Combined effects of micron-sized polyvinyl chloride particles and copper on seed germination of perilla.

Microplastics (MPs) and copper (Cu) pollution coexist widely in cultivation environment. In this paper, polyvinyl chloride (PVC) were used to simulate the MPs exposure environment, and the combined effects of MPs + Cu on the germination of perilla seeds were analyzed. The results showed that low concentrations of Cu promoted seed germination, while medium to high concentrations exhibited inhibition and deteriorated the morphology of germinated seeds. The germination potential, germination index and vitality index of 8 mg • L-1 Cu treatment group with were 23.08%, 76.32% and 65.65%, respectively, of the control group. The addition of low concentration PVC increased the above indicators by 1.27, 1.15, and 1.35 times, respectively, while high concentration addition led to a decrease of 65.38%, 82.5%, and 66.44%, respectively. The addition of low concentration PVC reduced the amount of PVC attached to radicle. There was no significant change in germination rate. PVC treatment alone had no significant effect on germination. MPs + Cu inhibited seed germination, which was mainly reflected in the deterioration of seed morphology. Cu significantly enhanced antioxidant enzyme activity, increased reactive oxygen species (ROS) and MDA content. The addition of low concentration PVC enhanced SOD activity, reduced MDA and H2O2 content. The SOD activity of the Cu2+8 + PVC10 group was 4.05 and 1.35 times higher than that of the control group and Cu treatment group at their peak, respectively. At this time, the CAT activity of the Cu2+8 + PVC5000 group increased by 2.66 and 1.42 times, and the H2O2 content was 2.02 times higher than the control. Most of the above indicators reached their peak at 24 h. The activity of α-amylase was inhibited by different treatments, but ß-amylase activity, starch and soluble sugar content did not change regularly. The research results can provide new ideas for evaluating the impact of MPs + Cu combined pollution on perilla and its potential ecological risk.

Green and efficient extraction of flavonoids from Perilla frutescens (L.) Britt. leaves based on natural deep eutectic solvents: Process optimization, component identification, and biological activity.

In this study, an ultrasonic-assisted natural deep eutectic solvent (NaDES) was used to extract flavonoids from Perilla frutescens (L.) Britt. leaves. Of 10 tested NaDESs, that comprising D-(+)-glucose and glycerol exhibited the best total flavonoid extraction rate. Response surface methodology (RSM) was used for extraction modeling and optimization, and the total flavonoid content reached 87.48 ± 1.61 mg RE/g DW, which was a significant increase of 5.36% compared with that of 80% ethanol extraction. Morphological changes in P. frutescens leaves before and after extraction were analyzed by scanning electron microscopy (SEM), and the mechanism of NaDES formation was studied by Fourier transform infrared (FT-IR) spectroscopy. Furthermore, 10 flavonoids were identified by UPLC-Q-TOF-MS. In addition, the NaDES extract had better biological activity according to five kinds of antioxidant capacity measurements, cyclooxygenase-2 (COX-2) and hyaluronidase (Hyal) inhibition experiments. Moreover, the stability test revealed that the total flavonoid loss rate of the NaDES extract after four weeks was 37.75% lower than that of the ethanol extract. These results indicate that the NaDES can effectively extract flavonoids from P. frutescens leaves and provide a reference for further applications in the food, medicine, health product and cosmetic industries.

Determination of Luteolin 7-Glucuronide in Perilla frutescens (L.) Britt. Leaf Extracts from Different Regions of China and Republic of Korea and Its Cholesterol-Lowering Effect.

Lowering blood cholesterol levels is crucial for reducing the risk of cardiovascular disease in patients with familial hypercholesterolemia. To develop Perilla frutescens (L.) Britt. leaves as a functional food with a cholesterol-lowering effect, in this study, we collected P. frutescens (L.) Britt. leaves from different regions of China and Republic of Korea. On the basis of the extraction yield (all components; g/kg), we selected P. frutescens (L.) Britt. leaves from Hebei Province, China with an extract yield of 60.9 g/kg. After evaluating different concentrations of ethanol/water solvent for P. frutescens (L.) Britt. leaves, with luteolin 7-glucuronide as the indicator component, we selected a 30% ethanol/water solvent with a high luteolin 7-glucuronide content of 0.548 mg/g in Perilla. frutescens (L.) Britt. leaves. Subsequently, we evaluated the cholesterol-lowering effects of P. frutescens (L.) Britt. leaf extract and luteolin 7-glucuronide by detecting total cholesterol in HepG2 cells. The 30% ethanol extract lowered cholesterol levels significantly by downregulating 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase expression. This suggests that P. frutescens (L.) Britt leaves have significant health benefits and can be explored as a potentially promising food additive for the prevention of hypercholesterolemia-related diseases.

Exogenous nanoselenium alleviates imidacloprid-induced oxidative stress toxicity by improving phenylpropanoid metabolism and antioxidant defense system in Perilla frutescens (L.) Britt.

Few studies have been conducted to investigate the impact of pesticides on the secondary metabolism of traditional Chinese medicine and strategies to mitigate the toxicity of pesticide-induced oxidative stress. The current study focuses on evaluating the potential impacts of nano selenium (NSe) and imidacloprid (IMI) on the quality, physiological biochemistry, and secondary metabolites in Perilla frutescens (L.) Britt. (P. frutescens). The study utilized metabolome analysis to explore the toxicity mechanism of IMI. The study noted that IMI-induced stress could emerge with detrimental effects by targeting the destruction of the phenylpropanoid biosynthesis pathway. IMI-induced phenylpropanoid metabolism disorder resulted in an 8%, 17%, 25%, 10%, 65%, and 29% reduction in phenylalanine, coniferyl aldehyde, ferulic acid, cafestol, p-coumaraldehyde, and p-coumaric acid levels, respectively. Under the treatment of exogenous NSe, the levels of these metabolites were increased by 16%, 32%, 22%, 22%, 92%, and 29%, respectively. The application of exogenous NSe increased the levels of these metabolites and improved the biochemical disorder and quality of P. frutescens leaves by optimizing the phenylpropanoid metabolic pathway and enhancing the antioxidant system. Overall, the results suggest that foliar application of NSe could alleviate the oxidative stress toxicity induced by IMI and improve the quality of P. frutescens.

Perilla frutescens: A traditional medicine and food homologous plant.

Perilla frutescens, an annual herb of the Labiatae family, has been cultivated in China for more than 2000 years. P. frutescens is the one of the first medicinal and edible plant published by the Ministry of Health. Its leaves, stems and seeds can be used as medicine and edible food. Because of the abundant nutrients and bioactive components in this plant, P. frutescens has been studied extensively in medicine, food, health care and chemical fields with great prospects for development. This paper reviews the cultivation history, chemical compositions and pharmacological activities of P. frutescens, which provides a reference for the development and utilization of P. frutescens resources.

Leaf Extract of Perilla frutescens (L.) Britt Promotes Adipocyte Browning via the p38 MAPK Pathway and PI3K-AKT Pathway.

The leaf of Perilla frutescens (L.) Britt (PF) has been reported to negatively affect adipocyte formation, inhibit body-fat formation, and lower body weight. However, its effect on adipocyte browning remains unknown. Thus, the mechanism of PF in promoting adipocyte browning was investigated. The ingredients of PF were acquired from the online database and filtered with oral bioavailability and drug-likeness criteria. The browning-related target genes were obtained from the Gene Card database. A Venn diagram was employed to obtain the overlapped genes that may play a part in PF promoting adipocyte browning, and an enrichment was analysis conducted based on these overlapped genes. A total of 17 active ingredients of PF were filtered, which may regulate intracellular receptor-signaling pathways, the activation of protein kinase activity, and other pathways through 56 targets. In vitro validation showed that PF promotes mitochondrial biogenesis and upregulates brite adipocyte-related gene expression. The browning effect of PF can be mediated by the p38 MAPK pathway as well as PI3K-AKT pathway. The study revealed that PF could promote adipocyte browning through multitargets and multipathways. An in vitro study validated that the browning effect of PF can be mediated by both the P38 MAPK pathway and the PI3K-AKT pathway.

Perilla frutescens: A traditional medicine and food homologous plant / 中草药·英文版

Perilla frutescens, an annual herb of the Labiatae family, has been cultivated in China for more than 2000 years. P. frutescens is the one of the first medicinal and edible plant published by the Ministry of Health. Its leaves, stems and seeds can be used as medicine and edible food. Because of the abundant nutrients and bioactive components in this plant, P. frutescens has been studied extensively in medicine, food, health care and chemical fields with great prospects for development. This paper reviews the cultivation history, chemical compositions and pharmacological activities of P. frutescens, which provides a reference for the development and utilization of P. frutescens resources.

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.

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).

Perilla (Perilla frutescens) leaf extract inhibits SARS-CoV-2 via direct virus inactivation.

BACKGROUND: While severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection presents with mild or no symptoms in most cases, a significant number of patients become critically ill. Remdesivir has been approved for the treatment of coronavirus disease 2019 (COVID-19) in several countries, but its use as monotherapy has not substantially lowered mortality rates. Because agents from traditional Chinese medicine (TCM) have been successfully utilized to treat pandemic and endemic diseases, we designed the current study to identify novel anti-SARS-CoV-2 agents from TCM. METHODS: We initially used an antivirus-induced cell death assay to screen a panel of herbal extracts. The inhibition of the viral infection step was investigated through a time-of-drug-addition assay, whereas a plaque reduction assay was carried out to validate the antiviral activity. Direct interaction of the candidate TCM compound with viral particles was assessed using a viral inactivation assay. Finally, the potential synergistic efficacy of remdesivir and the TCM compound was examined with a combination assay. RESULTS: The herbal medicine Perilla leaf extract (PLE, approval number 022427 issued by the Ministry of Health and Welfare, Taiwan) had EC50 of 0.12 ± 0.06 mg/mL against SARS-CoV-2 in Vero E6 cells - with a selectivity index of 40.65. Non-cytotoxic PLE concentrations were capable of blocking viral RNA and protein synthesis. In addition, they significantly decreased virus-induced cytokine release and viral protein/RNA levels in the human lung epithelial cell line Calu-3. PLE inhibited viral replication by inactivating the virion and showed additive-to-synergistic efficacy against SARS-CoV-2 when used in combination with remdesivir. CONCLUSION: Our results demonstrate for the first time that PLE is capable of inhibiting SARS-CoV-2 replication by inactivating the virion. Our data may prompt additional investigation on the clinical usefulness of PLE for preventing or treating COVID-19.

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.

Responses of glutathione and phytochelatins biosysthesis in a cadmium accumulator of Perilla frutescens (L.) Britt. under cadmium contaminated conditions.

Screening new accumulators of heavy metal and identifying their tolerance, enrichment capacity of heavy metals are currently hot issues in phytoremediation research. A series of hydroponic experiments were conducted to analyze the effects of glutathione and phytochelatins in roots, stems, and leaves of Perilla frutescens under cadmium stress. The results showed that the non-protein thiols in roots and stems mainly existed in the form of GSH, PC2, PC3, and PC4 under Cd stress condition, while in leaves they existed in the form of GSH, PC2, and PC3. Furthermore, the contents of GSH and PCs positively correlated with Cd, but negatively correlated with root vigor and chlorophyll content under Cd stress conditions. After 21 days of treatments, the contents of Cd in different parts of the plant were 1465.2-3092.9 mg· kg-1 in the roots, 199.6-478.4 mg·kg-1 in the stems and 61.3-96.9 mg· kg-1 in the leaves at 2, 5, 10 mg·L-1 Cd levels respectively, and the amount of Cd uptakes were up to 3547.7-5701.7 µg·plant-1. Therefore, P. frutescens performed high capacity in Cd accumulation, and PCs played a key role in Cd tolerance. The application prospect of the plant in phytoremediation Cd polluted soil was also discussed.

Comparative transcriptome and co-expression analysis reveal key genes involved in leaf margin serration in Perilla frutescens.

Objective: In this study, we aimed to identify the genes involved in leaf margin serration in Perilla frutescens. P. frutescens (Family: Lamiaceae) is widely grown in Asian countries. Perilla leaf is the medicinal part stipulated in the Chinese Pharmacopoeia. There are mainly two types of perilla leaves: one with serrated leaf margin which is the phenotype described in the pharmacopoeia and the other with smooth leaf margin. Methods: Transcriptome sequencing, co-expression analysis, and qRT-PCR analysis of six perilla tissues sampled from two different phenotypes (serrated and smooth leaves) were performed. Results: Forty-three differentially expressed genes (DEGs), which may potentially regulate leaf shape, were identified through de novo transcriptome sequencing between the two groups. Genes involved in leaf shape regulation were identified. Simultaneously, we validated five DEGs by qRT-PCR, and the results were consistent with the transcriptome data. In addition, 1186 transcription factors (TFs) belonging to 45 TF families were identified. Moreover, the co-expression network of DEGs was constructed. Conclusion: The study identified the key genes that control leaf shape by comparing the transcriptomes. Our findings also provide basic data for further exploring P. frutescens, which can help study the mechanism of leaf shape development and molecular breeding.

Isolation, characterization, and xanthine oxidase inhibitory activities of flavonoids from the leaves of Perilla frutescens.

Phytochemical investigation of the water extract from the leaves of Perilla frutescens (Lamiaceae) led to the isolation of a new flavanone, a new chalcone, and a new aurone, namely, (2S)-5,7-dimethoxy-8,4'-dihydroxyflavanone (1), 2',4'-dimethoxy-4,5',6'-trihydroxychalcone (2), and (Z)-4,6-dimethoxy-7,4'-dihydroxyaurone (3), respectively. The structures were unambiguously elucidated on the basis of spectroscopic data. And the absolute configuration of 1 was determined by analysis of electronic circular dichroism spectrum. The isolated compounds were evaluated for their inhibitory effects on xanthine oxidase in vitro. Among them, 2 showed more potent activity than the positive control allopurinol, a well-known XO inhibitor clinically used for treatment of gout. Lineweaver-Burk transformation of the inhibition kinetics data demonstrated that it was a mixed-type inhibitor.[Formula: see text].

Study on prescription process of nanoemulsion of Perilla frutescens essential oil and preliminary quality evaluation / 中草药

Objective: Using Perilla frutescens as a model drug, the nanoemulsion of Perilla frutescens essential oil (PFEO) were prepared, and the formulation process research and preliminary quality evaluation were carried out. Methods: The cosurfactants were determined according to the amount of PFEO dissolved in various excipients. The HLB value method was used to preliminarily screen surfactants suitable for oil-in-water (O/W) nanoemulsions, and the surfactants with dosage safety were further screened to determine the composition of nanoemulsion formulations. By drawing a pseudo-ternary phase diagram, the nanoemulsion region size, drug loading, water content, and conductivity, viscosity, particle size, distribution, and stability was comprehensively compared to optimize the prescription. This study investigated the appearance, physicochemical properties (viscosity, pH value, conductivity, electrical conductivity, particle size, Zeta potential), stability, in vitro permeability properties and nasal mucosa irritation of the nanoemulsion of PFEO. Results: The final optimized nanoemulsion formulation was 14.3% PFEO-9.5% Transcutol P-19.1% Labrasol-57.1% water. The nanoemulsion of PFEO prepared according to the optimized prescription was uniform, transparent, clear, with good fluidity. The viscosity was (3.68 ± 0.17) mPa∙s, pH value was (6.18 ± 0.03), the electrical conductivity was (109.61 ± 0.89) μS/cm, the Zeta potential was (-7.08 ± 1.82) mV, and the particle size was (49.98 ± 1.55) nm. The results of transmission electron microscope experiment showed that, the droplets of PFEO nanoemulsion were spherical with the particle size within 100 nm. The stability test results showed that the nanoemulsion of PFEO had centrifugal stability, dilution stability, long-term stability and temperature stability. After storage at room temperature and unsealed for one month and six months, the percentage change of the average perillaldehyde content of PFEO nanoemulsion and PFEO was 1.8% and 17.48%, respectively. The nasal mucosal irritation test results showed that the PFEO nanoemulsion administration group had no significant difference from the blank saline group. Conclusion: The appearance and related physical and chemical properties of PFEO nanoemulsion prepared by optimized prescription process meet the quality requirements of nanoemulsion, with drug stability, drug permeability and safety.

Comparative transcriptome and co-expression analysis reveal key genes involved in leaf margin serration in Perilla frutescens / 中草药·英文版

Objective: In this study, we aimed to identify the genes involved in leaf margin serration in Perilla frutescens. P. frutescens (Family: Lamiaceae) is widely grown in Asian countries. Perilla leaf is the medicinal part stipulated in the Chinese Pharmacopoeia. There are mainly two types of perilla leaves: one with serrated leaf margin which is the phenotype described in the pharmacopoeia and the other with smooth leaf margin. Methods: Transcriptome sequencing, co-expression analysis, and qRT-PCR analysis of six perilla tissues sampled from two different phenotypes (serrated and smooth leaves) were performed. Results: Forty-three differentially expressed genes (DEGs), which may potentially regulate leaf shape, were identified through de novo transcriptome sequencing between the two groups. Genes involved in leaf shape regulation were identified. Simultaneously, we validated five DEGs by qRT-PCR, and the results were consistent with the transcriptome data. In addition, 1186 transcription factors (TFs) belonging to 45 TF families were identified. Moreover, the co-expression network of DEGs was constructed. Conclusion: The study identified the key genes that control leaf shape by comparing the transcriptomes. Our findings also provide basic data for further exploring P. frutescens, which can help study the mechanism of leaf shape development and molecular breeding.

Research process on pharmacological effect and substance basis of Perilla frutescens / 中草药

Perilla frutescens is one of traditional Chinese diaphoretics, and is produced in many areas of China. The chemical composition is rich in P. frutescens, including volatile oil, aliphatic acids, flavonoids, phenolic acids, coloring matter and so on. Because of the function of relieving superficial pathogenic factors to dissipate cold and promoting qi flowing to regulate the stomach, P. frutescens can be used to treat the diseases of wind-cold, stagnation of gastrosplenic qi, vomiting and poisoning by eating fish and crab. The study showed that P. frutescens exhibited the effects which related with the traditional uses of relieving cough, bacteriostasis, relieving fever, analgesia, etc., and besides, it showed a few new founded effects, such as sedative effects, antioxidative effects, effects of reducing blood pressure, and regulating glucose/lipid metabolism. This paper summarized the research progess on the chemical composition and main pharmacological activities of P. frutescens, and discussed its therapeutic material basis based on the summarise, which could provide a reference for the development of P. frutescens.

Phytochemical and phytopharmacological review of Perilla frutescens L. (Labiatae), a traditional edible-medicinal herb in China.

Perilla frutescens (L.) Britt., a worldwide distributed plant, is an important economic crop and with a long cultivation history in China as well as some other countries in Asia. Except for the edible applications, the plant of P. frutescens is also traditionally used as a medicinal herb in China for thousands years. The leaves, seeds and stems of P. frutescens are recommended by the Chinese Pharmacopeia as three medicinal materials for various therapeutic applications. In the past decades, amount investigations have been done about different aspects for P. frutescens. However, no literature review about these works has been compiled. This review aims to present the findings of research conducted up-to-date (2015) on the traditional use, phytochemicals, pharmacological activities and toxicities of P. frutescens to provide scientific evidence for well-understanding and future research of P. frutescens. It was found that more than 100 compounds have been reported for P. frutescens and most of them are contributed to its medical benefits such as anti-allergic, anti-inflammatory, anti-oxidant, anticancer, anti-microbial, anti-depressive and anti-cough effects. Toxicology studies have been conducted to evaluate the safety of P. frutescens to provide information on their dosages and usages.

Chemical constituents from leaves of Perilla frutescens / 中草药

Objective: To investigate the chemical constituents from the aqueous extract of leaves of Perilla frutescens. Methods: The compounds were isolated and purified by chromatography on macroporous resin, silica gel, ODS, and preparative HPLC. Their structures were elucidated on the basis of chemical and spectroscopic methods, including MS, 1D and 2D NMR spectral techniques. Results: Seventeen compounds were isolated from the aqueous extract of leaves of P. frutescens, and were identified as (+)- isololiolide (1), dehydrovomifoliol (2), (-)-loliolide (3), scutellarin (4), p-hydroxybenzaldehyde (5), p-hydroxyacetophenone (6), 3-formylindole (7), trans-p-hydroxycinnamic acid (8), apigenin (9), luteolin (10), esculetin (11), caffeic acid (12), rosmarinic acid (13), methyl rosmarinate (14), sericoside (15), caffeic acid vinyl ester (16), and negletein (17). Conclusion: Compounds 1-2, 6-8, and 15 are firstly isolated from the plants of Perilla Linn.

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.