Medicinal Value and Side Effects of Dingxiang (Clove)
Dingxiang (Clove) is the dried flower bud of Syzygium aromaticum of the Myrtaceae family, also called Gongdingxiang (male clove), Xiongdingxiang or Dingzixiang. It has a distinctive aromatic scent that is refreshing to the heart. The near-ripe fruit of clove is also used medicinally as Mudingxiang (female clove), with essentially the same effects as male clove but weaker potency.
Traditional TCM considers clove pungent in flavor, warm in nature and non-toxic. It enters the Spleen, Stomach and Kidney meridians. It warms the middle and lowers counterflow, and warms the kidney to assist yang. It treats stomach cold, hiccup, epigastric and abdominal cold pain, poor appetite with vomiting and diarrhea, kidney deficiency with impotence, sore and cold lower back and knees, and yin-type flat abscesses. Because clove is pungent and warm and easily consumes fluids, it is contraindicated in yin deficiency with internal heat and in febrile diseases.
Clove has a good stomachic and analgesic effect and is a common medicine for gastrointestinal disorders. It not only aids digestion but also treats hiccup, borborygmus, abdominal pain and diarrhea. Dingxiang Shidi San (Clove and Persimmon Calyx Powder) is a classic formula for hiccup due to diaphragmatic spasm. Professor Ye Juquan combined Dingxiang Shidi San with Shaoyao Gancao Tang (clove 3 g, persimmon calyx 3 g, white peony 3 g, licorice 3 g) to treat hiccup from diaphragmatic spasm, with even more remarkable results.
The externally applied patent medicine Dingguier Qi Tie (Cinnamon and Clove Umbilical Patch) is a common treatment for childhood diarrhea; its main ingredients are clove and cinnamon. Clove and cinnamon in a 1:1 ratio made into a powder constitute the famous Ding Gui San (Clove-Cinnamon Powder), which treats not only hiccup and diarrhea but also cold-type abdominal pain, back pain and joint pain, taken orally or applied externally. A simple clove extract also treats vomiting from stomach cold, epigastric distending pain, hiccup, borborygmus, abdominal pain and diarrhea. Clove oil used together with menthol also wakes the spleen and strengthens the stomach.
I often combine Dingxiang Shidi San with Xuanfu Daizhe Tang to treat intractable vomiting and hiccup in cancer patients after chemotherapy; some patients also obtain relief from chemotherapy side effects simply by taking clove powder infused in water. However, clove has certain side effects and toxicity and is not suitable for all patients. Clove has an anticoagulant effect, so it carries a risk of gastric or cerebral hemorrhage; patients with low platelets and poor coagulation should use it cautiously, and even when needed it should not be used alone.
Clove was one of the ancient herbs used for concretions and yin-type flat abscesses. For instance, Li Dongyuan's classic formula Dingxiang Lanfan Wan is made mainly with clove and can be used for gastric cancer. Clove's special fragrance can mask the foul odor of many animal-derived medicines, so it can serve as an auxiliary herb combined with toad venom (Chansu), leech (Shuizhi), earthworm (Dilong) and Eupolyphaga (Di Bie Chong) to make powders or pills for anticancer use. Such a combination not only masks the foul smell of poorly flavored herbs but also strengthens the stomach and stops vomiting.
Clove powder applied externally, or clove steeped in wine and applied externally, treats mastitis, ringworm, various ulcerative skin diseases and toothache. The Guai Zheng Qi Fang records treating "malignant flesh of welling-abscesses by applying clove powder." This is because clove has good antibacterial and insecticidal effects: the clove oil it contains inhibits Pasteurella pestis, Vibrio cholerae, Bacillus anthracis, Salmonella typhi, Salmonella paratyphi, Corynebacterium diphtheriae, Shigella, Proteus, Escherichia coli, Bacillus subtilis and Staphylococcus aureus. Clove oil and eugenol also inhibit Brucella and avian tubercle bacillus. Moreover, clove oil and eugenol at dilutions of 1:8000-1:16000 inhibit Nocardia asteroides, Trichophyton schoenleinii, Microsporum gypseum and Epidermophyton inguinale. The alcoholic infusion of clove also kills animal roundworms, so clove is also used as a veterinary medicine.
However, clove is toxic. The oral LD50 of clove oil in mice is 1.6 g/kg; giving dogs 5 g/kg clove oil by mouth caused vomiting and diarrhea followed by death. Autopsy found ulcers and bleeding of the gastrointestinal mucosa, congestion and cloudy swelling of the liver and kidney, and necrosis of some liver cells. Clove's side effects are mainly related to its anticoagulant action. Although TCM does not classify clove among the blood-activating and stasis-resolving herbs, in fact its anticoagulant effect is better than aspirin and stronger than that of most blood-activating stasis-resolving herbs; this is also an important reason why clove has analgesic effects.
In clinical use, the adult daily dose of clove is mostly 3-6 g, or when made into pills and powders the daily dose is usually under 1 g; this dose is far below clove's LD50 and is very safe.