You seem to be suggesting that most conventional medicines today are derived from alternative medicines. That was true in the past, but I doubt it's still, or at least as, true today.

It's true that some of the alternative medicines of the past really worked, but the vast majority were useless placebos or actually harmful. Because modern medicine uses scientific studies of effectiveness it only uses treatments that can work. That's why, for example, there is no medication on the store shelf to ward off vampires or witches or evil spirits.

Furthermore, modern medicine has a much better understanding of why certain foods and herbs treat certain illnesses. For example, Vitamin C in citrus fruit cured skurvy in sailors. So, now we can take Vitamin C pills or drink Vitamin C enriched beverages to replace the limes that the sailors had to eat.

Don't give undo credit to alternative medicine because a few of its remedies worked. Most of its modern practitioners apply the same pseudoscientific methods of their predecessors, the witch doctors. That's no cause for praise.