The insecticidal activities of extracts from different parts of Cacalia tangutica (Franch.) H.-M. and two active ingredients, friedelin and stigmasterol, against Musca domestica L., Aedes albopictus (Skuse), and Spodoptera litura (F.) cells (SL cells) are reported. Extracts from leaves, flowers, and roots are highly active against adult M. domestica and the fourth-instar larvae of Ae. albopictus. The foliar extract was the most active with LC50 values of 1.74 mg/g and 196.94 microg/ml against adult M. domestica and fourth-instar larvae of Ae. albopictus, respectively. Extracts from stems were the least active. Friedelin and rotenone were highly active and equitoxic to these two insect species. The LC50 value of friedelin in adult M. domestica 48 h after treatment was 129.27 microg/g. The activity of stigmasterol on these two insect species was not obvious. However, the cytotoxicity of stigmasterol to S. litura cells was significantly greater than that of either friedelin or rotenone. At 25 microg/ml, the mortality of cells 24 h after treatment with stigmasterol was 23.0%. In contrast, friedelin and rotenone at the same concentration produced 16 and 18% mortality, respectively. Our results indicate differences between cytotoxicity in vitro and insect toxicity in vivo.

Alzheimer's disease (AD) is one of the major neurological disorders causing death in the elderly worldwide. As a neurodegenerative disease that is difficult to prevent and cure, the pathogenesis of AD is complex and there is no effective cure. A variety of natural products derived from plants have been reported to have promising anti‐AD activities, including flavonoids, terpenes, phenolic acids and alkaloids, which can effectively relieve the symptoms of AD in a variety of ways. This paper mainly reviews the pharmacological activity and mechanisms of natural products against AD. Although the clinical efficacy of these plants still needs to be determined by further high‐quality studies, it may also provide a basis for future researchers to study anti‐AD in depth.