Phytochemical and Antioxidant Activity of Avocado Leaf Extract (Persea americana Mill.)

Extraction of grape seeds by different solvents affects the activities of the resultant extract

Phenolic compounds are concentrated in grape seeds; 60-70% of the extractable grape phenols are found in the seeds. The focus of this research was to isolate the phytochemicals from grape seed and to determine their ability to prevent haemolysis, their antioxidant and microbiological activities. By using the extraction procedure, three solvents were used (distilled water, ethanol and methanol). A high-performance liquid chromatographic (HPLC) test was performed to analyse the phenolic compounds and flavonoids content that were used to determine the efficiency of the various solvents used in the extraction process. All the variables under study, namely yield percentage, phenolic component concentration, and flavonoid content got significantly affected by the choice of the solvent used. The flavonoid content of the extracts was in the order methanolic extract > ethanolic extract > water extract. The methanolic extract of the grape seeds exhibited the most powerful antioxidant and hemolysis inhibitory effects among the three extracts, followed by the ethanolic and water extracts. The antibacterial activity of methanolic extract was found to be higher as compared to the ethanolic extract against Staphylococcus aureus. The antibacterial activity of the ethanolic and methanolic extracts against Salmonella enteritidis, Bacillus subtilis, Aspergillus niger and Escherichia coli were found to be equivalent. In conclusion, grape seeds contained several bioactive compounds that exerted an antioxidant, hemolysis inhibition and anti-microbial activities. These activities depends on the concentration of phenolic compounds and flavonoids in the grape seed extracts. Methanol was the superior solvent in the extraction process followed by ethanol.

Effect of Avocado (Persea Americana Mill.) Peel Extract on the Diabetic Male White Rats: Preclinical Study

Background: Type 2 Diabetes Mellitus (DMT2) is one of the most common non-communicable diseases (NCDs) worldwide. T2DM is also the leading cause of death in most developed and developing countries. Objective: This study aimed to analyze the effect of avocado (Persea americana Mill.) skin extract on blood glucose levels in white male rats with diabetes (preclinical test). Method: Experimental research in vivo with True Experimental-PreTest and Post Test Only Control Group Design. The samples were 15 white male rats aged ±3 months, with a 150-200 grams bodyweight. Avocado peel was extracted with ethanol. Measurement of fasting blood glucose levels was carried out 3 times. Streptozotocin administration was used to increase glucose levels in experimental animals. Data analysis used Analysis of Variance (ANOVA) to analyze the data obtained from each treatment group, and the level of significance was expressed in =5%. Results: Fasting blood glucose levels in the first measurement for all groups were included in the normal category, about 48.73 mg/dL. Then the second measurement after being induced with STZ showed an increase in fasting blood glucose levels of mice with an average of 181.07 mg/dL. Furthermore, the 3rd measurement showed that mice's fasting blood glucose level was still high, except for group IV, which decreased to 97.33 mg/dL. The results of the comparative analysis of fasting blood glucose levels on the 2nd and 3rd measurements showed that most of them experienced a decrease, except in group V, and the intervention group which experienced a significant decrease, group IV with p-value = 0.003 and the magnitude of the decrease was 133.33 mg/dL. Conclusion: The concentration of 200 mg/kg BW of avocado peel extract significantly reduced fasting blood glucose levels by 133.33 mg/dL after STZ induction compared to other groups

Antioxidant and cytoprotective effects of avocado oil and extract (Persea americana Mill) against rotenone using monkey kidney epithelial cells (Vero)

Oxidative stress is known to be involved in development of numerous diseases including cardiovascular, respiratory, renal, kidney and cancer. Thus, investigations that mimic oxidative stress in vitro may play an important role to find new strategies to control oxidative stress and subsequent consequences are important. Rotenone, widely used as a pesticide has been used as a model to simulate oxidative stress. However, this chemical was found to produce several diseases. Therefore, the aim of this study was to investigate the antioxidant and cytoprotective effect of avocado (Persea americana Mill) extract and oil in monkey kidney epithelial cells (VERO) exposed to rotenone. VERO cells were exposed to IC₅₀ of rotenone in conjunction with different concentrations of avocado extract and oil (ranging from 1 to 1000 µg/ml), for 24 hr. Subsequently, cell viability and oxidative metabolism were assessed. Data demonstrated that avocado extract and oil in the presence of rotenone increased cellular viability at all tested concentrations compared to cells exposed only to rotenone. In addition, extract and avocado oil exhibited antioxidant action as evidenced by decreased levels of reactive oxygen species (ROS), superoxide ion, and lipid peroxidation, generated by rotenone. Further, avocado extract and oil appeared to be safe, since these compounds did not affect cell viability and or generate oxidative stress. Therefore, avocado appears to display a promising antioxidant potential by decreasing oxidative stress.

The Avocado (Persea americana Mill.) Leaf Extract on Streptozotocin-induced Pancreatic Cell Regeneration of White Rats (Rattus norvegicus)

Objectibe The rate of pancreatic cell regeneration after avocado leaf extract intervention in a diabetic animal model induced by streptozotocin was investigated in this study. Method: Experimental study was conducted on 18 male white rats as subjects, which were divided into 6 groups, 3 animals of each. Those were G1 (Feed + Streptozotocin + 10% Sucrose + 100 mg/kg b.w. of extract + 0.5% NaCMC), G2 (Feed + Streptozotocin + 10% Sucrose + 150 mg/kg b.w. of extract + 0.5% NaCMC), G3 (Feed + Streptozotocin + 10% Sucrose + 200 mg/kg b.w. of extract + 0.5% NaCMC), G4 (Feed + Streptozotocin + 10% sucrose + 0.5% Na-CMC), G5 (Feed + Streptozotocin + 10% sucrose + Glibenclamid + 0.5% Na-CMC), G6 (Normal healthy animal + Feed). Results: The pancreatic cells damage in animal diabetic model, G1 = 1.67 (moderate cell damage); G2 = 1.00 (mild cell damage); G3 = 0.33 (no damage); G4 = 3.00 (severe cell damage); G5 = 0.33 (no damage); G6 = 0.33 (no damage). Conclusion: The dose of 200 mg/kg b.w. of avocado leaf extract contributed the most significant recovery of pancreatic cell of diabetic animal induced with streptozotocin, equivalent to glibenclamide.