What are your thoughts on EGCG and Piperine and liver toxicity?

Hi all,

I would like to get your thoughts on something: Do you think that it is perfectly safe taking 300 mg EGCG daily (as green tea extract) with piperine? A person close to me has been taking that amount for a while and I got concerned about the dosage and if the addition of piperine would cause potential harm. I'm not sure how much piperine is in the EGCG product mentioned above but I opened a capsule, tasted it and could tell that it was very strong, very pungent, made me cough...    

Now from what I've read, 300 mg EGCG daily seems safe, without potentially raising alanine aminotransferase (an indicator of liver damage) but I'm not sure how the addition of piperine changes things... And yes I know the piperine would increase EGCG bioavailability but would it not also increase the potential for liver toxicity (by making the EGCG even more potent)?

So this is a multipart question: Is 300 mg EGCG alone or with piperine daily safe? And would piperine ALONE present any health issues? In other words, is piperine generally a good idea from a safety standpoint, over long term especially? I've read that piperine is acutely toxic to mice, rats and hamsters. Not sure how it translates to humans but I would appreciate any comments related to this.