Abstract:
In the present study, two medicinal plants
Melothria maderaspatana and Osbeckia octandra have been
investigated for antirhepatotoxic activity. Two
hepatotoxins carbon tetrachloride and ethanol were used in
the preliminary studies. Detailed studies were carried out
with animals where hepatotoxicity was induced with
carborrtetrachloride. An attempt has also been made to
isolate the active components.
The ability of the two plant extracts to protect
the liver against the changes mediated by
carbontetrachloride or ethanol confirms that both plants
possess antt-hepatotoxic properties at least against the two
chemicals used. Thus pre-or post treatment with either of
the plant extracts markedly decreased carbos.tetrachloride
mediated alterations in liver histopathology as well as
serum enzymes (alanine aminotransferase, aspartate
aminotransferase and alkaline phosphatase) levels and also
the ethanol mediated changes in serum and liver lipid,
cholesterol and glutathione levels. The magnitude of
antx-rhepatotoxic properties varied with the dosage used and
the time of storage. No significant seasonal variations
were observed with either of the two plants investigated.
The two plant extracts themselves did not have any effect on either the serum enzyme levels, the levels of^lipids,
cholesterol or the liver histopathology.
Results of studies on the mechanism of action
suggest that the two plant extracts may have slightly
different modes of action. Thus, while both plant extracts
were able to stimulate the immunological defense on the
test animals and protect the livers of these animals
against alterations in (a) the microsomal enzyme activity
(b) lipid peroxidation and (c) reduced glutathione levels,
only lielothria maderaspatana was able to enhance the
lysosomal stability in the liver. Osbeckia octandra was
unable to prevent lysosomal damage induced by
carbon tetrachloride.
Investigations with Melothria maderaspatana and
Osbeckia octandra showed that the extracts of these plants
had no toxicological effects on the histopathology of
various body organs, liver function, haematological
parameters (haemoglobin concentration, red blood cell
count, white blood cell count and packed cell volume) or on
the reproductive ability of these experimental animals.
The general conditions of the animals also did not change
and all the animals remained in good health throughout the
experimental period.
In the present investigation it was evident that
the liver protective actions of the crude extract of
Melothria maderaspatana plant is mediated by a mixture of
three alkaloids of almost similar potency, while in Osbeckia
octandra}it is mediated through the action of a flavonoid
and two other components which are possibly flavonoid
derivatives.
