Zanthoxylum paracanthum Kokwaro (Rutaceae) is an endemic Kenyan and Tanzanian\nplant used in folk medicine by local populations. Although other Zanthoxylum species have been\nstudied, only Z. paracantum stem extracts have been profiled, even though the roots are also\nused as herbal remedies. As root extracts may be another source of pharmaceutical compounds,\nthe CH2Cl2/MeOH (1:1) root bark extract was studied in this report. Eight root bark compounds\nwere isolated and their structural identities were confirmed by mass spectrometry (MS) and nuclear\nmagnetic resonance (NMR) (using COSY, HSQC, NOESY and HMBC) analyses. The structural\nidentities were determined as follows: the fatty acidâ??myristic acid (1); the sterolâ??stigmasterol (2);\nthe lignanâ??sesamin (3); two -carboline alkaloidsâ??10-methoxycanthin-6-one (6) and canthin-6-one\n(7); and three phenanthridine alkaloidsâ??8-acetonyldihydrochelerythrine (4), arnottianamide (5)\nand 8-oxochelerythrine (8). Some of these compounds were identified in the species for the first\ntime. These compounds and the extract were then tested in vitro against methicillin-resistant\nStaphylococcus aureus (MRSA), Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 29213) and\nCandida albicans (ATCC 10231) before tests for antiproliferative activity against the human breast\ncancer (HCC 1395), human prostate cancer (DU 145) and normal (Vero E6) cell lines were conducted.\nMinimum inhibition concentration values of 3.91, 1.95, 0.98 and 7.81 microg/mL against MRSA, S. aureus,\nE. coli and C. albicans, respectively, were recorded. Among the isolates, canthin-6-one was the most\nactive, followed by 10-methoxycanthin-6-one. The root extract and some of the compounds also\nhad antiproliferative activity against the HCC 1395 cell line. Stigmasterol and canthin-6-one had\nIC50 values of 7.2 and 0.42. The root bark extract also showed activity, at 8.12 microg/mL, against the\nHCC 1395 cells. Out of the chemical isolates, 10-methoxycanthin-6-one and canthin-6-one showed\nthe strongest inhibition of the DU 145 cells. The root extract had significant antimicrobial and\nantiproliferative activities, supporting the traditional use of this plant in treating microbial infections\nand cancer-related ailments.
Loading....