Anti-hepatotoxic activities of Hibiscus sabdariffa L. in animal model of streptozotocin diabetes-induced liver damage
© Adeyemi et al.; licensee BioMed Central Ltd. 2014
Received: 2 April 2014
Accepted: 21 July 2014
Published: 30 July 2014
Flavonoid-rich aqueous fraction of methanolic extract of Hibiscus sabdariffa calyx was evaluated for its anti-hepatotoxic activities in streptozotocin-induced diabetic Wistar rats.
Diabetes Mellitus was induced in Wistar rats by a single i.p injection of 80 mg/kg b.w. streptozotocin (STZ) dissolved in 0.1 M citrate buffer (pH 6.3).
The ameliorative effects of the extract on STZ-diabetes induced liver damage was evident from the histopathological analysis and the biochemical parameters evaluated in the serum and liver homogenates. Reduced levels of glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) (3.76 ± 0.38 μM, 0.42 ± 0.04 U/L, 41.08 ± 3.04 U/ml, 0.82 ± 0.04 U/L respectively) in the liver of diabetic rats were restored to a near normal level in the Hibiscus sabdariffa -treated rats (6.87 ± 0.51 μM, 0.72 ± 0.06 U/L, 87.92 ± 5.26 U/ml, 1.37 ± 0.06 U/L respectively). Elevated levels of aspartate amino transferase (AST), alanine amino transferase (ALT) and alkaline phosphatase (ALP) in the serum of diabetic rats were also restored in Hibiscus sabdariffa -treated rats. Examination of stained liver sections revealed hepatic fibrosis and excessive glycogen deposition in the diabetic rats. These pathological changes were ameliorated in the extract-treated rats.
The anti-hepatotoxic activity of Hibiscus sabdariffa extract in STZ diabetic rats could be partly related to its antioxidant activity and the presence of flavonnoids.
KeywordsLiver Toxicity Diabetes mellitus Hibiscus sabdariffa Flavonoids Antioxidant
The liver plays a central and crucial role in the regulation of carbohydrate metabolism. Its normal functioning is essential for the maintenance of blood glucose levels and of a continued supply to organs that require a glucose energy source. In addition, it has great capacity to detoxify toxic substances and synthesize useful ones. Therefore, the damage which is caused by hepatotoxic agents is of grave consequence to the body as it deprives the liver of its principal functions. A significant amount of liver damage is induced by lipid peroxidation and other oxidative damages which are caused by the hepatotoxic chemicals[3, 4]. It has been reported that liver injury caused by a variety of deleterious agents induces inflammation, necrosis, fibrosis cirrhosis and functional deteriorations.
Diabetes is a chronic disease with a relatively high prevalence in many populations across the world. Diabetes is associated with several structural and functional liver abnormalities that affect glycogen and lipid metabolism[7–9]. Excess glycogen deposition, fibrosis, cirrhosis, steatohepatitis and Biliary disease in the liver has been reported in 55 – 80% of diabetic patients.
Plants used in traditional medicine for the treatment of liver disorders are of great interest, as they may serve as potential sources for new therapeutic agents that could be applied in the management and prevention of hepatic injuries. For example, plants rich in different phytochemical derivatives such as triterpenes, flavonoids or polyphenols, have been reported to exhibit antihepatotoxic effects in experimental liver-injury models induced by different types of hepatotoxicants, such as carbon tetrachloride, cadmium, galactosamine, acetaminophen and thioacetamide[11, 12].
Hibiscus sabdariffa (HS) (family: Malvaceae) has been reported as an ethnomedicinal remedy for a variety of ailments including hypertension, hyperlipidaemia, obesity, diabetes, Jaundice liver and urinary problems. It’s antihypertensive[14, 15] hypolipidaemic[16, 17] anti-obesity[18, 19] and anti-hyperglycemic[13, 17] effects have been confirmed in man and experimental animals and the possible mechanisms have also been delineated. Water-soluble extracts from Hibiscus sabdariffa L. contain several antioxidants, such as protocatechuic acid and anthocyanins[21, 22]. Recent studies have shown the potentials of these antioxidants in the protection of liver in chemically-induced peroxidative liver damage[22–24]. Hence this study investigates the potential anti-hepatotoxic properties of the flavonoid-rich extract of Hibiscus sabdariffa in animal model of streptozotocin diabetes- induced liver damage.
All chemicals used were of analytical grade. STZ was purchased from Sigma-Aldrich (St. Louis, MO, USA) Biochemical kits for AST, ALT and ALP assay were purchased from Randox laboratory (Crumlin, Co. Antrim, UK); Biochemical kits for catalase, GSH, GPx and TBARS assay were purchased from Bio Assay System (Hayward, CA 94545 USA) while kit for SOD assay was purchased from Cell technology Inc (Mountain View, CA 94043). Other histological reagents and stains were purchased from Sigma-Aldrich (St. Louis, MO, USA).
Healthy Wistar rats (200 – 250 g) of either sex obtained from the animal holding facility of the College of Healthy Sciences, Obafemi Awolowo University Ile-Ife were used for the experiment. They were maintained under standard environmental conditions of temperature, humidity and light and fed on standard rat pellets (Ladokun feeds, Ibadan, Nigeria) and water ad libitum. The animals were acclimatized to the laboratory for four weeks prior to the start of the experiment. The rats received humane care according to the USA’s National Institute of Health’s Guide for the Care and Use of Laboratory Animals and their experimental use was approved by the animal Ethics Committee of Obafemi Awolowo University Ile Ife.
The animals were randomly assigned into five groups A, B, C, D and E of twelve rats each. Group A was normal control (normoglycemic rats), group B was test group I (normoglycemic rats treated with Hibiscus sabdariffa calyx extract (HSCE)); group C was diabetic negative control (untreated diabetic rats given STZ as described in “Induction of Experimental Diabetes” section); group D was test group II (diabetic rats treated with HSCE); while group E was diabetic positive control (diabetic rats treated with protamin zinc insulin).
Matured calyxes of H. sabdariffa obtained from a local market in Ile-Ife, Nigeria were authenticated at the Forestry Research Institute of Nigeria (FRIN), Ibadan and a voucher specimen (FHI 107622) was submitted to the FRIN Herbarium for future reference.
Dried and pulverized calyxes of H. sabdariffa (200 g) were extracted three times with 70% methanol (500 mls × 3) with continuous stirring at room temperature for 24 hours each. The extract was concentrated in vacuo at 25°C using a vacuum rotary evaporator (RE 100B, Bibby Sterilin, United Kingdom) and the aqueous phase was partitioned with ethyl acetate (EtOAc). The aqueous fraction (coded HSCE) was freeze dried using a vacuum freeze drier (FT33- Armfield, England) and used for the experiment. Solvent elimination under reduced pressure and subsequent freeze-drying gave 11.75 g (i. e., 5.875% yield) of a dark red, powdery extract.
The following phytochemical analysis was carried out on leaves of Hibiscus sabdariffa using the procedure of as outlined below:
Test for flavonoids
0.5 g of plant sample was suspended in 5 ml of water and 2.5 ml of methanol was added to it and filtered. 1 ml of NaOH 10% was added to 1 ml of the filtrate. The presence of a yellow precipitate indicated the presence of flavonoids.
Test for tannins
7.5 ml of water was added to plant extract (1 g) and heated in a water bath. It was then filtered upon cooling. Few drops of iron III chloride (FeCl3) 0.5% were added to 2 ml of the filtrate. The appearance of a green or dark-blue precipitate indicated the presence of tannins.
Test for alkaloids
2 g of plant sample was heated in a test tube containing 25 ml of HCl (1%) for 15 min in a boiling water bath. The suspension was then filtered and 5 drops of Meyer's reagent (potassium tetra iodomecurate) were added into the filtrate (1 ml). The formation of a precipitate indicated the presence of alkaloids.
Test for saponins
0.5 g of plant extract was introduced into a test tube containing 7.5 ml of distilled water and the mixture heated for 5 min in a boiling water bath. The solution was then filtered and cooled to room temperature. Five millilitres of the filtrate was introduced into a test tube and agitated for 10 s. The formation of persistent foam indicated the presence of saponins.
Test for triterpenes and steroids
0.5 g of plant sample was dissolved in chloroform (3 ml) and a few drops of acetic anhydride and concentrated H2SO4 were added. A purple coloration indicated the presence of triterpenes while bluish-green coloration indicated the presence of steroids. The formation of two layers upon addition of H2SO4 is characteristic of the presence of both triterpenes and steroids.
Test for coumarins
One milligram of moistened sample was placed in a test tube and the test tube was covered with a filter paper moistened with 10% NaOH solution. After exposition of the paper to UV light for a few minutes, yellow green fluorescence was indicative of the presence of coumarins
Acute toxicity study
Rats fasted for 16 h were randomly divided into seven groups of five rats each. One group served as control and received 0.3 mls of distilled water orally. The other groups (test groups) were treated with graded doses of HSCE; 200, 400, 800, 1600, 3200 and 6400 mg kg-1 dissolved in distilled water orally. Signs of toxicity (convulsion, hypoactivity, weakness, ataxia and salivation) and mortality in each cage were assessed 24 hours, 48 hours and 72 hours after administration of extract. LD50 of HSCE was determined in the rats using method of Abdel-Barry et al..
Induction of experimental diabetes
Animals were fasted (but still allowed access to water) for 16 hours prior to induction. Diabetes mellitus was induced in groups C,D and E rats by a single i.p. injection of 80 mg/kg bw STZ dissolved in 0.1 M sodium citrate buffer (pH 6.3) as previously reported[28, 29]. Group A rats were injected with equivalent volumes of citrate buffer i.p.
Administration of drugs
Four weeks post induction of diabetes, daily doses of 1750 mg/kg bw HSCE was administered orally to the rats in test groups I and II (groups B and D) for 15 days by gavage while 1 IU/kg/day of protamine zinc insulin was administered i.p. to group E rats (diabetic positive control). Rats in group C (diabetic negative control) were left untreated.
Terminal sacrifice procedures
A mid-line incision was made through the anterior abdominal walls of the rats under terminal chloroform anaesthesia. The liver tissues were excised and weighed. Some of the liver tissues were fixed in in 10% formol saline for 48 hours for histological procedures, some fixed in Bouin’s fixative for 24 hours for histochemical procedure while other parts were frozen for biochemical assay.
Determination of liver weight
Liver tissues fixed in 10% formol saline were processed via paraffin wax embedding method. Sections of 5 μm thickness produced were stained with haematoxylin and eosin (HE) for general histological examination of the liver tissues, Gordon and Sweets reticulin stain (GSR) to histologically demonstrate reticulin fibres in the liver and with Masson trichrome stain (MT) to histologically demonstrate collagen fibres in liver. The sections were examined under Leica DM750 research microscope with a digital camera (Leica ICC50) attached. Digital photomicrographs were taken at various magnifications.
The tissues fixed in Bouin’s fixative were processed via paraffin wax embedding. Sections of 5 μm thickness produced were stained with periodic acid Schiff (PAS) with diastase control to histochemically demonstrate glycogen in the liver sections. Digital photomicrographs were also taken after examination under Leica DM750 research microscope
Assay for liver function markers
Blood samples were obtained from the rats by cardiac puncture at sacrifice and were kept for 30 min at room temperature. Serum was separated from the blood samples by centrifugation at 5000 rpm for 10 min at room temperature. Serum marker of liver function such as such as aspartate amino transferase (AST) alanine amino transferase (ALT) and alkaline phosphatase (ALP) as well as serum total proteins (TP) and albumin (ALB) were estimated spectrophotometrically, using enzymatic colorimetric assay kits (Randox, Northern Ireland) following standard methods.
Preparation of tissue homogenates
The excised livers were cut into separate portions for estimation of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPX), glutathione (GSH) and thiobarbituric reactive subatances (TBARS). Tissues were rinsed in ice rinsed in ice-cold phosphate buffered saline pH 7.4. The tissues were then homogenized at 4°C in five volumes of homogenizing buffer per gram of tissue using a motor driven glass-Teflon Potter-Elvejhem homogenizer. The homogenizing buffer for CAT and GPX assay contained 50 mM tris HCl pH 7.5, 5 mM EDTA and 1 mM dithiotreitol (DTT); SOD assay homogenizing buffer contained 50 mM sucrose, 200 mM mannitol and 1 mM EDTA prepared in 10 mM Tris buffer pH 7.4.; GSH assay homogenizing buffer contained 50 mM potassium phosphate (PH 7.0) and 1 mM EDTA while the homogenizing buffer for TBARS Assay was a radio-immuno precipitation assay (RIPA) buffer which contained 150 mM sodium chloride, 50 mM tris buffer pH 8.0, 1.0% triton X-100, 0.1% sodium duodecyl sulphate (SDS) and 0.5% sodium deoxycholate. The homogenates were centrifuged in Harrier 15/80 MSE ultracentrifuge at 13,000 rpm for 15 minutes to obtain the supernatant.
Biochemical assay for antioxidants and lipid peroxidation markers
The activities of CAT, SOD and GPX as well as the concentration of GSH and TBARS were determined in the resulting supernatants by a 96-well microplate-based assay using their specific quantitative colorimetric detection kits following manufacturers manual. Assay for catalase activity was based on catalase degradation of hydrogen peroxide using a redox dye; the activity of glutathione peroxidase was measured in the tissue homogenates by measuring NADPH consumption in the enzyme-coupled reaction; the activity of SOD was measured using sensitive colorimetric SOD assay kit which utilizes water soluble tetrazolium salt (WST-1) that produces a water-soluble formazan dye upon reduction with superoxide anion; concentration of glutathione was measured based on the reaction of 5, 5’- dithiobis 2-nitrobenzoic acid (DTNB) with reduced glutathione to form a yellow product while TBARS assay was based on the reaction of TBARS with thiobarbituric acid (TBA) to form a pink coloured product.
All values were presented as mean ± standard error of mean (SEM) for twelve rats in each of the five group of rats. The significance of difference in the means of all parameters was determined using one-way analysis of variance (ANOVA; 95% confidence interval). Dunnett multiple comparison (DMC) and Student Newman-Keul’s (SNK) post hoc tests were carried out for comparison of all groups with control and comparison of all pairs of groups respectively. All statistics were carried out in GraphPad Prism. Values of p < 0.05 were considered as significant.
No sign of toxicity was observed in all groups of animals tested within 72 hours. The LD50 of H. Sabdariffa in Wistar rats was found to be 3200 mg kg-1.
Effects of HSCE on liver weight
Effects of H. Sabdariffa on body weight and liver weight
Body weight (g)
Absolute liver weight (g)
Relative liver weight (%)
A (normal control)
181.92 ± 6.49†
7.83 ± 0.64†
4.31 ± 0.33†
B (Test I)
179.75 ± 7.11†
7.93 ± 0.68†
4.41 ± 0.35†
C (Diabetic -ve control)
141.58 ± 3.33*‡
5.17 ± 0.51*‡
3.66 ± 0.29†
D (Test II)
168.17 ± 6.15†
7.02 ± 0.57*§
4.17 ± 0.32†
E (Diabetic + ve control)
139.41 ± 2.55*‡
5.08 ± 0.43*‡
3.64 ± 0.31†
Effects of HSCE on liver function markers
Effects of H. Sabdariffa on the liver function markers
A (normal control)
11.38 ± 2.46†
10.72 ± 1.64†
85.13 ± 7.08†
B (Test I)
12.05 ± 2.36†
10.63 ± 0.33†
78.62 ± 5.28†
C (Diabetic -ve control)
45.72 ± 5.28*‡
54.05 ± 5.03*‡
181.94 ± 12.12*‡
D (Test II)
14.68 ± 1.64†
12.08 ± 2.42†
103.21 ± 6.98*§
E (Diabetic + ve control)
37.33 ± 5.15*§
43.12 ± 4.16*§
149.06 ± 9.12*‡
Effects of HSCE on serum proteins
Effects of H. Sabdariffa on the serum proteins
Total protein (g/dl)
A (normal control)
8.19 ± 0.36†
4.26 ± 0.42†
3.93 ± 0.31†
1.08 ± 0.18†
B (Test I)
8.25 ± 0.26†
4.05 ± 0.18†
4.20 ± 0.26†
0.96 ± 0.21†
C (Diabetic -ve control)
13.28 ± 0.68*‡
4.12 ± 0.79†
9.16 ± 0.56*‡
0.49 ± 0.06*‡
D (Test II)
7.95 ± 0.19†
3.86 ± 0.24†
4.09 ± 0.41†
0.95 ± 0.11†
E (Diabetic + ve control)
8.21 ± 0.15†
3.93 ± 0.65†
4.28 ± 0.12†
0.92 ± 0.13†
Effects of HSCE on liver antioxidants
Effects of H. Sabdariffa on the liver antioxidants and lipid peroxidation markers
TBARS (μM MDA)
A (normal control)
1.04 ± 0.07†
1.71 ± 0.06†
101.42 ± 6.11†
8.97 ± 0.71†
7.79 ± 0.72†
B (Test I)
1.09 ± 0.06†
1.67 ± 0.08†
95.04 ± 6.56†
7.78 ± 0.67†
7.12 ± 0.46†
C (Diabetic -ve control)
0.42 ± 0.04*‡
0.86 ± 0.06*‡
41.08 ± 3.04*‡
3.76 ± 0.38*‡
17.56 ± 1.02*§
D (Test II)
0.72 ± 0.06*§
1.37 ± 0.06*§
87.92 ± 5.26§
6.87 ± 0.51†
8.63 ± 0.65†
E (Diabetic + ve control)
0.37 ± 0.03*‡
0.97 ± 0.05*‡
46.58 ± 3.57*‡
3.26 ± 0.39*‡
11.56 ± 0.73*‡
Effects of HSCE on lipid peroxidation
The concentration of TBARS, a marker of lipid peroxidation was significantly higher (p < 0.05) in the liver of diabetic negative control rats than in normoglycemic rats (Table 4). However HSCE treatment lowered the level of TBARS significantly (p < 0.05) in the treated rats.
Histopathological assessment of the liver
Diabetes mellitus is associated with progressive metabolic derangement, worsening glycaemic control and morphological changes in the kidney, retina, liver, pancreas and other organs[38, 39]. Oxidative stress is known to play a significant role in the induction of these processes. A number of studies both in vitro and in vivo had shown that extracts of the calyx of H. sabdariffa has potent antioxidant activity[41, 42]. This potent antioxidation is thought to form the basis of many of the other healing activities of HSCE including its hepatoprotective activities. Compounds proven to have this antioxidant activity include anthocyanins and protocatechuic acid.
The results of this study showed a significant increase in lipid peroxidation in the liver of STZ diabetic rats. This confirms the earlier report on the ability of this diabetogenic compound to induce oxidative damage through generation of free radicals. The increase in lipid peroxidation in the liver may be due to the fact that it contains relatively high concentration of easily peroxidizable fatty acid. Administration of methanolic extract of H. sabdariffa reduced MDA, a marker of lipid peroxidation in the liver of diabetic rats suggesting that the extract possesses potent antioxidative properties. The present results are consistent with the report of previous researchers who earlier reported antioxidant effect of extracts from H. sabdariffa.
In this study, a marked decrease in the activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) in the liver of untreated diabetic rats were observed. The functions of these antioxidant enzymes are interconnected and a decrease of their activities results in the accumulation of lipid peroxides and increases oxidative stress in diabetic rats. Treatment of rats with extracts of H. sabdariffa ameliorated the STZ-induced decrease in the concentration of GSH as well as the activities of GPx, SOD and CAT. The results, therefore, lend support to the antioxidant properties of H. sabdariffa as demonstrated in both in vitro and various in vivo models[41, 46].
Hepatic cellular degeneration, degeneration of reticular fibres as shown in the silver impregnated liver section (Figure 2) and build up of collagen fibres as shown in the liver sections stained for presence of collagen (Figure 3) revealed the presence of hepatic fibrosis in the liver of STZ-diabetic rats and the insulin treated diabetic rats. The PAS stained sections also revealed an excessive accumulation of glycogen in the liver of the diabetic rats (Figure 4). However, there was restoration of the normal liver morphology in the H. sabdariffa – treated diabetic rats. This was shown by a regeneration of reticular fibres as well as reduction in the collagen staining in the liver section of the extract-treated rats. Also, PAS – stained liver section of this group of rats’ reveled glycogen staining that is comparable with that of the normal rats. Histopathological evaluation of the liver of these rats also revealed that H. sabdariffa extract also reduced the incidence of liver lesions, including hepatocyte swelling and necrosis induced by STZ.
Hepatic fibrosis is present in various chronic hepatic diseases. It is well known that constant fibrosis can lead to the development of hepatocellular carcinoma[47, 48]. Interrupting and/or reversing hepatic fibrosis may well be a new approach for improving its progression to hepatocellular carcinoma. However, the therapy for reversing liver fibrosis is not yet well established. This study demonstrated that H. sabdariffa extract had therapeutic effects on hepatic fibrosis secondary to diabetes induced by STZ in rats. The beneficial effects of H. sabdariffa extract in the treatment of chemically-induced fibrosis were evident in liver pathology, as evidenced by decreased severity of the liver morphological changes and fibrosis, generalized improvement of some types of pathological lesions such as fatty liver and cellular degeneration, and reduced hepatic collagen fiber staining. These ameliorative effects of H. sabdariffa extract may be mediated by inhibition of hepatic stellate cell activation. In accord with the preventive effects of H. sabdariffa extract’s components during the development of chemically induced hepatic damage[20, 21, 43, 49] the present study shows that H. sabdariffa extract is effective in the amelioration of STZ-induced liver fibrosis, which would confer a highly significant therapeutic advantage. Hibiscus sabdariffa extract is a composite of several antioxidants, such as protocatechuic acid[20, 50] and anthocyanins[21, 22] which prevents peroxidative liver damage.
The activities of AST, ALT and APL increased significantly in diabetic rats in agreement with previous findings. The extract of H sabdariffa significantly reduced the activities of AST and ALT in these rats. This finding is consistent with the finding of Ubani et al. who earlier reported that extract of H. sabdariffa lowered the activities of these liver marker enzymes in phenobarbitone induced rats.
In conclusion, this study demonstrated the potentials of Hibiscus sabdariffa extract in ameliorating the biochemical and histological changes in the liver of Wistar rats following experimental induction of diabetes mellitus in these rats using STZ. The ameliorative activity of Hibiscus sabdariffa extract in the liver of STZ diabetic rats could be partly related to its antioxidant activity and the presence of flavonnoids.
Hibiscus sabdariffa calyx extract
Thiobarbituric acid reactive substances
Aspartate amino transferase
Alanine amino transferase
Periodic acid schiff.
The first Author is grateful to the authorities of Obafemi Awolowo University Ile Ife for providing laboratory space and equipments for the research, Prof. C.A. Adebajo, department of Pharmacognosy for his useful suggestions and comment and to Mr Emiola Gbela (retired Chief Technologist, Department of Morbid anatomy and Forensic Medicine) for his technical assistance in the production of the microscopic slides.
- Levinthal GN, Tavill AS: Liver disease and diabetes mellitus. Clin Diabetes. 1999, 17 (2): 73-93.Google Scholar
- Subramoniam A, Pushpangadan P: Development of phytomedicine for liver diseases. Ind J Pharmacol. 1999, 31: 166-175.Google Scholar
- Muhtaseb MS, El Talwar D, Duncan A, St J, O'reilly D, Mckee RF, Anderson JH, Foulisa FIG: Free radical activity and lipid soluble anti-oxidant vitamin status in patients with long-term ileal pouch-anal anastomosis. Colorectal Dis. 2008, 11: 67-72.View ArticlePubMedGoogle Scholar
- Appiah I, Milovanovic S, Radojicic A, Nikolic-Kokic A, Orescanin-Dusic Z, Slavic M, Trbojevic S, Skrbic R, Spasic MB, Blagojevic D: Hydrogen peroxide affects contractile activity and anti-oxidant enzymes in rat uterus. Br J Pharmacol. 2009, 158: 1932-1941.View ArticlePubMedPubMed CentralGoogle Scholar
- Ishibashi H, Nakamura M, Komori A, Migita K, Shimoda S: Liver architecture, cell function, and disease. Semin Immunopathol. 2009, 31: 399-409. 10.1007/s00281-009-0155-6.View ArticlePubMedGoogle Scholar
- Jerrold MO: Diabetes Mellitus. Cecil Text Book of Medicine. 2000, WB Saunders, 1292-1293.Google Scholar
- Sanchez SS, Abregu AV, Aybar MJ, Sanchez Riera AN: Changes in liver gangliosides in streptozotocin-induced diabetic rats. Cell Biol Int. 2000, 24: 897-904. 10.1006/cbir.1999.0452.View ArticlePubMedGoogle Scholar
- Bolkent S, Yanardag R, Karabulut-Bulan O, Ozsoy-Sacan O: The morphological and biochemical effects of glibornuride on rat liver in experimental diabetes. Hum Exp Toxicol. 2004, 23: 257-264. 10.1191/0960327104ht444oa.View ArticlePubMedGoogle Scholar
- Koyuturk M, Tunali S, Bolkent S, Yanardag R: Effects of vanadyl sulfate on liver of streptozotocin-induced diabetic rats. Biol Trace Elem Res. 2005, 104: 233-247. 10.1385/BTER:104:3:233.View ArticlePubMedGoogle Scholar
- Stone BE, VanThiel DH: Diabetes mellitus and the liver. Sem Liver Dis. 1985, 5: 8-28. 10.1055/s-2008-1041754.View ArticleGoogle Scholar
- Iwu MM, Igboko OA, Elekwa OK, Tempesta MS: Prevention of thioacetamide-induced hepatotoxicity by biflavanones of Garcinia kola. Phytother Res. 1990, 4: 157-159. 10.1002/ptr.2650040407.View ArticleGoogle Scholar
- Dwivedi Y, Rastogi R, Garg NK, Dhawan BN: Perfusion with picroliv reverses biochemical changes induced in livers of rats toxicated with galactosamine or thioacetamide. Planta Med. 1993, 59: 418-420. 10.1055/s-2006-959722.View ArticlePubMedGoogle Scholar
- Lans CA: Ethnomedicines used in Trinidad and Tobago for urinary problems and diabetes mellitus. J Ethnobiol Ethnomed. 2006, 2: 45-10.1186/1746-4269-2-45.View ArticlePubMedPubMed CentralGoogle Scholar
- Ajay M, Chai HJ, Mustafa AM, Gilani AH, Mustafa MR: Mechanisms of the antihypertensive effect of Hibiscus sabdariffa L. calyces. J Ethnopharmacol. 2007, 109 (3): 388-393. 10.1016/j.jep.2006.08.005.View ArticlePubMedGoogle Scholar
- Herrera Arellano A, Miranda Sánchez J, Avila Castro P, Herrera Alvarez S, Jiménez Ferrer JE, Zamilpa A, Román Ramos R, Ponce Monter H, Tortoriello J: Clinical effects produced by a standardized herbal medicinal product of Hibiscus sabdariffa on patients with hypertension. A randomized, double blind, lisinopril controlled clinical trial. Planta Med. 2007, 73 (1): 6-12. 10.1055/s-2006-957065.View ArticlePubMedGoogle Scholar
- Hirunpanich V, Utaipat A, Morales NP, Bunyapraphatssara N, Sato H, Herunsale A, Suthisisang C: Hypocholesterolemic and antioxidant effects of aqueosus extracts from the dried calyx of Hibiscus sabdariffa L. in hypercholesterolemic rats. J Ethnopharmacol. 2006, 103: 252-260. 10.1016/j.jep.2005.08.033.View ArticlePubMedGoogle Scholar
- Farombi EO, Ige OO: Hypolipidaemic and antioxidant effects of ethanolic extract from dried calyx of Hibiscus sabdariffa in alloxan-induced diabetic rats. Fundam Clin Pharmacol. 2007, 21 (6): 601-609. 10.1111/j.1472-8206.2007.00525.x.View ArticlePubMedGoogle Scholar
- Alarcon Aguilar FJ, Zamilpa A, Perez Garcia MD, Almanza Perez JC, Romero NE, Campos Sepulveda EA, Vazquez Carrillo LI, Roman RR: Effect of Hibiscus sabdariffa on obesity in MSG mice. J Ethnopharmacol. 2007, 114 (1): 66-71. 10.1016/j.jep.2007.07.020.View ArticlePubMedGoogle Scholar
- Kim JK, So H, Youn MJ, Kim HJ, Kim Y, Park C, Kim SJ, Ha YA, Chai KY, Kim SM, Kim KY, Park R: Hibiscus sabdariffa L. water extract inhibits the adipocyte differentiation through the PI3K and MAPK pathway. J Ethnopharmacol. 2007, 114 (2): 260-267. 10.1016/j.jep.2007.08.028.View ArticlePubMedGoogle Scholar
- Liu CL, Wang JM, Chu CY, Cheng MT, Tseng TH: In-vivo protective effect of protocatechuic acid on tert-butyl hydroperoxide-induced rat hepatotoxicity. Food Chem Toxicol. 2002, 40 (5): 635-641. 10.1016/S0278-6915(02)00002-9.View ArticlePubMedGoogle Scholar
- Wang CJ, Wang JM, Lin WL, Chu CY, Chou FP, Tseng TH: Protective effect of Hibiscus anthocyanins against tertbutyl hydroperoxide-induced hepatic toxicity in rats. Food Chem Toxicol. 2000, 38 (5): 411-416. 10.1016/S0278-6915(00)00011-9.View ArticlePubMedGoogle Scholar
- Ali BH, Mousa HM, El-Mougy S: The effect of a water extract and anthocyanins of Hibiscus sabdariffa L. on paracetamol-induced hepatoxicity in rats. Phytother Res. 2003, 17 (1): 56-59. 10.1002/ptr.1084.View ArticlePubMedGoogle Scholar
- Olaleye MT, Joäo-Rocha BT: Acetaminophen-induced liver damage in mice: Effects of some medicinal plants on the oxidative defense system. Exp Toxicol Pathol. 2008, 59 (5): 319-329. 10.1016/j.etp.2007.10.003.View ArticlePubMedGoogle Scholar
- Choi JH, Chul YC, Lee KJ, Hwang PL, Chung YC, Jeong HG: Hepatoprotective effects of an anthocyanin fraction from purple-fleshed sweet potato against acetaminophen-induced liver damage in mice. J Med Food. 2009, 12 (2): 320-326. 10.1089/jmf.2007.0691.View ArticlePubMedGoogle Scholar
- National Research Council (NRC) Institute of Laboratory Animal Research (ILAR): Guide for the Care and Use of Laboratory Animals. 1996, Washington DC: National Academy Press, 259-7Google Scholar
- Wangchuk P, Keller PA, Pyne SG, Taweechotipatr M, Tonsomboon A, Rattanajak R, Kamchonwongpaisan S: Evaluation of an ethnopharmacologically selected Bhutanese medicinal plants for their major classes of Phytochemicals and biological activities. J Ethnopharmacol. 2011, 137: 730-742. 10.1016/j.jep.2011.06.032.View ArticlePubMedGoogle Scholar
- Abdel-Barry JA, Al-Hakiem MHH, Abdel-Hassan IA: Acute intraperitoneal toxicity (LD50) and target organ effects of aqueous extract of Trigonella foenumgraceum leaf in the mouse. Basrah J Sci. 1997, 58: C58-C65.Google Scholar
- Adeyemi DO, Komolafe OA, Adewole OS, Obuotor EM, Adenowo TK: Antihyperglycaemic activities of Annona muricata (Linn) Afr. J Trad CAM. 2009, 6 (1): 62-69.Google Scholar
- Adeyemi DO, Komolafe OA, Adewole OS, Obuotor EM, Abiodun AA, Adenowo TK: Histomorphological and morphometric studies of the pancreatic islet cells of diabetic rats treated with extracts of Annona muricata. Folia Morphol. 2010, 69 (2): 92-100.Google Scholar
- Drury RAB, Wallington EA: Carleton's Histological Technique. 1980, Oxford: Oxford University Press, 5Google Scholar
- Gordon H, Sweet HH: A simple method for the silver impregnation of reticulin. Am J Pathol. 1936, 12: 545-View ArticlePubMedPubMed CentralGoogle Scholar
- Cowell DC, Dowman AA, Lewis RJ, Pirzad R, Watkins SD: The rapid potentiometric detection of catalase positive microorganisms. Biosens Bioelectron. 1994, 9 (2): 131-138. 10.1016/0956-5663(94)80104-5.View ArticlePubMedGoogle Scholar
- Pascual P, Martinez-Lara E, Bárcena JA, López-Barea J, Toribio F: Direct assay of glutathione peroxidase activity using high- performance capillary electrophoresis. J Chromatogr B Biomed Sci Appl. 1992, 581: 49-56. 10.1016/0378-4347(92)80446-W.View ArticleGoogle Scholar
- Malstrom B, Andreasson L, Reinhammer B: The Enzymes”. Edited by: Byer P. 1975, New York: XIIB, Academic Press, 533-Google Scholar
- Blenn C, Althaus FR, Malanga M: Poly (ADP-ribose) glycohydrolase silencing protects against H2O2-induced cell death. Biochem J. 2006, 396: 419-429. 10.1042/BJ20051696.View ArticlePubMedPubMed CentralGoogle Scholar
- Ohkawa H, Ohishi N, Yagi K: Assay for lipid peroxides in animal tissues by thiobarbituric acid reaction. Anal Biochem. 1979, 95: 351-358. 10.1016/0003-2697(79)90738-3.View ArticlePubMedGoogle Scholar
- Betty RK, Jonathan AC: Essential Medical Statistics. 2003, USA: Blackwell science, 15-409. 2Google Scholar
- Cook MN, Girman CJ, Stein PP, Alexander CM, Holman RR: Glycaemic control continues to deteriorate after sulfonylureas are added to metformin among patients with type 2 diabetes. Diabetes Care. 2005, 28: 995-1000. 10.2337/diacare.28.5.995.View ArticlePubMedGoogle Scholar
- Cristina L, Roberto L, Stefano DP: β-cell failure in type 2 diabetes mellitus. Curr Diab Rep. 2008, 8: 179-184. 10.1007/s11892-008-0031-0.View ArticleGoogle Scholar
- Baynes JW, Thorpe SR: The role of oxidative stress in diabetic complications. Curr Opin Endocrinol. 1999, 3: 277-284.View ArticleGoogle Scholar
- Farombi EO, Fakoya A: Free radical scavenging and antigenotoxic activities of natural phenolic compounds in dried flowers of Hibiscus sabdariffa L. Mol Nutr Food Res. 2005, 49 (12): 11208-View ArticleGoogle Scholar
- Sáyago-Ayerdi SG, Goñi I: Hibiscus sabdariffa L: source of antioxidant dietary fiber. Arch Latinoam Nutr. 2010, 60 (1): 79-84.PubMedGoogle Scholar
- Liu LC, Wang CJ, Lee CC, Su SC, Chen HL, Hsu JD, Lee HJ: Aqueous extract of Hibiscus sabdariffa L. decelerates acetaminophen-induced acute liver damage by reducing cell death and oxidative stress in mouse experimental models. J Sci Food Agric. 2010, 90: 329-337. 10.1002/jsfa.3821.View ArticlePubMedGoogle Scholar
- Szkudelski T: The Mechanism of Alloxan and Streptozotocin Action in B cells of the Rat Pancreas. Physiol Res. 2001, 50: 536-546.Google Scholar
- Panneerselvam SR, Govindasamy S: Effect of sodium molybdate on the status of lipids, lipid peroxidation and antioxidant systems in alloxan-induced diabetic rats. Clin Chim Acta. 2004, 345: 93-98. 10.1016/j.cccn.2004.03.005.View ArticlePubMedGoogle Scholar
- Tseng TH, Kao ES, Chu CY, Chou FP, Lin Wu HW, Wang CJ: Protective effects of dried flower extracts of Hibiscus sabdariffa L. against oxidative stress in rat primary hepatocytes. Food Chem Toxicol. 1997, 35 (12): 1159-1164. 10.1016/S0278-6915(97)85468-3.View ArticlePubMedGoogle Scholar
- Nissen NN, Martin P: Hepatocellular carcinoma: the high risk patient. J Clin Gastroenterol. 2002, 35 (Suppl. 2): S79-S85.View ArticlePubMedGoogle Scholar
- Okita K, Sakaida I, Hino K: Current strategies for chemoprevention of hepatocellular carcinoma. Oncology. 2002, 62 (Suppl. 1): 24-28. 10.1159/000048272.View ArticlePubMedGoogle Scholar
- Liu JY, Chen CC, Wang WH, Hsu JD, Yang MY, Wang CJ: The protective effects of Hibiscus sabdariffa extract on CCl4-induced liver fibrosis in rats. Food Chem Toxicol. 2006, 44: 336-343. 10.1016/j.fct.2005.08.003.View ArticlePubMedGoogle Scholar
- Tseng TH, Wang CJ, Kao ES, Chu HY: Hibiscus protocatechuic acid protects against oxidative damage induced by tert-butylhydroperoxide in rat primary hepatocytes. Chem Biol Interact. 1996, 101 (2): 137-148. 10.1016/0009-2797(96)03721-0.View ArticlePubMedGoogle Scholar
- Hamden K, Ayadi F, Jamoussi K: Hatem Masmoudi and Abdelfattah Elfeki Therapeutic effect of phytoecdysteroids rich extract from Ajuga iva on alloxan induced diabetic rats liver, kidney and pancreas. Bio Factors. 2008, 33: 165-175.Google Scholar
- Ubani CS, Joshua PE, Anieke UC: Effects of aqueous extract of Hibiscus sabdariffa L. calyces on liver marker enzymes of phenobarbitone-induced adult wistar albino rats. J Chem Pharm Res. 2011, 3 (4): 528-537.Google Scholar
- The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1472-6882/14/277/prepub
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.