Herbal Research

Fu Ling

PORIA (PORIA)

Fu Ling is the dried scierotium of the fungus Poria cocos (Schw.) Wolf (Polyporaceae). The herb is mainly produced in the provinces of Anhui, Hubei, Henan and Yunnan. It is collected from July to September and dried in the shade.

CHEMISTRY

The herb contains large amount of polysaccharides called b-pachyman and several triterpene acids, including pachymic acid, tumulosic acid, eburicoic acid, pinicolic acid, 3b-hydroxylanosta-7,9(11),24-trien-2 I-oic acid, poricoric acid A (16a-hydroxy-3,4-secolanosta-4(28),7,9(11),24(31)-tetraen-3,21-dioic acid), poricoric acid B (16a-hydroxy-3,4-secolanosta-4(28),7,9(11),24-tetraen-3-,21-dioic acid), and 24-trien-21-oic acid. It also contains ergosterin, choline, histidine, adenine, lecithin and potassium1-3.
Furthermore, triterpene acids 3-O-acetyl-16a-hydroxytrametenoic acid, dehydropachymic acid, 3-epidehydrotumulosic acid, dehydroeburicomc acid, polyporemc acid C, and poricoric acids D and AM were recently isolated from the methanolic extract of the herb4.

PHARMACOLOGY

Diuretic Effect

Intraperitoneal administration of 0.5 g/kg of the 25% alcoholic extract for 5 days produced a significant diuretic effect in rabbits; the diuretic activity was comparable to that of 0.1 mg/kg of salyrgan by intramuscular administration. Oral administration of the alcoholic extract also produced diuretic effect in normal rats. But oral administration of the decoction showed no diuretic activity in rabbits5.

Sedative Effect

Intraperitoneal administration of the decoction decreased the spontaneous activity of mice and antagonized over-excitation induced by caffeine. It was also synergistic with the anesthetic effect of pentabarbital sodium in mice5.

Effect on Digestive System

The herb exerted a direct relaxant action on the isolated rabbit intestine. It inhibited gastric ulcer in rats provoked by pylorus-ligation and decreased gastric secretion and free acidity. The herb also protected rats against CCl4-induced hepatotoxicity, reducing GPT activity and preventing necrosis of hepatocytes5.

Anti-Thmor Promotion Effect

Topical application of the methanolic extract of the herb (2 mg/100 l1) significantly reduced the percentage of tumor-bearing mice and the number of tumors per mouse induced by DMBA plus TPA. The triterpene acids isolated from the herb produced inhibition on TPA-induced inflammatory ear edema in mice. Pachymic acid, dehydropachymic acid, 3-O-acetyl-16a-hydroxytrametenoic acid, 3b-hydroxylanosta-7,9(11),24-trien-21-oic acid, dehydroeburiconic acid, poricoric acids A and B were similar in antiinflammatory activity to hydrocortisone in this test4.

Other Effects

The aqueous, alcoholic or ether extract increased the contractility and heart rate of the isolated frog heart. The decoction of the herb in vitro inhibited Staphylococcus aureus, Mycobactrium tuberculosis and Proteus vulgaris. The alcoholic extract was lethal to leptospirae but the decoction was inactive5.

FUNCTIONS AND APPLICATIONS

Traditional Description

Fu Ling is sweet and tasteless in taste, and neutral in property, acting on the heart, lung, spleen and kidney channels. It has the functions of:

(i) inducing diuresis and excreting dampness, used in edema with oliguria;
(ii) invigorating the spleen function, used in lassitude, anorexia and loose stool; and
(iii) tranquilizing the mind, used in fright palpitation and insomnia.

Applications
Edema

The cake prepared from the herb was used in 30 edema patients (20 nonspecific edema and 10 renal or cardiac edema) at the dose corresponding to 3.5 g of the herb thrice daily. Marked effect was observed in 23 cases and improvement in 7 other cases3.

Schizophrenia

The decoction of 60 g of the herb was given daily to 53 patients with schizophrenia for 1 to 3 months. Three cases were cured, 11 markedly improved and 16 improved3.

Neurasthenia and insomnia

The herb is often used together with Suan Zao Ren (Semen Ziziphi Spinosae) in the treatment of neurasthenia and insomnia.

DOSAGE

9-15g.

SIDE EFFECTS AND TOXICITY

The LD50 values of the warm water macerate of the herb in mice were >10 g/kg by oral administration and >2 g/kg by intraperitoneal administration3.

REFERENCES

1. Zhou, RH. (1993) Resource Science of Chinese Medicinal Materials, pp. 163-168. Beijing: China Medical & Pharmaceutical Sciences Press.
2. Huang, K.C. (1993) The Pharmacology of Chinese Herbs, p. 133. Boca Raton: CRC Press.
3. Yin, J., Gun, L.G. (1993) Modern Research and Clinical Applications of Chinese Materia Medica U). pp. 489-492. Beijing: Academic Publisher.
4. Kaminaga, T., Yasukawa, K., Takido, M., Tai, T., Nunoura, Y. (1996) Inhibitory effect of Poria cocus on I 2-O-tetradecanoylphorbol- 13-acetate-induced ear oedema and tumour promotion in mouse skin. Phytotherapy Research, 10, 58 1-584
5. Wang, Y.S. (1983) Pharmacology and Applications of Chinese Materia Medica, pp. 767-770. Beijing: People's Health Publisher.