Citri Reticulatae
Also known as: Citri Reticulatae, CRP, Dried tangerine peel, Chenpi, Citrus reticulata peel, Citri Reticulatae Pericarpium
Overview
Citri Reticulatae Pericarpium (CRP) is the dried peel of Citrus reticulata, commonly known as tangerine peel. It is a widely utilized ingredient in Traditional Chinese Medicine (TCM) and also serves as a food additive. Its primary bioactive compounds include flavonoids, terpenes, and alkaloids. Traditionally, CRP has been employed to address digestive disorders and respiratory conditions, and as a general health tonic. Modern research is exploring its potential antioxidant, anti-inflammatory, cardiovascular, gastrointestinal, neuroprotective, and anticancer properties. While there is a moderate body of research, including in vitro, animal studies, and some human randomized controlled trials (RCTs), large-scale clinical trials focusing solely on CRP are limited. The evidence base, primarily from China, suggests promising effects, but more rigorous clinical studies are needed to confirm its efficacy and safety.
Benefits
CRP exhibits several evidence-based benefits, primarily due to its rich phytochemical profile. It demonstrates significant anti-inflammatory and antioxidant effects in in vitro and animal models, suggesting a role in reducing oxidative stress and inflammation markers. Traditionally, CRP is highly valued for its gastrointestinal benefits, including alleviating indigestion, nausea, and vomiting; some clinical data from herbal formulations containing CRP support improved digestive function. The flavonoids present in CRP may also offer cardiovascular protection by potentially improving lipid profiles and vascular function, although human data in this area are limited. Preclinical studies have indicated potential neuroprotective and anticancer activities, but these require further clinical validation. In TCM, CRP is often used for elderly individuals and patients with chronic digestive or respiratory conditions. However, quantitative effect sizes are not well-established due to the heterogeneity of studies and the limited number of RCTs focusing exclusively on CRP. Most clinical evidence stems from multi-herb formulas, making it challenging to isolate CRP's specific contributions. Traditional use suggests long-term consumption, with clinical trials of herbal formulas containing CRP typically ranging from weeks to months.
How it works
The therapeutic actions of Citri Reticulatae Pericarpium (CRP) are primarily mediated by its diverse array of bioactive compounds, particularly flavonoids such as hesperidin, nobiletin, and isorhamnetin. These compounds exert their effects by modulating key biological pathways. They are known to influence oxidative stress pathways, reducing cellular damage caused by free radicals. Additionally, CRP's constituents can modulate inflammatory cytokines and immune responses, contributing to its anti-inflammatory properties. Network pharmacology studies suggest that CRP has multi-target effects, including potential antiviral activity, by interacting with various immune and inflammatory pathways. The absorption and bioavailability of these compounds vary, with flavonoids generally exhibiting moderate oral bioavailability. Metabolism by liver enzymes and gut microbiota plays a crucial role in their activation and systemic distribution.
Side effects
Citri Reticulatae Pericarpium (CRP) is generally considered safe when consumed within traditional dosage ranges. Documented common side effects (occurring in more than 5% of users) are not well-established in the scientific literature; however, mild gastrointestinal discomfort is a possibility. Reports of uncommon or rare adverse effects are not clearly detailed. Due to the presence of various flavonoids, caution is advised regarding potential drug interactions, particularly with anticoagulants or medications metabolized by liver enzymes, although these interactions are not extensively studied. Specific contraindications and considerations for special populations, such as pregnant women, breastfeeding mothers, or children, lack robust scientific data. Traditional use suggests prudence in these groups. Overall, while CRP has a favorable safety profile based on its long history of traditional use, more comprehensive clinical safety data are needed to fully characterize potential risks and interactions.
Dosage
There is no standardized dosage for isolated Citri Reticulatae Pericarpium (CRP) due to its predominant use within traditional herbal formulas, which vary widely in composition and concentration. Clinical trials involving herbal formulas containing CRP have typically utilized treatment durations of 1 to 2 months. The optimal dosage is highly dependent on the specific preparation (e.g., powder, decoction, extract) and the presence of other co-ingredients in a formula. Absorption of CRP's bioactive compounds may be influenced by co-administration with other herbal components or food. Furthermore, the bioavailability of flavonoids can be significantly affected by individual gut microbiota composition. Given the lack of specific guidelines for isolated CRP, it is advisable to follow the recommendations of a qualified healthcare practitioner or the instructions provided with standardized herbal products containing CRP. Upper limits and safety thresholds for isolated CRP are not well-defined in current research.
FAQs
Is CRP effective alone or only in formulas?
Most clinical evidence for CRP's efficacy comes from multi-herb formulas. While isolated CRP shows promise in preclinical studies, its effects when used alone require further dedicated clinical investigation.
Is it safe for long-term use?
Traditional use supports long-term consumption of CRP. However, robust clinical safety data specifically for long-term use of isolated CRP are limited, warranting caution and professional guidance.
Can CRP help with COVID-19?
Preliminary network pharmacology and metabolomics studies suggest potential antiviral effects against COVID-19 by modulating immune pathways. However, these are predictive models, and clinical evidence is currently lacking.
What are the expected results from using CRP?
Based on current evidence, improvements in digestive symptoms and a reduction in inflammation markers are plausible outcomes, particularly when CRP is used as part of traditional herbal formulations.
Research Sources
- https://e-century.us/files/ijcem/10/6/ijcem0053067.pdf – This meta-analysis reviewed the efficacy of Erchen decoction, which includes CRP, in treating non-alcoholic fatty liver disease (NAFLD). It found that the herbal formula improved liver function and lipid profiles compared to control groups. A limitation was that the specific effects of CRP could not be isolated from the multi-herb formula.
- https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2022.1048926/full – This study utilized metabolomics and network pharmacology to identify potential anti-COVID-19 agents within CRP. It suggested that isorhamnetin and other flavonoids could target immune pathways relevant to COVID-19. The study was preliminary, relying on in silico and biochemical analyses without clinical trial data.
- https://pubmed.ncbi.nlm.nih.gov/38942157/ – This systematic review provided a detailed phytochemical profile of CRP and summarized its multiple pharmacological activities, including antioxidant, anti-inflammatory, and cardiovascular benefits. It highlighted the need for more clinical trials and pharmacokinetic studies to fully understand CRP's effects and mechanisms.
- https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2021.801418/pdf – This review discusses the traditional uses and modern pharmacological activities of Citrus reticulata, including its peel. It covers various bioactive compounds and their potential health benefits, reinforcing the traditional applications with scientific insights into its anti-inflammatory and antioxidant properties.
- https://onlinelibrary.wiley.com/doi/10.1155/2014/925069 – This article explores the chemical constituents and pharmacological effects of Citrus reticulata, focusing on its traditional uses and potential therapeutic applications. It details the presence of flavonoids and other compounds responsible for its reported antioxidant, anti-inflammatory, and gastrointestinal benefits, supporting its role in traditional medicine.
