EGCG (Epigallocatechin-3-gallate) is the major active principle catechin found in green tea. Skepticism regarding the safety of consuming EGCG is gaining attention, despite the fact that it is widely being touted for its potential health benefits, including anti-cancer properties. The lack of scientific data on safe dose levels of pure EGCG is of concern, while EGCG has been commonly studied as a component of GTE (Green tea extract) and not as a single active constituent. This study has been carried out to estimate the maximum tolerated non-toxic dose of pure EGCG and to identify the treatment related risk factors. In a fourteen day consecutive treatment, two different administration modalities were compared, offering an improved [i.p (intraperitoneal)] and limited [p.o (oral)] bioavailability. A trend of dose and route dependant hepatotoxicity was observed particularly with i.p treatment and EGCG increased serum lipid profile in parallel to hepatotoxicity. Fourteen day tolerable dose of EGCG was established as 21.1 mg/kg for i.p and 67.8 mg/kg for p.o. We also observed that, EGCG induced effects by both treatment routes are reversible, subsequent to an observation period for further fourteen days after cessation of treatment. It was demonstrated that the severity of EGCG induced toxicity appears to be a function of dose, route of administration and period of treatment.

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To understand the possible origin of hepatitis B virus (HBV), three of the four hyperendemic, primitive accessible tribes of the Andaman and Nicobar islands, India, were investigated. The Nicobarese tribe was investigated in 1989 and 1999. The S gene from 65 HBV isolates was amplified by PCR and sequenced. Genotyping and serotyping were carried out on the basis of phylogenetic and amino acid analyses of S gene. All 20 Nicobarese-89 isolates, nine Onges-99 isolates and the single Andamanese-99 HBV isolate were classified as genotype D. Of the Nicobarese-99 isolates, 32 (91?4 %) and three (8?6 %) were genotypes D and A, respectively. Per cent nucleotide identity between the S sequences representing different tribes varied from 98?06 to 98?59 % and varied from mainland isolates by 1?6-2?0 %. Although southeast Asian origin is postulated for the Nicobarese tribe, the presence of different genotypes suggests introduction of HBV after migration to these islands, probably from mainland India, 200 years back, when these islands became inhabited as a part of penal settlement during the British regimen.

The Andaman and Nicobar Islands, Union Territory of India, are home to six primitive tribes, namely the Great Andamanese, Onges, Jarawas and Sentinelese (Negrito race), and the Shompens and Nicobarese (Mongoloid race). These tribes account for about 8% of the island's population and the Nicobarese constitute >95% of the tribal population. Hepatitis B virus (HBV) infection is highly endemic among them with the prevalence of hepatitis B surface antigen (HBsAg) ranging from 23% among the Nicobarese to 66% among the Jarawas. The high HBsAg prevalence among pregnant mothers (20.5%), a linear increase in the age-specific rates of HBV exposure and the presence of HBsAg-positive individuals in every family suggested a combination of perinatal and horizontal transmission among the Nicobarese. Molecular studies of HBV isolates from the Onges, Nicobarese and Great Andamanese indicated a predominance of genotype D and there was a close similarity between these isolates and isolates from mainland India, suggesting that HBV may have been introduced from mainland India. In contrast, genotype C predominated among the Jarawas, with isolates similar to strains from Southeast Asian countries. Due to its high prevalence, hepatitis B vaccine is included in the childhood vaccination programme in these islands. It might be worth considering a pilot screening programme for chronic HBV patients to detect hepatocellular carcinoma.

The Andaman and Nicobar Islands, Union Territory of India, are home to six primitive tribes. Studies carried out earlier among these tribes revealed very high rates of hepatitis B infection. We have now studied hepatitis A and E infection among them. A total of 951 serum samples were collected from four accessible tribes (Nicobarese, Shompens, Onges and Great Andamanese) and tested for antibodies against hepatitis A and E viruses. In addition, 240 serum samples collected a decade earlier from age-stratified Nicobarese were also screened. Hepatitis A virus (HAV) infection was found to be highly endemic among all the tribes, whereas hepatitis E virus (HEV) infection was common among the Nicobarese and Shompens. The age group-wise prevalence of these infections among the Nicobarese showed different patterns, HAV prevalence rising significantly from those aged 10 years and thereafter reaching a plateau, whereas HEV prevalence was found to be more evenly distributed over all age groups, but rising somewhat after 30 years of age. Over the last decade, the prevalence of HAV among the Nicobarese has declined slightly, particularly in those aged 10 years or less whereas HEV infection has more than doubled over all age ranges. Different HEV prevalence observed among the tribes could not be attributed to differences in sanitation or water supply. This fact and the different age-wise patterns of HAV and HEV prevalences is suggestive of different modes of transmission of HEV that are not shared. The highest rates for HEV were among those tribes which reared pigs suggesting that pigs might serve as reservoir of HEV. Further studies are needed, however, to validate these findings.