Antibacterial effects of 18 medicinal plants used by the Khyang tribe in Bangladesh

Abstract

Context: The resistance of bacteria to antibiotics is raising serious concern globally. Asian medicinal plants could improve the current treatment strategies for bacterial infections. The antibacterial properties of medicinal plants used by the Khyang tribe in Bangladesh have not been investigated.Objective: The present study examines the antibacterial properties of 18 medicinal plants used by the Khyang tribe in day-to-day practice against human pathogenic bacteria.Materials and methods: Leaves, bark, fruits, seeds, roots and rhizomes from collected plants were successively extracted with hexane, ethyl acetate and ethanol. The corresponding 54 extracts were tested against six human pathogenic bacteria by broth microdilution assay. The antibacterial mode of actions of phytoconstituents and their synergistic effect with vancomycin and cefotaxime towards MRSA was determined by time-killing assay and synergistic interaction assay, respectively.Results and discussion: Hexane extract of bark of Cinnamomum cassia (L.) J. Presl. (Lauraceae) inhibited the growth of MRSA, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii with MIC values below 100 µg/mL. From this plant, cinnamaldehyde evoked at 4 × MIC in 1 h an irreversible decrease of MRSA count Log10 (CFU/mL) from 6 to 0, and was synergistic with vancomycin for MRSA with fractional inhibitory concentration index of 0.3.Conclusions: Our study provides evidence that the medicinal plants in Bangladesh have high potential to improve the current treatment strategies for bacterial infection.

Chemical Composition and Antibacterial Activity of the Essential Oil ofMesosphaerum suaveolens(Lamiaceae)

“…Among the species of this family, the species Mesosphaerum suaveolens (L.) Kuntze (Figure 1), known in Brazil as "bamburral" and "alfazema-brava," is popularly used in the treatment of diseases related to gastrointestinal and respiratory tract [12], so that we hypothesize that the species is abundant in phytochemical constituents, which present biological activity against strains of pathogenic microorganisms, such as bacteria. This hypothesis is supported by the pharmacological and biological activities of these species already evidenced in the literature, such as antioxidant activity [13], neuroprotective [14], gastro-protective [15], antitumor [16], antinociceptive [17], anti-inflammatory [18], antifungal [19], anti-bacterial [20], insecticide [21], larvicide [8], and allelopathic action [22].…”

Phytochemical and Pharmacological Investigations of Lannea grandis (Dennst.) Engl. Leaves Extracts

“…The preliminary phytochemical screening study revealed that the crude ethanol extract, petroleum-ether fraction and chloroform fraction of L. grandis were rich of some vital chemical groups like alkaloids, steroids, tannins, saponins, glycosides and gummy types plants secondary metabolites ( The demand for novel antimicrobial agents from natural sources is mounting day by day 24 . In order to find out the prospective antimicrobial principles, the plant L. grandis was subjected for preliminary antimicrobial screening by disc diffusion method.…”

The Effects of Thyme on IL-6 Level and the Bacterial Count in the Brain and Spleen of Mice Infected by Methicillin-Resistant Staphylococcus aureus (MRSA)

“…On the examination of the bacteria count on the spleen organs obtained the same results among groups given thyme alone or groups that were only given antibiotics and groups that were given a combination of thyme and antibiotics were not found any bacteria. This is possible because the spleen is the organ of the Reticulo Endothelial System (RES) which functions to consume bacteria and multiply when infection occurs, process antigens, and stimulate plasma cells to make antibodies (15). In the spleen organ, the high number of macrophages allows macrophages to kill MRSA bacteria effectively through the bloodstream, so that MRSA bacteria do not develop much in the spleen.…”