* Tomato plant belongs to the family of nightshade. The tomato leaf can be UNSAFE. In large amounts, tomato leaves can cause poisoning. Symptoms of poisoning may include severe mouth and throat irritation, vomiting, diarrhea, dizziness, headache, mild spasms, and death in severe cases.
* alkaloids/tomatine in the leaves would have high skin irritating properties.
* The possible risks of tomatine for humans have not been formally studied, so no NOAEL can be deduced. The toxicity of tomatine has only been studied on laboratory animals. The symptoms of acute tomatine poisoning in animals are similar to the symptoms of poisoning by solanine, a potato glycoalkaloid. These symptoms include vomiting, diarrhea, abdominal pain, drowsiness, confusion, weakness, and depression. Generally, tomatine is regarded to cause less toxic effects to mammals than other alkaloids such as solanine. The amount of tomatine absorbed by the human body as well as the possible metabolism is unknown. There is no evidence that consumption of tomatoes causes acute toxic or genotoxic effects.[21]
* The human consumption of moderate amounts of tomatine seems to occur without notable toxic effects. This is reinforced by the widespread consumption of “pickled green” and “fried green tomatoes” and the consumption of high-tomatine tomatoes (a variant of L. esculentum var. cerasiforme, better known as the "cherry tomato", indigenous to Peru) with very high tomatine content (in the range of 500–5000 mg/kg of dry weight).
* New York Times food science writer Harold McGee has found scant evidence for tomato toxicity in the medical and veterinary literature, and observes that dried tomato leaves (which contain higher concentrations of alkaloids than the fruits) are occasionally used as a food flavoring or garnish, without problems. He also reports that an adult human would probably have to eat over a pound of tomato leaves to ingest a toxic (not necessarily lethal) dose.