RESUMEN
Abstract Plants are a very rich source of pharmacologically relevant metabolites. However, the relative concentrations of these compounds are subject to the genetic make-up, the physiological state of the plant as well as environmental effects. Recently, metabolic perturbations through the use of abiotic stressors have proven to be a valuable strategy for increasing the levels of these compounds. Oxidative stress-associated stressors, including ionizing radiation, have also been reported to induce metabolites with various biological activities in plants. Hence, the aim of the current study was to investigate the effect of gamma radiation on the induction of purported anti-cancerous metabolites, glucomoringin and its derivatives, in Moringa oleifera Lam., Moringaceae. Here, an UHPLC-qTOF-MS-based targeted metabolic fingerprinting approach was used to evaluate the effect of gamma radiation treatment on the afore-mentioned health-beneficial secondary metabolites of M. oleifera. Following radiation, an increase in glucomoringin and three acylated derivatives was noted. As such, these molecules can be regarded as components of the inducible defense mechanism of M. oleifera as opposed to being constitutive components as it has previously been assumed. This might be an indication of a possible, yet unexplored role of moringin against the effects of oxidative stress in M. oleifera plants. The results also suggest that plants undergoing photo-oxidative stress could accumulate higher amounts of glucomoringin and related molecules.
RESUMEN
This study assessed the radiological health hazards to various body organs of workers working within Transnet Precinct in Richards Bay in Kwazulu-Natal, South Africa due to radionuclide content of mineral ores often stored within the facility. Thirty samples were collected from five mineral ores (rock phosphate, rutile, zircon, coal and hematite) and analyzed for 238U, 234U, 226Ra, 210Pb, 235U, 232Th, 228Ra, 228Th and 40K using delayed neutron activation analysis and low energy gamma spectroscopy. Rutile was found to be the most radioactive mineral ore within the facility with 210Pb concentration of 759.00 ± 106.00 Bq·kg-1. Effective annual dose rate in (mSv·y-1) delivered to different organs of the body: testes, bone marrow, whole body, lungs and ovaries from mineral ores were such that dose from mineral ores decreased in the order coal > rutile > rock phosphate > hematite > zircon. The organs with the highest received dose rate were the testes and this received dose was from coal. However, all of the calculated absorbed dose rates to organs of the body were below the maximum permissible safety limits.