Di Gu Pi, also known as Lycium Root Bark, Gou Nai Zi Root Bark, and Gou Di Ya Pi, is recorded in "Da Guan Ben Cao". It is the dried root bark of the Solanaceae plant Lycium chinense Mill. or Lycium barbarum L. from Ningxia. The roots are harvested in early spring or after autumn, washed, peeled, and dried.
[Processing Method] 1. Di Gu Pi in "Yao Xing Lun": "Finely file." In "Su Shen Liang Fang": "Remove the soil." In "Chuan Ya Wai Bian": "Wash with warm water, flatten and remove the core, only take the tender bark, dry and crush into fine powder." Currently, the original medicinal material is taken, impurities and residual wood core are removed, washed, slightly moistened, cut into shreds, and dried.
2. Fried Di Gu Pi in "Ju Fang": "Fry until fragrant." Currently, heat the pan, add wheat bran until smoking, pour in the slices of Di Gu Pi, stir-fry until the surface turns slightly yellow, remove, sift out the wheat bran, and let it cool.
[Appearance] Di Gu Pi is cylindrical or filamentous, varying in length. The outer surface is grayish-yellow to brownish-yellow, rough, with irregular vertical fissures, and easily peels into scales. The inner surface is yellowish-white to grayish-yellow, relatively flat, with fine longitudinal lines. It is light, brittle, and easily breaks. It has a slight odor and a slightly sweet and then bitter taste. Fried Di Gu Pi is similar in shape to Di Gu Pi, with a pale yellow surface.
[Quality Requirements] The total ash content should not exceed 11.0%.
[Processing Effects] Di Gu Pi has a sweet and cold nature. It belongs to the lung, liver, and kidney meridians. It has the functions of cooling blood and eliminating heat, and clearing lung and reducing fire. It is used for yin deficiency and hot flashes, bone steaming with night sweats, lung heat cough, hemoptysis, nosebleeds, and internal heat-induced polydipsia. For example, it can be used in the treatment of fatigue syndrome, bitter and thirsty mouth, and bone and joint fever or cold with a concoction of Lycium bark (from "Bei Ji Qian Jin Yao Fang"); or in the treatment of excessive thirst and excessive drinking with Di Gu Pi drink (from "Sheng Ji Zong Lu"). Frying with bran can moderate its cold nature.
