Stable, water extractable isothiocyanates from Moringa oleifera leaves attenuate inflammation in vitro

Moringa (Moringa oleifera Lam.) is an edible plant used as both a food and medicine throughout the tropics. A moringa concentrate (MC), made by extracting fresh leaves with water, utilized naturally occurring myrosinase to convert four mofinga glucosinolates into moringa isothiocyanates. Optimum conditions maximizing MC yield, 4-[(alpha-L-rhamnosyloxy)benzyllisothiocyanate, and 4-[(4'-O-acetyl-alpha L-rhamnosyloxy)benzyl]isothiocyanate content were established (1:5 fresh leaf weight to water ratio at room temperature). The optimized MC contained 1.66% isothiocyanates and 3.82% total polyphenols. 4-[(4'-O-acetyl-alpha-L-rhamnosyloxy)benzyllisothiocyanate exhibited 80% stability at 37 degrees C for 30 days. MC, and both of the isothiocyanates described above significantly decreased gene expression and production of inflammatory markers in RAW macrophages. Specifically, both attenuated expression of iNOS and IL-1 beta and production of nitric oxide and TNF alpha at 1 and 5 mu M. These results suggest a potential for stable and concentrated moringa isothiocyanates, delivered in MC as a food-grade product, to alleviate lowgrade inflammation associated with chronic diseases. (C) 2014 Elsevier Ltd. All rights reserved.