Cancer is the second leading cause of death globally, and despite the advances in drug development, it is still necessary to develop new plant-derived medicines. Compared with using conventional chemical drugs to decrease the side effects induced by chemotherapy, natural herbal medicines have many advantages. The present study aimed to discover the potential cytotoxicity of ethanol extract and its derived fractions (chloroform, ethyl acetate, butanol, and aqueous) of Adenosma bracteosum Bonati. (A. bracteosum) on human large cell lung carcinoma (NCI-H460) and hepatocellular carcinoma (HepG2). Among these fractions, the chloroform showed significant activity in the inhibition of proliferation of both cancerous cells because of the presence of bioactive compounds including xanthomicrol, 5,4’-dihydroxy-6,7,8,3’-tetramethoxyflavone, and ursolic acid which were clearly revealed by nuclear magnetic resonance spectroscopy (1H-NMR, 13C-NMR, Heteronuclear Multiple Bond Coherence, and Heteronuclear Single Quantum Coherence Spectroscopy) analyses. According to the radical scavenging capacity, the 5,4’-dihydroxy-6,7,8,3’-tetramethoxyflavone compound (AB2) exhibited the highest anticancer activity on both NCI-H460 and HepG2 with IC50 values of 4.57 ± 0.32 and 5.67 ± 0.09 µg/mL respectively, followed by the ursolic acid with the lower percent inhibition at 13.05 ± 0.55 and 10.00 ± 0.16 µg/mL, respectively (p < 0.05). Remarkably, the AB2 compound induced to significant increase in the production of reactive oxygen species accompanied by attenuation of mitochondrial membrane potential, thus inducing the activation of caspase-3 activity in both human lung and liver cancer cells. These results suggest that A. bracteosum is a promising source of useful natural products and AB2 offers opportunities to develop the novel anticancer drugs.

Adenosma bracteosum Bonati. (A. bracteosum) has been used in traditional and modern medicine in Vietnam for curing hepatitis. In this study, ethanol and aqueous extracts of A. bracteosum were evaluated for their α-glucosidase inhibitory activities and anti-hyperglycemic effects on glucose loaded hyperglycemic and streptozotocin (STZ) induced diabetic mice. The α-glucosidase inhibition of the extracts was evaluated by colorimetric assays, and the anti-diabetic activity was tested on a STZ-induced diabetic mice model. The ethanol and aqueous extracts showed a significant α-glucosidase inhibitory activity, which was more effective than acarbose at the same concentration. In the STZ-induced diabetic mice, both extracts showed a strong anti-hyperglycemic activity, with the group receiving 50 mg/kg of ethanol extract and the group receiving 50 mg/kg of aqueous extract presenting 64.42% and 57.69% reductions, respectively, in the blood glucose levels when compared with the diabetic control group, on day 21 (p > 0.05). Isoscutellarein-8-O-β-D-glucopyranoside (IG) was identified from the ethanol extract, which showed a strong inhibitory activity against α-glucosidase, with a ten times higher potency compared with the positive control acarbose. The anti-hyperglycemic effect of IG was effectively similar to the standard drug, glibenclamide, at the same dose of 10 mg/kg (p > 0.05). These results indicated that A. bracteosum has a great antidiabetic potential.