🌿 Folk Prescriptions

This phase yielded three insights: (1) One should not solely pursue single specific indicators. If a syndrome can be represented by a single specific indicator, it implies meeting disease diagnostic criteria and entering the “disease” category. The positive rate of abnormal indicators in kidney yang deficiency syndrome ranges from 60% to 85%, with scattered, latent changes in endocrine axes. (2) Syndrome represents a dynamic functional state, capable of progression and transformation. The body possesses strong regulatory capacity, constantly restoring homeostasis via feedback mechanisms. Pathological manifestations result from impaired regulatory control. (3) Although organ-based syndrome differentiation leads to inference about pathological origins, it does not identify specific anatomical entities or regulatory centers associated with the syndrome.
Since the mid-1980s, research has focused on formula-based syndrome differentiation. Traditionally, TCM judges the accuracy of syndrome differentiation through therapeutic effects—Zhang Zhongjing’s “treat the syndrome with the appropriate formula” demonstrates that syndrome existence can be confirmed by drug response. Organ-based syndrome differentiation must begin with observable clinical signs, meaning human subjects are the research objects. Due to limitations in sample collection, early studies concluded that the pathological origin of kidney yang deficiency lies in the hypothalamus—this remains speculative. To verify whether the regulatory center is located in the hypothalamus, the second phase required animal models for drug validation. Researchers used aged rats with physiological kidney deficiency and rats induced with exogenous glucocorticoids (corticosterone) to inhibit the hypothalamus-pituitary-adrenal axis, simulating kidney yang deficiency. These models offer clear etiology, controllable conditions, ease of sampling, and allow comparison across classic formulas—providing favorable conditions to clarify disease location and identify the regulatory center of drug action on kidney yang deficiency.
In 1986, it was observed that Bushen Yishou Pian significantly increased serum testosterone levels in elderly people, whereas Sijunzi Tang had no effect. Therefore, 24-month-old aged rats were divided into Bushen (treated with Bushen Yishou Pian) and control groups, compared with 4-month-old adult rats. Hypothalamic tissue was specifically collected. Results showed that aged rats had significantly reduced affinity of double-hydrogen testosterone receptors in the hypothalamus compared to adults. Bushen Yishou Pian effectively improved this receptor affinity, indicating direct action of kidney-tonifying herbs on the hypothalamus (2), providing one basis for locating kidney yang deficiency syndrome.
In 1990, in comparative studies of kidney-tonifying versus spleen-tonifying drugs, aged rats exhibited varying degrees of disturbance in hypothalamic TRH, LHRH, and monoamine neurotransmitters (NE, DA, 5-HT, 5-HIAA). The kidney-tonifying formula “Shou Er Kang” effectively improved these indices, while spleen-tonifying formulas showed minimal effects. This indicates that kidney-tonifying herbs can improve aging of catecholaminergic neurons in the hypothalamus, whereas spleen-tonifying herbs do not (3)—a second basis for kidney yang deficiency syndrome localization.