Complex sentence: It is analogous to Jamaican vomiting sickness in humans, with both diseases sharing the same causative toxin, and ingestion of "Acer negundo" seeds or other parts of the plant may be toxic to humans in large doses.
Split into simpler sentences: It is analogous to Jamaican vomiting sickness in humans, with both diseases sharing the same causative toxin. Ingestion of "Acer negundo" seeds or other parts of the plant may therefore be toxic to humans in large doses.