EVALUATION OF THE SURFACE TENSIO, LARVICIDAL AND ANTIBACTERIAL ACTIVITY OF PLANT EXTRACTS FROM THE LEAF OF THE ARACA TO COMBAT THE PROLIFERATION OF THE Aedes aegypti MOSQUITO IN STILL WATER CONTAINERS
The Aedes aegypti mosquito is one of the main transmitters of viral diseases in countries close to the equator. This vector promotes a series of generalized endemics that are difficult to control and prevent in these regions. Furthermore, the presence of bacteria in the environment favors the proliferation of mosquito larvae, which increases the probability of Aedes aegypti reproductive success. The Araçzeiro (Psidium guineense Sw.) is a plant present throughout the Brazilian Atlantic Forest and has in its composition, especially in the leaves, several substances that can be used to solve problems. Thus, we sought to verify the activity of flavonoids and polyphenols in terms of their antibacterial potential and the performance of saponins in their larvicidal potential, as well as surfactant, in order to prevent the accommodation of the mosquito in the water at the time of egg deposition and larvae respiration. The saponins were extracted from the araçazeiro leaf using a hydroalcoholic solvent and the flavonoids/polyphenols using methanol, the latter being subsequently rotaevaporated to maintain the non-toxic nature of the extract. Through the aqueous extracts, the content of total saponins by UV-VIS spectrophotometry, surfactant activity, larvicidal activity and toxicity were determined. In relation to the ethanolic extracts, the content of polyphenols and total flavonoids by UV-VIS spectrophotometry and high performance liquid chromatography (HPLC), antibacterial activity and toxicity were determined. The results showed that the aqueous extract has a satisfactory amount of saponins, as well as a surfactant potential due to the formation of foam and larvicidal activity in the two highest concentrations of the extracts. Ethanol extracts showed phenolic acids, especially gallic and ellagic acid, and flavonoids, especially catechin and quercetin, and antibacterial activity in most of the worked concentrations. Both extracts (aqueous and ethanolic) showed a dominant nontoxic character, which favors their use without risk to the environment, having an alternative and sustainable potential for controlling the proliferation of the Aedes aegypti mosquito.
朽木生花-初探以中藥萃取液對木材染色之防蟲抑菌效果
In our experiment, we used traditional Chinese medicine to dye on cheap wood, in addition to avoiding the impact of chemical paint on human body; After dyeing, the color and texture quality of the wood are improved, which makes cheap wood have higher price and improves the value of wood; At the same time, it can reduce the felling of slow growing precious wood, which has the functions of environmental protection, earth love and carbon saving. The test material was pretreated with hydrogen peroxide and surfactant, and the bleaching effect was obvious. After dyed with different Chinese medicinal, soak in strong acid and alkali solution for 15 minutes, which shows that strong acid and acid treatment is not allowed. On the other hand, after 15 minutes of immersion in detergent, the color difference value is less than 2, and the rubbing fastness is above grade 4. In the bacteriostasis experiment, no fungus grew in the first 3 days, and it did not grow in the 12th day. In the anti-termite experiment, the mortality rate on the fifth day was 65% for Lithospermum and 83.8% for Wolfberry, and the other groups had a good effect of total elimination. While plastic products have a great impact on the environment, wood that is dyed or modified with natural colored dye, its environmental value far exceeds the human visual perception.