Introduction

The prevalence of hepatopathies in the world indicates an increased incidence rate with severe consequences on the liver. The pathogenesis of liver fibrosis is not clear, but there is no doubt that reactive oxygen species (ROS) plays an important role in the pathological changes in the liver in alcoholic and toxic liver disease (Poli and Parola, 1997). The peroxidation of unsaturated fatty acids in the biological membrane gives rise to a disruption of membranes’ integrity and function which is implicated in serious pathological changes (Halliwell, 1987). Several endogenous protective mechanisms have been evolved to limit ROS and the damage caused by them (Sies, 1993). However, this protection may not be complete, hence, ROS becomes excessive.

Many natural agents are known to possess antioxidant properties and have been proposed in the treatment and prevention liver diseases or damage induced by oxidative stress (Sieber, 1997). There are also increasing evidence for the hepatoprotective activities of hydroxyl and polyhydroxyl- organic compounds found in vegetables, fruits and some herbs.(Bass, 1999). Preliminary phytochemical studies on Talinum triangulare (water leaf) found mostly in the southern part of Nigeria reveals the presence of Omega -3 fatty acid and high levels of nutritionally important vitamins (such as C, E ,and betacarotene), minerals (such as calcium, magnesium and potassium) and soluble fibres (pectin) all of which contributes to its highly elevated antioxidant values (Ezekwe et al ,2004). Other phytochemicals present in the plant are saponins, phytic acid, tannic acid and oxalate (Akindahunsi and Salawu, 2005).

The current study was designed to examine the hepatoprotective effect of aqueous extract of the leaves of Talinium triangulare against CCl4- induced hepatotoxicity in the Wistar rats animal model.

Materials and methods

T. triangulare were bought from the general market, Ilorin and were authenticated at the Department of Plant Biology, University of Ilorin. The leaves were washed in distilled water, shack dried and pulverized in 100grams of powdered material was soaked in 100mls of distilled water (1:10w/v), poured in a conical flask, agitated vigorously for 5 minutes and kept for 12hours. The mixture was filtered and evaporated to dryness at room temperature. The resultant powder was stored in the refrigerator for the study.

Animals and administration

Statistical analysis

Results

Administration of CCl4 for seven days led to significant (p<0.05) increases in the serum alkaline phosphates, alanine aminotransferase and aspartate aminotransferase which were significantly reduced in the groups treated with higher concentration of the extract. Histopathological examination of the liver section of the rats in the CCl4 treated group revealed an intense distortion of the hepatic architecture. The groups treated with 600mg/kg of the extract showed signs of protection against toxicity evident from reduced i, fatty degeneration, ii, necrosis and iii, vacuoles. The signs of hepatoprotection were not evident in the groups treated with the low doses.

Figure 1

Table 1: Serum levels of ALP, ALT and AST in the Experimental Groups

(p<0.05) Values are presented as means ± SEM for 6 rats per group. (*not significant compared to Group B).

Figure 2

Figure 1: Chart showing serum levels of ALT and AST in the various groups

Figure 3

Figure 2: Chart Showing Serum levels of ALP in the various groups

Discussion

Carbon tetrachloride (CCl4) is one of the most frequently used hepatotoxins in experimental studies of liver diseases (Uma and Rao, 2005). The hepatotoxic effects of CCl4 are largely due to its active metabolites, trichloromethyl radical. These activated radicals bind to micromolecules and reduce lipids peroxidative degradation of polyunsaturated fatty acids. This leads to the formation of lipid peroxides which in turn gives products like malonylaldehyde that cause damage to membranes ( Ulicna et al 2003). This lipid peroxidative degradation of biomembranes is one of the main causes of hepatotoxicity by CCl4. this is evidenced by a rise in the serum marker enzymes namely alkaline phosphates (ALP), aspartate aminotransferase (AST) and alanine aminotransferase (ALT). T. triangulare administration at 200mg/kg concentration did not significantly reduce the levels of ALP, AST and ALT but at higher concentrations, it significantly reduced these levels at which levels of the marker enzymes fell, indicating hepatoprotective activity.

In the study, an elevation in the levels of the end products of lipids peroxidation of the liver of rats treated with CCL4 was observed. The increase in ALP, AST and ALT suggests enhanced lipid peroxidation giving rise to liver damage and failure of the antioxidant defense mechanism to prevent formation of excessive free radicals. Treatment with T. triangulare reversed the changes (p<0.05) at high concentrations, hence it is possible that the mechanism of hepatoprotection of T. triangulare is due to its antioxidant effect. Histological studies showed minimal reduction in steatosis and degeneration of the liver tissue with treatment. This suggests that physiologic recovery preceded obvious histological changes. These results suggest that diets supplemented with T. triangulare will improve hepatoprotection against oxidative liver damage.

Correspondence to

G.A Adefolaju Department of Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, University of Ilorin, Ilorin, Nigeria. Phone: +2348053621122, +2347037761906, +23431743452. E-mail: adefolaju.ga@unilorin.edu.ng adefolajugbenga@yahoo.com adefolajugbenga@gmail.com