Effect of methanolic extract of Mexican sunflower (Tithonia diversifolia) leaves on the histology and iron metabolism of the liver of rabbits

Abstract

The effects of methanolic extract of Tithonia diversifolia leaves (METDL), a common broad spectrum medicinal plant with anti-malaria property was investigated on the histology and iron metabolism of liver of nine laboratory bred rabbits, with an average body weight of 1.0 kg each. They were allowed seven days to acclimatize to the environment. All the animals were maintained on the same diet and environmental conditions throughout the experiment. They were randomly divided into three groups (A, and B were the test while C was the control), each group consisted of three adult rabbits. A known quantity of METDL was mixed with part of their feed daily for 21 days. Group A was given 50 mg/kg/daily, B took 100  mg/kg/daily while C was given distilled water; their rectal temperature was taken alongside. They were  screened for morphological changes, sacrificed on 21st day with their liver harvested. The tissues were processed, stained by Haemetoxylin and Eosin (H and E) techniques, and Perl’s Prussian Blue (PPB)  reaction. Loss of weight was observed in Groups A and B only on the 20th and 10th days respectively. The difference was not statistically significant (p>0.05); rectal temperature remained normal in all the groups.  The liver sections of test animals demonstrated with PPB reaction, showed more of iron deposition that increased with dosage of the extract. There were significant histological deviations  observed in the liver sections of test animals compared with the control demonstrated by H and E  technique. Based on these findings, T. diversifolia consumption at a very high concentration and for a longer period may adversely affect the functions of the liver particularly iron metabolism.

Keywords: Tithonia diversifolia extract, liver, histology, iron-metabolism, rabbits.