SAN DIEGO -- A man who allegedly offered dangerous dietary supplements as alternative remedies for cancer and other ailments was arrested on suspicion of practicing medicine without a license, prosecutors said Thursday.

Kurt Walter Donsbach, 73, of Bonita, was charged with 11 felonies, including treating patients without a license, misbranding drugs for sale, grand theft, unlawfully dispensing drugs as a cure for cancer and falsely representing a cure for cancer.

He faces up to six years in prison if convicted.

"The defendant preyed on vulnerable patients who were looking for medical help," said District Attorney Bonnie Dumanis.

"Under the guise of providing natural and safe supplements, he sold victims potentially dangerous drugs."

Even though he has no medical license in California, Donsbach claimed to be a chiropractor and naturopathic doctor, and through a weekly, online radio broadcast from Chula Vista, he offered "alternative, natural and nutritional" remedies for many conditions and ailments including cancer and auto-immune disorders, prosecutors said.

His clinic advised one patient to inject herself with "neuropeptides" to treat arthritis, saying it would "re-program" her body's T-cells, prosecutors said.

FDA tests revealed the "neuropeptide" contained a steroid not disclosed on the packaging or labels. The patient paid thousands of dollars for the drugs and injected herself for six years, leading to severe bone density loss, according to authorities.

In another case, Donsbach claimed he had treated pancreatic cancer successfully about 60 percent of the time and provided a supplement to a patient.

Federal Drug Administration tests of the supplement revealed the presence of the drug nimesulide, a non-steroidal anti-inflammatory not approved by the FDA.

In Europe, marketing of nimesulide has been suspended because of high rates of liver failure that resulted in deaths and liver transplants, and authorities warned other "patients" of Donsbach to be wary of so-called "natural" or "dietary" supplements that may have been provided to them.

According to the FDA, people who take dietary supplements with nimesulide could get sick or die.

Donsbach was booked into jail in lieu of $1.5 million bail pending his arraignment Friday at the downtown San Diego courthouse.