Open Access

ARTICLE

Topical Application of Houttuynia cordata Thunb Ethanol Extracts Increases Tumor Infiltrating CD⁸⁺ /Treg Cells Ratio and Inhibits Cutaneous Squamous Cell Carcinoma in vivo

by Lipeng Gao^1,2,#, Rongyin Gui^1,#, Xinnan Zheng¹, Yingxue Wang¹, Yao Gong¹, Tim Hua Wang¹, Jichuang Wang³, Junyi Huang^1,2, Xinhua Liao^1,2,*

1 School of Life Sciences, Shanghai University, Shanghai, 200444, China
2 Shanghai Key Laboratory of Bio-Energy Crops, Plant Science Center, Shanghai University, Shanghai, 200444, China
3 Institute for Translational Medicine, Fujian Medical University, Fuzhou, 350122, China

* Corresponding Author: Xinhua Liao. Email:
# Lipeng Gao and Rongyin Gui contributed equally to this work

Oncologie 2022, 24(3), 565-577. https://doi.org/10.32604/oncologie.2022.022454

Received 10 March 2022; Accepted 28 June 2022; Issue published 19 September 2022

Abstract

Houttuynia cordata Thunb (HCT) is a medicinal and edible herb that has beneficial effects on various diseases due to its diuretic, anti-inflammatory, anti-oxidative, anti-microbial, anti-viral, anti-cancer and anti-diabetic properties. Most reports of its anti-cancer activity were conducted in vitro, and its effects on cutaneous squamous cell carcinoma (SCC) have not been investigated yet. Using DMBA/TPA induced SCC mice model, we found that topical treatment by HCT, as well as its bioactive ingredient monomer, efficiently inhibited tumor growth. Mechanistically, tumor infiltrating CD⁴⁺ , Foxp³⁺ T regulatory cells (Tregs) were significantly reduced and CD⁸⁺ /Treg cells ratio was largely increased in tumors after HCT treatment. In addition, several chemokines which function to recruit immune cells were largely reduced in SCC cancer cells treated by HCT in vitro. Our results demonstrate the therapeutic effects of HCT on cutaneous SCC and indicate it might inhibit cancer through regulating tumor infiltrating lymphocytes and the tumor immune microenvironments.

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