Uncovering Mechanisms of Zanthoxylum piperitum Fruits for the Alleviation of Rheumatoid Arthritis Based on Network Pharmacology

Zanthoxylum piperitum fruits (ZPFs) have been demonstrated favorable clinical efficacy on rheumatoid arthritis (RA), but its compounds and mechanisms against RA have not been elucidated. This study was to investigate the compounds and mechanisms of ZPFs to alleviate RA via network pharmacology. The compounds from ZPFs were detected by gas chromatography–mass spectrometry (GC-MS) and screened to select drug-likeness compounds through SwissADME. Targets associated with bioactive compounds or RA were identified utilizing bioinformatics databases. The signaling pathways related to RA were constructed; interactions among targets; and signaling pathways-targets-compounds (STC) were analyzed by RPackage. Finally, a molecular docking test (MDT) was performed to validate affinity between targets and compounds on key signaling pathway(s). GC-MS detected a total of 85 compounds from ZPFs, and drug-likeness properties accepted all compounds. A total of 216 targets associated with compounds 3377 RA targets and 101 targets between them were finally identified. Then, a bubble chart exhibited that inactivation of MAPK (mitogen-activated protein kinase) and activation of PPAR (peroxisome proliferator-activated receptor) signaling pathway might be key pathways against RA. Overall, this work suggests that seven compounds from ZPFs and eight targets might be multiple targets on RA and provide integrated pharmacological evidence to support the clinical efficacy of ZPFs on RA.

Elucidation of Japanese pepper (Zanthoxylum piperitum De Candolle) domestication using RAD-Seq

Japanese pepper,Zanthoxylum piperitum, is native to Japan and has four well-known lineages (Asakura, Takahara, Budou, and Arima), which are named after their production area or morphology. Restriction-site associated DNA sequencing (RAD-Seq) was used to analyse 93 accessions from various areas, including these four lineages. Single nucleotide variant analysis was used to classify the plants into eight groups: the Asakura and Arima lineages each had two groups, the Takahara and Budou lineages each had one group, and two additional groups were present. In one Asakura group and two Arima groups, the plants were present in agricultural fields and mountains, thus representing the early stage of domestication of the Japanese pepper. The second Asakura lineage group was closely related to plants present in various areas, and this represents the second stage of domestication of this plant because, after early domestication, genetically related lineages with desirable traits spread to the periphery. These results demonstrate that domestication of Japanese pepper is ongoing. In addition, this study shows that spineless plants are polyphyletic, despite the spineless lineage being considered a subspecies of Japanese pepper.

Elucidation of Japanese pepper (Zanthoxylum piperitum De Candolle) domestication using RAD-Seq

Japanese pepper, Zanthoxylum piperitum, is native to Japan and has four famous varieties: Asakura, Takahara, Budou, and Arima, named after their production area or morphology. Restriction-site associated DNA sequencing (RAD-Seq) was used to analyse 93 accessions from various areas, including these four varieties. The analysis of the single nucleotide variants was used to classify the plants into eight groups: each of the Asakura and Arima varieties has two groups, each of the Takahara and Budou varieties has one group, and two additional groups are present. In one group of the Asakura varieties and two groups of the Arima varieties, the plants were present in agricultural fields and mountains, representing the early stage of domestication of the Japanese pepper. The second group of the Asakura varieties was of genetically close plants present in various areas, which represents the second stage of domestication of this plant because, after early domestication, genetically related varieties of excellent traits spread to the periphery. These results demonstrate that the domestication of the Japanese pepper is ongoing. In addition, this study shows that spineless plants are polyphyletic, despite the spineless variety being considered a subspecies of the Japanese pepper.

Topical application of Zanthoxylum piperitum extract improves lateral canthal rhytides by inhibiting muscle contractions

Facial wrinkles are the predominant phenotypes of skin aging. To date, one of the most effective ways to improve wrinkles is botulinum toxin type A (BoNT/A) injection, which inhibits muscle contractions by reducing acetylcholine release from neurons. However, since BoNT/A is a hazardous neurotoxin, the injection can only be performed by medical doctors and the procedure is only possible through invasive injection, causing inconveniences such as pain. To overcome these inconveniences, we tried to find a way to reduce wrinkles non-invasively via mechanisms similar to BoNT/A. We first designed in vitro assays to test BoNT/A-like muscle contraction inhibition in two different model systems. By using the assays, we identified Zanthoxylum piperitum (Z. piperitum) fruit extract as a BoNT-like reagent (27.7% decrease of muscle contraction rates by 1000 ppm of Z. piperitum extract treatment). Next, we determined mechanisms of how Z. piperitum extract decreases muscle contraction rates and found that the extract treatment inhibits electrical signal transduction in neurons. We also showed that among known components of Z. piperitum extract, quercitrin is responsible for muscle contraction inhibition. We further identified that Z. piperitum extract has synergistic effects with acetyl hexapeptide-8 and BoNT/A light chain, which are well-known BoNT-like peptides. Finally, we showed that topical treatment of the Z. piperitum extract indeed decreases facial wrinkles and treatment of Z. piperitum extract with acetyl hexapeptide-8 has a tendency to improve wrinkles synergistically (14.5% improvement on average). The synergistic effect of the combination is expected to improve wrinkles effectively by implementing the BoNT/A mechanisms in a non-invasive way.