| dc.description.abstract | Water extract of Podocarpus sp (CADE-A), chloroform, methanol and a mixture of water extracts of Rhamnus prinoides, Carissa edulis, and Toddalia asiatica (CADE-B) have been used traditionally by Kenyan communities for the purpose of stimulating myometrial contractions, alleviating diabetes, polio, colics, malaria, bronchial pains, indigestion, remedy for paralysis and hypertension (Kokwaro, 1976). Solutions of 8ml CADE-A/kg b.w, 20mg/kg b.w. of chloroform and methanol extract of Podocarpus sp prepared in a solution containing 2.5g/kg b.w. of glucose improved glucose tolerance in group 1, 2 and 3 rabbits weighing mean 3.1 ± 0.90 kg. Absorption of sugar from the gut was improved by both CADE-A and chloroform extract where maximum absorption occurred at (140.70 ± 1.69 mg/lOOml) and (165.32 ±4.18 mg/lOOml) at 60 and 90 minutes respectively. Glucose absorption was improved slightly by methanol extract where it occurred at (117.24 ±2.14 mg/lOOml) after 90 minutes. I he end point blood glucose levels were significantly reduced in group 1 and 2 (P<0.01). The rate of absorption of glucose into the tissues in group 1, 2, and 3 were significantly reduced (P<0.01). During the oral glucose tolerance test, peak blood glucose levels in group 4 rabbits were 129.59± 2.05mg/100ml where it occurred at 120 minutes. The glucose tolerance curve of the rabbits over entire period of sampling was statistically significant (PO.01).
Muscle contraction of CADE-A and CADE-B on isolated rabbits heart and rats’ non-gravid myometrial strips show dose dependent inhibition of muscle contraction at physiological doses. The contraction in the heart is augmented by propranolol. Higher unphysiological levels cause concentration-dependent increase in tension in the intestinal musculature of the rabbit. CADE-A and CADE-B, both cause the reduction in amplitude of more than 20 % of the normal contraction of the heart. In addition each causes a slowing down of the heart rate by more than 20% of the normal and complete relaxation of the uterine musculature. Each extract increases the tension in the ileum by more than 70%. At very high doses, each extract causes concentration-dependent increases in tension and contractile response to these high doses of the extract is ionotropic - increasing the amplitude by about 35% of the normal. All these relaxations and increases in the tension of the isolated organs are statistically significant (P< 0.01).
The levels of essential elements in CADE-A were Copper 0.05 mg/L, Zinc 1.5mg/L, Chromium 0.034mg/L and Iron 1.4mg/L and likewise in CADE-B were Copper 0.60 mg/L, Zinc 0.030mg/L, Chromium O.lOOmg/L and Iron 4.2mg/L. These low concentration
levels of the first row transition elements are essential for action of many enzymes in biologically important molecules in life.
Saponins and sapogenins in the water extract are most probably the biochemical basis on hypoglycemic and muscle contraction. The compounds identified, isolated, characterized in Podocarpus sp bark extract are compound A, a sapogenin, melting point (mp) 201-203 °C, UV/Vis absorption at 472nm, molecular ion peak [M]* at m/z= 538 amu determined by MS-FAB analysis corresponding to molecular formula C32H42O7. Compound B, a saponin, melting point (mp-) 184-1870C, UV/Vis absorption at X™* 478nm and molecular ion peak [M]4 at m/z= 537.2 amu corresponding to the molecular formula C31H39NO7. | |
