Marrubiin

The ethno-medicinal approach to drug discovery represents one of the most important sources of new and safe therapeutic agents to the challenges confronting modern medicine and daily life. Many of the traditionally important medicinal plants contain active molecules or ones that serve as precursors to biosynthesised secondary metabolites to which the biological activity could be attributed. Marrubiin is one such compound and is a potential valuable compound which exists in high concentrations in many traditionally important Lamiaceae species which have demonstrated excellent pharmacological properties with commendably high safety margins. Marrubiin’s attributes include a low turnover, high stability and little catabolism, which are core characteristics required for therapeutic compounds and nutraceuticals of economic importance. In addition, marrubiin is considered a potential substrate for potent active compounds viz; marrubiinic acid, and marrubenol. The contribution of marrubiin to drug discovery thus needs to be put into prospective due to its ready availability, high potential applications and ease of modification. In this short review we highlight the most important chemical and pharmacological aspects reported on marrubiin since it was discovered

Electrochemical Screening and Evaluation of Lamiaceae Plant Species from South Africa with Potential Tyrosinase Activity

South Africa is a country with a wide variety of plants that may contain excellent anti-tyrosinase inhibitors. With wide applications in cosmetics, pharmaceuticals and food products, tyrosinase inhibitors have received very special attention in the recent past as a way of preventing the overproduction of melanin in epidermal layers which often over time brings detrimental effects on human skin. In this present study, a fast screening method using a cyclic voltammetry technique was applied in the evaluation of methanolic extracts of twenty-five species of plants from the Lamiaceae family for anti-tyrosinase activity. Among these plants, those that showed a fast current inhibition rate at a minimum concentration when compared to a kojic acid standard were classified as having the greatest anti-tyrosinase activity. These include Salvia chamelaeagnea, S. dolomitica, Plectranthus ecklonii, P. namaensis, and P. zuluensis. The results presented herein focused in particular on providng firsthand information for further extensive research and exploration of natural product materials with anti-tyrosinase activity from South African flora for use in cosmetics, skin care and medicinal treatments

Analyses of Corrosion Potential from Inhibitor-Admixed Steel-Reinforced Concrete: Implication on Steel-Rebar Corrosion Risk/Probability

Statistical analyses of three probability density functions, from Normal, Rayleigh and Weibull distributions, were applied for studying steel-rebar corrosion risk/probability in inhibitor admixed steel-reinforced concrete immersed in aggressive media of 3.0% NaCl and 0.5 M H2SO4. For these, different concentrations, ranging from 0 M to 0.29 M, of K2CrO4 were admixed in two-set steel-reinforced concrete with each set partially immersed in each of the aggressive test-solutions and which were monitored using open circuit potential techniques as per ASTM C876–91 R99. Analyses of the 30-days test-response from these showed that most of the corrosion test-data distributed like the Weibull and like the Normal distributions while just a few test-datasets distributed like the Rayleigh distribution, according to the Kolmogorov-Smirnov goodness-of-fit statistics. All the probability distribution fittings identified, in agreements, the 0.15 M K2CrO4 admixed steel-reinforced concrete with the least probability of corrosion risk in both of the acidic and the neutral saline test-solutions. These bear implications on the use of probability distribution analyses for economical monitoring of steel-rebar corrosion risk/probability and corrosion inhibitor admixture effects in steel-reinforced concrete in aggressive service-environments