Arsenic is a systemic poison, and chronic ingestion of arsenic can lead to a wide range of health problems, which are collectively called arsenicosis or chronic arsenic poisoning. The effects include skin lesions, cancer of the skin, lung a bladder, and gastro-intestinal and pulmonary condition. In the recent times it has caused serious health issues in the population worldwide. Arsenic toxicity through groundwater arsenic contamination is the world’s biggest natural groundwater calamities which got a huge impact on global public health. India is facing the consequences of arsenic poisoning mainly in the area of Ganga Brahmaputra fluvial plains. Arsenic is considered to be major environmental health disaster   . It is estimated that more than 200 million people are exposed to high level (<10 µg L−1) of arsenic toxicity through drinking water .
Liver is the organ which not only carries out the metabolic functions but also detoxifies the toxins. In arsenic exposure, arsenate is actively transported into cells by phosphate transporters in liver . Kidneys accumulate arsenic in the presence of repeated exposures. The kidneys are the major route of arsenic excretion, as well as major site of conversion of pentavalent arsenic into the more toxic and less soluble trivalent arsenic. Sites of arsenic damage in the kidney include capillaries, tubules, and glomeruli .
In various studies it has been observed that cucurbitacins present in C. sativus exhibited cytotoxicity and anti-cancer activity. Besides this, cucurbitacins also exhibited wide ranges of in-vitro or even in-vivo pharmacological effects and in used as purgative, anti-inflammatory and anti-fertility agent .
In the present study, cytoprotective effect of seeds of Cucumis sativus (Cucumber) was done on sodium arsenite induced liver and kidney injury through biochemical assay. No such study on the antidote effect of C. sativus on arsenic has been carried out till date. Therefore, the present study is designed to evaluate ameliorating effect of Cucumis sativus (cucumbers) to mitigate the arsenic toxicity in mice.
2. Materials and Methods
Animals: Swiss albino mice (Mus musculus), weighing 30 g to 35 g of 8 weeks old, were obtained from animal house of Mahavir Cancer Institute and Research Centre, Patna, India (CPCSEA Regd-No. 1129/bc/07/CPCSEA). The research work was approved by the IAEC (Institutional Animal Ethics Committee) with IAEC No. 2015/3E-16/12/15. Food and water to mice were provided ad libitum (prepared mixed formulated food by the laboratory itself). The experimental animals were housed in conventional polypropylene cages in small groups (2 each). The rats were randomly assigned to control and treatment groups. The temperature in the experimental animal room was maintained at 22˚C ± 2˚C with 12 h light/dark cycle.
Chemicals: Chemicals: Sodium Arsenite (98.5%) manufactured by Sigma-Aldrich, USA (CAS Number: 7784-46-5), was obtained from the Scientific store of Patna of Bihar India.
Medicinal plant used: Seed extract of Cucumis sativus (cucumbers) was used as antidote.
Preparation of Cucumis sativus (cucumbers) aqueous extract: In the present study, seed of Cucumis sativus (cucumbers) were procured locally from Patna, Bihar, India The identity of the medicinal plant was confirmed by Dr.Ashok Ghosh (Botanist), Department of Botany, Magadh University, Bihar, India. The collected seed of Cucumis sativus (cucumbers) were dried and were grinded to fine powder. The aqueous extract dose was calculated after LD50 estimation which was found to be 4000 mg kg−1 body weight and the final dose (1/8th dose) was fixed to 500 mg kg−1 body weight as maximum permissible dose (MPD).
Chronic Toxicity Study: Selected pathogen-free mice were sorted and sodium arsenite was administered at the dose of 3 mg/kg body weight dose for 4 weeks by Gavage method. Sacrifices were done at the end of 4th week of Sodium arsenite administration in each group.
Bioremediation: Sodium arsenite administration 3 mg/kg body weight for 4 weeks was followed by the administration of seed of Cucumis sativus (cucumbers) for 6 weeks at the dose of 500 mg/kg body weight. Animals were sacrificed on 6th weeks of administration.
Biochemical Assessment: Blood samples were collected by orbital puncture and centrifuged to separate the serum to carry out biochemical analysis. Biochemical analysis were performed through serum by standard kit process (Coral crest) through U.V Vis spectrophotometer. The Liver Function Tests (LFT) tests like Serum Glutamate Pyruvate Transaminase (SGPT), Serum Glutamate Oxalate Transaminase (SGOT), Alkaline Phosphatase (ALP) and Bilirubin tests were carried out while in Kidney Function Tests (KFT) Urea, Uric Acid and Creatinine tests were carried out.
Statistical Analysis: Results are presented as mean ± S.D and total variation present in a set of data was analysed through one-way analysis of variance (ANOVA). Difference among means has been analysed by applying Dunnett’s “t” test at 99.9% (p < 0.05) confidence level. Calculations were performed with the GraphPad Prism Program (GraphPad Software, Inc., San Diego, USA).
In the present study Cucumis sativus (cucumbers) seed extract treatment after 6th weeks showed a significant change in the Biochemical parameter. Following the Cucumis sativus (cucumbers) treatments, after 6 weeks the SGPT, SGOT, ALP and Bilirubin concentrations in the arsenic-treated mice decreased from 209.7 ± 6.74 U/ml to 54.00 ± 2.18 U/ml in SGPT level, from 128.7 ± 2.60 U/ml to 36.33 ± 1.32 U/ml in SGOT level, from 29.67 ± 1.76 K.A. Unit to 11.07 ± 0.49 K.A. Unit in ALP level, from 1.677 ± 0.06 mg/dl to 0.9100 ± 0.04 mg/dl in bilirubin levels respectively, compared with the post-arsenic values (Table 1).
Following the Cucumis sativus (cucumbers) treatments, after 6 weeks the Urea, Uric acid, and creatinine concentrations in the arsenic-treated mice decreased from 86.67 ± 2.96 mg/dl to 39.07 ± 1.02 mg/dl in Urea level, from 9.733 ± 0.23 mg/dl to 7.230 ± 0.09 mg/dl in Uric acid level, from 3.733 ± 0.23 mg% to 1.95 ± 0.14 mg% in creatinine levels respectively, compared with the post-arsenic values (Table 2).
In the present study, cytoprotective effect of seeds of Cucumis sativus (Cucumber) was observed on sodium arsenite induced liver and kidney injury through biochemical assay and histopathological study is an exclusively new work added in the field of toxicology. The findings show restoration in parameters of liver function tests and kidney function tests, as compared to sodium arsenite induced toxicity. The biochemical assay showed decrease in the levels of SGPT, SGOT, ALP, bilirubin, urea, uric acid and creatinine. This denotes that Cucumis
Table 1. Changes in Liver Function Test of mice exposed to Sodium arsenite at the dose of 3 mg/Kg body weight daily for 6 weeks and its amelioration by Cucumis sativus (cucumbers) for 6 weeks.
The data are presented as mean ± S.D, n = 6, significance at p < 0.0001.
Table 2. Changes in Kidney Function Test of mice exposed to Sodium arsenite at the dose of 3 mg/Kg body weight daily for 6 weeks and its amelioration by Cucumis sativus (cucumbers) for 6 weeks.
The data are presented as mean ± S.D, n = 6, significance at p < 0.0001.
sativus played vital role to combat the side effects of sodium arsenite.
The seeds of cucumber are rich by the number of constituents including crude proteins (42%) and fats (42.5%). The ash is rich with phosphate (P2O5, 0.62%). The extracted oil from seeds is clear and light yellow with specific gravity of 0.91; acid value 0.22; sopanification value 1930; soluble fatty acid (as butyric acid) 0.4% and unsopanification matter (0.91%). The fatty acid components are palmitic (0.63%), stearic (16.2%), linoleic (40.11) and oleic acid (38.70) . It contains a number of sterols such as codisterol, 25 (27)-dehydroporifersterol, clerosterol, isofucosterol, stigmasterol, campesterol, 22-dihydrobrassicasterol, sitosterol, 25 (27)-dehydrofungisterol, 25 (27)-hydrocondrillasterol, 24-β-ethyl-25 (27)-dehydrofungisterol, avenasterol, 22-dihydrispinosterol and 24-methylenecolesterol . The gibberellin hormone is also found in seeds. Seed cake contains water (1.13%) protein (72.53%) ash (9.7%), crude fiber (1%) and carbohydrates (8.64%).
In various studies it has been observed that Cucumber extract showed antioxidant activities against various assays including DPPH reduction assay, total oxyradical scavenging capacity (TOSC) assay, trolox equivalent antioxidant capacity (TEAC), total radical-trapping antioxidant parameter (TRAP) or ferric reducing-antioxidant power (FRAP) assays   . Melo et al.  reported the polyphenol contents in cucumber. Total phenolic contents, flavonols and proanthocyanidins were found to be 9.05 ± 0.83, 2.06 ± 0.09 and 55.66 ± 1.52 mg/100 g respectively in cucumber extract. The whole extract contains high concentrations of ascorbic acid (1.49 ± 0.85 mg/100 g) also (Melo et al. 2006). Like one more study, free phenolics content in cucumber was found to be 14.37 ± 1.48 mg/100 g of sample (73.8%), when it was examined along with another 10 vegetables . In this experiment bound phenolic compounds as Bound-E and Bound-W were found to be 2.92 ± 0.07 (15%) and 2.17 ± 0.06 (11.2%) mg/100 g of sample respectively with high percentages of vitamin C (23.5%).
Other effects of Cucurbitaceae plants of Indian origin including C. sativus have been well studied for blood sugar lowering potential at dose of 250 mg/kg by oral administration, it was found that the fruit does not affect the blood sugar level or depress the peak value, after glucose load  , whereas another study suggested that C. sativus decreases significantly the area under the glucose tolerance curve and the hyperglycemic peak on 27 healthy rabbits . The oral administration of the pectin extracted from the fruit of C. sativus at a dose of 5 g/kg body weight/day showed significant hypolipidemic action in normal as well as cholesterol-fed experimental animals . Allen  studied that lectin from the exudates of the fruit of the cucumber having an anti-parasitic function that strongly inhibited by chitin oligosaccharides.
The seeds are useful for quitting burning sensation, constipation, tonic and intermittent fevers . Gill et al.  suggested that the methanolic extract of C. sativus seeds possessed significant ulcer potential which could be due to the antioxidant activity at a dose of 300 mg/kg in pyloric ligation and water immersion stress induced rat models. The induction effect of UV-B on the antioxidant enzymes such as superoxide dismutase (SOD), guaiacol peroxidase (POD), ascorbic acid peroxidase (APX) and glutathione reductase (GR) and its suppressed modulation to detoxify excess ROS via external application of a-tocopherol and benzoquinone in cucumber cotyledons have also been examined . Boiled leaves with cumin seeds are useful for throat infection. Powdered leaf with sugar acts as a diuretic and it is also given to treat remitted and inflammatory fevers .
Therefore, the Cucumis sativus possesses ameliorative effect against arsenic induced toxicity in mice protecting the liver from its deleterious effects.
Thus, it is evident from entire study that Cucumis sativus plays a very effective and vital role in controlling deleterious effect caused by sodium arsenite by normalizing the biochemical parameters of liver and kidney.
The authors are thankful to Mahavir Cancer Institute and Research Centre for providing infrastructural facility during this work.