Antidepressant effect of Perilla frutescens essential oil through monoamine neurotransmitters and BDNF/TrkB signal pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese medicine posits that affect-mind ill-being is the primary cause of depression, with Qi movement stagnation as its pathogenesis. As such, clinical treatment for depression should prioritize regulating Qi and relieving depressive symptoms. The pharmacological properties of traditional Chinese medicine indicate that Perilla frutescens may have potential therapeutic effects on depression and other neuropsychiatric diseases due to its ability to regulate Qi and alleviate depressive symptoms. Although previous studies have reported the antidepressant effects of Perilla frutescens, the mechanism underlying PFEO inhalation-mediated antidepressant effect remains unclear.

AIM OF THE STUDY

The aim of this investigation is to elucidate the antidepressant mechanisms of PFEO by examining its effects on monoamine neurotransmitters and the BDNF/TrkB signaling pathway.

MATERIALS AND METHODS

The CUMS rat model of depression was established, and the depressive state of the animals was assessed through sucrose preference and forced swim tests. ELISA assays were conducted to determine monoamine neurotransmitter levels in the hippocampus and cerebral cortex of rats. Immunohistochemistry, western blotting, and RT-PCR experiments were employed to investigate the BDNF/TrkB signaling pathway's regulation of depression via PFEO inhalation.

RESULTS

It has been observed that inhalation administration of PFEO can significantly enhance the preference for sugar water in CUMS rats and reduce their immobility time during forced swimming. Additionally, there was an increase in the levels of monoamine transmitters in both the hippocampus and cerebral cortex of these rats. Furthermore, there was an upregulation in the expression levels of BDNF and TrkB positive cells as well as BDNF and TrkB proteins within both regions, along with increased BDNF mRNA and TrkB mRNA expression levels.

CONCLUSION

The antidepressant effect of PFEO via inhalation administration is speculated to be mediated through the monoamine neurotransmitters and BDNF/TrkB signaling pathway.

New depside and rosmarinic acid derivatives from Perilla frutescens and their anti-inflammatory activity

Two new depside derivatives 1 and 2 as well as a new pair of rosmarinic acid enantiomers 3a/b were isolated from the leaves of Perilla frutescens (L.) britt. The chemical structures of these compounds were identified based on detailed spectroscopic and physicochemical analyses (HR-ESI-MS, NMR) and comparison of literature data. Compounds 3a/b were obtained by chiral separation, and their absolute configurations were determined by comparison of experimental and calculated ECD spectra. Compounds 3a/b exhibited potential inhibitory activity on nitric oxide (NO) production induced by lipopolysaccharide in RAW264.7 cells with IC50 values of 15.92 ± 3.32 μM and 48.72 ± 4.12 μM.

[Comparison of active components in different parts of Perilla frutescens and its pharmacological effects]

Perilla frutescens is a widely used medicinal and edible plant with a rich chemical composition throughout its whole plant. The Chinese Pharmacopoeia categorizes P. frutescens leaves(Perillae Folium), seeds(Perillae Fructus), and stems(Perillae Caulis) as three distinct medicinal parts due to the differences in types and content of active components. Over 350 different bioactive compounds have been reported so far, including volatile oils, flavonoids, phenolic acids, triterpenes, sterols, and fatty acids. Due to the complexity of its chemical composition, P. frutescens exhibits diverse pharmacological effects, including antibacterial, anti-inflammatory, anti-allergic, antidepressant, and antitumor activities. While scholars have conducted a substantial amount of research on different parts of P. frutescens, including analysis of their chemical components and pharmacological mechanisms of action, there has yet to be a systematic comparison and summary of chemical components, pharmacological effects, and mechanisms of action. Therefore, this study overviewed the chemical composition and structures of Perillae Folium, Perillae Fructus, and Perillae Caulis, and summarized the pharmacological effects and mechanisms of P. frutescens to provide a reference for better development and utilization of this valuable plant.

On-Site Evaluation of Constituent Content and Functionality of Perilla frutescens var. crispa Using Fluorescence Spectra

Perilla frutescens leaves are hypothesized to possess antioxidant and amyloid-β (Aβ) aggregation inhibitory properties primarily due to their polyphenol-type compounds. While these bioactivities fluctuate daily, the traditional methods for quantifying constituent contents and functional properties are both laborious and impractical for immediate field assessments. To address this limitation, the present study introduces an expedient approach for on-site analysis, employing fluorescence spectra obtained through excitation light irradiation of perilla leaves. Standard analytical techniques were employed to evaluate various constituent contents (chlorophyl (Chl), total polyphenol content (TPC), total flavonoid content (TFC), and rosmarinic acid (RA)) and functional attributes (DPPH radical scavenging activity, ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), and Aβ aggregation inhibitory activity). Correlations between the fluorescence spectra and these parameters were examined using normalized difference spectral index (NDSI), ratio spectral index (RSI), and difference spectral index (DSI) analyses. The resulting predictive model exhibited a high coefficient of determination, with R2 values equal to or greater than 0.57 for constituent contents and 0.49 for functional properties. This approach facilitates the convenient, simultaneous, and nondestructive monitoring of both the chemical constituents and the functional capabilities of perilla leaves, thereby simplifying the determination of optimal harvest times. The model derived from this method holds promise for real-time assessments, indicating its potential for the simultaneous evaluation of both constituents and functionalities in perilla leaves.

The Role and Mechanism of Perilla frutescens in Cancer Treatment

Perilla frutescens is an annual herb of the Labiatae family and is widely grown in several countries in Asia. Perilla frutescens is a plant that is used medicinally in its entirety, as seen in its subdivision into perilla seeds, perilla stalks, and perilla leaves, which vary more markedly in their chemical composition. Several studies have shown that Perilla frutescens has a variety of pharmacological effects, including anti-inflammatory, antibacterial, detoxifying, antioxidant, and hepatoprotective. In the absence of a review of Perilla frutescens for the treatment of cancer. This review provides an overview of the chemical composition and molecular mechanisms of Perilla frutescens for cancer treatment. It was found that the main active components of Perilla frutescens producing cancer therapeutic effects were perilla aldehyde (PAH), rosmarinic acid (Ros A), lignan, and isoestrogen (IK). In addition to these, extracts of the leaves and fruits of Perilla frutescens are also included. Among these, perilla seed oil (PSO) has a preventive effect against colorectal cancer due to the presence of omega-3 polyunsaturated fatty acids. This review also provides new ideas and thoughts for scientific innovation and clinical applications related to Perilla frutescens.

Comprehensive HPLC fingerprint analysis based on a two-step extraction method for quality evaluation of Perilla frutescens (L.) Britt

Abundant chemical components are key to ensure the evaluation accuracy of fingerprint analysis of traditional Chinese medicines (TCMs). A two-step extraction method combining supercritical fluid extraction (SFE) and water ultrasonic extraction was established for the quality evaluation of Perilla frutescens (L.) Britt. Weakly polar components were extracted under optimal SFE conditions (15% co-solvent (EtOH : n-hexane = 1 : 14, (v/v)), 40 °C, 250 bar, and 30 min), and polar components were subsequently extracted by an ultrasonic step (100% water as solvent, 40 °C, and 45 min). Then, HPLC methods were established, which were validated to be accurate, stable, and reliable. In this work, 25 batches of samples were evaluated and the data were analysed by similarity analysis (SA) and hierarchical cluster analysis (HCA). The similarity values of SFE extracts and aqueous extracts were respectively 0.616-0.999, and 0.252-0.997, proving the importance of the extraction method for the accuracy of the subsequent fingerprint analysis results. For the HCA, 25 samples were divided into two categories (leaves and stems), among which four batches of leaves with less similarity were considered as stems, indicating that quality differences of P. frutescens depending on medicinal parts and origin exist. The two-step extraction method developed in this work has been proved to be suitable for the quality evaluation of TCMs with complex compositions.

Microwave-ultrasonic technique development coupled with natural deep eutectic solvents in anthocyanin extraction from perilla leaves (Perilla frutescens var. Acuta)

BACKGROUND

As potent antioxidants, anthocyanins can protect the body from free radicals. However, the traditional solvent extraction method has the disadvantages of requiring a high extraction temperature and long extraction time, so it is necessary to develop an efficient extraction method for anthocyanins.

RESULTS

In this study, the technique of natural deep eutectic solvents (DESs) was applied to extract anthocyanins from purple perilla leaves with the aid of microwave-ultrasonic assisted extraction (MUAE). The response surface methodology (RSM), based on the Box-Behnken design (BBD), predicted the maximum extraction yield of anthocyanins to be 619.62 mg (100 g)^-1 under the following conditions: x₁ (ultrasonic extraction power) = 357.25 W, x₂ (time) = 25.62 min, and x₃ (temperature) = 57.80 °C. The biological activity of the extract obtained was evaluated by examining its radical-scavenging effect on 1,1-diphenyl-2-picrylhydrazyl, hydroxyl radical, and superoxide anion radicals. Its bacteriostatic impact was investigated on four typical bacteria: Shewanella putrefaciens (S. putrefaciens), Pseudomonas fluorescens (P. fluorescens), Escherichia coli (E. coli), and Staphylococcus aureus (S. aureus).

CONCLUSION

The integrated extraction method of DESs with MUAE was efficient, energy-saving, green, and sustainable. © 2022 Society of Chemical Industry.

Antiasthmatic Compounds Targeting β2-Adrenergic Receptor from Perilla frutescens Improved Lung Inflammation by Inhibiting the NF-κB Signaling Pathway

Asthma is a highly prevalent and heterogeneous chronic respiratory disease and is often treated with inhaled corticosteroids or in combination with a β₂-adrenergic receptor (β₂-AR) agonist. However, around 5% of asthma remains uncontrolled, and more effective antiasthmatic drugs with known mechanisms are in high demand. Herein, we immobilized β₂-AR on the polystyrene amino microsphere surface in a one-step fashion. The successful immobilization of β₂-AR was verified by scanning electron microscopy and chromatographic analysis. We screened rosmarinic acid (RA) as the bioactive compound targeting β₂-AR in Perilla frutescens (L.) Britton by mass spectroscopy. The binding constant between RA and β₂-AR was determined to be 2.95 × 10⁴ M^-1 by adsorption energy distribution and frontal analysis. The antiasthmatic effect and mechanism of RA were examined on a murine model of allergic asthma induced by ovalbumin (OVA) and aluminum hydroxide. The results showed that RA significantly reduced lung inflammatory cell numbers, the production of Th2 cytokines, and the secretion of total IgE, OVA-specific IgE, and eotaxin. The decreased inflammatory cell infiltration and mucus hypersecretion were associated with the inhibition of the NF-κB signaling pathway. Moreover, the mRNA expression levels of AMCase, CCL11, CCR3, Ym2, and E-selectin in the lung tissues were effectively reduced. It is the first time that RA was proven to target β₂-AR and be effective in counteracting allergic airway inflammation via the NF-κB signaling pathway. Therefore, the immobilized β₂-AR preserves the potential in screening antiasthmatic compounds from herbal medicine, and RA can be developed as an effective agent for the treatment of allergic asthma.

Quantitative Comparison and Chemical Profile Analysis of Different Medicinal Parts of Perilla frutescens (L.) Britt. from Different Varieties and Harvest Periods

Perilla frutescens (L.) Britt. is a plant that has been classified as one of the "One Root of Medicine and Food", and it can be used both as medicine and as food. To explore the influence of different varieties and harvest periods on the quality of different medicinal parts of P. frutescens, a comprehensive study on the chemical constituents of P. frutescens based on plant metabolomics was conducted. A total of 57 nonvolatile chemical components and 105 volatile chemical components of P. frutescens were characterized by ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) and gas chromatography-mass spectrometry (GC-MS). Furthermore, 35, 27, and 2 nonvolatile constituents as well as 16, 16, and 18 volatile constituents were identified as potential markers for discriminating P. frutescens between different medicinal parts, different varieties, and different harvest periods, respectively. Besides, 22 bioactive compounds of P. frutescens were quantitatively determined by a new sensitive UPLC-MS/MS method. This study comprehensively compares the differences and similarities of P. frutescens among the different medicinal parts, different varieties, and different harvest periods, and the results of this study may provide a theoretical basis and guidance for studying the quality evaluation and the optimization of the harvest period of this plant.

Perilla frutescens: A Rich Source of Pharmacological Active Compounds

Perilla frutescens (L.) Britton, an important pharmaceutical and nutraceutical crop, is widely cultivated in East Asian countries. In this review, we present the latest research findings on the phytochemistry and pharmacological activities of P. frutescens. Different databases, including PubMed, Scopus, CNKI, Agricola, Scifinder, Embase, ScienceDirect, DOAJ, and Web of Science, were searched to present the best review. In this review, we clearly represent the active constituents responsible for each and every pharmacological activity, plausible mechanism of action, and maximum inhibitory concentrations, as well as IC₅₀ values. Approximately 400 different bioactive compounds, including alkaloids, terpenoids, quinines, phenylpropanoids, polyphenolic compounds, flavonoids, coumarins, anthocyanins, carotenoids, neolignans, fatty acids, polycosanols, tocopherols, and sitosterols, have been reported in the leaves, seeds, roots, and aerial parts of P. frutescens. The bioactive constituents of P. frutescens exhibited different enzyme-inhibition properties, including antihyaluronidase effects and aldose reductase inhibitory, α-glucosidase inhibitory, xanthine oxidase inhibitory, and tyrosinase inhibitory properties. P. frutescens showed strong anti-inflammatory, antidepressant, anti-spasmodic, anticancer, antioxidant, antimicrobial, insecticidal, neuroprotective, and hepatoprotective effects. Hence, the active constituents of P. frutescens used in the treatment of diabetes and diabetic complications (retinopathy, neuropathy, and nephropathy), prevention of hyperuricemia in gout patients, hyper pigmentation, allergic conditions, skin inflammation, skin allergy, atopic dermatitis, periodontosis, androgenic alopecia, gastric inflammation, oesophagitis, carcinogenesis, cardiovascular, Alzheimer’s, Parkinson’s, and cerebral ischemic disorders. Furthermore, we revealed the most active constituents and possible mechanisms of the pharmacological properties of P. frutescens.

Comparative Analysis of Polycyclic Aromatic Hydrocarbons and Halogenated Polycyclic Aromatic Hydrocarbons in Different Parts of Perilla frutescens (L.) Britt

Perilla frutescens (L.) Britt., a medicinal herb and edible plant, is very popular among East Asian countries. The perilla leaves, stems and seeds can be used as traditional medicines and foods. Polycyclic aromatic hydrocarbons (PAHs) and halogenated PAHs (HPAHs) are organic pollutants that are widely present in the environment, such as in water, air and soil, and are harmful to humans. In this study, the contents of 16 PAHs and 4 HPAHs in perilla leaves, stems and seeds were determined by gas chromatography tandem mass spectrometry (GC-MS). A total of 12 PAHs were detected in all samples, and no HPAHs were detected. The total contents of PAHs in perilla leaves, stems and seeds varied from 41.93 to 415.60 ng/g, 7.02 to 51.52 ng/g and 15.24 to 180.00 ng/g, respectively. The statistical analyses showed that there were significant differences in the distribution of PAHs in perilla leaves, stems and seeds. On the basis of the toxic equivalent quantity (TEQ) and incremental lifetime cancer risk (ILCR) model, the cancer risks of the intake of perilla leaves, stems and seeds were assessed to be from 3.30 × 10⁻⁸ to 2.11 × 10⁻⁵, 5.52 × 10⁻⁹ to 5.50 × 10⁻⁸ and 1.20 × 10⁻⁸ to 1.41 × 10⁻⁷, respectively. These were lower than 10⁻⁴ (the priority risk level of the EPA) and suggested that there may be almost no cancer risk from the intake of these traditional Chinese medicines (TCMs).

Extraction, preparative monomer separation and antibacterial activity of total polyphenols from Perilla frutescens

Polyphenols exhibit potential functional activities, especially rosmarinic acid (RosA) and caffeic acid (CafA). In this study, two different methods, ultrasonic-assisted ethanol extraction (60%) and ultrasound-assisted cellulase (≥15 000 Ug-1, 2%) hydrolysis, were used for the extraction of the total phenolics from 44 species of Perilla frutescens. The Folin-Ciocalteu method of detection showed that the content of the total phenolics extracted by cellulase hydrolysis was the highest and attained up to 28.00 mgGAE per gextracts for ZB1. Continuously, the extracts were purified using XDA-8 macroporous resin and medium-pressure liquid chromatography (MPLC), and the content of the total phenolics improved to 66.62 mgGAE per gextract. A high-performance liquid chromatography (HPLC) assay showed that the total polyphenols were mainly composed of gallic acid, caffeic acid, rosmarinic acid, luteolin and apigenin. Besides, a sequential XDA-8 macroporous resin combined with high-speed counter-current chromatography (HSCCC)/MPLC system was established for the simultaneous isolation and preparation of RosA (purity 98.29%) and CafA (purity 97.01%) from the extracts. Furthermore, the antibacterial activities of the total polyphenols were evaluated by the disc diffusion method and scanning electron microscopy (SEM) observation. The results verified that the total polyphenols had effective antibacterial activity on three kinds of bacteria including E. coli, S. aureus, and B. subtilis in a concentration-dependent manner. All of these results demonstrated that the ultrasound-assisted cellulase hydrolysis extraction of the total polyphenols and the proposed three-step separation of RosA and CafA gave high yields and good purity, and they exhibited effective antibacterial ability.

Sedative and hypnotic effects of Perilla frutescens essential oil through GABAergic system pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese medicine believes that depression syndrome has become one of the core pathogenesis of insomnia. The pharmacology of traditional Chinese medicine points out that Perilla frutescens has the effect of regulating Qi and relieving depression, promoting Qi circulation to relieve pain, so Perilla frutescens may have the potential therapeutic effect on insomnia. Related studies have reported the sedative and hypnotic effects of Perilla frutescens, but these studies have not yet explored the mechanism of sedative and hypnotic effects of Perilla frutescens essential oil (PFEO) through inhalation administration.

AIM OF THE STUDY

The purpose of this study is to explore the underlying sedative and hypnotic mechanisms of PFEO through the GABAergic system pathways.

MATERIALS AND METHODS

Established the PCPA insomnia model of mice, The open field test, pentobarbital-induced falling asleep rate, latency of sleeping time, and duration of sleeping time experiments were used to evaluate the behavior of mice, the enzyme-linked immunosorbent assay was used to analyze the content of 5-HT and GABA in hypothalamus and cerebral cortex. Immunohistochemical experiment, Western blot experiment and RT-PCR experiment were used to study the mechanism of PFEO through GABAergic pathway to regulate insomnia. The main volatile constituents of PFEO were analyzed by gas chromatography-mass spectrometry (GC-MS).

RESULTS

The inhalation of PFEO has sedative and hypnotic effects, which reduce significantly the autonomic activity of PCPA insomnia mice, increase falling asleep rate, shorten latency of sleeping time, and prolong duration of sleeping time; the results of enzyme-linked immunosorbent assay show that PFEO increase the content of 5-HT and GABA in hypothalamus and cerebral cortex. The results showed that inhalation of PFEO increase the expression of GABAAα1 and GABAAα2 positive cells, increase the level of GABAAα1 and GABAAα2 protein and also increase the level of GABAAα1 mRNA and GABAAα2 mRNA in the hypothalamus and cerebral cortex. The highest content of PFEO is Perillaldehyde (54.37%), followed by 1,4-Cineole (7.42%), Acetaldehyde diethyl acetal (6.61%), D-Limonene (5.09%), Eucalyptol (4.94%), etc. CONCLUSION: The inhalation of PFEO has sedative and hypnotic effects, it is speculated that the mechanism of which may be the sedative and hypnotic effects through the GABAergic pathway.

Multi-omics analysis of the bioactive constituents biosynthesis of glandular trichome in Perilla frutescens

BACKGROUND

Perilla frutescens (L.) Britt is a medicinal and edible plant widely cultivated in Asia. Terpenoids, flavonoids and phenolic acids are the primary source of medicinal ingredients. Glandular trichomes with multicellular structures are known as biochemical cell factories which synthesized specialized metabolites. However, there is currently limited information regarding the site and mechanism of biosynthesis of these constituents in P. frutescens. Herein, we studied morphological features of glandular trichomes, metabolic profiling and transcriptomes through different tissues.

RESULTS

Observation of light microscopy and scanning electron microscopy indicated the presence of three distinct glandular trichome types based on their morphological features: peltate, capitate, and digitiform glandular trichomes. The oil of peltate glandular trichomes, collected by custom-made micropipettes and analyzed by LC-MS and GC-MS, contained perillaketone, isoegomaketone, and egomaketone as the major constituents which are consistent with the components of leaves. Metabolomics and transcriptomics were applied to explore the bioactive constituent biosynthesis in the leaves, stem, and root of P. frutescens. Transcriptome sequencing profiles revealed differential regulation of genes related to terpenoids, flavonoids, and phenylpropanoid biosynthesis, respectively with most genes expressed highly in leaves. The genes affecting the development of trichomes were preliminarily predicted and discussed.

CONCLUSIONS

The current study established the morphological and chemical characteristics of glandular trichome types of P. frutescens implying the bioactive constituents were mainly synthesized in peltate glandular trichomes. The genes related to bioactive constituents biosynthesis were explored via transcriptomes, which provided the basis for unraveling the biosynthesis of bioactive constituents in this popular medicinal plant.

Perilla frutescens Extracts Enhance DNA Repair Response in UVB Damaged HaCaT Cells

Physiological processes in skin are associated with exposure to UV light and are essential for skin maintenance and regeneration. Here, we investigated whether the leaf and callus extracts of Perilla frutescens (Perilla), a well-known Asian herb, affect DNA damage response and repair in skin and keratinocytes exposed to Untraviolet B (UVB) light. First, we examined the protective effects of Perilla leaf extracts in UVB damaged mouse skin in vivo. Second, we cultured calluses using plant tissue culture technology, from Perilla leaf explant and then examined the effects of the leaf and callus extracts of Perilla on UVB exposed keratinocytes. HaCaT cells treated with leaf and callus Perilla extracts exhibited antioxidant activities, smaller DNA fragment tails, and enhanced colony formation after UVB exposure. Interestingly, keratinocytes treated with the leaf and callus extracts of Perilla showed G1/S cell cycle arrest, reduced protein levels of cyclin D1, Cyclin Dependent Kinase 6 (CDK6), and γH₂AX, and enhanced levels of phosphorylated checkpoint kinase 1 (pCHK1) following UVB exposure. These observations suggest that the leaf and callus extracts of Perilla are candidate nutraceuticals for the prevention of keratinocyte aging.

The Contents of Polyphenols in Perilla frutescens (L.) Britton var. frutescens (Egoma) Leaves are Determined by Vegetative Stage, Spatial Leaf Position, and Timing of Harvesting during the Day

The leaf of Perilla frutescens (L.) Britton var. frutescens (egoma) is a rich source of polyphenolic compounds, including rosmarinic acid. However, there is still a lack of detailed information concerning the content of phenolic compounds in these leaves. Since some flavonoids were found as a conjugated form, leaves were used untreated or hydrolyzed using β-glucuronidase for analysis. Enzymatic hydrolysis method successfully identified some polyphenols, which have not been reported before. Scutellarin, a flavone glucuronide with a molecular mass similar to that of luteolin 7-O-glucuronide, was present in egoma leaves. Scutellarin was the second most abundant polyphenolic compound, after rosmarinic acid. Egoma leaves at the top of the plant contained a higher amount of rosmarinic acid and scutellarin compared to that in the leaves below. The difference in plant growth stage also influenced the rosmarinic acid and scutellarin contents, while the time of harvesting during the day did rosmarinic acid contents only. This is the first time that scutellarin, a traditional Chinese medicine, widely used for the treatment of cerebrovascular disease, was quantitatively determined in egoma leaves. The present study may help adding value to egoma leaves, developing dietary supplements, functional foods, and cosmetics.

Comprehensive Comparison of Two Color Varieties of Perillae Folium Using Rapid Resolution Liquid Chromatography Coupled with Quadruple-Time-of-Flight Mass Spectrometry (RRLC-Q/TOF-MS)-Based Metabolic Profile and in Vivo/in Vitro Anti-Oxidative Activity

Perillae Folium (PF), which is extensively used as a dietary vegetable and medicinal herb, contains two varietal forms corresponding to purple perilla leaf (Perilla frutescens var. crispa) and green perilla leaf (Perilla frutescens var. frutescens). However, the components and efficacy of different PF varieties remain underexplored so far. In the present work, a nontargeted rapid resolution liquid chromatography coupled with quadruple-time-of-flight mass spectrometry (RRLC-Q/TOF-MS)-based metabolomics approach was developed to investigate the difference in the chemical compositions between green PF and purple PF. A total of 71 compounds were identified or tentatively identified, among which 7 phenolic acids, 10 flavonoids, and 9 anthocyanins were characterized as differential metabolites. In addition, heatmap visualization and ultraperformance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (UPLC-TQ-MS/MS)-based quantitative analysis revealed that flavonoids and anthocyanins especially had higher contents in purple PF. Furthermore, the anti-oxidative activities of two varietal PFs were evaluated in vivo zebrafish and in vitro human umbilical vein endothelial cells (HUVECs). The results showed that the purple PF had more pronounced anti-oxidative activities than did the green PF, which may be due to the presence of anthocyanins and a higher concentration of flavonoids in its phytochemical profile. The outcome of the present study is expected to provide useful insight on the comprehensive utilization of a PF resource.

Characterization of Metabolic Changes under Low Mineral Supply (N, K, or Mg) and Supplemental LED Lighting (Red, Blue, or Red-Blue Combination) in Perilla frutescens Using a Metabolomics Approach

In order to achieve premium quality with crop production, techniques involving the adjustment of nutrient supply and/or supplemental lighting with specific light quality have been applied. To examine the effects of low mineral supply and supplemental lighting, we performed non-targeted metabolite profiling of leaves and stems of the medicinal herb Perilla frutescens, grown under a lower (0.75×) and lowest (0.1×) supply of different minerals (N, K, or Mg) and under supplemental light-emitting diode (LED) lighting (red, blue, or red-blue combination). The lowest N supply increased flavonoids, and the lowest K or Mg slightly increased rosmarinic acid and some flavonoids in the leaves and stems. Supplemental LED lighting conditions (red, blue, or red-blue combination) significantly increased the contents of chlorophyll, most cinnamic acid derivatives, and rosmarinic acid in the leaves. LED lighting with either blue or the red-blue combination increased antioxidant activity compared with the control group without LED supplementation. The present study demonstrates that the cultivation of P. frutescens under low mineral supply and supplemental LED lighting conditions affected metabolic compositions, and we carefully suggest that an adjustment of minerals and light sources could be applied to enhance the levels of targeted metabolites in perilla.

Intake of Alpha-Linolenic Acid-Rich Perilla frutescens Leaf Powder Decreases Home Blood Pressure and Serum Oxidized Low-Density Lipoprotein in Japanese Adults

Oxidized low-density lipoprotein (Ox-LDL) is known to be highly atherogenic. Thus, decreasing the blood levels of Ox-LDL through dietary means is an important approach to reduce cardiovascular events in high-risk individuals. In this randomized placebo-controlled human interventional trial, we aimed to evaluate whether Perilla frutescens leaf powder (PLP) ameliorates Ox-LDL and home blood pressure, along with its biological antioxidant potential. Healthy Japanese volunteers aged 30-60 years (n = 60) were randomized to PLP and placebo groups. The PLP group consumed PLP dried using a microwave under reduced pressure, and the placebo group consumed pectin fiber daily for 6 months. Home blood pressure, serum biochemical parameters, and fatty acid profiles of erythrocyte plasma membranes were analyzed. Plasma Ox-LDL levels significantly decreased in the PLP group but not in the placebo group. Mean changes in the biological antioxidant potential and alpha-linolenic acid levels in the erythrocyte plasma membrane were significantly increased in the PLP group than in the placebo group. In subjects with prehypertension (systolic blood pressure [SBP] ³ 120 mmHg), the mean reduction in morning or nocturnal SBP was significantly greater in the PLP group than in the placebo group. Thus, PLP intake may be an effective intervention to prevent cardiovascular diseases.

Rosmarinic acid in Perilla frutescens and perilla herb analyzed by HPLC

High-quality perilla leaves are defined as those having purple upper and lower surfaces and a pleasant smell. The Japanese Pharmacopoeia specifies the content of essential oils in perilla leaves but not the content of rosmarinic acid. Rosmarinic acid is a common component of Labiatae plants such as shiso (Perilla frutescens Britton var. crispa W. Deane). Rosmarinic acid has been reported to exhibit anti-inflammatory and anti-oxidant activity but the factors affecting the content of rosmarinic acid in plants remain unknown. This study describes a simple and reproducible method for quantifying rosmarinic acid. We elucidated the main causes for the different rosmarinic acid contents of plants by examining various samples of perilla using the proposed method. Significant differences in rosmarinic acid content between varieties and cultivators were observed. The rosmarinic acid content was higher in green perilla compared with red perilla, in wild species compared with cultivated species, and in plants cultivated in outdoor nurseries compared with in indoor nurseries. The proposed quantitative method was used to examine the rosmarinic acid content in a Kampo formula, Hangekobokuto, and was found to be higher in decoctions prepared using the Kouge method compared with the typical preparation method. We examined the chlorophyll and caffeic acid contents of several samples and their relationship with the rosmarinic acid content.

Anti-Arthritic Activities of Supercritical Carbon Dioxide Extract Derived from Radiation Mutant Perilla Frutescens Var. Crispa in Collagen Antibody-Induced Arthritis

We investigated the anti-arthritic effects of the radiation mutant Perilla frutescens var. crispa leaf extract (SFE-M) and wild type leaf extract (SFE-W), both prepared by supercritical carbon dioxide (SC-CO2) extraction, on collagen antibody-induced arthritis (CAIA) in Balb/c mice. Animals were randomly divided into four groups: control, CAIA, CAIA + SFE-M (100 mg/kg/day), and CAIA + SFE-W (100 mg/kg/day). The mice were subjected to the respective treatments via oral gavage once daily for 4 days. Mice treated with SFE-M developed less severe arthritis than the CAIA mice. They showed significantly improved arthritic score, paw volume, and paw thickness compared to the CAIA mice from days 3 through 7. Furthermore, histopathological analysis of ankle for inflammation showed that SFE-M treatment reduced inflammatory cell infiltration and edema formation. Similarly, the neutrophil-to-lymphocyte ratio (NLR) in the whole blood was 37% lower in mice treated with SFE-M compared with the CAIA mice. However, treatment with SFE-W did not result in any significant difference compared with the CAIA group. In conclusion, SFE-M treatment delays the onset of arthritis and alleviates its clinical manifestations in CAIA mice.

Anti-Amyloidogenic Effects of Asarone Derivatives From Perilla frutescens Leaves against Beta-Amyloid Aggregation and Nitric Oxide Production

Alzheimer's disease (AD) is a progressive, neurodegenerative brain disorder associated with loss of memory and cognitive function. Beta-amyloid (Aβ) aggregates, in particular, are known to be highly neurotoxic and lead to neurodegeneration. Therefore, blockade or reduction of Aβ aggregation is a promising therapeutic approach in AD. We have previously reported an inhibitory effect of the methanol extract of Perilla frutescens (L.) Britton (Lamiaceae) and its hexane fraction on Aβ aggregation. Here, the hexane fraction of P. frutescens was subjected to diverse column chromatography based on activity-guided isolation methodology. This approach identified five asarone derivatives including 2,3-dimethoxy-5-(1E)-1-propen-1-yl-phenol (1), β-asarone (2), 3-(2,4,5-trimethoxyphenyl)-(2E)-2-propen-1-ol (3), asaronealdehyde (4), and α-asarone (5). All five asarone derivatives efficiently reduced the aggregation of Aβ and disaggregated preformed Aβ aggregates in a dose-dependent manner as determined by a Thioflavin T (ThT) fluorescence assay. Furthermore, asarone derivatives protected PC12 cells from Aβ aggregate-induced toxicity by reducing the aggregation of Aβ, and significantly reduced NO production from LPS-stimulated BV2 microglial cells. Taken together, these results suggest that asarone derivatives derived from P. frutescens are neuroprotective and have the prophylactic and therapeutic potential in AD.

Bioconversion of essential oil components of Perilla frutescens by Saccharomyces cerevisiae

The essential oil of perilla (Perilla frutescens) contains volatile low molecular weight compounds such as monoterpenes and phenylpropenes. The composition of the essential oil is classified into about ten chemotypes. The biosynthesis of these constituents is strictly controlled genetically. Among the compounds contained in perilla essential oil, the bioconversion of pure compounds such as perillaldehyde, limonene, and citral has been reported, but that of many other components has not. In addition, changes in the volatile components of raw plant material during brewing have also been investigated for wine and beer. In this study, we examined the bioconversion of perilla essential oil components by Saccharomyces cerevisiae during the brewing of liquor with perilla leaves. S. cerevisiae was added to the ethanol-water extract of dried leaves of P. frutescens and P. citriodora for seven essential oil types: perillaldehyde type, piperitenone type, perillene type, perillaketone type, elsholtziaketone type, citral type, and phenylpropanoid type. Volatile compounds in the reaction mixtures were analyzed by solid-phase microextraction (SPME)-GC-MS, revealing bioconversion of perillaldehyde, isoegomaketone, neral, and geranial by S. cerevisiae. Analysis of the conversion products suggests that they were formed by the reduction of C=C bonds and aldehydes, as well as by esterification and dehydration reactions.

Rosmarinic Acid Enriched Fraction from Perilla frutescens Leaves Strongly Protects Indomethacin-Induced Gastric Ulcer in Rats

Gastric ulcers are a common problem in upper gastrointestinal tract (GI) disorders. Nonsteroidal anti-inflammatory drugs (NSAIDs) are one of the most aggressive factors leading to inducing gastric ulcers. Natural products with lower toxicity and safety are currently sought as a potential source to minimize the effect of the gastric ulcers. Perilla frutescens or Nga-mon (in Thai) leaves are rich in rosmarinic acid (RA), which has antioxidant, anti-inflammatory, and anticancer effects. This study investigates the protective effect of ethanolic extract (EE) and aqueous fraction (AF) from Perilla frutescens leaves, which are rich in RA, on indomethacin- (IND-) induced gastric ulcer in a rat model. The EE at the doses of 50 and 500 mg/kg body weight, AF at the doses of 50, 250, and 500 mg/kg body weight, or famotidine (a standard drug) were administered for 14 days prior to ulcer induction. The ulceration was performed by intragastric administration of IND. Gross gastric ulcers and biological and histological parameters were examined. The pretreatment with AF had more significant effects than EE, including reduced ulcer index, decreased gastric secretion volume and decreased acidity, but it had an elevated gastric pH relative to the IND-induced gastric ulcer. In a histopathological study, the EE and AF decreased mucosal ulcer, inflammatory infiltration, and degenerative lining cells. The IND-induced expression of inflammatory mediators was significantly attenuated with EE and AF. The experiment also remarkably showed the preservation of mucus and apoptosis protection of EE and AF on a gastric mucosal ulcer. The findings demonstrated that the EE and AF of perilla leaves were capable of protecting the stomach against gastric ulcers induced by IND through anti-inflammatory and antiapoptotic mechanisms that should be further investigated. It is suggested that Perilla frutescens leaf could be a potential alternative source of RA as a therapeutic agent and food supplement for NSAID-induced gastric injuries.

Extracts from Paeonia lactiflora Pallas, Rehmannia Glutinosa var. Purpurea Makino, Perilla Frutescens var. Acuta Kudo may increase the endometrial receptivity through expression of leukemia inhibitory factor and adhesion molecules

OBJECTIVE

To find out the combination of the extracts from Paeonia lactiflora Pallas (PL), Reh- mannia Glutinosa var. Purpurea Makino (RG), Perilla Frutescens var. Acuta Kudo (PF) to increase endometrial receptivity.

METHODS

Herbal medicines were extracted with boiling water and polysaccharides were removed. We examined the effect of PL, RG, and PF (PRP), a most effective herbal formula deduced from constitutive ingredient herbs of Antai Yin which is composed of PRP, on the leukemia inhibitory factor (LIF) expression and endometrial receptivity.

RESULTS

The combination of the extracts from PRP induced the LIF expression in Ishikawa cells and increased the adhesion between Ishikawa and JAr cells. In addition, PRP-induced attachment of JAr cells onto Ishikawa cells and expression of adhesion molecules, ITGAV, ITGB5, CD44s, and L-selectin, are significantly reduced by knock-down of LIF expression.

CONCLUSION

Induced by the combination of the PRP extracts, the adhesion between trophoblast and endometrial cells are mediated by expression of LIF and adhesion molecules. Thus, we suggest the combination of the PRP extracts may be a novel therapy for enhancing embryo implantation rate.

[Study on morphological classification and chemical-type of Perilla frutescens cultivated germplasm]

Fifty cultivated Perilla seeds were collected all over the country and planted in Beijing experiment field for morphology and chemical-type researches. Twenty morphological characteristics were selected and observed, and the essential oil from leaves was extracted by steam distillation and analyzed by GC-MS to confirm chemical-types. There were significant diversities in plant height, leaf color and morphology, and fruit color and weight. Clustering analysis was carried out based on these morphological characteristics. Six types were divided with their chemical-type designated. Type Ⅰ: Six germplasms, attributed to P. frutescens var. crispa, with dwarf plants, thin creased purple leaf, named Crispa, their chemical types were diversified, including EK, PAPK, PA and PK. Type Ⅱ: Six germplasms, attributed to P. frutescens var. crispa, plants were taller than type I and with thin and creased green leaf, named Big Crispa, all PK type. Type Ⅲ: Seventeen germplasms, attributed to P. frutescens var. frutescens with leaf color upside green and underside purple, tall plant and wide distribution all over the China, named Ordinary Frutescens, all PK. Type Ⅳ: Four germplasms, attributed to P. frutescens var. acuta with tall plant and small seed, named Acuta, all PK. Type Ⅴ: Seven germplasms, attributed to P. frutescens var. frutescens with green leaves, tall plants and long clusters, named Long-spike Frutescens, all PK. Type Ⅵ: Ten germplasms, attributed to P. frutescens var. frutescens with big, thick and creased leaf, named Thick-leaf Frutescens, including PK, PP, PL and PA. The morphological classification of this paper would lay the foundation for the taxonomic naming and following evaluation of the Perilla germplasm resources.This study also showed that there was no correspondence but a certain correlation between volatile oil chemical-types and subspecies classification and morphological characteristics of Perilla.

Chemical Eustress Elicits Tailored Responses and Enhances the Functional Quality of Novel Food Perilla frutescens

Consumer demand for fresh and functional horticultural products is on the rise. Perilla frutescens, L. Britt (Lamiaceae) is a potential specialty/niche crop for consumption and therapeutic uses with high contents of phenolic and volatile compounds. Plant growth, mineral composition, polyphenol profile and aroma volatile components of two perilla genotypes in response to salinity (non-salt control, 10, 20 or 30 mM NaCl) applied as chemical eustressor were assessed. Salinity suppressed growth and yield of both genotypes, although the red-pigmented genotype was less sensitive than the green-pigmented one. Mild (10 mM NaCl) and moderate (20 and 30 mM NaCl) salinity suppressed foliar potassium, magnesium, nitrate and chlorophyll a concentrations of both genotypes and increased the levels of rosmarinic acid, total polyphenols and target aroma volatile components. Green perilla showed higher yield and biomass production and higher content of protein, dry matter, calcium, magnesium, perilla ketone and cis-jasmone, whereas red perilla exhibited higher content of potassium, chlorophyll a, rosmarinic acid, total polyphenols, perilla aldehyde and benzaldehyde. Our findings support that chemical eustressors such as mild to moderate salinity offer valuable means to manipulate phytochemical and aroma profiles.

Ethnomedicinal, Phytochemical and Pharmacological Investigations of Perilla frutescens (L.) Britt

Perilla frutescens (L.) Britt. (PF) is an annual herbal medicinal, aromatic, functional food, and ornamental plant that belongs to the mint family, Lamiaceae. The origin of perilla traces back to East Asian countries (China, Japan, Korea, Taiwan, Vietnam, and India), where it has been used as a valuable source of culinary and traditional medicinal uses. The leaves, seeds, and stems of P. frutescens are used for various therapeutic applications in folk medicine. In the absence of a comprehensive review regarding all aspects of perilla, this review aims to present an overview pertaining to the botanical drug, ethnobotany, phytochemistry, and biological activity. It was found that the taxonomic classification of perilla species is quite confused, and the number of species is vague. Perilla has traditionally been prescribed to treat depression-related disease, anxiety, asthma, chest stuffiness, vomiting, coughs, colds, flus, phlegm, tumors, allergies, intoxication, fever, headache, stuffy nose, constipation, abdominal pain, and indigestion, and acts as an analgesic, anti-abortive agent, and a sedative. Until now, 271 natural molecules have been identified in perilla organs including phenolic acids, flavonoids, essential oils, triterpenes, carotenoids, phytosterols, fatty acids, tocopherols, and policosanols. In addition to solvent extracts, these individual compounds (rosmarinic acid, perillaldehyde, luteolin, apigenin, tormentic acid, and isoegomaketone) have attracted researchers' interest for its pharmacological properties. Perilla showed various biological activities such as antioxidant, antimicrobial, anti-allergic, antidepressant, anti-inflammatory, anticancer, and neuroprotection effects. Although the results are promising in preclinical studies (in vitro and in vivo), clinical studies are insufficient; therefore, further study needs to be done to validate its therapeutic effects and to ensure its safety and efficacy.

Aqueous Extract of Perilla frutescens var. acuta Relaxes the Ciliary Smooth Muscle by Increasing NO/cGMP Content In Vitro and In Vivo

The leaves of Perilla frutescens var. acuta (PFA) are commonly used as a traditional medicine in Korea, Japan, and China. We previously showed that PFA attenuates eye fatigue by improving visual accommodation through a clinical study. However, detailed mechanisms and chemical compounds have not been studied. In this study, we analyzed the active compounds in an aqueous extract of PFA involved in ciliary muscle relaxation in vitro and in vivo. NMR and MS analyses showed that the PFA extract contained mainly luteolin-7-O-diglucuronide and apigenin-7-O-diglucuronide. The composition after freeze-drying and spray-drying was similar. Freeze-dried PFA (50 µg/mL, 100 µg/mL, and 200 µg/mL) increased nitric oxide and cGMP levels in ciliary muscle cells isolated from the eyes of rats. [Ca²⁺]i decreased in a dose-dependent manner. Furthermore, Sprague-Dawley rats treated with freeze-dried PFA (200 mg/kg, orally) showed significantly increased cGMP levels compared with the control group and irradiated with white light. Our results suggest that PFA extract has the potential to reduce eye fatigue by relaxing ciliary muscles.

Microcapsules biologically prepared using Perilla frutescens (L.) Britt. essential oil and their use for extension of fruit shelf life

BACKGROUND

Perilla essential oil (EO) possesses high antioxidant, antimicrobial and insecticidal activities, and has proven to be more reliable than chemically synthesized food preservatives. Nevertheless, EOs have disadvantages of facile photo-degradation and oxidation, which limit their use in agriculture and food industries. Microencapsulation technology that generates a polymeric coating surrounding EOs could overcome these disadvantages.

RESULTS

The EO concentration had a significant effect on encapsulation efficiency (EE) and loading capacity (LC). The best encapsulation conditions were obtained with 2% v/v EO, for which EE and LC were 57% and 36%, respectively. EO-loaded microspheres exhibited a crimped surface with phanic lumps by scanning electron microscopy. Thermal stability experiments revealed droplets that began to decompose sharply at 108 °C, with a 61% weight, loss, which was much lower than EOs of 98%. EO-loaded microcapsules demonstrated good antibacterial activity. Strawberry preservation studies showed that EO-loaded microcapsules could significantly inhibit strawberry decay, maintain the quality of strawberries and prolong shelf life.

CONCLUSION

Perilla EO-loaded microcapsules were successfully prepared by ionic gelation and were effective at inhibiting several bacterial strains. EO-alginate microcapsules could effectively delay the volatilization of EO. Perilla EO-loaded microcapsules therefore have potential for use as an antimicrobial and preservative agent in the food industry. © 2017 Society of Chemical Industry.

The promotion of hair regrowth by topical application of a Perilla frutescens extract through increased cell viability and antagonism of testosterone and dihydrotestosterone

This study investigated the potential hair regrowth effects associated with a plant extract of Perilla frutescens, which was selected due to its putative hair regrowth activity. Extracts were prepared from dried P. frutescens suspended in distilled water, where the resultant aqueous suspension was fractionated sequentially using hexane, ethyl acetate, n-butanol, and distilled water. We observed that the n-butanol fraction resulted in the highest hair regrowth activity. The n-butanol soluble fraction of P. frutescens extract (BFPE) was further separated using AB-8 macroporous resin and silica gel chromatography to obtain rosmarinic acid (RA), which demonstrated effective hair growth regeneration potential. BFPE also showed in vivo anti-androgenic activity following the use of a hair growth assay in testosterone-sensitive male C57Bl/6NCrSlc mice. Furthermore, the effects of cell viability promotion were investigated following an in vitro analysis in primary hair follicle fibroblast cells (PHFCs) treated with RA. The results suggested that RA was the active compound in P. frutescens that triggers hair growth, and RA could be a potential therapeutic agent for the promotion of hair growth and prevention of androgenetic alopecia (AGA).

Radical Scavenging Properties of Roasted Egoma (Perilla frutescens var. frutescens) Oils and Identification of Their Characteristic Scavengers

The radical scavenging activity of commercially available roasted (deep colored) and unroasted (light colored) egoma (Perilla frutescens var. frutescens) oils was evaluated by the DPPH radical scavenging method. The antiradical activity of roasted oils was higher than that of unroasted oils, and the activity of methanol-water extracts from the roasted egoma oils was significantly higher than that of unroasted oils. The antiradical activity of the methanol-water fractions was strongly correlated to that of whole oils (r=0.72) and the color depth of oils (r=0.93), which was an index of roasting. Fractionation of the methanol-water extract of a roasted egoma oil according to molecular size using ultra membrane filters revealed that the fraction under 3 kDa had the strongest radical scavenging activity. Subsequent preparative HPLC separation using an ODS column also revealed that the second fraction was the most active. Our HPLC analytical method for DPPH radical scavengers in complex mixtures detected four strong radical scavenger peaks in the fraction. Among the detected peaks, two peaks were determined to be derived from rosmarinic acid and luteolin by comparison with the retention times and UV spectra of the authentic samples, and the other two compounds could not be identified because no characteristic UV spectra were observed. These identified polyphenols (rosmarinic acid and luteolin) have been reported to be present in the non-oily part of egoma seeds. They probably migrated to the oily part during the egoma oil roasting process.

Alpha-Linolenic Acid from Perilla frutescens var. japonica Oil Protects Aβ-Induced Cognitive Impairment through Regulation of APP Processing and Aβ Degradation

Alzheimer's disease (AD) is characterized by progressive cognitive and memory impairment. The major pathological hallmark of AD is the accumulation of amyloid beta (Aβ), which is produced from the amyloid precursor protein (APP) through cleavage of β- and γ-secretase. Recently, dietary plant oil containing ω-3 polyunsaturated fatty acid has become an attractive alternative source to fish oil containing eicosapentaenoic acid or docosahexaenoic acid (DHA). We investigated whether ALA isolated from perilla oil has direct effects on improvement of cognitive ability and molecular mechanisms in APP processing in comparison with DHA. In the present study, ICR mice were treated orally with ALA or DHA (100 mg/kg/day) for 14 days after i.c.v. injection of Aβ_25-35. Administration of ALA resulted in a prevention of learning and memory deficit in Aβ_25-35-injected mice compared with the control group, as observed in T-maze, novel object recognition, and Morris water maze tests. ALA supplementation also markedly ameliorated the Aβ_25-35-induced oxidative stress by inhibition of lipid peroxidation and nitric oxide overproduction in the mouse brain, liver, and kidney, almost down to the levels in DHA-administered group. These effects of ALA on protective mechanisms were related to the regulation of APP processing via promoting nonamyloidogenic pathway such as up-regulation of soluble APP alpha, C-terminal fragment alpha/beta ratio, and A disintegrin and metalloprotease10 protein expressions. Furthermore, ALA inhibited the amyloidogenic pathway through the down-regulation of β-site APP-cleaving enzyme and presenilin2. ALA also enhanced Aβ degradation enzyme, insulin-degrading enzyme. In conclusion, the present study indicated a beneficial effect of ALA in improving the cognitive ability against Aβ_25-35, and these effects were comparable to those exerted by DHA. Its neuroprotective effects are mediated, in part, by regulation of APP processing and Aβ degradation, and thus, ALA might be a potential candidate for prevention or treatment of neurodegenerative diseases such as AD.

Pollination effects on antioxidant content of Perilla frutescens seeds analysed by NMR spectroscopy

The effects of Perilla frutescens pollination on the content of seed antioxidants were analysed by agronomical and pollination trials, comparing seeds produced from bagged plants in 2013 (A) to prevent access to pollinating insects, and seeds from open-pollinated plants in 2013 (B) and 2015 (C). The seeds of open-pollinated plants were significantly more numerous and heavier than those of self-pollinated plants. 1H NMR seed analysis showed a higher presence of phenolic compounds in open-pollinated seeds, mainly rosmarinic acid and flavonoids, apigenin and luteolin. Flavonoids were present in the glucosylated form in seeds (A) and (C), and in the aglycone form in seeds from (B) plants. Saturated and unsaturated fatty acids (palmitic, linoleic and linolenic) were more abundant in seeds from self-pollinated flowers. Pollination performed almost exclusively by the honeybee notably increased the antioxidant content in perilla seeds and gave rise to a reduction in the fatty acid content.

A New Monoterpene from the Leaves of a Radiation Mutant Cultivar of Perilla frutescens var. crispa with Inhibitory Activity on LPS-Induced NO Production

The leaves of Perilla frutescens var. crispa (Lamiaceae)—known as ‘Jureum-soyeop’ or ‘Cha-jo-ki’ in Korean, ‘ZI SU YE’ in Chinese, and ‘Shiso’ in Japan—has been used as a medicinal herb. Recent gamma irradiated mutation breeding on P. frutescens var. crispa in our research group resulted in the development of a new perilla cultivar, P. frutescens var. crispa (cv. Antisperill; PFCA), which has a higher content of isoegomaketone. The leaves of PFCA were extracted by supercritical carbon dioxide (SC-CO₂) extraction, and phytochemical investigation on this extract led to the isolation and identification of a new compound, 9-hydroxy-isoegomaketone [(2E)-1-(3-furanyl)-4-hydroxy-4-methyl-2-penten-1-one; 1]. Compound 1 exhibited inhibitory activity on nitric oxide (NO) production in lipopolysaccharide (LPS)-activated RAW264.7 cells with an IC₅₀ value of 14.4 μM. The compounds in the SC-CO₂ extracts of the radiation mutant cultivar and the original plant were quantified by high-performance liquid chromatography with diode array detection.

Assessment of the phenolic profile, antimicrobial activity and oxidative stability of transgenic Perilla frutescens L.overexpressing tocopherol methyltransferase (γ-tmt) gene

This study evaluated the effects of enhanced concentrations of α-tocopherol and phenolic compounds on the resistance and stability of Perilla oil in transgenic Perilla frutescens plants against various tested pathogenic bacteria by over-expressing the γ-tmt gene. The concentration of phenolic compounds in the non-transgenic samples was 9313.198 ± 18.887 μg g^-1 dry weight (DW), whereas the total concentration of the transgenic samples ranged from 9118.015 ± 18.822 to 10527.612 ± 20.411 μg g^-1 DW. The largest increases in phenolic compounds in the transgenic plants in comparison with the control plants were observed in gallic acid, pyrogallol, 5-sulfosalicylic acid, catechin, chlorogenic acid, vanillin, syringic acid, naringenin, salicylic acid, quercetin, o-coumaric acid, kaempferol, and hesperetin. o-coumaric and benzoic acid acid were the most abundant phenolic acids found in the transgenic plants. Gram-negative bacteria (Salmonella typhimurium) were the most susceptible microorganism against transgenic ethyl acetate extracts with lower measurement of minimum inhibitory concentration (MICs) (0.25 ± 0.03 mg/ml) at an extract concentration of 2 mg/ml in dried plant material. The same extracts were more effective against gram-positive bacteria (Bacillus subtilis) when compared to control plants with MICs values of 0.52 ± 0.02 mg/ml. The suplementation of 20 μg of α-tocopherol (1000 ppm) in combination with ethyl acetate extracts enhanced the antimicrobial activity against S. typhimurium and B. subtilis, compared to the non-transgenic plants. The acid value of transgenic Perilla oil improved by 91.2% and 35.54% relative to the non-transgenic control oil and commercial Perilla oil, respectively. The low acid value suggests that the oil will be less susceptible to lipase action, and more economically viable and thus, may also improve the oil quality for industrial purposes. In addition, extracts obtained from transgenic plants could be a potential source of antimicrobial agents for the treatment of bacterial infections.

Development of User-Friendly Method to Distinguish Subspecies of the Korean Medicinal Herb Perilla frutescens Using Multiplex-PCR

Perilla (Perilla frutescens) is an economically and culturally important plant in East Asia. Plant breeding between cultivars has enhanced the genetic diversity of perilla overall, but means that functionally diverse subspecies are more difficult to identify and distinguish. In this study, we developed gene-based DNA markers to distinguish between the Korean herbal medicinal perilla varieties. We identified informative simple sequence repeat (SSR) regions on the promoter regions of the Myb-P1 and dihydroflavonol 4-reductase (DFR) genes, as well as a large insertion-deletion (indel) region in the limonene synthase (LS) gene, and developed markers to characterize the distinct subspecies differences (PfMyb-P1pro, PfDFRpro, and PfLS, respectively). Using the PfLS primers, a 430-bp region could be amplified from P. frutescens var. acuta, crispa, and f. viridis (known as Jasoyeop, Jureum-soyeop, and Chungsoyeop, respectively), but not from P. frutescens var. japonica (Dlggae). The PfMybpro primers resulted in PCR products of 314 or 316, 330, 322, and 315 bp from Dlggae, Jasoyeop, Jureum-soyeop, and Chungsoyeop, respectively, and the PfDFRpro primers resulted in products of 189 or 202, 187 or 189, 185 or 189, and 193bp, respectively, for the four perilla subspecies. Combining these three reactions into a single multiplex PCR approach resulted in subspecies-specific PCR band patterns for six common types of commercial perilla, distinguishing between three varieties of Dlggae (Cham-Dlggae, Ip-Dlggae, and Bora-Dlggae), as well as identifying Jasoyeop, Jureum-soyeop, and Chungsoyeop. These user-friendly markers will be valuable as a simple and efficient method for identifying the Korean medicinal herb Jasoyeop, as well as distinguishing between other functionally distinct subspecies, which may have broad applications in the Korean herbal industry.

Comparison of the Anti-Inflammatory Activities of Supercritical Carbon Dioxide versus Ethanol Extracts from Leaves of Perilla frutescens Britt. Radiation Mutant

In this study, we aimed to compare supercritical carbon dioxide extraction and ethanol extraction for isoegomaketone (IK) content in perilla leaf extracts and to identify the optimal method. We measured the IK concentration using HPLC and inflammatory mediators in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells from the extracts. The IK concentration was 10-fold higher in perilla leaf extracts by supercritical carbon dioxide extraction (SFE) compared with that in perilla leaf extracts by ethanol extraction (EE). When the extracts were treated in LPS-induced RAW 264.7 cells at 25 µg/mL, the SFE inhibited the expression of inflammatory mediators such as nitric oxide (NO), monocyte chemoattractant protein-1 (MCP-1), interleutkin-6 (IL-6), interferon-β (IFN-β), and inducible nitric oxide synthase (iNOS) to a much greater extent compared with EE. Taken together, supercritical carbon dioxide extraction is considered the optimal process for obtaining high IK content and anti-inflammatory activities in leaf extracts from the P. frutescens Britt. radiation mutant.

Rapid High Performance Liquid Chromatography Determination and Optimization of Extraction Parameters of the α-Asarone Isolated from Perilla frutescens L

Response surface methodology (RSM), based on a central composite design, was used to determine the best liquid-to-raw material ratio (10:3–15 mL/g), extraction time (1–3 h), and ethanol concentration (50%–100%) for maximum content of α-asarone from Perilla frutescens (PF) extract. Experimental values of α-asarone were 9.51–46.36 mg/g; the results fitted a second-order quadratic polynomial model and correlated with the proposed model (R² > 0.9354). The best conditions were obtained with extraction time of 1.76 h, liquid-to-raw material ratio of 10:13.5 mL/g, and ethanol concentration of 90.37%. Under these conditions, the model predicted extraction content of 40.56 mg/g, while experimental PF content of α-asarone was 43.84 mg/g dried plant. Optimized conditions determined for maximum content of α-asarone were similar to the experimental range. Experimental values agreed with those predicted, thus validating and indicating suitability of both the model and the RSM approach for optimizing extraction conditions. In addition, a reliable, reproducible and accurate method for the quantitative determination of α-asarone by High Performance Liquid Chromatography (HPLC) analysis was developed with limit of detection (LOD), limit of quantitation (LOQ) values of 0.10 and 0.29 µg/mL and excellent linearity (R² > 0.9999).

Perilla frutescens leaves extract ameliorates ultraviolet radiation-induced extracellular matrix damage in human dermal fibroblasts and hairless mice skin

ETHNOPHARMACOLOGICAL RELEVANCE

Perilla frutescens (L.) Britt. (Lamiaceae) is a traditional herb that is consumed in East Asian countries as a traditional medicine. This traditional herb has been documented for centuries to treat various diseases such as depression, allergies, inflammation and asthma. However, the effect of Perilla frutescens on skin has not been characterized well.

AIM OF THE STUDY

The present study aimed to investigate the effect of Perilla frutescens leaves extract (PLE) on ultraviolet radiation-induced extracellular matrix damage in human dermal fibroblasts and hairless mice skin.

MATERIALS AND METHODS

Human dermal fibroblasts and Skh-1 hairless mice were irradiated with UV and treated with PLE. Protein and mRNA levels of various target molecules were analyzed by western blotting and quantitative RT-PCR, respectively. Histological changes of mouse skin were analyzed by H&E staining. To elucidate underlying mechanism of PLE, activator protein-1 (AP-1) DNA binding assay and the measurement of reactive oxygen species (ROS) were performed.

RESULTS

PLE significantly inhibited basal and UV-induced MMP-1 and MMP-3 expression dose-dependently, and also decreased UV-induced phosphorylation of extracellular signal-regulated kinases and c-Jun N-terminal kinases. This inhibitory effects of PLE on MMP-1 and MMP-3 were mediated by reduction of ROS generation and AP-1 DNA binding activity induced by UV. Furthermore, PLE promoted type I procollagen production irrespective of UV irradiation. In the UV-irradiated animal model, PLE significantly reduced epidermal skin thickness and MMP-13 expression induced by UV.

CONCLUSION

Our results demonstrate that PLE has the protective effect against UV-induced dermal matrix damage. Therefore, we suggest that PLE can be a potential agent for prevention of skin aging.

[Perilla resources of China and essential oil chemotypes of Perilla leaves]

This study, based on the findings for Perilla resources, aimed to describe the species, distribution, importance, features, utilization and status of quantitative Perilla resources in China. This not only helps people to know well about the existing resources and researching development, but also indicates the overall distribution, selection and rational use of Perilla resource in the future. According to the output types, Perilla resources are divided into two categories: wild resources and cultivated resources; and based on its common uses, the cultivated resources are further divided into medicine resources, seed-used resources and export resources. The distribution areas of wild resources include Henan, Sichuan, Anhui, Jiangxi, Guangxi, Hunan, Jiangsu and Zhejiang. The distribution areas of medicine resources are concentrated in Hebei, Anhui, Chongqing, Guangxi and Guangdong. Seed-used resources are mainly distributed in Gansu, Heilongjiang, Jilin, Chongqing and Yunnan. Export resource areas are mainly concentrated in coastal cities, such as Zhejiang, Jiangsu, Shandong and Zhejiang. For the further study, the essential oil of leaf samples from different areas were extracted by the steam distillation method and analyzed by GC-MS. The differences in essential oil chemotypes among different Perilla leaves were compared by analyzing their chemical constituents. The main 31 constituents of all samples included: perillaketone (0.93%-96.55%), perillaldehyde (0.10%-61.24%), perillene (52.15%), caryophyllene (3.22%-26.67%), and α-farnesene (2.10%-21.54%). These samples can be classified into following five chemotypes based on the synthesis pathways: PK-type, PA-type, PL-type, PP-type and EK-type. The chemotypes of wild resources included PK-type and PA-type, with PK-type as the majority. All of the five chemotypes are included in cultivated resources, with PA-type as the majority. Seed-used resources are all PK-type, and export resources are all PA-type. The P. frutescens var. frutescens include five chemotypes, with PK-type as the majority. The PK-type leaves of P. frutescens var. acuta are green, while the PA-type leaves are reddish purple. The P. fruteseens var. crispa was mainly PA type with reddish purple leaves. The differences of the main chemotypes provide a scientific basis for distinguishing between Zisu and Baisu in previous literatures. Based on the lung toxicity of PK and the traditional use of Perilla, the testing standard of essential oil and Perilla herb shall be built, and PA type is recommended to be used in traditional Chinese medicine.

Ultrasonically enhanced extraction of luteolin and apigenin from the leaves of Perilla frutescens (L.) Britt. using liquid carbon dioxide and ethanol

The present study reports on the ultrasonic enhancement of the liquid carbon dioxide (CO2) extraction of luteolin and apigenin from the leaves of Perilla frutescens (L.) Britt., to which ethanol is added as a cosolvent. The purpose of this research is also to investigate the effects of the particle size, temperature, pressure, irradiation power, irradiation time, and ethanol content in the liquid CO2 solution on the extraction yield using single-factor experiments. We qualitatively and quantitatively analyzed the yields in the extract using HPLC (high-performance liquid chromatography). The liquid CO2 mixed with ethanol was used at temperatures of 5, 20 and 25 °C with extraction pressures from 8 to 14 MPa. The yields of luteolin and apigenin in the extraction were clearly enhanced by the ultrasound irradiation, but the selectivity of the extract was not changed. The yields of luteolin and apigenin in the extract were also significantly improved by adjusting the operating temperature, the irradiation time, and the ethanol content in the liquid CO2 solution, but no change in the selectivity of the extract was observed.

Bioassay-Guided Isolation and Identification of Xanthine Oxidase Inhibitory Constituents from the Leaves of Perilla frutescens

Activity-directed fractionation and purification processes were employed to identify xanthine oxidase (XO) inhibitory compounds from the leaves of Perilla frutescens. The total extract was evaluated in vitro on XO inhibitory activity and in vivo in an experimental model with potassium oxonate-induced hyperuricemia in mice which was used to evaluate anti-hyperuricemic activity. The crude extract showed expressive urate-lowering activity results. Solvent partitioning of the total extract followed by macroporous resin column chromatography of the n-butanol extract yielded four extracts and eluted parts. Among them, only the 70% ethanol eluted part of the n-butanol extract showed strong activity and therefore was subjected to separation and purification using various chromatographic techniques. Five compounds showing potent activity were identified by comparing their spectral data with literature values to be caffeic acid, vinyl caffeate, rosmarinic acid, methyl rosmarinate, and apigenin. These results indicate that pending further study, these compounds could be used as novel natural product agents for the treatment of hyperuricemia.

Improved antioxidant activity in transgenic Perilla frutescens plants via overexpression of the γ-tocopherol methyltransferase (γ-tmt) gene

The main goal of this study was to generate transgenic Perilla frutescens with enhanced antioxidant properties by overexpressing the γ-tocopherol methyltransferase (γ-tmt) gene. In this study, the antioxidant activity of methanolic crude extracts of transgenic and non-transgenic control plants was investigated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method. Free radical scavenging activity was evaluated using α-tocopherol and butylated hydroxyl toluene as standard antioxidants. In general, the ethyl acetate fraction of transgenic P. frutescens showed stronger DPPH radical scavenging activity than the ethyl acetate fraction from non-transgenic control plants (IC50 2.00 ± 0.10 and 5.53 ± 0.40 μg ∙ ml(-1), respectively). High-performance liquid chromatography analysis of phenolic acids in leaf extracts confirmed increased levels of 16 individual phenolic compounds in two transgenic lines (pf47-5 and pf47-8) compared with control plants. Changes in the phenolic compound profile and α-tocopherol content were correlated with the antioxidant properties of transgenic plants, indicating that the introduction of transgene γ-tmt influenced the metabolism of phenolic compounds and subsequently produced biochemical changes in the transformants. There were no significant differences in photosynthetic rate in the transgenic plants as compared to the non-transgenic control plants, suggesting that the alteration of phenolic compounds and tocopherol composition had little impact on photosynthesis.

[Advances in research of volatile oil and its different chemotypes in leaves of Perilla frutescens]

The volatile oil is the main component in the leaves of Perilla frutescens. According to the main types of monoterpenoids or aromatic compounds, it can be divided into different chemotypes and the main chemotypes of Chinese producing Perilla are PA type (mainly containing Perilla aldehyde and limonene), PK type (mainly containing perillaketone) and PP type (subdivided as PP-a type, with apiole as its main component; PP-m type, with myristicin as its main component; PP-e type, with elemicin as main component; PP-as type, with asarone as main component). Based on the biosynthetic pathways analysis, we also found that the formation of the particular chemotype is usually controlled by a single gene or a few genes, and different types have different pharmacological effects. In this paper, the classification under the species P. frutescens, main chemotypes of the volatile oil, and their biogenesis and regulation, pharmacological effect and influence factors are summarized and reviewed.

Characterization of Anthocyanins in Perilla frutescens var. acuta Extract by Advanced UPLC-ESI-IT-TOF-MSn Method and Their Anticancer Bioactivity

The anthocyanin extract from a domestic Perilla cultivar (Perilla frutescens var. acuta) were isolated and characterized with high mass accuracy and multi-dimensional fragmentation by means of ultra-performance liquid chromatography (UPLC) and electrospray ionization-ion trap-time of flight mass spectrometry analysis (ESI-IT-TOF-MSⁿ). The new developed and applied LC-MS method focused on in-depth screening of anthocyanin compounds with similar structures which also provided a new approach of anthocyanin characterization without the use of external standards. Selective detection of interested anthocyanins was achieved utilizing extracted ion chromatogram (EIC) analysis, while MSⁿ spectra were recorded to allow identification of the anthocyanin based on characteristic fragmentation patterns. Seven anthocyanins including one feruloyl (Cyanidin 3-O-feruloylglucoside-5-O-glucoside), two caffeoyl (Cyanidin 3-O-caffeoylglucoside-5-O-glucoside, Cyanidin 3-O-caffeoylglucoside-5-O-malonylglucoside) and four coumaroyl substituted anthocyanins (Cis-shisonin, Malonyl-cis-shisonin, Shisonin, and Malonyl-shisonin) were identified. Annexin-V FITC/PI flow cytometric assay was performed to analyze the influence of anthocyanin extract of P. frutescens var. acuta on cell apoptosis. The results suggested that Perilla anthocyanins can induce Hela cell apoptosis by a dose dependent manner.

Sensitization of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-resistant primary prostate cancer cells by isoegomaketone from Perilla frutescens

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is currently in clinical trials as a cancer treatment due to its ability to induce apoptosis selectively in cancer cells. Nevertheless, the risk of developing resistance warrants the development of sensitizers that can overcome resistance to TRAIL. In this study, isoegomaketone (1) acted as a synergistic TRAIL sensitizer by mediating up-regulation of DR5 expression in primary prostate cancer RC-58T/h/SA#4 cells. Combined with 1, TRAIL exhibited enhanced apoptotic activity in a human prostate cancer cell line designated RC-58T/h/SA#4, as indicated by increases in annexin V-positive and sub-G1 cell populations as well as condensation of chromatin or apoptotic bodies. Combined treatment also activated caspases-8, -9, and -3; increased the protein levels of Bax, AIF, and cytosolic cytochrome c; and induced PARP cleavage while reducing Bcl-2 protein expression. Human recombinant DR5 Fc chimera efficiently attenuated 1-induced apoptosis, thereby demonstrating the critical role of DR5 in 1-mediated apoptotic cell death. Furthermore, DR5 expression induced by 1 was mediated via a ROS-independent pathway that required CHOP and p53. Overall, these findings provide evidence that 1 potentiates TRAIL-mediated apoptosis through up-regulation of DR5 via a ROS-independent pathway. This suggests that 1 has potential for increasing the effectiveness of prostate cancer therapy with TRAIL.

Identification and quantitation of phenolic compounds from the seed and pomace of Perilla frutescens using HPLC/PDA and HPLC-ESI/QTOF/MS/MS

INTRODUCTION

Perilla frutescens (L.) Britt., an essential traditional Asian crop and Chinese medicine, potentially exerts anti-oxidation effects through its phenolic compounds. These compounds have already been reported in perilla seed, however, little is reported in Perilla pomace, the primary waste during oil production of Perilla seed.

OBJECTIVE

To investigate major phenolic compounds in perilla seeds and pomaces in order to check whether the pomace could be an alternative resource to the seed for nutritional and medical purposes.

METHODS

Compounds in extracts of perilla seeds and pomaces were separated by high-performance liquid chromatography and detected by photodiode array, and by electrospray ionisation with quadrupole time-of-flight tandem mass spectrometry. Herb-markers selected by principal components analysis were then quantified in both seeds and pomaces. Moreover, a fingerprinting approach and multiple discriminant analysis were applied to screen the phenolic markers in 22 samples.

RESULTS

Ten phenols were tentatively identified, among which four (rosmarinic acid, luteolin, apigenin and rosmarinic acid-3-O-glucoside) were selected as herb-markers. Perilla seeds and pomaces showed similar phenol profiles, however, the pomaces contained almost two times the amount of the four herb-markers than the seeds.

CONCLUSION

The results indicated perilla pomace is a promising alternative source of phenolic compounds that could be recovered and potentially used as natural anti-oxidants.

Structural characterisation and antioxidant activity evaluation of phenolic compounds from cold-pressed Perilla frutescens var. arguta seed flour

A total of 11 phenolic compounds, as well as sucrose (12) and tryptophan (13), were isolated from cold-pressed Perilla frutescens var. arguta seed flour using column chromatography, and their chemical structures were identified as 3'-dehydroxyl-rosmarinic acid-3-o-glucoside (1), rosmarinic acid-3-o-glucoside (2), rosmarinic acid (3), rosmarinic acid methyl ester (4), luteolin (5), luteolin-5-o-glucoside (6), apigenin (7), caffeic acid (8), caffeic acid-3-o-glucoside (9), vanillic acid (10) and cimidahurinine (11) using NMR and time-of-flight mass spectrometry. Of these components, compound 1 is novel, and this is the first report of compounds 10 and 11 in perilla seeds. HPLC quantification combined with antioxidant activity evaluation revealed that rosmarinic acid and rosmarinic acid-3-o-glucoside were the dominant phenolic antioxidants with strong antioxidant activities.

Rosmarinic acid extract for antioxidant, antiallergic, and α-glucosidase inhibitory activities, isolated by supramolecular technique and solvent extraction from Perilla leaves

Rosmarinic acid extract with potent biological activities was successfully isolated by supramolecular technique and solvent extraction from Perilla leaves. By the supramolecular complex which was formed from flavocommelin and Perilla leaf extract as initial materials, the supernatant containing rosmarinic acid was isolated. Rosmarinic acid extract (62.9 ± 4.5% purity) was partly purified by partitioning ethyl acetate and water. Rosmarinic acid extract exhibited high total phenolic content of 433.9 ± 58.6 μg/mg of gallic acid equivalent, effective DPPH radical scavenging activity (SC50 of 5.5 ± 0.2 μg/mL), antiallergic activity (IC50 of 52.9 ± 6.7 μg/mL), and α-glucosidase inhibitory activity (IC50 of 0.23 ± 0.01 mg/mL). Rosmarinic acid extract shows high potential for diabetes mellitus and allergy treatments by inhibiting α-glucosidase activity and measuring β-hexosaminidase, related to life-style disease.