Toxic medicinal herbs cannot be taken directly. They must be processed to reduce or eliminate their toxicity before they can be used in formulas. So how are toxic Chinese herbs such as Ban Xia, Chuan Wu, Cao Wu, Ma Qian Zi, and Tian Nan Xing processed to reduce their toxicity? The following briefly explains the precautions for Chinese medicinal herbs, hoping to be helpful to you!
Precautions for Chinese Medicinal Herbs:
Ban Xia: After processing, the strong pungent sensation is removed and the toxicity is reduced. It is best to choose winter or spring for processing, as it is prone to rotting in summer or autumn.
Processed Ban Xia: Take clean Ban Xia, sort by size, soak in water until there is no white heart inside, remove and drain, cut into thick slices, mix with ginger juice until fully absorbed, then add coarse alum powder and mix thoroughly until evenly translucent. Put it in a jar and marinate for 48 hours, then add water along the edge of the jar until it exceeds the level of Ban Xia by about 10 cm, continue to marinate for 2-4 days, until there is no tingling sensation when chewed, remove and wash off the alum powder, dry to obtain processed Ban Xia.
Pharmacological studies have shown that raw Ban Xia has the highest toxicity and has emetic effects, while various processed Ban Xia have significantly reduced toxicity and have antiemetic effects.
Processed Cao Wu: Take clean Cao Wu, sort by size, soak in water or saturated lime water until there is no dry heart inside, remove, boil in water for 4-6 hours, cut open the larger and solid ones, without white heart inside, taste slightly numbing on the tongue, remove and dry until 60% dry or moist, then cut into slices and dry. The content of Aconitine should comply with the requirements of the pharmacopoeia. Another method is to soak Cao Wu for 7 days, changing the water 2-3 times a day, until no spicy taste can be detected, remove and dry. Another method is to mix Cao Wu with licorice and ginger decoction, let it absorb, then mix with tofu, steam in a steamer for about 3 hours, remove and dry for half-drying, remove the auxiliary materials, and cut into slices and sun-dry.
Processed Ma Qian Zi: Put fine sand in a pot and heat it, then add Ma Qian Zi and stir-fry until it swells and turns brown or dark brown. Remove the sand and scrape off the fuzz, and the processed Ma Qian Zi is ready. Crush the processed Ma Qian Zi into fine powder, adjust the content of Shikonin to 0.80% according to the methods specified in the pharmacopoeia, by mixing with starch. The processing of Ma Qian Zi is to reduce toxicity and standardize the content of Shikonin. The toxicity of Ma Qian Zi depends on the temperature and time of sand scalding, which should be properly controlled.
Processed Tian Nan Xing: Take clean Tian Nan Xing, sort by size, soak in water, change the water 2-3 times a day. If foam appears, add 2 kg of alum per 100 kg of Tian Nan Xing. After soaking for a day, change the water again until there is a slight tingling sensation when tasted. Layer Tian Nan Xing, ginger slices, and alum evenly in a jar, add water to submerge them, for about 3-4 weeks. Then boil in a pot until there is no white heart, remove the ginger slices, let it dry until 60% dry, then cut into slices and sun-dry.
