| dc.description.abstract | Plants provide awide range of useful chemicals for inanaging many ailments. Large numbers of
biologically active compounds with wide varieties of structures have been isolated from plants
with some developed into drugs. Plants are therefore a promising source of compounds for
management of dis~ases or use as templates for designing new' =detivatives with improved
properties. This is necessary because infective agents have developed resistance to most of the
existing drugs. The plants Cissampelos pare ira. Tinospora oblongifolia and Triclisia sacleuxii
are used widely in traditional medicine to manage varieties of ailments including malaria and
bacterial infections. [Iheir crude extracts have shown diverse biological activities but the active
compounds are not known. This research set out to isolate and characterise the antiplasmodial
and antibacterial compounds from the aerial parts Cissampelos pare ira, stems of Tinospora
oblongifolia and Triclisia sacleuxii. The crude extracts were subjected to antiplasmodial and
antibacterial assays. Antiplasmodial assay were done using a non-radioactive assay technique to
determine 50% growth inhibition on cultured parasites. Two parasitic strains, chloroquine (CQ)"
sensitive Sierra I (D6) and CQ-resistant Indochina I (W2), of Plasmodium falciparum were
grown. Chloroquine and mefloquine were used as positive controls. Staphylococcus aureus
Staphylococcus epidermidis, Escherichia coli and Pseudomonas aeruginosa were used in the
antibacterial assay by disc diffusion assay for the crude extracts and microdilution assay for the
isolates. For positive control streptomycin was used. With the exception of the n-hexane extracts,
all the other extracts from the three plants displayed moderate to good in vitro antiplasmodial
activity. However, the crude extracts had poor selectivity indices with methanol extract of C.
pareira displaying the best selectivity index (3.93). All the tested antibacterial strains were
susceptible to all the extracts of the three plants with the exception of the n-hexane extracts to
which they were resistant. The largest diameter of zone of inhibition (21.4 mm) was observed
with n-butanol extract of T. sacleuxii against S. aureus. A bisbenzylisoquinoline alkaloid,
isotetrandrine (172),i,two protoberberine alkaloids; palmatine (130) and columbamine (132) two
ferrulamides; trans-li-feruloyltyramine (167) and trans-N-caffeoyltyramine (168), three lignans;
yangambin (171) syringaresinol (166) and sesamin (170), a cyclitol, epiquercitol (173) an
aldehyde, 4-hydrox)'I:"benzaldehyde (165), two sterols; p-sitosterol (164) and stigmasterol (178),
a p-carboline alkaloid; 1-(6-hydroxy-l-( 4-hydroxybenzyl)-3,4-dihydro-l H-pyrido[3,4-b [indol-
2(9H)-yl)tetracosan-l-one (sacleuximine),(169) two glucosides; ~-sitosterol glucoside (177) and
withanolide E glucoside (183), two esters; 2-(4'-hydroxyphenyl)-ethyl lignocerate (174) and
docosyl-3, 4-dihydroxy-trans-cinnamate (175), a ceramide; 2', 3'-dihydroxy-N-{(2S,3S,4R)-
1,3,4-trihydroxyicosan-2-yl} tetracosanamide (176), three triterpenes; lupeol (181), lanosterol
(179) and oleanolic: acid (180) and a flavonoid; epicatechin (182), were isolated. Three
compounds displayed potent antiplasmodial activity. Compound 172 displayed an IC50 of 0.31\
and 0.11 11M, compound 130 IC50 0[0.19 and 0.83 11M and compound 132 ICso 0[0.98 and o.ie
11M against the CQ sensitive D6 and CQ resistant W2 Plasmodium falciparum strains
respectively. They. also displayed good selectivity indices with compound 132 displaying the
highest index of 54.75. Compound 166 was the most active antibacterial compound with MlC
values ranging frornlO.9 to 14.8 J..lM:Isolation of compound 173 and lignans (166, 170 and 171'
are reported for the first time from the genus Triclisia. The compounds 169 and 176 are reporter
for the first time. Antibacterial activity of T. sacleuxii and antiplasmodial and antibacteria
activitie-Sof T. obl« .ngifolia are reported for the first time. This research validates the use of thes.
plants in folk medicine in the management of a variety of ailments. The identified COlTIl- ound
are recommended for further development into drugs to help reduce the disease burden. | en_US |
