Schizonepeta tenuifolia Formula: 
Anti-hemorrhoid Activity via Anti-angiogenesis in Hemorrhoid Rats

Background Hemorrhoids are a prevalent condition characterized by anal vein dilation and prominent vascular hyperplasia, accompanied by symptoms such as rectal bleeding, itching, and discomfort. Currently, the conventional treatments possess limitations. The present research focuses on evaluating the anti-hemorrhoidal efficacy of Schizonepeta formula wash (SFW) and the underlying mechanisms. Purpose The present research aims to evaluate the anti-hemorrhoidal efficacy of Schizonepeta Formula Wash (SFW) and the underlying mechanisms. Methods Rat models of hemorrhoids were established by croton oil induction. The anti-hemorrhoid efficacy of SFW was investigated via histopathological experiments. The correlation between the anti-hemorrhoid activity and anti-angiogenic property of SFW was explored through immunofluorescence assays of vascular endothelial markers cluster of differentiation 31 (CD31) and von Willebrand factor (vWF). The impacts of SFW on the biological functions of human umbilical vein endothelial cells (HUVECs) were validated in vitro by employing cell counting kit-8 (CCK-8), transwell, and tube formation experiments. Results The efficacy of SFW treatment in reducing anorectal swelling, mucosal injury, tissue thickening, and anorectal swelling index (ASI) was comparable to that of Pilex in the hemorrhoid model. SFW treatment also improved histopathological features, including less vascular hyperplasia, restored epithelial and mucosal integrity, and reduced granulocyte and plasma cell infiltration. Mechanically, SFW treatment inhibited angiogenesis in hemorrhoidal rats, as manifested by the reduced expression of CD31 and vWF compared to the model group. The proliferation, migration, and tube formation of HUVEC were significantly inhibited by SFW in vitro , which suggested that SFW exerts its anti-hemorrhoidal activity by hindering angiogenesis. Conclusion This study investigated the efficacy of SFW treatment on hemorrhoids and found that its anti-hemorrhoidal activity was exerted through suppressing angiogenesis. Furthermore, this study provides a theoretical basis for developing alternative treatments for hemorrhoids.