Inflammatory and Cytotoxic Activities of Abietane Terpenoids from Nepeta bracteata Benth.

Nepeta bracteata Benth. is used clinically to treat tracheal inflammation, coughs, asthma, colds, fevers, adverse urination, and other symptoms, along with functions in clearing heat and removing dampness. However, there have been few studies characterizing the material basis of its efficacy. Therefore, the aim of this study was to screen for compounds with anti-inflammatory activities in N. bracteata Benth. Using silica gel, ODS C18, and Sephadex LH-20 column chromatography, as well as semipreparative HPLC, 10 compounds were separated from N. bracteata Benth. extract, including four new diterpenoids (1-4), one amide alkaloid (5), and five known diterpenoids (6-10). The structures of all the isolates were elucidated by HR-ESI-MS, NMR, and CD analyses. Using lipopolysaccharide (LPS)-stimulated RAW 264.7 cells, we investigated the anti-inflammatory activities of compounds 1-10. It is worth noting that all were able to inhibit nitric oxide (NO) production with IC50 values < 50 µM and little effect on RAW 264.7 macrophage viability. Compounds 2 and 4 displayed remarkable inhibition with IC50 values of 19.2 and 18.8 µM, respectively. Meanwhile, screening on HCT-8 cells demonstrated that compounds 2 and 4 also had moderate cytotoxic activities with IC50 values of 36.3 and 41.4 µM, respectively, which is related to their anti-inflammatory effects.

Effect of Nepeta bracteata Benth. on allergic rhinitis symptoms: A randomized double-blind clinical trial.

BACKGROUND: Allergic rhinitis (AR) is one of the health problems in the world. It is necessary to develop new treatment procedure for control of this disease. The aim of this study was to assess the effect of Zofa (Nepeta bracteata Benth) on AR patients. MATERIALS AND METHODS: In this double-blind randomized clinical trial study, 71 patients (37 patients in treatment and 34 in placebo group) participated. In treatment group, N. bracteata syrup (NBS) was used for 4 weeks as three times a day. The efficacy of the drug regarding AR symptoms (rhinorrhea, sneezing, nasal obstruction, itchy nose, and ocular symptoms) were evaluated through a visual analog scale (VAS) by 0-10 before administration and at the end of the whole treatment period. The collected information was entered in the SPSS software (version 18) and was analyzed using the Fisher's exact test, Chi-square test, independent sample t-test, and paired sample test. RESULTS: The improvement of AR symptoms in the group receiving NBS was significantly higher compared to control group (4.73 ± 1.84 vs. 0.38 ± 2.06; P < 0.0001). Furthermore, the mean of total VAS before and after the treatment (in case group) was 7.10 ± 1.92 and 2.37 ± 1.76, respectively (P < 0.001). CONCLUSION: The results of this study indicate that N. bracteata has significant effects on improving the symptoms of AR. Hence, it can be a good alternative to AR symptoms relief.

Abietane-Type Diterpenoids From Nepeta bracteata Benth. and Their Anti-Inflammatory Activity.

Terpenes possess a wide range of structural features and pharmaceutical activities and are promising for drug candidates. With the aim to find bioactive terpene molecules, eight new compounds were isolated from the medicinal plant Nepeta bracteata Benth., including seven new abietane-type diterpenoids (1-7), along with a new ursane-type triterpenoid (8). The structures of compounds 1-8 were elucidated through the detailed spectroscopic analyses of their 1D and 2D NMR and MS data, and the absolute configurations of compounds 1-7 were determined by comparing their experimental and calculated ECD spectra. Compound 1 was a novel degraded carbon diterpene with the disappearing of methyl signal at C-19, while compound 7 possessed a new norabietane-type diterpenoid carbon skeleton with the presence of five-membered lactone arising from ring rearrangement. The anti-inflammatory of all obtained isolates were evaluated on lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and the results of anti-inflammatory activity screening showed that compared with the LPS model group, all compounds were significantly down-regulation the TNF-α inflammatory factor at the specific concentration, except for compound 6.