Antibacterial-guided isolation of constituents from <i>Senna alata </i>leaves with a particular reference against Multi-Drug-Resistant <i>Vibrio cholerae </i>and <i>Shigella flexneri</i>

Abstract

Senna alata is widely used in Cameroon for the treatment of several infections which include gonorrhoea, gastro-intestinal and skin diseases. Therefore, its leaves were investigated for antibacterial principles. Extraction of plant material was done with methanol, follow by partition with hexane. Separation and purification of compounds was done using a combination of chromatographic techniques. Isolated compounds were identified by means of spectroscopic methods and comparison with literature data. The antibacterial activity of extracts, fractions and compounds was assessed by evaluating the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against Multi-Drug-Resistant (MDR) Vibrio cholerae and Shigella flexneri. Three secondary metabolites namely kaempferol, luteolin and aloeemodin were isolated from methanol residue active extract. The antibacterial results showed that the MeOH residue extract, fractions A and C, as well as compounds 1-3 exhibited variable MIC values, depending on the bacterial strains. Aloe-emodin (MIC = 4 to 128 μg/mL) exhibited the highest antibacterial activity against MDR Vibrio cholerae and Shigella flexneri. From these results obtained, S. alata leaf could be considered as a natural antibacterial source due to the presence of flavonoid and anthraquinone compounds.

Antimicrobial activities of flavonoid glycosides from Graptophyllum grandulosum and their mechanism of antibacterial action

“…Taking into account the medical importance of the test microbial species, the result can be considered as promising for the development of new antimicrobial drugs. The antimicrobial activities of purified flavonoids corroborated with those of early reports against bacteria and fungi [ 5 , 11 , 26 – 28 ]. The antibacterial activity of the samples against V. cholerae and S. flexneri are particularly noteworthy since these strains were MDR clinical isolates which were resistant to commonly used drugs such as ampicillin, streptomycin, nalidixic acid, furazolidone and co-trimoxazole [ 16 , 29 , 30 ].…”

Chemical constituents, usage and pharmacological activity of Cassia alata

“…GC/MS characterization results on C. alata leaves showed that there were 7 compounds including 7 ((6Z)-7,11-dimethyl-3-methylidenedodeca-1,6,10-triene), 8 (4a,8-dimethyl-2-(prop-1-en-2-yl)-1,2,3,4,4a,5,6,8a-octahydronaphthalene), 9 (4,4,7a-trimethyl-5,6,7,7a-tetrahydro-1-benzofuran-2(4H)-one), 10 ( 3,7-dimethylocta-1,6-diene), 11 (hexadecanoic acid methyl ester), 12 (hexadecanoic acid), and 13 (octadecanoic acid methyl ester) [ 19 ]. Alkaloid compounds from C. alata leaves have also been identified, namely 14 ( adenine) [ 20 ], 15 (Chrysoeriol), 16 (quercetin), 17 (5,7,4′-trihydroflavanone), 18 ( kaempferol-3-O-beta-D-glucopyranosyl-(1→6)-beta-D-glucopyranoside), 19 ( n -dotriacontanol), 20 ( n -triacontanol), 21 (stearic acid), 22 palmitic acid [ 21 ], 23 diomestin [ 22 ], 24 (luteolin) [ 23 ], and 25 (1,3,5-trihydroxy-7-methylanthracene-9,10-dione) [ 24 ].…”

“… [ 84 ] Seed Antioxidant DPPH radical scavenging and ferric reducing The antioxidant IC 50 values of seed in DPPH and ferric reducing were 4.01 ± 0.11 and 0.40 ± 0.21 μmol/mg, respectively. [ 23 ] Thrombolitic I n vitro thrombolytic activity The extract showed potent thrombolytic activity against negative control (water). [ 21 ] Anticancer Brine Shrimp Lethality by using shrimp larvae ( Artemia salina Leach) The cytotoxicity of ethanol extract of C. alata seed and gallic acid had LC 50 value 4.31 and 4.53 ppm, respectively.…”

“… [ 45 ] DPPH radical scavenging and ferric reducing The antioxidant IC 50 values of flower in DPPH and ferric reducing were 4.16 ± 0.21 and 0.33 ± 0.51 μmol/mg, respectively. [ 23 ] DPPH radical scavenging Methanol extract gave ED 50 175.36 μg/ml, while BHT had 14.17 ± 1.38 μg/ml. [ 15 ] DPPH radical scavenging Aqueous extract had EC 50 823 μg/ml.…”

Ethnobotanical Description and Biological Activities of Senna alata

“…Aloe emodin exhibited strong MIC activities (4 to 128 μg/ml). e marked activities could be linked to the anthraquinone and flavonoids compounds detected [59]. e antibacterial activity of chrysoeriol-7-O-(2″-O-beta-D-mannopyranosyl)-beta-Dallopyranoside,3-O-gentiobioside, quercetin, naringenin, and rhamnetin-3-O-(2″-O-beta-D-mannopyranosyl)-beta-D-allopyranoside isolated from chloroform, ethanol, petroleum ether, methanol, and aqueous leaves extract of S. alata, significantly inhibited the growth of B. subtilis, V. cholerae, Streptococcus sp., S. aureus, and E. coli.…”