Preliminary Phytochemical and Hepatoprotective Studies on Turnip Brassica...

[Full title: Preliminary Phytochemical and Hepatoprotective Studies on Turnip Brassica rapa L.]

Life International Journal of Pharmacology ISSN 1811-7775 Life science alert ansinet Asian Network for Scientific Information

International Journal of Pharmacology 2(6): 670-673, 2006 ISSN 1811-7775 2006 Asian Network for Scientific Information Preliminary Phytochemical and Hepatoprotective Studies on Turnip Brassica rapa L. 'Syed Rafatullah, Mohammed Al-Yahya, Jaber Mossa, 'Ahmed Galal and Kamal El-Tahir Medicinal, Aromatic and Poisonous Plants Research Center, Department of Pharmacognosy, *Department of Pharmacology, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh-11451, Saudi Arabia Abstract: In the present study, the pre-treatment of rats with Turnip (Brassica rapa L.). juice protected the animals against CCL-induced hepatotoxicity. The treatment significantly reduced the serum GOT, GPT, alkaline phosphatase (ALP) and bilirubin level at a dose of 16 mL kg body weight. Besides, the juice also replinished the lowered nonprotein sulfhydryl (NP-SH) concentration in the liver tissue after CCL treatment. The preliminary phytochemical screening showed the presence of flavonoids, anthocyamins and sulfur containing constituents. The present results reveal that turnip possesses a hepatoprotective action, through its antioxidative potentials. Key words: Tumip, Brassica rapa, phytochemical screening, hepatoprotection INTRODUCTION The liver is an organ of paramount importance. It plays a pivotal role in the metabolism of xenobiotics (foreign compounds entering the body) (Rajesh and Latha, 2004). Herbal medicines have received great altention as an alternative to conventional therapy and the demand for these remedies has currently increased (De Smet, 2002). Consumption of herbs and vegetables is known to benefit life via the prevention of style-related diseases including liver disorders. Plants of the genus Brassica belong to the family Brassicaceae and include several of the most. commonly consumed vegetables all over the world (Focciolo. 1988). The commonly consumed species include turnip Brassica rapa locally known as Lifft or Shaljam, which is used as a vegetable. Turnip is medicinally used as an antiscorbutic, antiarthritic, resolvent and stimulant. It is also used as a stomachic and laxative (Chopra et al., 1956). It is known in the Unani and Arab traditional medicine for its use in chronic gastritis, constipation, cholecystitis, cholecystolithiasis and in liver diseases (Pithford, 2002). Hartwell (1971) reported that it is a remedy for cancer. In this communication, we present the results of preliminary phytochemical screening and the antihepatotoxic and antioxidative effects of B. rapa on carbon tetrachloride (CCL)-induced liver damage in rats. MATERIALS AND METHODS Juice preparation: Fresh turnip was purchased from a local vegetable market in Riyadh, Kingdom of Saudi Arabia and identified. The pink bulbs/rools were washed, soaked by blotting paper, then squeezed in an electrical blender to obtain the juice. Animals: Wistar albino rats, of either sex and approximately the same age (8-10 weeks), weighing 180-200 g. obtained from the Experimental Animal Care Center, College of Pharmacy, King Saud University, Riyadh were used. Swiss albino mice were used for studies of sleeping time. The amimals were kept at a constant temperature (22-2°C), humidity (55%) and lightdark conditions (12/12 h light/dark ratio). The animals were provided with Purina chow and free access to drinking water ad libitum. The conduct of experiments and the procedure of sacrifice (using ether) were approved by the Ethics Committee of the Experimental Animal Care Society, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia. Phytochemical screening: A phytochemical analysis of the underground parts of turnip was conducted for the detection of alkaloids, cardiac glycosides, flavonoids, tannins, anthraquinones, saponins, volatile oil, cyanogenic glycosides, coumarins, sterols, triterpenes and sulphur containing compounds (Farnsworth, 1966). Carbon tetrachloride-induced liver toxicity: Rats were divided into five groups (I, II, III, IV and V) (N 6 animals/group). Group I was kept as a control group. Groups II, III, IV and V received 0.25 mL of CC₁ in liquid paraffin (1:1) 100 g body weight intraperitoneally (Sen et al., 1993). Group III was administered silymarin Corresponding Author: Dr. Syed Rafatullah, Medicinal, Aromatic and Poisonous Plants Research Center. College of Phu, King Saud University, P.O. Box 2457, Riyadh-11451, Saudi Arabia Fax: ++966-1-4676383 670

Int. J. Pharmacol., 2 (6): 670-673, 2006 10 mg kg body weight orally and groups IV and V were treated with turnip juice 8 and 16 ml. kg body weight. Drug treatment was started 5 days prior to CC₁₁ administration and continued until the end of he experiment. After 48 h following CC, administration, animals were sacrificed using ether anaesthesia. Blood was collected by heart puncture, allowed to clot and serum separated. Liver was dissected out and used for biochemical studies. Parameters measured: The serum levels of glutamicoxaloacetic transaminase (GOT), glutamic-pyruvate transaminase (GPT), alkaline phosphatase (ALP) and total bilirubin activities were determined using Reflotron" Plus analyzer and Roche kits. Estimation of nonprotein sulfhydryl groups (NP-SH): The activity of NP-SH was measured according to the method of Sedlak and Lindsay (1968). The liver tissue was homogenized 117 ice-cold 0.02 M ethylenediaminetetraacetic acid (EDTA). Aliquots of 5 ml. of the homogenates were mixed in 1.5 in. test tubes with 4 mL of distilled water and 1 mL of 50% trichloroacetic acid was added. The tubes were shaken intermittently for 10-15 min and centrifuged at 3,000 g. Two milliliters of supematant were mixed with 4 mL of 0.1 M Tris buffer, pII 8.9 and 0.1 mL of 0.1% (5, 5dithio-bis-[2-nitrobenzoic acid]) (DTNB) was added and the sample was shaken. The absorbance, using a spectrophotometer, was read within 5 min of addition of DTNB at 412 nm against a reagent blank with no homogenate. Measurement of phenobarbital sleeping time: Mice were divided into four groups of 10 animals each. Group 1 received the vehicle (0.3 ml, of saline), group II received CCL, only. Groups III and IV received turnip juices 8 and 16 mL kg body weight. Thirty minutes later, the animals of groups and IV were treated with sodium Phenobarbital (50 mg kg-1. intraperitoneally). The time interval between the onsel, and the regaining of the righting reflex was measured as the sleeping time (Dandiya and Collumbine, 1959). RESULTS Phytochemical screening: The preliminary phytochemical screening of the underground part of the turnip revealed the presence of flavonoid derivatives, sulphur-containing compounds and anthocyanins. Effects of turnip juice on SGOT, SGPT, ALP and bilirubin activities: The results of hepatoprotective effects of turnip juice on CCL intoxicated rats are shown in Table 1. In the CCL-treated group, serum GOT, GPT, ALP and bilirubin were significantly increased as compared to normal rals group. The groups treated with 8 and 16 mL kg body weight of turnip juice showed significant decreases in the elevated levels of SGOT, SGPT, ALP and bilirubin in a dose-dependent manner. Treatment ol rals with silymarin ma known hepatoprotective drug used as a reference standard also exhibited significant protective effect against CCLinduced liver damage. Effect of turnip juice on NP-SH activities: Nonproteinsulfhydryl activities in CCL-treated in rats were decreased drastically when compared with normal group. Treatment with turnip juice restored this decrease in content. produced by CCL towards normalization in higher dose (16 m. kg) (Table 2). Effect of turuip juice on Phenobarbital-induced sleeping time: There was a significant lowering of Phenobarbitalinduced sleeping time following the turnip juice administration (16 mL kg, where, the lower dose (8 mL kg) showed an insignificant reduction in sleeping time in CCL-induced acute liver toxicity (Table 3). Table 1: Effect of turnip juice on some enzymes and bilirubin in rats with CCL-induced liver damage Treatments in 61 Dose (inL kg) Control Normal saline CCL only 1.25 Silymarin+CCL 10 Turnip juice+CCL 8 Turnip juice CCL 16 GOT (UL) 65.75.18.04 426.00+35.42 224.00+32.29***1 SGPT (UL) 33.7-7.78 339.00+14.22 125.91±20.15***1 ALP (UL-) 482.666-21.89 875.50+39.33 580.83+27.44*** 703.00±26.87*** 644.83137.30m Bilirubin (mg dL¨¹) 0.61-0.07 2.40+0.15 1.12±0.19*** 320.00±16.18* 266.00130.18* 255.130.58×6 203.66124.12 1.95=0.20 1.56-0.26th *p<0.05; **p<0.01, ***p<0.001 Student's test as compared with the control nommal saline) group as compared with the CCL only group. GOT glutamic-oxaloacetic transaminase; GPT = glutamic-py mvate transaminase; ALP = alkaline phosphatase Table 2: Effect of turnip juice on the level of nonprotein sulfhydryl (NP-SH) groups in the liver of rat treated with CCL, Treatments (n = Control CCL Control (nomal saline) Turnip juice+CXL Turnip juice CCL₁ Dose (ml kg) 1.25 8.00 16.00 NP-SH (mean±SE) mmol, of tissue *As compared with the contral (normal saline) group; tas compared with the control (CCL). **p<0.01; ***p<0.001 Shident's t-test. 6.60±4.81 4.18±0.24**** 1.61±0.31 5.2910.18 671

Int. J. Pharmacol., 2 (6): 670-673, 2006 Table 3: Effect of turnip juice on duration of Phenobarbital sleeping time in mice treated with C001, Treatment (n = 6) P'henobarbital CCL-Phenobarbital CCL-Turnip juice-Phenobarbital CCL-Turnip juice-Phenobarbital Dose (mL kg') 50 50 4 16 Sleeping time (min) Reduction in sleeping time (%) 40.80+6.46 107.10+12.08 74.00+10.11 42.10+4.58 ***p<0.001 student's t-test. As compared to the Phenobarbital group; as compared to the CC1,+Phenobarbital group DISCUSSION Various pharmacological and chemical substances which belong to the intrinsic or idiosyncratic group of hepatotoxins may induce a level of hepatic damage varying from asymptomatic hepatic functional disturbances to widespread liver necrosis. Carbon tetrachloride, which is an intrinsic hepatotoxin, was used to induce hepatic damage in this study since it has previously been shown to exert its toxic effects on the liver (Kus et al., 2004). Administration of (CCL) to rats causes severe liver injury which is recognized by an increase in serum levels of the hepatic enzymes SGOT and SCPT, which are indices of liver cell damage (Teocharis et al., 2001). The biochemical mechanisms involved in the development of CC1, hepatotoxicity have long been investigated. It is generally believed that it is duc 10 lipid peroxidation caused by carbon trichloromethyl radical. (CC1). CCL is biotransformed by cytochrome P450 to the trichloromethyl-free radical that induces membrane lipid peroxidation and disturbs Ca² homeostatis to produce hepatocellular injury (Recknogel et al., 1989). Earlier experimental studies have shown that CCL administration caused an increase in serum levels of GOT, GPT and ALP in mice (Al-Shabanah et al., 2000). In the present study, turnip juice treatment significantly reduced the elevated serum levels of GOT, GPT, ALP and bilirubin. In some earlier studies. it has been reported that some Brassica species, including turnip have anti-carcinogenic activity (Kristal. 2002). Brassica vegetables are consumed for health improvement, which is related to their antioxidant activity (Plumb et al., 1996; Verhoeven et al. 1997). These beneficial effects have been attributed to the compounds which possess antioxidant activity. The major antioxidants of up and related vegetables are likely to be phenolic compounds such as flavonoids. These antioxidants scavenge radicals and inhibit the chain. initiation or break the chain propagation (the second defense line) (Robards et al., 1999; Shi et al., 2001). Additionally, it has also been shown that CCL-induced depletion of hepatic NP-SII is significantly prevented by fresh juice of turnip. Furthermore, the inhibitory effect of the juice on CCL-induced prolongation of sleeping time suggest the ability of juice constituents to reverse the 672 30.9 60.6 damage exerted by CCL on the cytochrome P450 involved in metabolism of phenobarbitone. In conclusion, the present study indicates that tummip juice treatment prevents CCL-induced liver damage in rats, possibly through its antioxidant action and further supports the earlier findings on other Brassica species. These findings also substantiate the claims of herbal and Unani medicine practitioners, using turnip in liver ailments. REFERENCES Al-Shabanali, O.A., K. Alam, M.N. Nagi, A.C. Al-Rikabi and A.M. Bekairi, 2000. Protective effect of aminoguanidine, a nitric oxide synthase inhibitor, against carbon tetrachloride induced hepatotoxicity in mice. Life Sci., 66: 265-70. Chopra, R.N., S.L. Nayer and K. Chopra, 1956. Glossary of Indian Medicinal Plans. CSIR, New Delhi, pp 75. Dandiya, P.C. and H. Collumbine. 1959. Studies on Acorus calamus: Pharmacological actions of essential oil. J. Pharm. Exp. Ther., 125: 353. De Smet, P.A., 2002. Herbal remedies. New England J. Med., 347: 2046-2056. Farnsworth, N.R., 1966. Biological and phytochemical screening of plants. J. Pharm. Sci., 55: 225. Hartwell. J.I., 1971. Plants Used Against cancer. A Survey. Llyodia, pp: 30-34. Kristal, A.R., 2002. Brassica vegetables and prostate cancer risk: A review of the epidemiologic evidence. Pharmaceut. Biol., 40: 55-58. Kus, L., N. Colakoglu, H. Pekmez, D. Seckin, M. Ögeturk and M. Sarsilmaz, 2001. Protective effects of caffeic acid phenethyl ester (CAPE) on carbon tetrachlorideinduced hepatotoxicity in rals. Acta Histochem., 106: 289-297. Pithford, P., 2002. Healing with Whole Foods: Asian Traditions and Modern Nutrition. Published by North Atlantic Books, Berkeley, California, USA. Plumb W., V. Lambert, S. Chambers and S. Wanigatunga et al., 1996. Are whole extracts and purified glucosinolates from cruciferous vegetables antooxidants? Free Radic. Res., 25: 75-86. Rajesh, M.G. and M.S. Latha, 2001. Protective activity of Glycyrrhiza glabra Linn. On carbon tetrachlorideinduced peroxidative damage. Indian J. Pharmacol., 305: 284-287.

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