Anti-inflammatory functions of Houttuynia cordata Thunb. and its compounds: A perspective on its potential role in rheumatoid arthritis

Abstract

Abstract. The aim of this review was to take a look at the anti-inflammatory functions of Houttuynia cordata Thunb. (HCT) that have been illustrated in the literature and to explore new fields in which HCT could be used in the future. The use of HCT has been described in broad inflammatory domains, where it has exhibited a variety of activities, including antiviral, antibacterial, antiparasitic and immunostimulant activity, with high efficiency, mild features and definite therapeutic effects. The numerous anti-inflammatory functions of HCT have demonstrated that HCT has wide application prospects. New uses of HCT and the full extent of its utilization await further investigation. The basic pathological change of rheumatoid arthritis (RA) is synovial proliferation which leads to joint destruction in the long-term. There are types of drugs that have been used clinically for patients with RA, however, due to their side-effects or high prices their broad usage is limited. A safe and low-cost drug is urgently required to be developed for the clinical usage of patients with RA. Thus, HCT has the potential to be a good candidate in the treatment of rheumatoid arthritis. Contents1. Introduction 2. Antiviral activity 3. Antibacterial activity 4. Antiparasitic activity 5. Other anti-inflammatory activity 6. Effects on immunity 7. Conclusion IntroductionHouttuynia cordata Thunb. (HCT) is a perennial herbaceous plant that grows in the wild in moist and shady locations in Asian countries, including China, Japan and India. HCT has antiviral, antibacterial, immunostimulant and other anti-inflammatory effects (1), which have led it to being widely used in the pharmaceutical industry and folk medicine (2-5). In recent years, its anti-inflammatory effects have been deeply studied and have indicated that HCT is clinically applicable in the treatment of inflammatory diseases. The anti-inflammatory mechanism of HCT is closely associated with inflammatory cells, particularly those that secrete cytokines. The antiviral, antibacterial and immunostimulant effects of HCT are also being elucidated. Antiviral activityHand, foot, and mouth disease (HFMD). HFMD is a common viral illness that typically infects infants and children under the age of 5 years. Enterovirus 71 (EV71) and coxsackievirus A16 (CVA16) are the two main pathogens of HFMD, which accounted for >70% of the total cases during an outbreak in China in 2008 (6). HCT demonstrated therapeutic efficacy and relative safety when used to treat HFMD during recent epidemics (7,8). However, there have been no microbiological studies validating the usefulness of HCT for treating HFMD.Chen et al (9) studied the antiviral activity of HCT in a series of experiments in which African green monkey kidney epithelial (Vero) cells were infected with EV71 or CVA16 and treated with various concentrations of an HCT extract for 72 h. The results showed that HCT significantly blocked the cytopathic effect associated with EV71 but did not exhibit significant activity against CVA16 infection. However, a...

Houttuynia cordata Facilitates Metformin on Ameliorating Insulin Resistance Associated with Gut Microbiota Alteration in OLETF Rats

“…In our study, the levels of both serum and fecal endotoxin as well as serum TNF-α and IL-1β concentrations in the metformin + HCE group were significantly lower than those in the metformin group, indicating that the anti-inflammatory activity of Houttuynia cordata is stronger than that of metformin. It was reported that Houttuynia cordata supercritical extract (HSE) was able to reduce the production of TNF-α and prostaglandin E2 (PGE2) in a carrageenan-air pouch model of inflammation in mice, suggesting that HSE exerts anti-inflammatory effects by inhibiting TNF-α and cyclooxygenase 2 (COX-2)-PGE2 pathways [ 42 ]. Using lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages as an in vitro inflammatory model, it was shown that ethyl acetate fraction of Houttuynia cordata extract (HCE-EA) downregulated nitric oxide (NO), PGE2, TNF-α, and IL-6 production, as well as inducible nitric oxide synthase (iNOS) and COX-2 expression [ 43 ].…”

Houttuynia cordata Thunb: An Ethnopharmacological Review

“…Sodium houttuyfonate also showed potential therapeutic activity for rheumatoid arthritis, which is the destruction of the joint caused by pathological hyperplasia of the synovium. Through in vitro synovial cell experiments, sodium houttuyfonate effectively inhibited the proliferation of synovial cells in a dose-dependent manner within the range of 25 μg/ml∼200 μg/ml ( Li et al, 2014 ; Li and Zhao, 2015 ).…”

Extraction and activity of chemical constituents from Houttuynia cordata Thunb by ultrasonic method

“…Decyl acetaldehyde, the main antibacterial active component of Houttuynia cordata Thunb, has an obvious antibacterial effect on a variety of bacteria, acid-fast bacilli and fungi, but its properties are unstable (1)(2)(3). The synthetic sodium bisulfite adduct of decanoylacetaldehyde in China is called synthetic houttuynin and has an obvious antibacterial effect on a variety of gram-positive and negative bacteria (4).…”