A Novel Study on Carpet-Dye-Induced Dermatitis and Other Changes in Rattus norvegicus

MATERIALS AND METHODS

Model: Fourteen mature Rattus norvegicus of either sex weighing 350±10 g maintained as per guideline of Institutional Ethical Committee, were taken for experiment by dividing them in two groups of 07 animals each. The animals were housed in Poly propylene cages [45 cm (length)x25 cm (width)x20 cm (height)] under standard rearing conditions at 25±2°C room temperature, 35-55 relative humidity and 12 h alternate light: dark cycle. First group of 07 rats including both males and females were used as control.

Fig. 1:	Structure of Black-T Supra (Eriochrome Black-T) carpet dye

They were fed normal gram pellets soaked in water and the second groups of seven rats were used as experimental animals. They were fed orally with gram pellets mixed with 20 mg kg^-1 of b.wt. per day of Black-T Supra carpet dye and tap water ad libitum. The observations were recorded for hair fall, dermatitis, cataract, weight and the behavioural changes for three months post experimentation.

Experimental material carpet dye Black-T Supra (Eriochrome Black-T): Carpet dye Black-T Supra was purchased from the site of carpet belt of Sant Ravidas Nagar Bhadohi, Uttar Pradesh region. This is synthetic azo dye used in textile, carpet, plastic and rubber dyeing industries (Fig. 1).

Statistical analysis: The data on weight gain/loss was analyzed using student’s ‘t’ test according to the method of Petrie and Watson (2002).

RESULTS AND DISCUSSION

Carpet dye Black-T Supra (Fig. 1) has been extensively used in carpet belt of Sant Ravidas Nagar Bhadohi, Uttar Pradesh, India. Toxicological effects of dyes are known in different forms of changes on body of the test animals. Anderson (1960) and Srivastav (2004) observed chromium induced dermatitis in mammals. Eriochrome Black-T (Black-T Supra) is a kind of synthetic azo dye widely applied in dying industry. It can be decomposed into 20 carcinogenic aromatic amines which can cause changes in human body’s DNA structure, pathological changes and many kinds of cancer after the activation effect (Tao, 2011). Various synthetic azo dyes induce variety of tumors in mice and rats and inhibit biosynthesis of RNA, DNA and protein (Miyadera, 1975). When dyes are orally administered, azo compounds are found to reduce mainly in liver and intestine.

Fig. 2(a-b):	(a) Patches of hair fall in experimental rat and (b) No Patches of hair fall in control

There is significant effect of Black T Supra dye on b. wt. of R. norvegicus as variation between body weight of control and experimental R. norvegicus is highly significant (Table 1).

Contact dermatitis (Skin infection) was induced under stress of long-term exposure to hexavalent chromium as reported earlier. Shin et al. (2005) also investigated ear dermatitis in ICR female mice under Oxazalone stress. Saganuwan et al. (2008) found rough hair coat due to the stress of potassium permanganate in Swiss albino mice. Terakawa et al. (2008) examined atopic dermatitis in mice under repeated topical application of 2,4-dinitrofluorobenzene (DNFB) paint. The present study revealed that the carpet dye caused the appearance of small patches of hair fall in experimental rats from fifth week due to dermatitis which slowly increased in area and became in the form of large patches by 12th week (Fig. 2a, b). The dermatitis in the form of hair fall under stress of Black-T Supra carpet dye in the present study thus corroborates with the earlier finding.

Table 1:	Effect of carpet dye Black T Supra on body weight of R. norvegicus
*p<0.001

Kumar et al. (2011) found haemocytic anaemia under stress of Black-T Supra carpet dye which may be the reason of hair fall in experimental R. norvegicus causing dermatitis.

The data shown in Table 1 revealed highly significant increase in body weight of R. norvegicus (p<0.001) under Black-T Supra stress (456.14±1.12 control and 487.36±1.52 experimental). A similar result was also reported by Saganuwan et al. (2008) in Swiss albino mice under potassium permanganate stress which was non significant (p<0.05). But Al-Shinnawy (2009) found highly significant decline in body weight (p<0.01) of Rattus norvegicus with the high dose (75 mg kg^-1) of Amaranth (red azo dye) due to hypocholesteremia. In the present experiment, it was observed that the urination is much less in experimental R. norvegicus than the control ones. The highly significant increase in body weight of treated rats may be due to retention of water and accumulation of food which may be due to catabolism and not by cholesteremia.

Further, Srivastav (2004) reported development of cataract in the eyes of R. norvegicus under chromium stress and the same was found in the same species under Black-T Supra stress after fifth week of experimentation. The development of cataract may be due to haemocytic anaemia and accumulation of carpet dye through blood into the eye ball (Kumar et al., 2011). This may be due to inhibition of biosynthesis of RNA, DNA and protein.

In addition to, development of cataract, a desperate walking was also observed after fourth and fifth week respectively. Srivastav (2004) and Saganuwan et al. (2008) found imbalance in walking and dullness under chromium and potassium permanganate stress in R. norvegicus and Swiss albino mice. The cataract and desperate walking in the present study under Black-T Supra carpet dye stress may be due to blindness and muscular weakness respectively. The imbalance in walking may also be due to inhibition of required biosynthesis of protein in muscles. Thus, the stress of Black-T Supra in R. norvegicus causes dermatitis, cataract, increase in weight and desperate walking which indicate its toxic effect.

CONCLUSION

Impact of carpet dye black T supra which is greatly used in carpet industry on Rattus norvegicus has been studied. Gram mixed with sub-lethal dose of Black T Supra carpet dye was fed to Rattus norvegicus for three months and the symptoms of dermatitis in the form of hair fall in patches on surface of body started from fifth week onward. The area of patches of hair fall increased between 6th to 12th weeks. In controls, such effect was not observed. In addition, a little increase in body weight, cataract in eyes and desperate walking in experimental animals were observed after fifth week of feeding Black T Supra dye.

ACKNOWLEDGMENTS

The authors are thankful to Head, Department of Zoology and Principal, K.N. Govt. Postgraduate College Gyanpur, S.R.N. Bhadohi for providing laboratory facilities. The authors are also thankful to Vice-Chancellor, Nehru Gram Bharati University, Allahabad and Department of Zoology, MMV, B.H.U. Varanasi for providing necessary infrastructural facilities and encouragement. We wish to express our sincere thanks to Dr. J.P. Pandey Scientist, CTR and TI, Ranchi, India and S. Sisodia for help in Statistical analysis and collection of literature.