Abstract
Liver disease is still a global health concern and the drugs used to treat the condition are also implicated in exacerbating the problem. Many are sources are constantly screened for bioactivity in order to compensates shortcomings from current treatments. hepatocurative potential of aqueous stem bark extract of Cassia sieberiana in liver rats. Phytochemical analysis, acute toxicity study and effect of aqueous stem bark extract of Cassia sieberiana in rats induced with CCl into five groups of six rats each. With one group being normal control while the others were induced with 150 mg/kg CCl 4 to induce liver damage followed by daily administratio doses (50, 100 and 150 mg/kg) of aqueous stem bark extract of Cassia sieberiana (ASBEC) for four weeks. Three rats from each group were randomly selected and sacrificed 48hours after CCl induction in order to confirm liver damage, while the re sacrificed after four weeks. The blood samples were collected to determine serum levels of liver enzymes, total proteins, bilirubin(s) and albumin. section was carried out. The phytochemical analysis revealed the presence of tannins, saponins, cardiac glycosides, alkaloid and flavonoids. The acute toxicity of ASBEC shows no sign of toxicity at a maximum dose of 5000mg/kg. The biochemical markers of liver injury control. There is no statistically significant change (P > 0.05) in the serum biomarkers of liver injury in the extract treated groups compared to the positive (normal saline) control. the biochemical parameters indicate some hepatocurative effects of the extract against CCl induced liver toxicity and this was supported by the hispathological exa Hence, the curative latent of the Cassia sieberiana may be due to the presence of high concentration of tannins and saponins.
INTRODUCTION
Medicinal plants have been identified and used for treatment purposes in different parts of the world. The use of traditional medicine has increased lower cost and safety as compared to synthetic (Abdolrasool et al., 2013) . Treatment of liver by traditional medicine is an essential constituent of alternative medicine (Obidah et al., sieberiana is an important plant used in Nigeria for alleviation and treatment of diseases. It belongs to Acasia family and is distributed across the Semi North-eastern Nigeria and ranges from giant trees to small annual herbs (Biu et al., 2013) used in treatment of malaria, jaundice, rheumatism (Abdulrazak et al., 2015) reported that the fruits are used for the treatment of ulcer, piles and stomachache (Toma et al., aqueous decoctions of the roots, stem bark and the fruit pulp have been used traditionally in North Liver disease is still a global health concern and the drugs used to treat the condition are also implicated in exacerbating the problem. Many are sources are constantly screened for bioactivity in order to compensates shortcomings from current treatments. Thus, the current study evaluates the hepatocurative potential of aqueous stem bark extract of Cassia sieberiana in liver-damaged albino rats. Phytochemical analysis, acute toxicity study and effect of aqueous stem bark extract of Cassia s induced with CCl 4 liver damaged were conducted. The rats were randomly divided into five groups of six rats each. With one group being normal control while the others were to induce liver damage followed by daily administratio doses (50, 100 and 150 mg/kg) of aqueous stem bark extract of Cassia sieberiana (ASBEC) for four weeks. Three rats from each group were randomly selected and sacrificed 48hours after CCl induction in order to confirm liver damage, while the remaining three rats in all the groups were sacrificed after four weeks. The blood samples were collected to determine serum levels of liver enzymes, total proteins, bilirubin(s) and albumin. Histopathological examination on the liver section was carried out. The phytochemical analysis revealed the presence of tannins, saponins, cardiac glycosides, alkaloid and flavonoids. The acute toxicity of ASBEC shows no sign of toxicity at a maximum dose of 5000mg/kg. The extract produced dose-dependent reduction in the biochemical markers of liver injury (P ≤ 0.05) compared to the negative (CCl 4 -only treated group) control. There is no statistically significant change (P > 0.05) in the serum biomarkers of liver the extract treated groups compared to the positive (normal saline) control. the biochemical parameters indicate some hepatocurative effects of the extract against CCl induced liver toxicity and this was supported by the hispathological examination of rat's liver. Hence, the curative latent of the Cassia sieberiana may be due to the presence of high concentration of tannins and saponins.
Keywords: Albino rats, Carbon tetrachloride (CCl 4 ), Cassia sieberiana, Hepatoprotection, Liver
Medicinal plants have been identified and used for treatment purposes in different parts of the world. of traditional medicine has increased due to synthetic drugs . Treatment of liver damage by traditional medicine is an essential constituent of 2009). Cassia is an important plant used in Nigeria for alleviation and treatment of diseases. It belongs to oss the Semi-Arid ranges from giant trees to 2013). The plant is treatment of malaria, jaundice, diarrheoa and . It was also reported that the fruits are used for the treatment of et al., 2009). The aqueous decoctions of the roots, stem bark and the fruit pulp have been used traditionally in North-eastern Nigeria for the treatment of inflammatory conditions (Madusolomuo et al., 1999) (Abdolrasool et al., 2013) .
Liver is an organ responsible for metabolism of xenobiotics that may be harmful to the body and detoxify them to harmless substances. It also has a wide range of biochemical functions, including synthesis and other biomolecules 2014). Liver damage can result from xenobiotics (Friedman, 2014) or viral hepatitis and inherited metabolic diseases (Bolanle et al., 2014) reported that carbon tetrachloride (CCl radical mediated lipid peroxidation and liver damage (Murtala et al., 2016) . Many reports showed similarities between human liver cirrhosis and CCl induced liver damage (Ellahi et al., justifies the use of CCl 4 to induced liver damage in experimental animals. Liver disease is still a global health concern and the drugs used to treat the condition are also implicated in exacerbating the problem. Many are sources are constantly screened for bioactivity in Thus, the current study evaluates the damaged albino rats. Phytochemical analysis, acute toxicity study and effect of aqueous stem bark extract of Cassia liver damaged were conducted. The rats were randomly divided into five groups of six rats each. With one group being normal control while the others were to induce liver damage followed by daily administration of graded doses (50, 100 and 150 mg/kg) of aqueous stem bark extract of Cassia sieberiana (ASBEC) for four weeks. Three rats from each group were randomly selected and sacrificed 48hours after CCl 4 maining three rats in all the groups were sacrificed after four weeks. The blood samples were collected to determine serum levels of liver examination on the liver section was carried out. Therefore, there is the urgent need to investigate a medicinal plant that has hepatocurative effect to determine its potential in treating liver diseases.
MATERIALS AND METHODS Collection, Identification and Authentication
Cassia sieberiana stem bark was collected from Gwarzo town area, Kano state. It was identified and authenticated at Biological Science Department of Bayero University, Kano, by a botanist and a voucher number of 89 was assigned to it.
Preparation of the Plant Extract
The stem bark was washed with distilled water and dried at room temperature for seven days. The bark was then grounded into fine powder using pestle and mortar and 100g of the powder was soaked in 400cm 3 of distilled water for 24hrs. The extract was filtered using Whattman filter paper No. 1. The filtrate was dried using rotarory evaporator, weighed and reconstituted Phytochemical Analysis
The phytochemical analysis of C. sieberiana aqueous extract was carried out to determine that levels of tannins, saponins, alkaloids, flavonoids (as described by Gracelin et al., (2013) ) and cardiac glycosides (as described by Soladoye and Chukwuma (2012) ).
Experimental Animals
Adult male Wistar rats of either of average body weight of 397.94±99.45 g were obtained from animal house facility of Department of Biological Sciences, Bayero University, Kano, Nigeria. The rats were kept in well ventilated animal house at room temperature for 2 weeks to acclimatized. They were fed with standard animal diet (Top Feed ® ) and allow free access to water ad libitum.
Acute Toxicity
The LD 50 was determined using Lorke method (1983) . Nine (9) albino rats were used in phase I of the method, the rats were divided into 3 groups of 3 rats each, The animals were treated with 10, 100 and 1000 mg/kg body weight of aqueous stem bark extract of Cassia sieberiana (ASBEC) and were monitored for 24hrs, for signs of toxicity and death. In phase II, four (4) rats were used and divided into four (4) groups of one rat each. They were treated with ASBEC at doses of 1600, 2900 and 5000 mg/kg body weight. They were monitored for 24 hours for signs of toxicity and death.
Experimental Design
A total of forty-three (43) rats were used in this study. Thirteen (13) rats were used for acute toxicity study, and thirty (30) rats were divided into five groups of 6 rats each for the assessment of ASBEC effect on CCl 4 induced liver damage. Three rats from each of the five groups were sacrificed after 48 hours of CCl 4 induction to confirm liver damage. The confirmation was followed by the daily administration of 50, 100 and 150mg/kg of the ASBEC to Groups III, IV and V animals respectively while Group I was neither induced with CCl 4 nor treated with the extract and therefore served as positive control. The rats in group II were induced with CCl 4 but not treated with the extract and therefore served as negative control. Group II  3  150  Nil  Group III  3  150  50  Group IV  3  150  100  Group V  3  150  150 After four weeks, the three remaining animals form each group (I to V) were sacrificed to assess liver status.
Induction of Liver Damage
Liver injury was induced by single administration of 150 mg/kg of CCl 4 intraperitoneally. A stock solution of CCl 4 was prepared 1:1 by dissolving 25cm 3 of CCl 4 in 25cm 3 of pure olive oil.
Biochemical Assays
The total protein (TP), alkaline phosphatase (ALP), alanine transaminase (ALT), aspartate transaminase (AST), albumin (ALB), total bilirubin (TB), direct bilirubin (DB) levels in the serum of treated rats were evaluated using assay Randox Laboratories kits (Randox Laboratories LTD, United Kingdom, BT29 4QY).
Histopathology Analysis
The liver specimens of the sacrificed rats were transported in 10% buffered formalin to the Histopathology department of Aminu Kano Teaching Hospital, Kano, where histopathological analysis was conducted.
Statistical Analysis
Results of biochemical parameters were expressed as mean plus or minus standard deviation (M ± SD) and analysed using One-way analysis of variance (ANOVA) followed by Tukey's post hoc test for multiple comparison among groups. Probability value (P) of ≤ 0.05 was considered statistically significant.
RESULTS

Phytochemical Analysis
The quantitative phytochemical analysis showed that ASBECS is rich in tannins followed by saponins but contains low levels of cardiac glycosides, alkaloid and flavonoids (Table 2) . 
BAJOPAS Volume 11 Number 2 December, 2018

Acute Toxicity Studies
The oral LD 50 of Cassia sieberiana in rats was estimated to be 5000 mg/kg. There was no mortality or obvious signs of toxicity in both phases. This shows that ASBECS is practically nontoxic to the rats.
CCl 4 -induced Liver Damage
A significant increase (P ≤ 0.05) in the mean serum level of liver enzymes (AST, ALT and ALP), total bilirubin (TB) and direct bilirubin (DB) were observed with a significant decrease (P ≤ 0.05) in the mean level of total protein (TP) and albumin (AB) in CCl 4induced rats compared to the standard (Group I) control (Table 3) .
Hepatocurative Effect of Aqueous Stem Bark

Extract of Cassia sieberiana in Rats
The aqueous stem bark extract of Cassia sieberiana had produced a dose-dependent and statistically significant (P ≤ 0.05) reduction in all parameters of liver function test in the treated groups compared to the negative control (CCl 4 -only treated). However, there is no statistically significant improvement in the deranged liver function parameters in the treated groups compared to the standard (normal saline only) control (Table 4 ).
Histological Analysis.
The results obtained from histopathological study is represented in Figure 1 through 5. Figure 1 shows a photomicrograph of cross section of a rat's liver in Group I. Figure 2 shows the liver of a rat induced with 150 mg/kg of CCl 4, Figure 3 , 4 and 5 show the liver of rats treated with graded doses of the extract (50, 100 and 150 mg/kg) for four weeks after induction with CCl 4. 
DISCUSSION
Phytochemicals exhibit a diverse physiological and pharmacological activities that includes disease preventive properties. The result obtained from phytochemical analysis of the Cassia sieberiana stem bark aqueous extract revealed high concentration of tannins, followed by saponins, alkaloids, cardiac glycosides and then flavonoids. These results agree with the findings of Aliyu, et al. (2013) , Donkor, et al. (2014) and Awomukwu, et al. (2015) who reported that the aqueous leaf extract of Cassia sieberiana revealed high concentration of tannins in Cassia sieberiana. However, the types and amount of phytochemicals obtained during an extraction process depends significantly on solvent used (Bello et al., 2016) . Hence the lower concentrations of cardiac glycosides, alkaloids and flavonoids does not means that they are low in the plant but probably because they are poorly soluble in aqueous solvent. Nevertheless, the presence of the phytochemical compound in the plant provide empirical basis for its traditional medicinal uses (Tella et al., 2005) . As such higher concentrations of tannins and saponins may be responsible for hepato-curative effect of the plant. Determination of LD 50 is usually the initial step in the evaluation of the toxic characteristics of a substance. It is aimed at estimating the toxicity profile of a compound following single exposure (Lorke, 1983) .
The result of the LD 50 of Cassia sieberiana aqueous bark extract does not show any sign of toxicity or mortality up to the maximum dose of a higher dose of 5000mg/kg. This shows that ASBEC is practically nontoxic to the rats. This agrees with the findings of Donkor, et al. (2014) who reported that the root of Cassia sieberiana shows no sign of toxicity.
Liver is an important organ in the body. It plays a key role in metabolic processes. Carbon tetrachloride (CCl 4 ) is a well-established hepatotoxin that acts via a highly reactive trichloromethyl radical generation that causes free radical-mediated lipid peroxidation (Alamgeer et al., 2017) of the cytoplasmic membrane phospholipids causing functional and morphological changes in the cell membrane which leads to accumulation of lipid derived oxidants causing liver injury (Obidah et al., 2009 ). These damages lead to the leakage of liver components (AST, ALP, ALT, total bilirubin, direct bilirubin) into the serum that are supposed to be contained within the hepatocytes, while at same time compromising the liver's synthesizing capacity (Donkor et al., 2014) as observed in decrease in serum levels of total protein (TB) and albumin (AB). Hence, this provides a good model for inducing liver damage. There was statistically significant reversal of the parameters of liver damage in dose dependent manner after ASBEC administration compared to the CCl 4 only treated group. The extract did not produce statistically significant reversal in the parameters of liver damage compared to the positive (normal saline treated) control. This shows that the plant has active metabolites with hepato-regenerative and/or hepatocurative activity. Condensed tannins have been suggested to have free radical scavenging and antioxidant activities (Pithayanukul et al., 2009 ) with anti-inflammatory property via cyclo-oxygenase 2 modulation (Smith et al., 2000) . Condensed tannins in ASBEC may be responsible for the hepatoprotective/hepatocurative activities observed. Similarly, saponins have been reported also to exhibit hepatoprotective activity via modulation of its antioxidant (Elekofehinti et al., 2012) and antiinflammatory activities (Akkol et al., 2007) .
CONCLUSION
The oral administration of aqueous stem bark extract of Cassia sieberiana shows a capacity for hepatocurative properties in rats. The presence of high concentrations of tannins and saponins in the ASBEC may be responsible for the hepato-curative effect observed.

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