The bioavailability and metabolism of anthocyanins and ellagitannins following acute intake of grumixama fruit, native Brazilian cherry, by humans, and its in vitro antiproliferative activity against breast cancer cells (MDA-MB-231) were investigated. A single dose of grumixama juice was administered to healthy women (n = 10) and polyphenol metabolites were analyzed in urine and plasma samples collected over 24 h. The majority of the metabolites circulating and excreted in urine were phenolic acids and urolithin conjugates, the gut microbiota catabolites of both classes of polyphenols, respectively. According to pharmacokinetic parameters, the subjects were divided into two distinct groups, high and low urinary metabolite excretors. The pool of polyphenol metabolites found in urine samples showed a significant inhibition of cell proliferation and G2/M cell cycle arrest in MDA-MB-231 cells. Our findings demonstrate the large interindividual variability concerning the polyphenol metabolism, which possibly could reflect in health promotion.

Good anatomical sections can only be obtained with a perfectly sharp knife. Permanent steel microtome knives are present in numerous plant anatomy labs and they yield excellent results, with the only caveat that they need to be re-sharpened after use. Automatic knife sharpeners have been especially designed for this purpose, but they require abrasives in their use, which may be expensive and hard to obtain. Here we describe and illustrate in detail an inexpensive, fast, widely accessible technique to sharpen permanent microtome knives using different sandpaper grits. Knives sharpened with this technique have already been in use for over a decade and are suitable for all types of botanical specimens both embedded and unembedded.