ABSTRACT
The rhizome of giant taro (Alocasia macrorrhiza (L.) Schott), which is a highly adaptable wild plant, is a traditional Chinese herbal medicine. In the current study, the antiproliferative constituents of giant taro were investigated and six new (1-6) and four known piperidine alkaloids (7-10) were isolated from its rhizomes. Their chemical structures and absolute configurations were elucidated using various spectroscopic methods and the Mosher ester method. The isolated alkaloids were screened for the antiproliferative activity through MTT assay. The results indicated that piperidine alkaloids exerted potential antiproliferative activity against HepG2, AGS and MCF-7 tumor cells. Further researches showed that compounds 3-5 dose-dependently decreased the colony formation rate and induced the apoptosis of AGS cells, while compound 4 induced AGS cell death via the proapoptotic pathway. This study demonstrates that the piperidine alkaloids isolated from giant taro exhibit significant antitumor activity, which provides phytochemical evidence for further development and utilization.
Subject(s)
Humans , Alkaloids/pharmacology , Alocasia/chemistry , Piperidines/pharmacology , Plants , Rhizome/chemistryABSTRACT
BackgroundA novel coronavirus named as "SARS-CoV-2" has spread widely in many countries since December 2019, especially in China. This study aimed to quantify the age-specific transmissibility by using a mathematical model. MethodsAn age-specific susceptible - exposed - symptomatic - asymptomatic - recovered - seafood market (SEIARW) model was developed based on two suspected transmission routes (from market to person and person to person). The susceptible people from Wuhan City were divided into different age groups. We used the subscript i and j to represent age group 1 to 4 (i = j; 1: [≤] 14 years; 2: 15-44 years; 3: 45-64 years; 4: [≥] 65 years) and 1 to 5 (i = j; 1: [≤] 5 years; 2: 6-14 years; 3: 15-24 years; 4: 25-59 years; 4: [≥] 60 years), respectively. Data of reported COVID-19 cases were collected from one published literature from 26 November to 22 December, 2019 in Wuhan City, China. The age-specific transmissibility of the virus was estimated accordingly secondary attack rate (SAR). ResultsThe age-specific SEIARW model fitted with the reported data well by dividing the population into four age groups ({chi}2 = 4.99 x 10-6, P > 0.999), and five age groups ({chi}2 = 4.85 x 10-6, P > 0.999). Based on the four-age-group SEIARW model, the highest transmissibility occurred from age group 2 to 3 (SAR23 = 17.56 per 10 million persons), followed by from age group 3 to 2 (SAR32 = 10.17 per 10 million persons). The lowest transmissibility occurred from age group 1 to 2 (SAR12 = 0.002 per 10 million persons). Based on the five-age-group SEIARW model, the highest transmissibility occurred from age group 4 to 5 (SAR45 = 12.40 per 10 million persons), followed by from age group 5 to 4 (SAR54 = 6.61 per 10 million persons). The lowest transmissibility occurred from age group 3 to 4 (SAR34 = 0.0002 per 10 million persons). ConclusionsSARS-CoV-2 has high transmissibility among adults and elder people but low transmissibility among children and young people.
ABSTRACT
Rosmarinic acid (RA), isolated from herbal balm mint plants, has demonstrated potent anti-tumor properties against liver cancer. However, the precise underlying mechanisms remain unclear. This study aimed to investigate the molecular mechanisms of RA in HepG2 cells. RA anti-tumor activity was assessed using 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyl-tetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays, and Hoechst 33258 staining. Apoptosis and the cell cycle distribution were evaluated by flow cytometry. A proteomics approach was used to identify differentially expressed proteins following RA treatment in HepG2 cells, and quantitative reverse transcription-quantitative polymerase chain reaction was used to validate the results. Bioinformatics analysis was also implemented to further understand the identified proteins, and western blotting was used to analyze the associated proteins. Our results suggested that RA treatment significantly inhibits the viability of HepG2 cells. The MTT and LDH assays indicated dose-dependent decreases in cell proliferation following RA treatment. Hoechst 33258 staining and flow cytometry analysis showed that RA exhibits an apoptosis-inducing effect and induces cell cycle arrest in G1. The proteomics analysis successfully identified 16 differentially expressed proteins. Bioinformatics analysis indicated that the identified proteins participated in several biological processes and exhibited various molecular functions, mainly related to inactivation of the glycolytic pathway. Further western blotting analysis showed that RA could downregulate the expression of glucose transporter-1 and hexokinase-2, leading to the suppression of glucose consumption and generation of lactate and ATP. Taken together, our study found that RA exhibits significant cytotoxic effects by inhibiting cell proliferation and inducing apoptosis and cell cycle arrest, possibly by blocking the glycolytic pathway in human HepG2 cells.
