The Diuretic, Edema-Reducing, Liver-Protective and Anti-Cancer Actions of Zhuling (Polyporus)
The Chinese medicinal zhuling is the dried sclerotium of the fungus Polyporus umbellatus (Polyporaceae), grown mainly in Shaanxi, Shanxi, Hebei, Yunnan and Henan. Zhuling has a black skin and yellow interior; the Bencao Tujing says it has “a black skin and grows in blocks, resembling pig dung,” hence the name zhuling or zhuling (pig-poria). In Zhejiang and other places it is folk-called “wild boar dung”; in Sichuan it is called “pig-shi ling,” and in the northeast “wild boar food.” When used medicinally, the rough outer skin is removed, and it is cut into thin slices for decoction or for pills and powders.
Zhuling’s most striking effect is to promote urination and percolate dampness. Traditional TCM holds that zhuling is sweet and bland in taste and neutral in nature, entering the liver, kidney and bladder meridians. It specializes in percolation and discharge, excels at promoting urination, and is a common herb for difficult urination, edema, diarrhea, lin syndrome and turd vaginal discharge.
Zhuling is one of the frequently used herbs in oncology, because it is among the must-use herbs for treating ascites, pleural effusion, pericardial effusion and pelvic effusion. Moreover, zhuling polysaccharide both enhances immunity and protects the liver, and has anti-tumor effects, inhibiting cell proliferation in mouse sarcoma S180, cervical cancer U14, and liver cancer.
But TCM works through the ages all record that zhuling “fortifies the spleen but injures the kidney,” so it is not advised for those without water-dampness. The Bencao Yanxi holds that long-term use of zhuling “will surely damage kidney qi and cloud the eyes.” The Yixue Qiyuan says: “Compared with other bland-percolating herbs, it greatly dries out and wastes fluids; do not take it if there is no dampness pattern.”
The contemporary renowned physician Professor Wang Pei stood alone against this consensus, believing zhuling has no kidney-damaging side effect. Citing the Shennong Bencao Jing, Professor Wang said zhuling, taken long-term, “lightens the body and prolongs life,” making it an excellent longevity tonic. Professor Wang often prescribes “Erling Yimi Dazhou” (Two-Poria Coix Jujube Congee) as a dietary therapy for malignant-tumor patients, composed of zhuling 30 g, fuling 30 g, raw yiyiren 30 g, and ten dazao (jujubes), with rock sugar to taste; a little shanyao (Chinese yam) and yiner (tremella) may also be added. According to Professor Wang’s writings, many advanced malignant-tumor patients, after eating this, gained in constitution, regained weight, and extended their survival. This dietary formula is a good one for treating effusions; however, zhuling is not cheap, and using 30 g per day may be beyond the means of poor patients.
Some literature records that 8 g of zhuling per day is already effective for adults, and doses above 8 g show little difference from just 8 g; thus whether large doses are necessary is doubtful. But Professor Wang Pei’s claim that zhuling not only has no kidney-damaging side effect but actually boosts patients’ immunity and anti-tumor activity has been confirmed by modern pharmacological research. I use zhuling often and have also not seen it damage the kidney or cloud the eyes, so the ancient records of zhuling’s side effects are inaccurate.
Zhuling has a strong diuretic action; ancients treated edema from difficult urination during pregnancy simply by taking zhuling alone, ground to powder and washed down. Zhuling is often combined with fuling; for example, the Zhuling San in the Jingui Yaolue uses equal parts zhuling, fuling and baizhu, ground to powder and taken washed down, for “vomiting with the disease located above the diaphragm and a desire to drink water”—a symptom often seen in gastric retention or pleural-effusion patients. Among Zhang Zhongjing’s classical formulas there are also a Zhuling Tang and a Wuling San, both of which use zhuling together with fuling. Zhuling Tang is composed of zhuling, fuling, zexie, huashi (talc) and ejiao (ass-hide glue), treating the pattern of water-heat binding; Wuling San is composed of zhuling, fuling, baizhu, zexie and guizhi, treating the water-retention pattern caused by failure of bladder qi transformation.
Paired with various herbs, zhuling treats all kinds of phlegm-fluid and edematous disorders. The Yaolun says of zhuling: “With banxia, phlegm-fluid is dissipated; aided by (da)fupi (areca husk), edema recedes; it achieves the merit of checking diarrhea when led by baizhu; it brings the quick effect for lin and strangury with cheqianzi.” This means zhuling combined with banxia treats phlegm-fluid, with dafupi treats edema, with baizhu treats diarrhea, and with cheqianzi treats urinary obstruction. The Deyi Bencao says zhuling “with jizibai (white chicken dung) treats childhood urinary retention”; jizibai is the white portion of chicken droppings, which promotes urination, discharges heat, expels wind and resolves toxins, but is rarely used today.
An injection made from zhuling’s water extract can treat psoriasis—commonly known as psoriasis vulgaris; zhuling-polysaccharide injection also works well for immunodeficiency. Some research has also used zhuling for chronic viral hepatitis: zhuling can cause HBeAg seroconversion in some patients, repair liver-tissue damage, and shows no toxic side effects even with long-term use.