidiabetic, antiplasmodial and antiviral properties. These species have slight toxicity and cytotoxic activity when extracted at high concentrations but no mutagenic activity was detected. CONCLUSIONS To date, few studies have documented the usage (nutrition and pharmacology) of Ceratotheca sesamoides and triloba. More studies investigating the nutritional content as well as methods of its improvement are necessary if the plant is to be included as a domesticated vegetable crop. Safety and toxicity analysis of this leafy vegetable need to be extensively studied as the plants are consumed in high quantities.

Dissecting the role of two cytokinin analogues (INCYDE and PI-55) on in vitro organogenesis, phytohormone accumulation, phytochemical content and antioxidant activity.

There is a continuous search for new chemical entities to expand the collection of suitable compounds to increase the efficiency of micropropagation protocols. Two cytokinin (CK) analogues, 2-chloro-6-(3-methoxyphenyl)aminopurine (INCYDE) and CK antagonist 6-(2-hydroxy-3-methylbenzylamino)purine (PI-55) were used as a tool to elucidate the auxin-CK crosstalk under in vitro conditions in the medicinally important plant, Eucomis autumnalis subspecies autumnalis. These compounds were tested at 0.01, 0.1 and 10 μM alone as well as in combination with benzyladenine (BA) and naphthaleneacetic acid (NAA). The organogenesis, phytohormone content, phytochemical and antioxidant response in 10 week-old-in vitro regenerated E. autumnalis subspecies autumnalis was evaluated. INCYDE generally favoured shoot regeneration while the effect of PI-55 was more evident in root proliferation. Overall, INCYDE promoted the accumulation of higher concentrations and varieties of endogenous CK relative to the PI-55 treatments. In contrast, higher concentration of indole-3-acetic acid and 2-oxindole-3-acetic acid were generally observed in PI-55-supplemented cultures when compared to plantlets derived from INCYDE. Both CK analogues (individually and in-conjunction with exogenously applied PGRs) significantly influenced the phytochemicals and consequently the antioxidant potential of the in vitro regenerants. These results provided insight on how to alleviate root inhibition, a problem which causes considerable loss of several elite species during micropropagation.

Influence of biostimulants-seed-priming on Ceratotheca triloba germination and seedling growth under low temperatures, low osmotic potential and salinity stress

Extreme temperatures, drought and salinity stress adversely affect seed germination and seedling growth in crop species. Seed priming has been recognized as an indispensable technique in the production of stress-tolerant plants. Seed priming increases seed water content, improves protein synthesis using mRNA and DNA and repair mitochondria in seeds prior to germination. The current study aimed to determine the role of biostimulants-seed-priming during germination and seedling growth of Ceratotheca triloba (Bernh.) Hook.f. (an indigenous African leafy vegetable) under low temperature, low osmotic potential and salinity stress conditions. Ceratotheca triloba seeds were primed with biostimulants [smoke-water (SW), synthesized smoke-compound karrikinolide (KAR1), Kelpak® (commercial seaweed extract), phloroglucinol (PG) and distilled water (control)] for 48h at 25°C. Thereafter, primed seeds were germinated at low temperatures, low osmotic potential and high NaCl concentrations. Low temperature (10°C) completely inhibited seed germination. However, temperature shift to 15°C improved germination. Smoke-water and KAR1 enhanced seed germination with SW improving seedling growth under different stress conditions. Furthermore, priming seeds with Kelpak® stimulated percentage germination, while PG and the control treatment improved seedling growth at different PEG and NaCl concentrations. Generally, high concentrations of PEG and NaCl brought about detrimental effects on seed germination and seedling growth. Findings from this study show the potential role of seed priming with biostimulants in the alleviation of abiotic stress conditions during seed germination and seedling growth in C. triloba plants.