Exploring the Mechanism and Clinical Application of Polygonum Cuspidatum and Herbaceous Rhizoma Herbal Medicine in the Treatment of Psoriatic Arthritis based on "Clearing Away Heat and Detoxifying, Activating Blood Circulation and Unblocking Meridians"

Abstract

Psoriatic arthritis (PsA) is a chronic heterogeneous autoimmune disease secondary to psoriasis. It has dual lesions of scaly skin lesions and erosive arthritis. It belongs to the categories of “white boils”, “Bi syndrome” and “Lijie disease” in traditional Chinese medicine. The core pathogenesis of the disease in the active stage is that heat poison accumulates blood, blood stasis blocks the meridians, and poisons and blood stasis cement each other: the heat poison burns the blood, and when it penetrates the skin, it causes erythema, hypertrophy, scales and itching; blood stasis blocks the muscles and joints, resulting in red, swollen, hot and painful joints, and morning stiffness and deformity; the heat poison tortures the blood and causes blood stasis, and the blood stasis for a long time regenerates the fire poison, forming a vicious cycle, which is the fundamental reason for the recurrence of the disease and the progressive destruction of bones. Polygonum cuspidatum and Hedyotis diffusa are classic medicinal pairs commonly used in rheumatology, immunology and dermatology. They are closely related to the core pathogenesis of PsA poison and blood stasis, and together they have the functions of clearing away heat and detoxification, cooling blood and dispersing blood stasis, activating blood circulation and dredging collaterals, diuresis and purging turbidity. Modern pharmacology has confirmed that polydatin, resveratrol, and emodin in Polygonum cuspidatum can inhibit the NF-κB and NLRP3 inflammasome pathways at multiple targets, downregulate key pro-inflammatory factors such as TNF-α, IL-6, IL-17, and IL-23, and also regulate the renal uric acid transporter., inhibit the HIF-1α/VEGF pathway to reduce the formation of synovial pannus; the iridoid glycosides and flavonoids contained in Hedyotis diffusa can inhibit abnormal activation of CD4⁺T cells, regulate Th17/Treg immune balance in two directions, and have antioxidant, diuretic and detoxification effects. The combination of the two medicines can clear away toxins without stagnation of Qi and blood, activate blood circulation and dissipate blood stasis without depleting healthy Qi, achieve simultaneous regulation of skin and joints, and dual intervention of local inflammation and systemic immune disorders. This article comprehensively discusses the etiology and pathogenesis of traditional Chinese medicine, theory of drug pair compatibility, basis of active substances, molecular synergy mechanism, clinical application of syndrome differentiation, integrated traditional Chinese and Western medicine programs, existing research shortcomings and future scientific research directions. It systematically combs the scientific connotation of polygonum cuspidatum-white flower snake tongue herbal medicines in the intervention of PsA, and provides a complete theoretical basis and clinical practical reference for the syndrome differentiation and treatment of this disease with traditional Chinese medicine, synergism and detoxication, and new drug development.