Plantago major L. in Vietnam was investigated for its chemical composition and also evaluated the biological activities against enzyme α-
glucosidase and free radicals activities. The powder mixture of dried leave and roots of this species was extracted separately by three
solvents: dichloromethane, water, water:alcohol (50:50, v:v). The chemical composition of dichloromethane extract was analyzed by GC-MS
system to identify eighteen components, out of which eight biologically active compounds viz. 5-hydroxymethylfurfural, n-hecxadecanoic
acid, 9,12-octadecadienoic acid (Z,Z)-methyl ester, allogibberic acid, β-tocopherol, campesterol, γ-sitosterol, lup-20(29)-en-3-ol and
friedenlan-3-one were presented. The concentration of radical scavenging activity DPPH expressed by IC50 for water, water:alcohol
(50:50, v:v) and dichloromethane with 208.7, 89.3 and 62.05 μg/mL, respectively. The dichloromethane, water and water:alcohol (50:50,
v:v) extract of Plantago major exhibited α-glucosidase inhibitory activity with IC50 values of 116.4, 302.7, 195.9 μg/mL, respectively,
which was comparable with acarbose (98.4 μg/mL). Plantago major L. in Vietnam may be effective inhibitors as the antidiabetic candidate
and helpful to reduce the postprandial glucose levels.