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Medicinal plants are a valuable source of essential medicines and herbal products for healthcare and disease therapy. Compared with chemical synthesis and extraction, the biosynthesis of natural products is a very promising alternative for the successful conservation of medicinal plants, and its rapid development will greatly facilitate the conservation and sustainable utilization of medicinal plants. Here, we summarize the advances in strategies and methods concerning the biosynthesis and production of natural products of medicinal plants. The strategies and methods mainly include genetic engineering, plant cell culture engineering, metabolic engineering, and synthetic biology based on multiple "OMICS" technologies, with paradigms for the biosynthesis of terpenoids and alkaloids. We also highlight the biosynthetic approaches and discuss progress in the production of some valuable natural products, exemplifying compounds such as vindoline (alkaloid), artemisinin and paclitaxel (terpenoids), to illustrate the power of biotechnology in medicinal plants.
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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.
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Objective:To investigate the relationship between meaning in life and procrastination of college students, and whether time value plays an mediating role between them.Methods:A total of 605 college students in Guizhou completed general procrastination scale, time value scale and life meaning scale.SPSS 22.0 software and PROCESS maro program were used for descriptive statistics, correlation analysis and mediating effect exploration.Results:(1) The procrastination score of college students was (34.40±7.74), the score of time value was (33.17±4.41), and the score of meaning in life was(46.03±8.81). (2) Procrastination was negatively correlated with meaning in life and time value ( r=-0.38, -0.16 respectively, P<0.01). While meaning in life was positively correlated with time value( r=0.31, P<0.01). (3) The mediating effect of time value perception between meaning seeking and procrastination was 22.6%.The direct effect of meaning in life on procrastination was 77.4%. Conclusion:College students with high meaning seeking is less procrastination, and time value mediates the effect between procrastination and meaning in life.Improving college students' meaning in life is conducive to indirectly reducing procrastination through time value.
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Objective:To explore the difference in the proliferation, migration and ultraviolet radiation effect between double-head and unilateral pterygium fibroblasts (HPFs) cultured in vitro. Methods:Pterygium tissue was obtained from patients who underwent pterygium excision with conjunctival transposition from March 2017 to March 2018 in the Second Affiliated Hospital of Guangzhou Medical University.Nineteen cases with bilateral pterygium and 19 cases with unilateral pterygium were selected for this research.Twelve cases of normal conjunctival tissue were obtained from donor eyes.The fibroblasts were divided into HPFs-nasal (HPFs-N), HPFs-temporal (HPFs-T), unilateral HPFs and human conjunctiva fibroblasts (HCFs), which was taken from the nasal side of the bilateral pterygium, the temporal side of the bilateral pterygium, the unilateral pterygium and the normal conjunctiva, respectively.Human pterygium and normal conjunctival fibroblasts were isolated and cultured by tissue culture method.The fibroblasts were divided into an ultraviolet irradiation group and a normal light illumination group.The cell growth curve was detected by methyl thiazolyl tetrazolium (MTT) assay.The cell scratch healing rate was detected by the cell scratch test after 48 hours.The expression of α-smooth muscle actin αwas detected by immunofluorescence staining, and the number of positive cells in each group was compared.The fibroblasts cultured in vitro were irradiated with ultraviolet irradiation, and the cell scratch healing rate, growth curve and expression of α-SMA were observed.The study protocol was approved by the Ethics Committee of the Second Affiliated Hospital of Guangzhou Medical University.Written informed consent was obtained from each subject. Results:The pterygium and conjunctival fibroblasts were spindle shaped, and the growth rate was gradually increased from day 1 to day 7.The growth rate of HPFs-N was the fastest, and the growth rate of HCFs was the slowest.The growth rate of the four types of fibroblasts was significantly increased after exposure to ultraviolet.There were significant differences in the cell scratch healing rates and α-SMA positive cell expression rates among the four fibroblast types under different lighting conditions ( Fgroup=158.064, P<0.05; Fcell type=326.582, P<0.05. Fgroup=4.731, P<0.05; Fcell type=172.813, P<0.05), of which the scratches healing rate in the HPFs-N cells after 48 hours under the normal light conditions was (79.67±0.86)%, which was significantly higher than HPFs-T ([54.04±0.33]%), unilateral HPFs ([64.12±0.21]%) and HCFs ([58.86±0.41]%), the α-SMA positive cell expression rate in the HPFs-N cells after 48 hours under the normal light conditions was (28.87±1.02)%, which was significantly higher than that in HPFs-T ([13.67±0.23]%), unilateral HPFs ([20.35±1.72]%) and HCFs ([5.12±0.45]%) (all at P<0.05); the cell scratch healing rates and α-SMA positive cell expression rates were significantly increased in the ultraviolet irradiation group than those in the normal light illumination group (all at P<0.05). Conclusions:The nasal side of double-head pterygium fibroblasts is more proliferous and more migratory than that of the unilateral pterygium, the expression of α-SMA is also increased, which can be further enhanced by ultraviolet irradiation.
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AIM: To investigate the effects of nitric oxide (NO) and NO synthase (NOS) inhibitor NG-nitro-L arginine (L-NA) on LPS induced-lung injury in rats. METHODS: Forty healthy male SD rats, weighing 300?20 g, were used. The animals were anesthetized with 20% urethane 1 g?kg -1. Common carotid artery (CAA) and jugular vein were exposed through a median incision in the neck. Mean arterial pressure (MAP) was measured through a pressure transducer connected with intubation of CAA. The animals were randomly divided into five groups: group 1: control; group 2: LPS (5 mg?kg -1, iv); group 3: high dose L-NA (20 mg?kg -1 intraperitoneal injection, ip); gropu 4: middle dose L-NA (10 mg?kg -1, ip); group 5: low dose L-NA (5 mg?kg -1, ip). Group1 : 0.9% saline solution was given and the animals were killed 6 h after the saline solution. Gruop 2: saline solution was given 3 h after LPS and the animals were killed 3 h after administration. Group 3, 4 and 5: L-NA was given 3 h after LPS iv and the animals were killed 3 h after administration, respectively. The pulmonary was removed immediately. The pulmonary coefficient and water content in pulmonary tissue were calculated (%). The NO 2-/NO 3- content in plasma, MDA content and NOS, SOD activity in the pulmonary tissue were measured. RESULTS: L-NA significantly decreased pulmonary coefficient and water content in pulmonary tissue and ameliorated LPS induced lung injury. The effect in high dose group was better than that in low dose group. L-NA significantly decreased NO 2-/NO 3- content in plasm, decreased MDA content and inhibited NOS activity and enhanced SOD activity in the pulmonary tissue. CONCLUSION: It may be concluded that L-NA has a beneficial effect on lung injury induced by LPS.