Study On The Dynamic Changes Of Total Phenolic And Total Flavonoid Content Extracted From J. Mandshurica Maxim And Their Antioxidant And Antitumor Activity

Juglans mandshurica Maxim is widely distributed in our country, and has a wealth of plant resources. In the present study, the green extraction method was used and the extraction process conditions were optimized. Under the optimal parameters, total phenols and total flavonoids from different parts of Juglans mandshurica Maxim at various developmental stages was extracted rapidly, and the best harvest time also was determined. Meanwhile, we also explored the antioxidant and anti-tumor activity of the extract from different growth stages and various organs of Juglans mandshurica Maxim. Our study provided scientific guidance for reasonable development and efficient utilization of Juglans mandshurica Maxim.The results as follows:1. The optimum parameters of the ultrasonic-assisted extraction process for total phenols and total flavonoids were as follows:Liquid/solid ratio:20:1, Extraction time:40 min, Ethonal concentration:60%, Extraction temperature:30℃. Under the optimal parameters, the average extraction yields of total phenols and total flavonoids were 50.54 mg.g"1 and 10.11 mg.g"1, respectively.2. Study on the dynamic changes of total phenolic and total flavonoid content extracted from J. mandshurica MaximAccording to the optimized extraction condition parameters obtained from the above experiments, an UV spectroscopy method was established to determinate the dynamic changes of total phenolic and total flavonoid content extracted from different growth period and different parts of J. mandshurica Maxim. The results showed that there is a big difference in total phenolic and total flavonoid content due to different parts of the organization. Compared with sprig and epicarp, total flavonoid and phenolic content in leaves and bark is relatively high. Meanwhile, the trend of total flavonoid and phenolic content harvested from different periods and parts was different. Compared to other months, total flavonoid and phenolic content of leaves extract in July was the highest, while the content of total phenolics and total flavonoids in bark extract was high in May. As for the epicarp, the total flavonoid content of epicarp harvested in August was about 1.97 times of that in September.3. Study on antioxidant activity of extracts of J. mandshurica MaximIn this paper, antioxidant activity of extracts of J. mandshurica Maxim was studied in vitro. Spectrophotometric colorimetry method was used to detect the effect of extracts from different periods and parts on DPPH radical scavenging capability, and the correlation between total phenolic and total flavonoid content and DPPH radical scavenging capability was analyzed.The results showed that extracts of J. mandshurica Maxim have a certain ability to scavenge DPPH free radicals, but there are some differences between extracts from different parts and different times and DPPH radical scavenging activity. Generally speaking, the ability of extracts in leaves and bark to scavenge DPPH free radicals was better than that of extracts in sprig and epicarp. Moreover, the ability of leaves extracts in July to scavenge DPPH free radicals was the best, and the IC50 value was 0.21 ±0.01 mg·mL-1. Bark extracts in May had a strong ability to scavenge DPPH free radicals, the IC50 was 0.12±0.03 mg·mL-1. However, the ability of sprig and epicarp extracts to scavenge DPPH free radicals was poor. Furthermore, the analysis showed that there was an association between antioxidant activity and total flavonoids and phenolic content extracted from J. mandshurica Maxim.4. Study on antitumor activity of extracts of J. mandshurica Maxim Human liver cancer SMMC-7721 cells or human breast cancer Mcf-7 cells were treated by different concentration of extracts (0.03mg.mL-1、0.06 mg·mL-1、0.12 mg·mL-1、0.25 mg·mL-1、0.50 mg·mL-1 and 0.1 mg·mL-1) for 24 h. The anti-proliferative activity of extracts was determined by MTT assay. The results showed that extracts from different parts had a certain growth inhibitory effects on two kinds of cells in dose-dependently maner. Meanwhile, because of different growth period, it also had different effects on the proliferation of tumor cells. Compared to other months, leaves extract in July had a good inhibitory effect on Mcf-7 and SMMC-7721 cells. Moreover, the morphologic images also confirmed the anti-tumor effect. Although other parts of J. mandshurica Maxim had certain inhibitory effect on the two kinds of tumor cells, the inhibition rate of the growth of tumor cells was lower than that of the leaf extracts.