ARTOCARPUS COMMUNIS FORST. ROOT-BARK AQUEOUS EXTRACT-AND STREPTO-ZOTOCIN-INDUCED ULTRASTRUCTURAL AND METABOLIC CHANGES IN HEPATIC TISSUES OF WISTAR RATS|
Adewole, Stephen O. & Ojewole, John A. O.
Decoctions and infusions of Artocarpus communis (Forst.) (family: Moraceae) root-bark are commonly used traditionally among the Yoruba-speaking people of Western Nigeria as folk remedies for the management, control and/or treatment of an array of human diseases, including type 2, adult-onset diabetes mellitus. Although numerous bioactive flavonoids have been isolated from the roots, stem-bark and leaves of A. communis, to the best of our knowledge, the effects of the plant's root-bark extract on animal model of diabetes mellitus and on liver tissues have hitherto, not been reported in the biomedical literature. In view of this, the present study was undertaken to investigate the glycaemic effect of, and hepatic tissue ultrastructural, morphological and metabolic changes induced by, A. communis root-bark aqueous extract (ACE) in Wistar rats. The ultrastructural, morphological and metabolic effects of ACE have been compared with those induced by streptozotocin (STZ) in rat experimental paradigms. Four groups (A, B, C and D) of Wistar rats, each group containing 10 rats, were used. Diabetes mellitus was induced in the diabetic groups B and C animals by intraperitoneal injections of STZ (75 mg/kg body weight), while group A rats received A. communis root-bark aqueous extract (ACE, 100 mg/kg body weight, i.p.) alone.
Control group D rats received distilled water in quantities equivalent to the volume of ACE administered
intraperitoneally. The rats in group C were additionally treated with ACE (100 mg/kg body weight i. p.) daily from
day 3 to day 10 after STZ treatment. Hepatic glucokinase, hexokinase, glutamate dehydrogenase, succinate
dehydrogenase, β-hydroxybutyrate dehydrogenase, serum insulin and blood glucose levels of the animals were
measured and recorded before and after ACE, STZ and STZ+ACE treatments. Hepatic tissues were also processed
for transmission electron microscopy. Electron microscopic examinations showed toxic, deleterious alterations in
the ultrastructures of groups A, B and C hepatic cells, the most prominent deleterious effects being on the
hepatocytes. Ultrastructural changes observed within the hepatocytes of groups A, B and C rats include disrupted
mitochondria with increase in lipid droplets, extensive hepatocellular vacuolation, scanty rough endoplasmic
reticulum (RER) and ribosomes. Large glycogen clusters were also noticed displacing the mitochondria and RER in
group A rats. Group A rats also developed significant hyperglycemia (p<0.05) immediately after ACE
administration, while groups B and C rats developed hyperglycemia 24 hours after STZ treatment. When compared
with the control group D rats, the activities of all the three subsystems were disrupted, leading to overall inhibition
of oxidative phosphorylation of the liver mitochondria in groups A, B and C rats, but remain normal in the untreated
group D control rats. The findings of the present study indicate that A. communis root-bark aqueous extract induces
hyperglycaemia in the experimental animal model used, and that the plant’s extract disrupts the ultrastructural
characteristics and architecture of hepatocytes as well as oxidative energy metabolism.
Artocarpus communis; streptozotocin; hyperglycaemic effects; hepatic tissues; ultrastructural and metabolic changes