Antioxidant and antimicrobial activities of fruit extracts from different fresh chili peppers.

BACKGROUND: The aim of the current study was to assess the antimicrobial and antioxidant potential of ethanol extracts obtained from the fruit of five species of fresh chili pepper, Capsicum (C.) baccatum L. (Aji Amarillo), C. chinense (Fidalgo Roxa), C. annuum (Cherry Chocolate), C. pubescens (Rocoto Orange) and C. frutescens (Peruvian Purple). METHODS: To obtain the ethanol extracts, accelerated solvent extraction (ASE) was applied. DPPH assay was used to determine the antioxidant activity of the extract samples. The disc diffusion method was used to measure antimicrobial activity against nine investigated microorganism species. RESULTS: The tested extract samples exhibited DPPH radical scavenging activities ranging from 0.24 ±0.01 (Peruvian Purple) to 0.72 ±0.02 (Aji Amarillo) mg TEAC∙g–1 dw. The differences between all the varieties were statistically significant (P < 0.05; except for the Cherry Chocolate and Rocoto Orange), and the potential of antioxidant capacity increased in the following manner: Peruvian Purple < Fidalgo Roxa < Rocoto Orange < Cherry Chocolate < Aji Amarillo. The results from the antimicrobial evaluation showed that the Capsicum extracts had no uniform inhibition activity against tested gram-negative, gram-positive bacteria, and yeast. Specifically, Aji Amarillo fruit extract revealed the strongest antimicrobial activity against S. pneumoniae (6.33 ±0.58 mm), followed by Cherry Chocolate against S. pneumoniae (5.33 ±0.58 mm), Rocoto Orange against S. enterica (5.27 ±0.58 mm), Fidalgo Roxa against C. albicans (4.67 ±0.58 mm), and Peruvian Purple against S. pneumoniae (4.57 ±0.58 mm). CONCLUSIONS: Considering these results, Capsicum spp. can be used as a source of novel antioxidant and antimicrobial compounds.

Evaluation of the antioxidant potential of Capsicum annuum L., C. baccatum L. and C. chinense Jacq. cultivars.

BACKGROUND: Economically important vegetables are a strong source of antioxidants with different characteristics. Capsicum L. (pepper) is an important agricultural plant because of its economical, medicinal, and nutritional values. METHODS: This study aimed to test antioxidant parameters in the fruits of 9 cultivars of Capsicum annuum L. (CA 01-09), 7 cultivars of C. baccatum L. (CB 01-07), and 11 cultivars of C. chinense Jacq. (CC 01-11). The antioxidant activity of the investigated Capsicum cultivars was measured, along with the free radical scavenging activity (FRSA), using the DPPH method, and the molybdenum reducing power (MRP) was expressed as mg TE (Trolox equivalent) per g of DW (dry weight). Total polyphenol content (TPC), expressed as mg GAE (gallic acid equivalent) per g of DW, total flavonoid content (TFC), expressed as mg QE (quercetin equivalent) per g of DW, and total phenolic acid content (TPAC), expressed as mg CAE (caffeic acid equivalent) per g of DW, were the basic antioxidant parameters of antioxidant activity in this study. RESULTS: All investigated Capsicum extracts exhibited FRSA from 1.45 (CC-06) to 8.21 (CC-05) mg TE/g and MRP from 24.84 (CA-06) to 198.21 (CB-07) mg TE/g. The TPC of the tested extracts ranged from 10.13 (CB-03) to 38.68 (CB-07) mg GAE/g. The TFC of the studied samples showed values from 5.73 (CB-03) to 27.32 (CB-07) mg QE/g and TPAC from 2.24 (CB-03) to 13.07 (CC-07) mg CAE/g. A very strong correlation was found in the investigated cultivars between TPC and TPAC (r = 0.932, 0.839 and 0.848, respectively), and between TPC and TFC (r = 0.921, 0.982 and 0.939, respectively). Very strong relations were also found between TPC and FRSA (r = 0.820) in the C. annuum cultivars and between TPC and MRP (r = 0.898) in the C. baccatum cultivars. CONCLUSIONS: This study found useful results concerning the antioxidant potential of the fruits of Capsicum cultivars. The data obtained demonstrate the strong antioxidant activity of cultivars of Capsicum, which can be used in the food industry because of the commercial importance of these fruits.

Evaluation of the antioxidant activity and phenolic content of Chinese quince (Pseudocydonia sinensisSchneid.) fruit.

BACKGROUND: Neglected and underutilized plant species could serve as a valuable source of natural bioactive compounds. The objective of this study was to evaluate the biological activity of Chinese quince (Pseudocydonia sinensis Schneid) genotypes of Ukrainian and Slovak origin. METHODS: The content of the total antioxidant activity (DPPH method and molybdenum reducing antioxidant power), total polyphenol, flavonoid and phenolic acid compounds in the pulp and peel of Chinese quince were compared across five genotypes from Slovakia and three from Ukraine. RESULTS: All tested samples exhibited DPPH• radical scavenging activities with values from 6.17 to 9.56 mg TEAC (Trolox equivalent antioxidant capacity) per gram of dry matter (DM). Antioxidant activity, measured using the molybdenum reducing antioxidant power method, ranged from 69.82 to 225.04 mg TEAC per gram of DM. Total polyphenol content was from 34.73 to 82.02 mg GAE (gallic acid equivalent), while total flavonoid content was from 0.50 to 26.72 mg QE (quercetin equivalent) per gram DM. Phenolic acid content varied from 1.12 to 8.39 mg CAE (caffeic acid equivalent) per gram DM. The peel extracts contained the highest content of bioactive compounds when compared with the pulp extract (from 15.30 to 32.60%). All observed parameters differed significantly between the genotypes. Strong positive correlations (p ≤ 0.05) were observed between the content of phenolic acids and flavonoids in the peel in plants from Slovakia (r = 0.951, r = 0.928, respectively); between the phenolic acid and antioxidant capacities detected using the MRP method – r = 0.950 and r = 0.955 for peel and pulp, respectively; between the determination of antioxidant activity by the DPPH and MRP methods in the peel and pulp in plants from Ukraine (r = 0.986, r = 0.998, respectively). Significantly positive correlations were found between all the parameters in the samples of Ukrainian origin. CONCLUSIONS: The results showed that all fruit extracts exhibited strong antioxidant activities, which generally correlated positively with the total phenolic content. This study demonstrates that Chinese quince fruit grown in Ukraine and Slovakia is a perspective source of valuable polyphenol content with high antioxidant activity and is a valuable fruit for use in the agriculture and food industries.

Dietary bioflavonoid quercetin modulates porcine ovarian granulosa cell functions in vitro.

Quercetin is a dietary bioflavonoid used widely as a food supplement and is generally recognized as safe. The aim of this in vitro study was to examine the steroid hormone (progesterone and 17- ß estradiol) release, proliferation (PCNA and cyclin B1) and apoptosis (caspase 3 and p53) of porcine ovarian granulosa cells after the addition of quercetin at concentrations 0.01, 0.1, 1, 10 and 100 µmol L-1. Progesterone release was stimulated at the concentration 10 µmol L-1. Quercetin neither had any impact on 17-ß estradiol secretion nor on the presence of PCNA. However, a significant enhancement of the occurrence of cyclin B1 was noted except for the lowest concentration 0.01 µmol L-1. Quercetin did not have any influence on the number of granulosa cells containing caspase 3, but at the concentration 10 µmol L-1 it inhibited p53 occurrence. Results confirm the safety of quercetin in porcine ovarian granulosa cell model and further suggest its possible concentration-dependent influence on ovarian functions through pathway that may involve progesterone, cyclin B1 and p53.