Zhegucai, also known as Meishezao, Yantoucai, Zhuhuancai, Dizao, Ludi Cai, and Wocai, is the dried alga of the red alga species Zhegucai. It is harvested in summer and autumn, and can be used dried or fresh. It is mainly produced in coastal areas of Guangdong, Zhejiang, and Fujian provinces in China. Guangdong is the main producing region, particularly in Haifeng and Chaoshan.
【Functions and Indications】
It can expel roundworms and is used for roundworm infections. It is also used in modern medicine for chronic bronchitis, indigestion, and roundworm infections.
【Dosage and Administration】
Internally, take 30 to 60g of fresh Zhegucai, decocted in water. Reduce the dosage for children. It can also be taken as powdered dried herb. Take it twice, before going to bed and on an empty stomach in the morning.
【History of Medicinal Use】
1. Zhangpu: The earliest record of Zhegucai can be found in the "Zhangpu County Annals" more than 400 years ago. According to the record, "It grows on rocks in the sea, crumbles easily, and is dark in color. When children eat it, it can expel worms from the intestines." Similar records can also be found in the "Minnan Materia Medica" and Zhao Xuemin's "Compendium of Materia Medica Addendum." The "Compendium of Materia Medica Addendum" quotes the "Zhangzhou Prefecture Annals," saying, "Zhegucai is crumbled and has dark flowers. It grows in Zhangpu... It is used to treat worm infestation in children, and taking it can expel worms." According to Japanese scholars, it is believed to be a member of the Rhodophyta (seaweed) family. This has caused confusion between Seaweed and Zhegucai, but Seaweed does not grow in Zhangpu. Dried Seaweed is yellowish-brown, not dark. It was later confirmed by Chinese scholars, including Zeng Chengkui, that the Zhegucai used for expelling roundworms in Zhangpu is indeed Zhegucai.
2. Guangdong: The "Guangdong Chinese Materia Medica" states that Zhegucai is also known as Meishezao. It is a marine alga species... The algal body is black, 1-4cm long and about 1mm wide, flat and narrow. It has branching and curved arms, and is irregularly wrinkled. It is brittle with a seaweed-like smell and a slightly salty taste. The "Lingnan Summary of Chinese Herbs" also mentions Zhegucai: "It can expel worms and is used to treat roundworm infections. It can be used in combination with other herbs like Shijunzi, Kulianpi, and Binglang."
3. Fujian: Zhegucai has been used in folk medicine in Fujian for the treatment of roundworm infections for at least a few hundred years. It is mainly produced in Haicheng, Zhangpu, and Wenzhou in Zhejiang. It grows between rocks along the coast, especially in the east of Shantou. In the "Spore Plant Names," it is called "Meishezao." It has various local names, such as "Yantoucai" (Wenzhou, Zhejiang), "Huichongcai" (southern Fujian), "Ludicai" and "Wucai" (Fuan, Fujian), "Chizao" (Lianjiang, Fujian), "Zhuhuancai" (Xiapu Sansha), and "Shiba" (Tonggu, Taishan County, Guangdong).
4. Hong Kong: Zhegucai produced in Hong Kong has the effects of expelling parasites, invigorating the spleen, resolving phlegm, and eliminating accumulation. It calms the mind and is used to treat children with abdominal distension and pain caused by worm infestation or food accumulation, as well as indigestion. It is effective in cases with symptoms such as abdominal swelling with visible veins, abdominal swelling with thin limbs, loss of appetite and weight loss, and yellowish complexion, restlessness, and irritability. Based on this, a compound Zhegucai powder and Meishezao tablets have been developed in China. They have been clinically proven to be effective in treating roundworm infections in children, especially the compound Zhegucai powder, which has a small dosage but excellent efficacy in expelling worms. It extracts the active ingredient, "Meirencao acid," from Zhegucai using advanced methods, overcoming the problem of decomposition upon heating, which was encountered when extracting the acid from Seaweed using traditional methods in Chinese literature. The product has been clinically verified, with a worm expelling efficacy of 96.8% and an egg conversion rate of 90.7%. It also has good efficacy in treating accompanying symptoms, such as loss of appetite, umbilical pain, night frights and crying, and abdominal masses, with a treatment effectiveness of over 85% for all these symptoms. No toxic side effects have been observed in clinical trials. The Zhegucai powder is more suitable for children to take due to its small and concentrated dose, and it has become an ideal medication for treating roundworm infections in children, highly regarded by parents. In the 1980s, Li Changchun also conducted research on the hypotensive effects of Zhegucai and its mechanism of action.
【Pharmacological Actions】
1. Worm Expelling Action
The main active component responsible for the worm expelling action of Zhegucai is Meirencao acid. Zhegucai decoction can kill earthworms in a glass container. It can cause excitation followed by inhibition of roundworms (in pigs or humans). Using roundworm activity mapping, a 5% Zhegucai physiological saline solution can inhibit and even paralyze pig roundworms. After 20% decoction was used to culture pig roundworms, the worm bodies shrunk and their activity decreased after 20-30 minutes. They were still alive the next day, but the activity mapping indicated that the decoction inhibited their activity and caused paralysis. When taken by adults or children, most of the roundworms are expelled within 24 hours, with a high efficacy rate of up to 80%. However, the conversion rate of worm eggs to negative is very low (about 20%). The effective worm expelling component is water-soluble. Prolonged high heat can partially destroy it and render it ineffective. Long-term storage of dried Zhegucai can also reduce its efficacy. The conversion rate of Meirencao acid in worm expelling is also not high, at about 50% when used alone (10-15mg per dose). However, when used in combination with Shandaonian (100mg) and Meirencao acid (5-10mg), the effect is better.
2. Other Effects
A 10% Zhegucai bait can kill houseflies. It has a particularly strong effect on mold algae, killing all of them within 62 hours. Although the concentrated water extract can inhibit the hearts of dissected frogs, it has no significant effect on the hearts of dissected rabbits, in situ dog hearts, or perfused rat hind limbs. When administered intravenously to anesthetized dogs, it slightly lowers blood pressure, but with rapid tolerance. It can excite the isolated intestines of rabbits, causing rhythmic or even tonic contractions. This may be related to the mild abdominal pain, diarrhea, nausea, and vomiting experienced by a few patients after taking the herb.
【Clinical Applications】
Worm Expelling
According to observations of more than 1,000 cases, the overall efficacy rate of worm expulsion is 84-88%. More than 60% of the cases expelled the worms within 24 hours after taking the herb, with the earliest expulsion occurring within 3-6 hours and the latest within 3-5 days. The number of worm expulsions varied from 1 to 114, with most cases having 1-10 worms expelled. In some cases, worm eggs were still present in the stools after 3 weeks of treatment, but the number decreased compared to before treatment. Therefore, it is believed that a single dose of the herb cannot achieve a complete cure.
Based on whether the expelled worms are dead or alive, it is believed that Zhegucai has both worm expelling and worm killing effects. When the dosage is low, it may only stimulate the worms and cause them to be expelled. However, when the dosage is higher or the duration of action is longer, it can have a killing effect on the worms. It is also believed that after being stimulated by the drug, the worms go through an excitatory disturbance followed by a gradually paralyzed state, leading to death. Children have a higher sensitivity in the intestines, so when the worms are stimulated and become excited, it enhances the secretion of intestinal glands and promotes intestinal peristalsis, resulting in the expulsion of worms within a short period of time. Therefore, in children under 12 years old, most of the expelled worms are alive, and most of them are expelled within 24 hours. In older individuals, due to increased inhibitory activity in the cerebral cortex, the number of bowel movements decreases when the worms become stable, allowing the worms to stay in the intestines for a longer period of time and have a chance to remain in contact with the medicine for a longer time. Therefore, worm expulsion usually occurs 3 days after taking the herb, and most of the expelled worms are dead, with some showing damage to the outer surface of the worms.
Usage
A. Take 500g of dried Zhegucai and decoct it in water three times. Mix the filtrate and concentrate it to 500mL. Give 5mL per dose for children aged 2-5, 10mL for those aged 6-10, 15mL for those aged 11-15, and 20mL for those aged 16 and above. Take it before going to bed and on an empty stomach in the morning, or at 9am and 4pm.
B. Take fresh Zhegucai, wash it, and stir-fry it with salt and oil as a dish, or stir-fry it with eggs. It can also be dried and powdered, mixed with flour, and made into cookies for consumption.
Dosage: For adults, take 120g per dose; for those aged 8-16, take 90g; for those aged 4-8, take 60g; for those aged 1-4, take 30g (all measurements are for fresh herb). Some cases have shown effectiveness with a dosage of only 30g, and adults can take 60g.
C. Take dried Zhegucai, decoct it three times over low heat, and concentrate it to 100% water extract. Divide it into three groups from different producing areas (Zhangpu, Haicheng, and Pingtan), and further divide each group into normal dosage and double dosage observation groups. Take it before going to bed and on an empty stomach in the morning, or at 9am and 4pm. Take it in two doses with sugar water. For the normal dosage, take 5mL for those aged 2-5, 10mL for those aged 6-10, 15mL for those aged 11-15, and 20mL for those aged 16 and above. For the double dosage, multiply the normal dosage by 2. Observe and treat a total of 1,313 cases of roundworm infection over a week.
The results showed that out of 1,040 cases in the Zhangpu group, there were 839 cases in the normal dosage group, of which 738 cases expelled worms, resulting in an effective worm expulsion rate of 87.97%. In the double dosage group with a single dose, there were 106 cases, of which 59 cases expelled worms, resulting in an effective worm expulsion rate of 55.66%. In the double dosage group with two doses, there were 95 cases, of which 78 cases expelled worms, resulting in an effective worm expulsion rate of 82.10%. However, the worm expulsion effects were significantly worse in the Haicheng and Pingtan groups, with effective worm expulsion rates of 11.81% and 10.71% respectively, indicating the importance of the producing region recorded in the literature as "from Zhangpu." Among the 875 cases in the Zhangpu group that expelled worms, 597 cases (68.22%) expelled worms within 24 hours after taking the herb, with the earliest expulsion occurring 6 hours after taking the herb and the latest expulsion occurring 5 days later. A few cases experienced mild abdominal pain, dizziness, vomiting, diarrhea, and loss of appetite, but these reactions were mild and disappeared within 1-2 days as the worms were expelled.
Side Effects
A few cases experienced abdominal discomfort, abdominal pain, diarrhea, vomiting, loss of appetite, and dizziness. These side effects were generally mild.
【Precautions】
1. Precautions for Use
Avoid using it in cases of low blood pressure and during pregnancy.
2. Toxic Side Effects
When mice were orally administered a Zhegucai decoction at a dosage of 20g/kg, no symptoms of toxicity or death were observed. It is also almost non-toxic to other laboratory animals. When taken by humans, side effects are also rare, and no obvious reactions were observed in some patients who took 250g of fresh herb, suggesting that it has extremely low toxicity. A few cases experienced mild abdominal pain, diarrhea, and transient dizziness as side effects.
