The phenolic extract of Senecio biafrae leaves was investigated to determine the in vitro antioxidant, phenolic profiles, and inhibition of key enzymes relevant to type II diabetes mellitus (α‐amylase and α‐glucosidase) and Alzheimer's disease (acetylcholinesterase and butrylcholinesterase). Here, ACHE is linked to early-onset autosomal dominant Alzheimer disease.