I went looking on the Net for the herbs that are used in the cough syrup King To Nin Jiom Pei Pa Kao and found these which I have compiled below.
Each one works to alleviate cough, phlegm and all manner of lung problems. I got the info from this website: http://www.fzrm.com/plantextract.htm in case you want to go on your own TCM herb hunting adventure or find out what those Latin terms actually mean.
Fourleaf Ladybell Root or Nan Sha Shen nourishes yin and removes heat from the lung, resolves phlegm, and reinforces qi. Suitable if you have heat in the lung with dry cough; cough with scanty sticky sputum; or deficiency of both qi and yin with feverishness and thirst.
Bulbus Fritillaria Cirrhosa or Chuan Bei Mu removes heat, moistens the lung, resolves phlegm and relieves cough. Good for those with dry cough due to heat in the lung; cough with bloody sputum in consumptive diseases.
Folium Eriobotrya Japonica or Loquat Leaf removes heat from the lung and the stomach, and relieves cough and vomiting.
Indications: Cough and dyspnea caused by heat in the lung; vomiting, fever and thirst caused by heat in the stomach.
Poria cocos or Indian Bread is the dried sclerotium of the fungus, Poria cocos. Poria is collected mostly in July to September, removed from soil, piled up, spread, and air-dried. This is repeated until all water evaporates before it is dried in the shade. Normally it is known as Fu Ling (white slices you see sometimes in Chinese herb shops).
Fu Ling or Poria cocos helps invigorate the spleen and calms the mind. Useful for curing dizziness and palpitation caused by retained fluid; diminished function of the spleen marked by anorexia, loose stools or diarrhea; restlessness and insomnia.
Exocarpium citrus Grandis or Pomelo peel, another ingredient in Nin Jiom, acts to dispel cold, eliminate damp and phlegm, and arrest emesis or nausea. Good for cough, itchy throat and profuse expectoration in colds; nausea, vomiting and epigastric distension caused by improper diet or excessive drinking.
Platycodon Root or Radix Platycodon Grandiflorum helps relieve cough, soothes sore throat and promotes expectoration and discharge of pus. Usually used when there's cough with much phlegm and hoarseness.
Pinellia Tuber or Rhizoma Pinelliae Preparatum also helps to remove damp and phlegm.
Chinese Magnoliavine Fruit or Fructus Schisandra Chinensis replenishes qi, promotes fluid secretion, tonifies kidney. It is used for chronic cough and asthma; nocturnal emission, permatorrhea; enuresis, frequent urination; protracted diarrhea; spontaneous sweating, night sweating; impairment of body fluid with thirst, shortness of breath and feeble pulse; diabetes caused by internal heat; palpitation and insomnia.
Snakegourd Seed or Semen Trichosanthes Kirilowii resolves phlegm and is a laxative and as such is good for those with dry cough with sticky sputum and constipation.
Common Coltsfoot Flower or Flos Tussilago Farfara relieves cough and resolves phlegm, nourishes the lung to keep the adverse qi downward.
Thinleaf Milkwort Root or Radix Polygala Tenuifolia promotes sputum expectoration and reduces swelling. It is used for those suffering from insomnia,dream-disturbed sleep, forgetfulness,palpitation ,trance; cough with a difficulty in expectorating sputum; boils and sores as well as swelling and pain in the breasts.
Bitter Apricot Seed or Semen Prunus Armeniaca relieves cough and asthma, and helps relax bowels. It is often used for cough and asthma accompanied by stuffiness in the chest and profuse expectoration; constipation due to deficiency of blood and fluid.
Among all these herbs, there is of course, the well known Fresh Ginger or Rhizoma Zingiberis Recens. Fresh ginger promotes sweating, dispels cold, warms the stomach, relieves phlegm and cough.It is usually used if there's cough with thin whitish sputum.
Nin Jiom also contains Liquorice Root or Radiz Glycyrrhiza Glabra which improves the spleen and replenishes Qi. Liquorice root also removes heat and counters any toxicity in the body, dispels phlegm and cough. Chewing on a liquorice root (easily available at any Chinese herbal shop) as a quick remedy to alleviate cough helps! Just chew the root to get its juice (like chewing gum). Spit out the root once you've extracted all the juice of course.
Other ingredients include menthol which is a saturated, cyclic alcohol obtained from peppermint oil; honey or known as Mel which helps relieve dryness, replenishes the spleen and stomach and counteracts toxicity.
So you see, there's a bunch of herbs (roots, seeds, leaves) used in the preparation of the traditional Nin Jiom cough syrup.
It's amazing to know that more than 15 herbs/ingredients are used in such a simple yet effective remedy for coughs.