Comparative phytochemical, antioxidant, and antibacterial study of different parts of Doigota plants (Bixa orellana L.)

Abstract

Background Bixa orellana L. is a plant native to Brazil but grows in other parts of the world including Bangladesh. This plant has been used for many years by indigenous people around the globe for a variety of applications. In Bangladesh, it is known as Doigota and the plant is underutilized and reported endangered. The present study aimed to perform comparative profiling where aqueous, ethanolic, and methanolic extracts of the seed, branch, and leaf of B. orellana plants were investigated for in vitro phytochemicals, antioxidant, and antibacterial activities. Results Phytochemical screening indicated the presence of nine different phytochemicals in varying degrees, which suggests the chemical diversity of this plant. Quantification of phenolics, flavonoids, and tannins was performed where leaf extracts contained significantly higher quantities of these phytochemicals than extracts from seed and branch. The highest phenolics (186.02 mg/g) were found in the methanolic extract of the leaf, whereas the highest flavonoids (61.01 mg/g) and tannins (36.74 mg/g) were found in aqueous extract of the leaf. Antioxidant activity has been evaluated by DPPH scavenging assay where the aqueous extract of leaf showed 93.62% scavenging activity at 800 μg/mL extract concentration. Although the extracts prevented the growth of both Gram-positive and Gram-negative bacteria, the antibacterial activity (zone of inhibition) of aqueous and methanolic extracts of the leaves were higher than those of the seed and branch extracts against Gram-negative (Escherichia coli) and Gram-positive (Bacillus subtilis) bacteria, respectively. Conclusions We found that B. orellana leaf extracts possess the highest antibacterial activities. The extracts had significant antioxidant and free radical-scavenging activities. The antioxidant and antibacterial activities could be attributed to high flavonoid and phenolic contents. These results suggest that the extracts of B. orellana possess bioactive compounds that could be used for different purposes such as source of new antibiotics or alternative natural preservatives in food matrices due to mainly their antioxidant and antibacterial activities.

Combined Antimicrobial Effect of Bio-Waste Olive Leaf Extract and Remote Cold Atmospheric Plasma Effluent

“…The antibacterial properties of plants have been widely investigated [ 3 ]. In fact, a great variety of plant species containing components which exhibit antimicrobial activity against a wide range of Gram-positive and Gram-negative bacteria has been reported, including Hibiscus , Rosmarinus officinalis , Thymus vulgaris , Malva sylvestris and Allium sativum , among others [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. Plant antimicrobials are more attractive than the synthetic food preservatives, as they are generally recognized as safe and capable of benefiting human health, including essential oils [ 15 ].…”

A comprehensive multi-directional exploration of phytochemicals and bioactivities of flower extracts from Delonix regia (Bojer ex Hook.) Raf., Cassia fistula L. and Lagerstroemia speciosa L.

“…The freshly prepared crude extracts were qualitatively tested for the presence of secondary metabolites such as alkaloids, carbohydrates, coumarins, glycosides, flavonoids, phenols, resins, saponins, tannins and terpenoids by following the methods described in previous literatures [ 29 , 30 ].…”

Phytochemical analysis, antioxidant and antibacterial activities of methanolic rhizome extract of Bergenia pacumbis: A valuable medicinal herb

“…The presence of reducing compounds was indicated by brick-red precipitation [31,32]; (13) Test for proteins (Xanthoproteic test): A few drops of concentrated nitric acid were added to the extract (1 mL). The presence of proteins was indicated by the formation of a yellowcolored solution [37]; and (14) Test for coumarins (sodium hydroxide test): To about 1 mL of extract, 1.5 mL of 10 % NaOH was added. The formation of yellow color is the indication of the presence of coumarins [37].…”

“…The presence of proteins was indicated by the formation of a yellowcolored solution [37]; and (14) Test for coumarins (sodium hydroxide test): To about 1 mL of extract, 1.5 mL of 10 % NaOH was added. The formation of yellow color is the indication of the presence of coumarins [37].…”

“…On the other hand, the Gramnegative bacterium has an outer membrane that contains lipopolysaccharide (LPS) in the outer leaflet and phospholipids in the inner leaflet, as well as an inner peptidoglycan layer, making the cell wall impermeable to antibacterial compounds. The cell wall of Gram-negative bacterium is more complex in a layout that acts as a diffusion barrier and makes it less susceptible to antibacterial agents than the Gram-positive bacterium [33,37]. The presence of porins at the outer membrane and the active efflux processes involved in Gramnegative bacterium is responsible for higher resistance [4].…”