ABSTRACT
Aim: To partially-purify, characterize and investigate the inhibition pattern of proteins from the leaves and seeds of Moringa oleifera. Methodology: Crude proteins obtained from the leaves and seeds were partially-purified by a twostep method: cold acetone precipitation and sephadex G-75 gel filtration chromatography and Angiotensin Converting Enzyme (ACE) inhibitory activities determined using Cushman and Cheung method with some modifications on the assay conditions. The effects of pH, temperature and some digestive enzymes on the inhibitory proteins were determined. The inhibition pattern was also investigated using Lineweaver-Burk plots. Results: The ACE inhibitory proteins from the leaves and seeds were purified 8.41 and 12.40 folds with a yield of 38 and 35.18%, respectively on sephadex G-75 column. The optimum pH and temperature of the inhibitory proteins were 8.2 and 37.6°C, for leaves and 7.8 and 39°C, for seeds, respectively. The partially-purified ACE inhibitors exhibited a mixed type of inhibition. The Km of inhibitory proteins obtained from the leaves increased from 3.51mM without the inhibitor to 4.79mM and 5.62mM in the presence of 0.5 and 1mg/ml of the inhibitor, respectively, while Vmax decreased from 0.953μmol/min without inhibitor to 0.784μmol/min and 0.629μmol/min, in the presence of 0.5 and 1mg/ml of the inhibitor, respectively, with a Ki of 3.51mM. For the seeds, the Km increased from 2.89mM (without inhibitor) to 5.747mM (at 1mg/ml inhibitor), while Vmax decreased from 0.910 (without inhibitor) to 0.628μmol/min (at 1mg/ml inhibitor), with a Ki of 1.58mg/ml. The digestive enzymes, pepsin and trypsin significantly (P<0.05) reduced the activity of the partially-purified inhibitors from both leaves and seeds compared to captopril. In conclusion, ACE inhibitory proteins from M. oleifera may be beneficial as nutraceutical or drug for blood pressure regulation in hypertensive patients.
ABSTRACT
Aim: The protective effect of some selected vegetables {Moringa (Moringa oleifera), Cabbage (Brassica oleracea) and Tomato (Solanum lycopersicum)} against hepatocardio toxicity of halofantrine (an antimalarial drug) was evaluated in 72 albino rats. Study Design: The rats were grouped into eight of nine rats each. Three different doses; 7.1, 14.2 and 21.3mg/Kg of halofantrine were given to group II, III and IV respectively. Group V was co-administered with halofantrine and moringa extract 7.1 and 0.20mg/Kg respectively, Group VI co-administered with halofantrine and cabbage extract 7.1 and 0.10mg/Kg respectively, Group VII co-administered with halofantrine and Tomato extract 7.1 and 0.20mg/Kg respectively and Group VIII co-administered with halofantrine, moringa, cabbage and tomato extracts 7.1, 0.20, 0.10 and 0.20mg/Kg respectively). Group I was neither given the drug nor the vegetable extract serving as normal control. Methodology: The liver and heart function indices were evaluated using standard methods. Results: Serum liver enzymes, heart marker enzymes and concentration of malondialdehyde (MDA) were analyzed after 16, 96 and 192 hours of oral administration. Halofantrine administration caused significant increase (p<0.05) in the activities of all the enzymes with a peak at the 16th hour. Malondialdehyde had a peak at the 192 hours. The oral co-administration of vegetables extract showed a significant decrease (p<0.05) in the enzyme activities and concentration of malondialdehyde as compared sole administration of halofantrine. The result showed that Moringa, Cabbage and Tomato may have hepato and cardio protective effects against halofantrine toxicity. It may be concluded that consumption of vegetables may be beyond the nutritional needs but also for protective purposes.