Antioxidant and Anti-Cytotoxicity Effect of Phenolic Extracts from Psidium guajava Linn. Leaves by Novel Assisted Extraction Techniques

Abstract

Phytochemicals (PCs) are gaining popularity due to their antioxidant effects and potential protection against infection, cardiovascular disease, and cellular metabolic activity. These PCs must be retained as much as possible during extraction. This research focused on the extraction of PC from Psidium guajava Linn. leaves due to higher antioxidant potential. Solvent extraction (SE), microwave-assisted extraction (MAE), and ultrasound-assisted extraction (UAE) using distilled water (DW) or 60% (v/v) ethanol/water (ET) were used for the extraction of PC. ET shows higher total phenolic (TPC) and total flavonoid content (TFC) as well as higher antioxidant activity than DW. Phytochemical screening demonstrated that all of the screening showed positive results in all extraction methods, except glycoside. There were no significant differences (p > 0.05) in TPC and TFC during MAE/ET, SE/ET, and UAE/ET. Antioxidant analysis shows that MAE and SE resulted in high (p < 0.05) DPPH and FRAP values for ET and DW, respectively. MAE/ET showed the highest inhibitory activity (IC50 = 16.67 µg/mL). HPLC and TLC analysis reveal the fingerprint of morin, which might function as an anticancer agent with other bioactives. Increasing the extract content increased the inhibitory activity of SW480 cells via MTT assay. In conclusion, MAE/ET is the most efficient among the extraction techniques in terms of anti-cytotoxicity effects.

Nutritional Composition, Mineral Profiling, In Vitro Antioxidant, Antibacterial and Enzyme Inhibitory Properties of Selected Indian Guava Cultivars Leaf Extract

“…Krupa et al [35] also reported that the methanolic extract of Moringa concanensis seeds showed the highest TPC with 76.41 mg GAE/g, which was also lower than our results. Similar to this, Mazumder et al [36] studied the TPC of guava leaf and reported 66.00 ± 1.21 mg GAE/g which was relatively lower than the results of the present study. As with TPC, the methanolic extract dominated over the other extracts for flavonoid content.…”

Optimization of Ethanolic Extraction of Phenolic Antioxidants from Lychee and Longan Seeds Using Response Surface Methodology

“…The seeds were dried using a tray drier (BP-80, KN Thai TwoOp, Bangkok, Thailand) at 50 • C for 24 h. A hammer mill (Model CMC-20) was used to grind the dry seeds into a fine powder. The pulverized seeds were passed through a sieve with a mesh size of 20 (0.84 mm), followed being kept in a high-density polyethylene zipper (Ziploc ® , San Diego, CA, USA) and stored at −20 • C until further use [34,35].…”

“…The entire extraction volume was made of up to 30 mL of ethanol and distilled water (50:50, v/v) solution. Ethanol is used to extract phenolic antioxidant in compliance with the standards governing the use of food-grade solvents [34]. The suspensions were stirred at 150 rpm for 4 h at room temperature (28 ± 2 • C).…”