Correlation of antioxidant activity and volatile oil chemical components from Schizonepeta tenuifolia herbs by chemometric methods

Comparison of Three Different Extraction Methods on Schizonepeta tenuifolia (Benth.) Briq Essential Oil: Chemical Constituents and in Vitro and in Silico Biological Activities

This study evaluated the effects of three extraction methods, hydrodistillation (HD), steam distillation (SD), and lipophilic solvent extraction (LSE), on the yield, chemical composition, and in vitro/in silico biological activities of Schizonepeta tenuifolia (Benth.) Briq essential oil (STEO). The highest yield of STEO was obtained by HD (0.750±0.040 %), followed by SD (0.440±0.020 %) and LSE (0.350±0.030 %). Although their contents varied, menthone and pulegone predominated in HDEO, SDEO, and LSEO. HDEO displayed the strongest antioxidant ability, with a 2,2-diphenyl-1-picrylhydrazyl (DPPH) IC50 value of 14.164±0.090 mg/mL and (2,2'-azino-bis (3ethylbenzothiazoline-6-sulfonic acid)) (ABTS) value of 0.326±0.023 mg/mL. SDEO demonstrated the highest antimicrobial activity against Staphylococcus aureus and Escherichia coli and HDEO the highest potent anti-inflammatory activity. The molecular docking of menthone and pulegone demonstrated strong binding to inflammatory targets, including prostaglandin-endoperoxide synthase 1 (PTGS1) and 2 (PTGS2) and tumor necrosis factor alpha (TNF-α). In short, the extraction method significantly affected the yield, composition, and biological activity of STEO.

Unlocking the combined action of Mentha pulegium L. essential oil and Thym honey: In vitro pharmacological activities, molecular docking, and in vivo anti-inflammatory effect

Mentha pulegium L., a plant widely embraced for its therapeutic properties by populations worldwide, including Morocco, has long been recognized for its potential in treating various ailments. This study aims to comprehensively evaluate the antioxidant, anti-inflammatory, and dermatoprotective properties of essential oil derived from M. pulegium, and thyme honey as well as their combined effects. To unravel the chemical composition, a rigorous GC-MS analysis was conducted. Subsequently, we examined their antioxidant potential through three distinct assays: DPPH●, hydrogen peroxide assay, and xanthine oxidase assay. The anti-inflammatory properties were scrutinized through both in vitro and in vivo experiments. Simultaneously, the dermatoprotective efficacy was investigated in vitro by evaluating tyrosinase inhibition. Our findings revealed that pulegone constitutes the predominant compound in M. pulegium essential oil (MPEO), constituting a remarkable 74.82 % of the composition. Significantly, when the essential oil was combined with thym honey, it exhibited superior anti-inflammatory and dermatoprotective effects across all in vivo and in vitro tests. Moreover, our in silico molecular docking analysis hinted at the potential role of cyclohexanone, 3-methyl, an element found in the MPEO, in contributing to the observed outcomes. While this study has unveiled promising results regarding the combined in vitro, in vivo and in silico biological activities of the essential oil and honey, it is imperative to delve further into the underlying mechanisms through additional experimentation and alternative experimental methods. Understanding these mechanisms in greater detail will not only enhance our comprehension of the therapeutic potential but also pave the way for the development of innovative treatments and applications rooted in the synergy of these natural compounds. Furthermore, it would be advantageous to test different possible combinations using experimental design model. Moreover, it would be better to test the effect of single compounds of MPEO to clearly elucidate their efficiency. MPEO alone or combined with thyme honey may be a useful for the development of novel biopharmaceuticals.

Spectrum-effect relationship between GC-QTOF-MS fingerprint and antioxidant, anti-inflammatory activities of Schizonepeta tenuifolia essential oil

Schizonepeta tenuifolia (Benth.) Briq, a traditional Chinese medicine, is an annual herbaceous plant that is widely distributed in China, Japan, and Korea. The essential oil (EO) of S. tenuifolia has antioxidant and anti-inflammatory properties. However, the components contributing to its antioxidant and anti-inflammatory activities remain unclear. This study was aimed at investigating the spectrum-effect relationship between GC-MS fingerprint and the antioxidant and anti-inflammatory effects of S. tenuifolia EO. Here, the fingerprints of EO from 10 batches of S. tenuifolia from various sources were established using GC-MS, and the antioxidant and anti-inflammatory bioactivities were evaluated using 2,2-diphenyl-1-picrylhydrazyl and nitric oxide inhibitory assays, respectively. Finally, 13 common peaks were identified from 10 batches of S. tenuifolia by searching against the standard mass spectra in NIST 14 and comparing the literature retention index. The different sources of S. tenuifolia EO exhibit mild antioxidant activities and significant anti-inflammatory effects. In particular, menthone (peak 3), isomenthone (peak 4), pulegone (peak 7), piperitone (peak 8), and β-caryophyllene (peak 11) might be the dominant constituents responsible for the antioxidant and anti-inflammatory activities of S. tenuifolia EO. This method may provide a time-saving, convenient way to screen the potential effective components of S. tenuifolia EO.