59 research outputs found
EFFECTS OF VARYING CONCENTRATIONS OF THE CRUDE AQUEOUS AND ETHANOLIC
This study evaluated, using replicated laboratory bioassays, the toxicities of the crude aqueous and
ethanolic extracts of Dalbergia sissoo Roxb. 1832 (family Leguminosae) fruits, leaves, roots and stem bark
against egg masses of Biomphalaria pfeifferi (Krauss, 1848), the snail intermediate host of Schistosoma mansoni
(Sambon, 1907) in Nigeria. Viable 0-24 hr-old embryonated egg masses were separately exposed to five
different concentrations (7.81-2000 mg/l) of extracts for 24 hrs, washed in dechlorinated tap water and incubated
at room temperature for a maximum of 4 weeks. The LC50 and LC90 values of test extracts for egg masses were
calculated by probit analysis. The activities of the tested extracts were concentration-dependent. However, only
the ethanolic extract of the fruits demonstrated significant activity (24 hr-LC90 value < 100 mg/l: 89.29 mg/l).
Mortalities of eggs were manifested at the gastrula/exogastrula and or the prehatch snail stage of development.
The percentage of dead embryos at the prehatch snail stage decreased while the deaths of embryos at the
gastrula/exogastrula stage increased, with increasing concentration of extract. Lethality of the ethanolic extract
of D. sissoo fruits to embryonated egg masses of B. pfeifferi is an added advantage to its potential development
for use as a plant molluscicide, as the overall efficacy of a molluscicide is greatly enhanced if it also shows
significant toxicity towards snail eggs
Activation of dinitrophenol-induced adenosine triphosphatase in rat brain mitochondria by aflatoxin B1
Assessment and Characterization of Ca2+ - ATPase expression in selected isolates and clones of Plasmodium Falciparum
Ca2+-ATPase expression in 15 selected isolates from malaria patients at
the University College Hospital (UCH) Ibadan and two cloned strains
(W2-chloroquine resistant, D6-chloroquine sensitive) of P. Falciparum
was assessed using spectrophotometric assay method. The kinetics of
activity of Ca2+ - ATPase in three isolates (NCP 14, NCP5, NCP1) and
two clones (W2, D6) also assessed. 12% SDS – PAGE analysis of
total proteins in one isolate (NCP14) and two clones (W2, D6) was also
investigated. All the selected isolates and the two cloned strains
exhibited measurable Ca2+-ATPase activity. The Ca2+ - ATPase activity
in cloned strain D6 (6.50 ± 0.74μmolPi/min/mg protein) was
higher than in cloned strain W2 (3.93 ± 0.61μmolPi/min/mg
protein. The Ca2+-ATPase activity in isolates from malaria patients
varied widely (1.95 ± 0.74 – 21.56
±1.43μmolPi/min/mg protein). The kinetic constants obtained
for the two cloned strains showed that clone W2 had a higher Vmax (Vmax
= 363μmolPi/min/mg protein) than clone D6 (Vmax =
74μmolPi/min/mg protein). All the isolates and the two cloned
strains showed similar affinity for ATP (Km ~ 10mM). Scan of SDS-PAGE
gel of total proteins in the isolate and cloned strains showed the
presence of oligopeptide bands of molecular weights range of 148-176
KDa; 116-123 KDa respectively. These suggest the presence of predicted
polypeptide of Ca2+ - ATPase nature of molecular weight estimate of 139
KDa. The study agrees with previous findings that Ca2+-ATPase is
functionally expressed in P.falciparum, The study also indicates that
Ca2+ - ATPase functional expression may vary with isolate or clone but
the ATP binding mechanism to the enzyme is similar in all isolates and
clones of P.falciparum. The study further suggests a possible
association between acquisition of chloroquine resistance and Ca2+-
ATPase functional expression in P.falciparum
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