Alzheimer’s disease (AD) is a complex neurological disorder characterised by decrease level of ACh and increased AChE expression. Inhibition of AChE is one of the common strategies to treat AD as it leads to increase Ach level quantitatively at the synaptic cleft. Acetylcholinesterase inhibitors (AChEIs) are used to treat various neurodegenerative disorders, and many are FDA approved for the management and cure of AD. AChEIs produce long term symptomatic effect, that contribute in other pathological mechanisms of the disease (e.g. formation of amyloid–β plaques) and have provided a rationale to the discovery of this class of inhibitors. Currently prescribed AChE inhibitors are Galantamine (natural alkaloid) and Rivastigmine (synthetic alkaloid compound) and have been considered beneficial for the treatment of mild to moderate AD. However, there is a need for the discovery of more effective compounds derived from natural sources as well as form synthetic sources as potential AChEIs. Findings and advances about natural and synthetic derivatives as potential sources of AChEIs will be collectively summarised in this review paper.

The present study evaluated a range of biological activities of Euphorbia tithymaloides L. (Family: Euphorbiaceae) in relation to diabetes and associated complications. This plant has antioxidant and anti-inflammatory properties, but its potential for the management of hyperglycaemia and subsequently, the inhibition and reversal of advanced glycation end products has not yet been pinpointed. The objectives of this work centred around comparative iv-vitro phytochemical screening of different plant parts, followed by antidiabetic, antiglycation and glycation-reversing activities of Euphorbia tithymaloides. Rutin and luteolin, two main bioactive compounds with significant antiglycation potentials, were also quantified using a recently developed and validated HPLC-PDA method. Leaf extract showed significantly higher potency than root and stem extracts in terms of antioxidant, anti-inflammatory, antidiabetic and antiglycation activity. A combination of enzymatic inhibition and HPLC phytochemical screening provided additional evidence to consider this plant a promising source for deepening the investigation on antidiabetic plant agents.