Antioxidant, anti-inflammatory and neuroprotective activities of plastoquinones from the seed fat of Pycnanthus Angolensis
Pycnanthus angolensis (African nutmeg), native to several West African countries, was investigated for new medicinal uses. Sustainably harvested in Ghana, the seed fat is processed into kombo butter by farmer cooperatives. This plant-based butter is rich in myristoleic acid, a precursor to cetyl myristoleate (CMO) which is currently marketed as a supplement in the treatment of joint pain. Separate from the myristoleic acid and as a waste product from the processing of kombo butter into CMO, the effluent was found to contain high concentrations of the plastoquinones sargaquinoic acid (KB-1), sargachromenol (KB-2) and sargahydroquinoic acid (KB-3). These three major phytochemicals, along with kombo butter and plastoquinone-enriched extract, were tested in vitro for antioxidant activity in the ABTS and DPPH assays, and for anti-inflammatory activity using RT-PCR and Western blot analysis to measure inhibition of both COX-2 and iNOS mRNA and protein expression in LPS-induced RAW 264.7 mouse macrophages. Additionally, KB-3 and an acetylated derivative exhibited neuroprotective activity in vivo using the pMCAO model, demonstrating their potential for use following ischemic stroke.