Preclinical evaluation of Zanthoxylum piperitum Benn., traditional muscle pain remedy, for joint inflammation

ETHNOPHARMACOLOGICAL RELEVANCE

Zanthoxylum piperitum has been used as a traditional Asian medicine to treat hypertension, stroke, bruise and muscle pain. It has been known to induce detoxification; affect anti-bacterial, anti-oxidant, and tyrosinase activity; inhibit osteosarcoma proliferation; anti-osteoarthritis inflammation. In this study, we aim to identify the therapeutic effect of Z. piperitum 90% EtOH extract (ZPE-LR) on rheumatoid arthritis.

MATERIAL AND METHODS

We investigated the anti-rheumatoid arthritis and -immunomodulatory activities of the ZPE-LR in collagen-induced arthritic (CIA) mice, a rheumatoid arthritis animal model. In order to assess the analgesic effects of ZPE-LR in vivo, acetic acid injection, formaldehyde injection, hot plate model was used. The mechanism for anti-inflammatory activity of ZPE-LR was identified with LPS-stimulated Raw 264.7 cells.

RESULTS

Pharmacologically, oral administration of ZPE-LR into CIA mice resulted in a significant and dose-dependent decrease in clinical arthritis score and paw swelling compared to untreated negative control. Pathologic examination showed that ZPE-LR prevented morphological change in cartilage and destruction of phalanges in CIA mice. This protective effect was associated with reduced pain, inflammatory mediators such as NO, TNF-α, IL-1β, and IL-6, as well as COX-2 and iNOS expression. Furthermore, reduction of phosphor-ERK and BDNF indicates a novel rheumatoid arthritis-regulating mechanism by ZPE-LR treatment.

CONCLUSIONS

These data suggest that the administration of ZPE-LR remarkably inhibited CIA progression and might be helpful in suppressing inflammation and pain in rheumatoid arthritis.

Extract from Zanthoxylum piperitum Induces Apoptosis of AGS Gastric Cancer Cells Through Akt/MDM2/p53 Signaling Pathway

OBJECTIVE

To determine the effect of Zanthoxylum piperitum extracet (ZPE) on apoptosis and analyze anticancer substances in ZPE, changes in proteins related to apoptosis, and pathological changes in tumors in mouse.

METHODS

Fifteen 4-week-old female BALB/c nu/nu mice were divided into 3 groups depending on ZPE dose, with 5 in each group. AGS gastric carcinoma cells (1 × 10⁶ cells/200 µL) were subcutaneously injected into the flank of each mouse. One week after the injection of AGS cells, ZPE was administered to the skin tissue [10 or 50 mg/(kg·d)] in the low- and high-dose groups, respectively for 20 days. Control animals were injected with vehicle only. After 3 weeks, the tumor was extracted and carried out for immunohistochemistry, the tendency of apoptosis and p53 in the body was checked using TdT-mediated dUTP nick-end labeling (TUNEL) assay. For 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, annexin V dead cell staining, cell cycle arrest and Western blotting, AGS gastric carcinoma cells were incubated with various concentrations of ZPE for 24 h. Cell survival rates were analyzed by MTT assays. Apoptosis was analyzed using annexin V dead cell staining and cell cycle arrest and measured using Muse cell analyzer.

RESULTS

High performance liquid chromatography (HPLC) analysis showed that ZPE contained organic sulfur compounds such as alliin and S-allylcysteine. MTT assay results revealed that ZPE (10-85 µ g/mL) could effectively inhibit the growth of AGS gastric cancer cells at higher concentrations (P<0.05, P<0.01). The annexin V & dead cell staining assay and cell cycle arrest assay confirmed a dose-dependent increase in the apoptosis rate and G₁ phase in ZPE (10-70 µ g/mL) groups. ZPE decreased the expression of anti-apoptotic proteins (p-Akt, p-MDM2, Bcl-2), while increased pro-apoptotic proteins (cleaved PARP, p53, pro-Caspase 3, Bax). TUNEL assays revealed an increase in cell apoptosis. Immunohistochemistry staining confirmed the involvement of p53.

CONCLUSION

ZPE decreases AGS cell proliferation and induces apoptosis by inhibiting Akt and MDM2 expression.

Effect of freezing treatment in tea preparation using Camellia sinensis leaves

This study was conducted to examine the effect of freezing in the tea preparation using Camellia sinensis leaves in order to develop new technology for improving tea quality. Effects of single and combined treatments of freezing (F: - 20 °C, 15 days), steaming (S: 100 °C, 3 min), and hot-air drying (HD: 50 °C, 12 h) on the physicochemical characteristics of tea (powder and hot-water leachate) prepared from treated Camellia sinensis leaves were investigated. The L ^* , b ^* , and C ^* values of the powder were the highest in SHD-treated leaves, followed by HD-, SFHD-, and FHD-treated leaves. Redness (+a ^* value) was only seen in FHD-treated leaves and greenness (- a ^* value) was the highest in SHD-treated leaves. Browning index of the leachate was significantly lower in SHD- and SFHD-treated leaves than in FHD-treated leaves (p < 0.05). Soluble solids, acidity, and phenolic compounds of FHD-treated leaves were significantly lower than in SHD- and SFHD-treated leaves (p < 0.05). Sucrose was highest in SHD-treated leaves and glucose was highest in FHD-treated leaves. Sensory preference was better evaluated in FHD-treated leaves than in SHD- and SFHD-treated leaves. These results suggest that freezing treatment in tea processing promotes browning and component decomposition and enhances sensual preference. Therefore, freezing has a potential application in the tea manufacturing.