Aurantii Nobilis Pericarpium
Also known as: Aurantii Nobilis Pericarpium, Dried tangerine peel, Chenpi, Citrus reticulata
Overview
Aurantii Nobilis Pericarpium, derived from the dried peel of the mandarin orange (Citrus reticulata), is a prominent ingredient in East Asian traditional medicine, particularly in Traditional Chinese Medicine (TCM) and Kampo formulations. It is traditionally valued for its role in addressing digestive issues and respiratory conditions. Modern research, primarily focusing on multi-herb formulas containing this ingredient, highlights its potential in managing neuropsychiatric and inflammatory disorders. Its therapeutic effects are attributed to bioactive compounds like hesperidin and nobiletin, which are aromatic flavonoids. While direct evidence for the isolated peel is limited, its efficacy within complex herbal formulas, such as Yokukansan, is supported by several randomized controlled trials and systematic reviews.
Benefits
Aurantii Nobilis Pericarpium, predominantly as a component of multi-herb formulas like Yokukansan (YKS), demonstrates significant neuropsychiatric benefits. A meta-analysis of randomized controlled trials (RCTs) showed YKS significantly reduced behavioral and psychological symptoms of dementia (BPSD), including delusions and agitation, with a weighted mean difference of -7.20 in Neuropsychiatric Inventory (NPI) scores (p < 0.00001 to 0.0009), indicating a clinically meaningful effect. This suggests strong evidence for its role in improving dementia-related symptoms. Furthermore, studies suggest anti-inflammatory and neuroprotective effects, with YKS modulating serotonergic (5-HT1A and 5-HT2A receptors) and glutamatergic systems. While not isolated to Aurantii Nobilis Pericarpium, related Kampo formulas have shown anti-inflammatory effects in animal models of chronic obstructive pulmonary disease (COPD), suggesting potential systemic benefits. Systematic reviews of TCM, including formulas with this ingredient, also indicate improvements in geriatric symptoms like cognitive decline and behavioral disturbances.
How it works
The primary mechanism of action for Aurantii Nobilis Pericarpium, particularly its bioactive flavonoids like hesperidin, involves modulating neurotransmitter systems. It acts as a partial antagonist of 5-HT1A receptors and downregulates 5-HT2A receptors, which are crucial for mood and behavioral regulation. Additionally, it influences glutamate neurotransmission by inhibiting glutamate release and stimulating glutamate transporters, thereby potentially protecting neurons from excitotoxicity. These neurochemical modulations are believed to underpin its efficacy in managing neuropsychiatric symptoms, especially in dementia. The absorption and bioavailability of its active compounds are influenced by the specific preparation and co-administration with other herbs in traditional formulas.
Side effects
Aurantii Nobilis Pericarpium is generally well tolerated, especially when used within traditional Kampo formulas. Clinical trials, particularly those involving Yokukansan (YKS) for dementia-related symptoms, have reported no significant adverse effects, indicating a favorable safety profile in elderly populations. Safety data for the isolated ingredient are limited, but its long history of traditional use and consistent findings from clinical studies of formulas suggest a low risk of adverse reactions. There are no major drug interactions or contraindications extensively documented in high-quality studies. However, caution is advised when combining Aurantii Nobilis Pericarpium-containing formulas with other serotonergic agents due to the theoretical potential for additive effects, although no direct evidence of serotonin syndrome has been reported. Overall, the risk of side effects appears to be low, particularly when used as part of established traditional formulations and under clinical supervision.
Dosage
Dosage for Aurantii Nobilis Pericarpium is typically standardized within multi-herb Kampo formulas rather than as an isolated ingredient. For instance, in the Kampo formula Yokukansan (YKS), which contains Aurantii Nobilis Pericarpium, the total formula is commonly administered in doses ranging from 2.5 to 7.5 grams per day. The specific amount of dried citrus peel within this total formula varies. There is no established maximum safe dose for the isolated ingredient, as its clinical use primarily follows traditional formulations where it is combined with other herbs. Optimal dosing is dependent on the specific formula, the clinical indication, and individual patient factors. It is crucial to adhere to the dosage recommendations provided for the complete herbal formula rather than attempting to dose the isolated ingredient.
FAQs
Is Aurantii Nobilis Pericarpium effective alone?
Most clinical evidence for Aurantii Nobilis Pericarpium's efficacy comes from its use within multi-herb formulas like Yokukansan; its effectiveness as an isolated ingredient is not well established.
Is it safe for elderly patients?
Yes, clinical trials involving elderly dementia patients using formulas containing Aurantii Nobilis Pericarpium have shown good tolerability and a favorable safety profile.
How quickly do benefits appear?
Improvements in neuropsychiatric symptoms, particularly in dementia, have been observed within weeks to months in randomized controlled trials using formulas containing this ingredient.
Are there risks of serotonin syndrome?
While no direct evidence of serotonin syndrome has been reported, caution is warranted when combining Aurantii Nobilis Pericarpium-containing formulas with other serotonergic drugs due to potential additive effects.
Research Sources
- https://onlinelibrary.wiley.com/doi/pdf/10.1111/ggi.12803 – This meta-analysis of 4 RCTs (n≥30 per group) found that Yokukansan (containing Aurantii Nobilis Pericarpium) significantly reduced BPSD scores (NPI) in elderly dementia patients over 4-12 weeks (p<0.00001), with good tolerability and low heterogeneity (I2=0%). It provides strong evidence for the formula's efficacy in managing neuropsychiatric symptoms in dementia.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC11074295/ – This preclinical study, with some clinical relevance, investigated Kampo formulas containing dried citrus peel in an animal model of COPD. It demonstrated anti-inflammatory effects via cytokine modulation, suggesting potential systemic benefits, though it provides indirect evidence for Aurantii Nobilis Pericarpium's isolated effects.
- https://www.liebertpub.com/doi/10.1089/jicm.2022.0532 – This systematic review of 37 RCTs/meta-analyses examined the use of TCM, including Kampo formulas with Aurantii Nobilis Pericarpium, in geriatrics. It concluded that these treatments improved various geriatric symptoms, including cognition and behavior, despite heterogeneity in the studies and formulas reviewed.