In vitro anti-HIV, cytotoxicity and nutritional analysis of Trianthema portulacastrum L. (Aizoaceae).

The development of antiretroviral therapy has brought a tremendous relief to the world as it minimizes mortality, reduces HIV transmission, and suppresses progression in infected patients. However, the orthodox antiretroviral therapy is faced with limitations which have necessitated a continuous search for more novel plant-based antiviral compounds, which can bypass the existing barriers created by drug resistance and target more viral proteins. Despite the edibility and enormous pharmacological benefits of T. portulacastrum, little is known about its nutrient profiles and potential use as a natural source of antiviral drug. This study focuses on the full feed analysis and anti-HIV potential of two biotypes of T. portulacastrum. Ethanolic extracts of both biotypes of T. portulacastrum (T01 and T02) had significant inhibitory effects on the level of replication of the HIV-1. Both extracts induced the inhibition of at least 50% of the HIV-1 viral load at considerably low IC50 values of 1.757 mg/mL (T01) and 1.205 mg/mL (T02) which is comparable to the AZT standard. The protein composition ranged between 8.63-22.69%; fat (1.84-4.33%); moisture (7.89-9.04%); fibre (23.84-49.98%); and carbohydrate content (38.54-70.14%). Mineral contents of tested T. portulacastrum varied considerably in different parts of the plant. Nitrogen N mineral ranged between 13.8-36.3 mg/g; sodium Na (2.0-14.0 mg/g); potassium K (14.0-82.0 mg/g); magnesium Mg (2.8-7.1 mg/g); calcium Ca (9.1-24.7 mg/g); phosphorus P (1.3-3.6 mg/g); iron Fe (193.5-984.0 ppm); zinc Zn (42.5-96.0 ppm); manganese Mn (28.5-167.5 ppm); and copper Cu (2.0-8.5 ppm). These mineral values are comparable or higher than values quoted for common vegetables, suggesting that T. portulacastrum is a nutrient-dense vegetable that could provide alternative sources of antiviral nutrients to HIV-infected individuals. Further studies are recommended to unravel key metabolites responsible for high nutrient profiles and antiretroviral effects in T. portulacastrum.

Nutrients and phytochemical density in Mesembryanthemum crystallinum L. cultivated in growing media supplemented with dosages of nitrogen fertilizer.

Mesembryanthemum crystallinum L. is an annual halophyte that originated from southern Africa. However, little has been reported about factors that modulate the quantity of secondary metabolites in the plant. In this study, the twin effect of different nitrogen concentrations (0.36, 0.6, 0.8 g/L) and growing media (LECA clay, peat, vermiculite and silica sand) on plant growth, chlorophyll contents, minerals, proximate and antioxidant metabolites in hydroponically cultivated M. crystallinum was investigated. This is important to determine the dosage of N fertilizer that will optimize the bio-productivity and biosynthesis of secondary metabolites and antioxidants in M. crystallinum grown in a hydroponic system. The untreated plant (0 g/L N) was taken as the control. At the end of the experiment, optimum yields in leaf number (9.2), fresh weight (50.40 g), Ca, N, and Protein (34.04 %) were recorded in M. crystallinum grown with peat enhanced with different dosages of N-fertilizer. Likewise, chlorophyll level, dry weight, ABTS/TEAC, FRAP, ADF and NDF contents were optimized in LECA clay treated with N-fertilizer. Silica sand with 0.36 g/L dosage of nitrogen fertilizer optimized P, Mn and Zn levels, so also the moisture (9.83 % at 0.8 g/L N), fat (2.38 %, 0 g/L N) and carbohydrates (44.98 and 44.95 %). The highest ash content, Mg and Fe were recorded in the untreated vermiculite as well as polyphenols and K, at 0.6 g/L; Cu and root length (14.60 cm), at 0.8 g/L. In conclusion, different dosages of nitrogen fertilizer and growing media could enhance the growth potential, chlorophyll, phytochemicals, and nutritional properties of M. crystallinum.

Potassium Application Enhanced Plant Growth, Mineral Composition, Proximate and Phytochemical Content in Trachyandra divaricata Kunth (Sandkool).

Wild leafy vegetables are commonly included in the diet of people in rural homesteads. Among various wild edible vegetables in South Africa, Trachyandra divaricata (Sandkool) is one of the most abundant but underutilized due to the dearth of literature on its cultivation and nutritional value. In the present study, the effect of potassium application and pruning on growth dynamics, mineral composition, and proximate and phytochemical content in T. divaricata were evaluated. Treatments consisted of three potassium concentrations (0.0072, 0.0144, and 0.0216 M) supplemented in the form of potassium sulphate (K2SO4) with four pruning levels (unpruned, 5, 10, and 15 cm) applied in each treatment. The potassium doses were added to the nutrient solution, while the control treatment was sustained and irrigated with nutrient solution only. The results revealed a significant increase in flower bud yield, height, total dry and wet weight of shoots and roots, as well as ash and neutral detergent fibre in plants irrigated with 0.0072 M of K2SO4 without pruning. Conversely, chlorophyll content and Ca were comparable among treatments, while the highest yield of Na, P, N, and Zn was recorded in treatment 100 mL of K2SO4 with 10 cm pruning. Likewise, the highest antioxidant value (Polyphenols, Flavonol and DPPH) was obtained from plants irrigated with 0.0072 M of K2SO4 with 10 cm pruning. Based on these findings, T. divaricata is a promising leafy vegetable as a minimum dose (0.0072 M) of K with moderate pruning optimised its productivity in terms of growth, biomass parameters, nutritional content, and antioxidant potential. Due to its rich nutritional value, the plant should be domesticated and studied further for its potential nutraceutical benefits.

Variabilities in alkaloid concentration of Sceletium tortuosum (L.) N.E. Br in response to different soilless growing media and fertigation regimes in hydroponics.

This study was designed to investigate the variations in alkaloid concentrations of Sceletium tortuosum when grown in soilless mediums under different fertigation regimes and to examine the suitability of the plant for hydroponic cultivation. A mother plant obtained from Verve Dynamics (Pty) Ltd (a manufacturer and supplier of purified botanical extracts) was cultivated into three hundred plants used for this research study. Twenty treatments were evaluated with 15 sample replicates. Treatments were made up of 4 different soilless growing media, namely: pure silica sand, 50% silica sand with 50% coco-peat, 50% silica sand with 50% vermiculite, and 50% silica sand with 50% perlite. These growing media were tested in conjunction with 5 different fertigation regimes (FR). Plants grown in FR1 received aqueous nutrient solution once every week, FR2 received aqueous nutrient solution once every second week, FR3 received aqueous nutrient solution once every third week, FR4 received aqueous nutrient solution once every fourth week and FR5 received aqueous nutrient solution once every fifth week respectively. Results from this experiment showed that different soilless growing media and fertigation had varying effects on alkaloid concentrations in S. tortuosum. It was also observed that roots contained higher amounts of delta 7 mesembrenone and mesembrenone, while shoots contained higher amounts of the alkaloid mesembrine.