SAN FRANCISCO—A 56-year-old woman died from poisoning caused by herbal tea leaves that she purchased from a local store in Chinatown. It was reported that at least one more person, a man in his 30s became critically ill after ingesting a different blend of tea bought from the same store.

The victim, Yu-Ping Xie bought herbal tea from a store called Sun Wing Wo Trading Co. located on Grant Avenue in San Francisco. An hour after consuming the tea, Xie experienced abnormal heart rates and needed immediate resuscitation. She was admitted to the Pacific campus of California Pacific Medical Center where she died on Saturday, March 18. The individual who was admitted to the hospital after also suffering similar tea-poisoning was  discharged after is recovering, the SF Gate reported.

Investigations revealed the cause of poisoning to be a plant based-toxin known as Aconite. Aconite was found in both the patient’s herbal tea blends. Popular for its anti-inflammatory properties, Aconite is a common ingredient in herbal teas. The toxin needs to undergo appropriate processing in order to be rendered safe for consumption.

Fresh Aconite is extremely toxic with no anti-toxin available. According to webmd.com, “Aconite root is unsafe when taken by mouth. All species of the plant are dangerous, and so are processed products. Aconite contains a strong, fast-acting poison that causes severe side effects such as nausea, vomiting, weakness or inability to move, sweating, breathing problems, heart problems, and death.”

The owner of the herbal tea shop is working with health inspectors to determine the exact source of the plant toxin in the stash of tea leaves at his shop. Officials from health department have removed the tea leaves consumed by the two victims. Health officials urged all the customers of Sun Wing Wo Trading Co. to get rid of any tea ever purchased from the store.