Acetylcholinesterase inhibition, antioxidant, antiinflammatory, antimicrobial and phytochemical properties of Huernia hystrix.

Huernia species are typical famine-food plants consumed in southern Ethiopia. H. hystrix is a heavily exploited ethnomedicinal succulent plant traded in traditional medicine systems especially on South Africa's eastern seaboard. This study investigated the acetylcholinesterase (AChE) inhibition, antioxidant, antiinflammatory and antimicrobial properties of extracts obtained from the stems and roots of this plant. At the same concentration level (625.0, 312.5 or 156.3 µg/mL), the whole plant extract showed higher AChE inhibitory activity when compared with the stem and root extracts; a finding suggesting the presence of AChE inhibitors acting additively or synergistically in the whole plant extract. The roots showed strong antioxidant activity (in DPPH and β-carotene assays) comparable to that of butylated hydroxytoluene (BHT), indicating the presence of potent antioxidant compound(s) that can be exploited as alternatives for use in the food and cosmetic industries and/or as nutraceuticals. All the petroleum ether (PE) (except root PE) and dichloromethane (DCM) extracts demonstrated good inhibitory activity (> 70%) in cyclooxygenase (COX-1 and COX-2) assays at a 0.25 µg/μL concentration. Most of the extracts showed broad-spectrum inhibitory and lethal activities against the microorganisms used in this study. The observed biological activities might be due to the iridoid, phenolic and flavonoid contents of the plants.