ABSTRACT
Aim: Study aimed to evaluate the in vitro antisalmonellal and antioxidant properties of Tectona grandis, a medicinal plant commonly used in traditional Cameroonian medicine for the treatment of typhoid fever. Study Design: In vitro Antimicrobial and antioxidant analyses of plant extract using established protocols. Place and Duration of Study: Plant materiel collection at Loum (Moungo Division, Littoral region of Cameroon), identification at the National Herbarium of Cameroon, extraction of plant and all analyses at the Research Unit of Microbiology and Antimicrobial Substances, Department of Biochemistry, University of Dschang-Cameroon, between August 2018 and April 2019. Methodology: In vitro antisalmonellal activity of Tectona grandis extracts was evaluated by the liquid microdilution method as well as their antioxidant activity using by standard methods of H2O2 trapping, FRAP, DPPH radical trapping and OH radical trapping. Quantification test of total phenols and flavonoids and phytochemical screening of extract were also done. Results: The results showed that most of the Tectona grandis extracts had minimal inhibitory concentrations (MICs) ranging from 64 to 1024 μg/mL. Ethanolic extract, 70% ethanol extract and aqueous decoction are the most effective compared to aqueous extracts with activities between 64 and 128 μg/mL on the bacteria tested. Antioxidant tests showed that all extracts except macerated and aqueous infused extracts exhibited high DPPH trapping activities. The antioxidant activities of the extracts are proportionally linked in most cases to their flavonoid and total phenol contents at a concentration of 200 µg/mL. Aqueous decoction showed better H2O2 trapping activity at concentrations less than or equal to 25 µg/mL. Conclusion: These results show that the ethanolic extract and decocted aqueous of Tectona grandis leaves can be used as an alternative to treat salmonellosis.
ABSTRACT
The Phytochemical study of Methanol/dichloromethane extract of root of Leplaea mayombenis led to the isolation and identification four limonoids: (8S,9R,10R,11S,13R,17R)-6,11-dihydroxy-14,15-epoxy-4,4,8,10,13-pentamethyl-17-(2-oxo-2,5-dihydrofuran-3-yl-)-11,12,13,15,16,17-hexahydro-4H-cyclopent[α] phenanthrene-3,7(8H,9H,10H,14H)-dione (1), (8S,9R,10R,11S,13R,17R)-6,11-dihydroxy-14,15-epoxy-4,4,8,10,13-pentamethyl -17-(23-methoxy-2-oxo-2,5-dihydrofuran-3-yl-)-11,12,13,15,16,17-hexahydro-4H-cyclopent [α] phenanthrene 3,7(8H,9H,10H,14H)-dione (2), (8S,9R,10R,11S,13R,17R)-6,11-dihydroxy-14,15-epoxy-17- ((s)-2-hydroxy-5-oxo-2,5-dihydrofurano-3-yl)-4,4,8,10,13-pentamethy-l,10,11,12,13,15,16,17-octahydro-4H-cyclopent [α] phenanthrene-3,7(8H,9H,10H,14H)-dione (3), 8S,9R,10R,11S,13R,17R)-1,6,11-trihydroxy-14,15-epoxy-17- [((2s)-2-hydroxy-5-oxo-2,5-dihydrofurano-3-yl)]-4,4,8,10,13-pentamethyl-l,10,11,12,13,15,16,17-octahydro-4H-cyclopent[α]phenanthrene-3,7(8H,9H,10H,14H)-dione (4), one cycloartane : 9,10-cyclopropyl-(3S,5R,8R,13R,14S,17R))-4,4,13,14,17-pentamethyl-l7-((2R,5S,6R)-5,6,7-trihydroxy-6-methylheptan-2-yl)-hexadecahydro-1H-cyclopentane[α]phenanthrèn-3-ol (5) and three steroids: β-sitosterol (6), stigmasterol (7) and stigmasterol 3-O-β-D-glucopyranoside (8). Their structures were elucidated on the basis of spectroscopic analysis and by comparison of their spectral data with those reported in the literature. To the best of our knowledge, all these compounds were isolated for the first time from the Leplaea mayombensis. The antimicrobial studies showed that isolated compounds exhibit antimicrobial activity with inhibition zone diameters varying from 0.00 ± 0.00 to 29.00 ± 0.00 mm on both bacteria and fungi. 9,10-cyclopropyl-(3S,5R,8R,13R,14S,17R) )-4,4,13,14,17-pentamethyl-l7-((2R,5S,6R)-5,6,7-trihydroxy-6-methylheptan-2-yl)-hexadecahydro-1 H-cyclopentane[α] phenanthrèn-3-ol (5) was the most active against Escherichia coli (28.00±0.00 mm), Pseudomonas sp (27.00±0.00 mm), Lactobacillus acidophilus (29.00±0.00 mm), Streptococcus pneumonia (23.00±0.00 mm) and Serratia entomophili (29.00±0.00 mm), C. albicans (12±0.00 mm), and T. viridae (13±0.00 mm) The results from this study support the conclusion that L. mayombensis contain many classes of antimicrobial compounds and therefore justify their traditional usage in the treatment of infectious diseases.