Assessment of antioxidant and antibacterial efficacy of some indigenous vegetables consumed by the Manipuri community in Sylhet, Bangladesh

The rapid dietary changes experienced by indigenous people worldwide threaten the use of traditional foods, which are often undervalued. This study focused on evaluating the antioxidant and antibacterial efficacy of five vegetables typically consumed by the Manipuri ethnic groups in the Sylhet region of Bangladesh: Yongchak seed (<i>Parkia speciosa</i>), Telikadam seed (<i>Leucaena leucocephala</i>), Phakphai leaf (<i>Persicaria odorata</i>), Sheuli leaf (<i>Nyctanthes arbor-tristis</i>), and bamboo shoot (<i>Bambusa</i> spp.). The samples were dried and powdered to assess the antioxidant activity through total phenolic content (TPC), total flavonoid content (TFC), total tannin content (TTC), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. Antibacterial efficacy was determined by measuring the zone of inhibition (ZOI), minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). Leafy vegetables exhibited higher TPC, TFC, and TTC than seeds and shoots, with <i>N. arbor-tristis</i> leaf showing the highest TPC (99.16 ± 2.07 mg GAE/g DW) and <i>P. odorata</i> leaf exhibiting the highest TFC (9.19 ± 0.7 mg QE/g) and TTC (3.59 ± 0.26 mg TAE/g). However, <i>Bambusa</i> spp. shoot extract showed the highest antioxidant potential (IC₅₀: 1.66 ± 0.05 mg/mL). All samples exhibited higher ZOI against gram-positive bacteria (<i>Bacillus</i> spp. and <i>Staphylococcus</i> spp.), ranging from 10 ± 2.65 to 19.33 ± 2.08 mm. <i>L. leucocephala</i> seed extract showed the highest antibacterial activity against both the tested gram-positive bacteria with a MIC of 15.6 mg/mL. Conversely, the <i>P. odorata</i> leaf extract exerted the strongest antibacterial effect against gram-negative bacteria, with the lowest MIC values for <i>Klebsiella</i> spp. (31.25 mg/mL) and <i>Escheria coli</i> (62.5 mg/mL). The findings of this investigation suggest that the selected indigenous vegetables could be valuable sources of phytochemicals with potential antioxidant and antibacterial activities. Incorporating and promoting these traditional foods into the diet may improve food security, dietary diversity, and public health in Bangladesh.