The husband and two sons of 56-year-old Yu-Ping Xie are suing the man they say was responsible for their mother's death by poisoning, which occurred last week following weeks of hospitalization after the Chinatown herbalist prescribed her a custom tea blend to improve her immune system. As son Jin Deng tells the Chronicle, Yui-Wun Chan, the proprietor of Sun Wing Wo Trading Co., sold the tea to his mother, and this was the first time that she'd dabbled in traditional Chinese medicine since the family immigrated to the US 13 years ago.

Xie died Saturday after being poisoned by a plant toxin known as Aconite, but which goes by multiple other names in different cultures. She was one of two people who were sickened by different tea blends containing the toxin, and the other, a man in his 30s, has since recovered and left the hospital according to the city's health department.

Deng, 31, his younger brother, and father say their devastated by the loss of their hardworking mother and wife, who worked multiple jobs and "would do anything unconditionally to help us."

San Francisco attorney Charles Kelly filed the lawsuit on behalf of the family this week, and he tells the Chronicle that it should be a wake-up call to the state to enact regulations surrounding traditional herbalists like Chan — who unlike acupuncturists and other practitioners do not face any official scrutiny.

The shop at 1105 Grant Avenue remains open, and the health department says that they've removed the toxic product from the store.

Previously: One Of Two People Poisoned By Tea From Chinatown Herbalist Has Died

The shop where the tea was sold. Photo: Google