Powerful chemical components of plants. Alkaloids contain nitrogen and help to protect the plant against animals and insects that may harm them; they also help to regulate growth.
There are over 6000 alkaloids but well known ones include nicotine, quinine, atropine, ephedrine and caffeine.
They have many different actions in the body, some examples are:
Ephedrine=CNS stimulant and relaxes airways
Yohimbine dilates blood vessels in moderate doses, stimultes blood flow
Atropine controls heart rate
Morphine and codiene =pain relief
Vinblastine regulate cell growth, can control development of tumors or other abnormalities.