Bioaccessibility of phenolic compounds and antioxidant activity in raw and pickled capers

Capers are excellent sources of phenolic compounds, which possess antioxidant activity and a variety of health benefits. Capers are often not eaten fresh due to their bitterness, instead, they are usually brined and eaten as pickles. For phenolics to display beneficial effects, they should be bioaccessible. This research aimed to investigate the bioaccessibility values of phenolics in raw and pickled capers. Before and after in vitro digestion, total phenolic content (TPC), total flavonoid content (TFC), ABTS, DPPH, and FRAP antioxidant activities and individual phenolics were determined in raw (RC) and pickled capers (PC). TPC, TFC, and antioxidant activity of capers were not affected by pickling. The bioaccessibility of TPC in RC and PC was 77.8% and 72.9%, respectively. In vitro digestion decreased ABTS, DPPH, and FRAP antioxidant activity values in RC and PC significantly (p < 0.05). Rutin (quercetin-3-O-rutinoside) and kaempferol-3-O-rutinoside were found to be the main phenolic compounds before and after in vitro digestion in all caper samples. After in vitro digestion, rutin content decreased, while kaempferol-3-O-rutinoside content in capers was stable. The results suggest that capers are really good sources of bioaccessible phenolics.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05824-x.

The Capparis spinosa var. herbacea genome provides the first genomic instrument for a diversity and evolution study of the Capparaceae family

Background

The caper bush Capparis spinosa L., one of the most economically important species of Capparaceae, is a xerophytic shrub that is well adapted to drought and harsh environments. However, genetic studies on this species are limited because of the lack of its reference genome.

Findings

We sequenced and assembled the Capparis spinosa var. herbacea (Willd.) genome using data obtained from the combination of PacBio circular consensus sequencing and high-throughput chromosome conformation capture. The final genome assembly was approximately 274.53 Mb (contig N50 length of 9.36 Mb, scaffold N50 of 15.15 Mb), 99.23% of which was assigned to 21 chromosomes. In the whole-genome sequence, tandem repeats accounted for 19.28%, and transposable element sequences accounted for 43.98%. The proportion of tandem repeats in the C. spinosa var. herbacea genome was much higher than the average of 8.55% in plant genomes. A total of 21,577 protein-coding genes were predicted, with 98.82% being functionally annotated. The result of species divergence times showed that C. spinosa var. herbacea and Tarenaya hassleriana separated from a common ancestor 43.31 million years ago.

Conclusions

This study reported a high-quality reference genome assembly and genome features for the Capparaceae family. The assembled C. spinosa var. herbacea genome might provide a system for studying the diversity, speciation, and evolution of this family and serve as an important resource for understanding the mechanism of drought and high-temperature resistance.

In vitro effects of Capparis spinosa L. extract on human sperm function, DNA fragmentation, and oxidative stress

ETHNOPHARMACOLOGICAL RELEVANCE

Oxidative stress is one of the underlying causes of male infertility. Medicinal plants have many benefits for infertility treatment in men.

AIM OF THE STUDY

In the present study, we evaluated in vitro effects of Capparis spinosa leaf extract on human sperm function, DNA fragmentation, and oxidative stress.

MATERIALS AND METHODS

We conducted this study on the hydroalcoholic extract of C. spinosa. Polyphenol compounds and antioxidant effects of the leaf and fruit extract were determined by HPLC and DPPH method, respectively. Flavones and flavonols, total flavonoid, total phenolic content, tannin, and the total carbohydrate content were determined calorimetrically. Semen samples from 50 healthy men (20-45 years) were divided into control and experimental (15, 30, and 45 ppm of C. spinosa leaf extract) groups. Motility, viability, lipid peroxidation, and DNA fragmentation were evaluated 24 h after incubation.

RESULTS

The antioxidant effect of leaf extract was six times greater than fruit. Progressive and total motility of caper-treated groups (30 and 45 ppm) were crucially higher than the control group. Viability in all treatments was significantly higher than the control group. There was no significant difference in lipid peroxidation. DNA fragmentation in the caper-treated group (45 ppm) was significantly lower than the control group.

CONCLUSIONS

Our results suggest the potential positive in vitro effect of C. spinosa leaf extract on human sperm function. The use of C. spinosa leaf extract or its active metabolites in the sperm culture medium may be beneficial for maintaining motility, vitality, and sperm DNA. Since these effects were observed at very low concentrations of caper, other non-antioxidant mechanisms must be considered.

Antioxidant and anti-inflammatory effect of Asphodelus microcarpus methanolic extracts

ETHNOPHARMACOLOGICAL RELEVANCE

Asphodelus microcarpus is an important medicinal plant belonging to family Liliaceae. This plant is used in traditional medicine to treat abscesses by local application of the powder; the roots are used against white spots, and specifically used for ear pain.

AIM OF THE STUDY

The aim of the present study was to assess the in vitro antioxidant effects and the in vivo anti-inflammatory activity of the different parts methanolic extracts of the Asphodelus microcarpus: aerial part (APME), leaf (LME), stem flowers (SFME) and root (RME).

MATERIAL AND METHODS

The antioxidant potency of extracts was evaluated by DPPH (2, 2-diphenyl-l-picrylhydrazyl), ABTS, β-carotene bleaching assays, iron chelating, free hydroxyl radicals (HO^•) assays, and reducing power. The anti-inflammatory effect of the extracts was evaluated using the carrageenan induced rat paw edema and xylene-induced ear edema in mice.

RESULTS

The estimation of polyphenols and flavonoids showed that the leave methanolic extract contains a high amount of polyphenols and flavonoids: 755.3 ± 0.036 mg Gallic acid equivalent and 42.2 ± 0.043 mg Rutin equivalent/g of dried material, respectively. Oral administration of the APME and RME extract produced significant (p < 0.05) anti-edematogenic effect with a dose of 500 mg/kg in the carrageenan induced paw edema after 6 h (58.04%, 58.75%, respectively). APME, LME; SFME and RME extracts at 100, 300 and 500 mg/kg, exhibited significant (p < 0.05) inhibition of xylene induced ear edema.

CONCLUSION

the present study confirms the use of A. microcarpus in traditional medicine as anti-inflammatory agent.

Metabolomic study of wild and cultivated caper (Capparis spinosa L.) from different areas of Sardinia and their comparative evaluation

Capparis spinosa L. (Capparidaceae), also known as caper, is widely known for its very aromatic flower buds (capers),that are largely employed as a flavouring in cooking. Capparis species are regarded as a potential source of important bioactive compounds, in fact, due to their botanical relationship with Brassica species; they contain glucosinolates, secondary plant metabolites, that have been studied for their potential anticarcinogenic properties. In addition, the presence of other numerous beneficial compounds such as polyphenols, alkaloids, lipids, vitamins and minerals have been reported. The aim of this study was to individuate and determinate the principal bioactive compounds occurring in different part (leaves, buds and flowers) of wild and cultivated C. spinosa collected from different area of Sardinia (Italy). Ultra-high performance liquid chromatography-triple quadrupole/linear ion trap tandem mass spectrometry methods were used for identification and simultaneous determination of 27 bioactive molecules. Analysis of different samples revealed qualitative and quantitative differences in the content of flavonoids, glucosinolates, anthocyanins and phenolic acids. In particular, glucocapparin resulted the most abundant with values ranging from 112 to 364 mg/100 g Fresh Weight (FW); followed by rutin with highest value of 126 mg/100 g FW, 4-hydroxyglucobrassicin with highest value of 42 mg/100 g FW and isorhamnetin 3-O-rutinoside with highest value of 24 mg/100 g FW. Based on this metabolomic targeted approach, quantitative results were treated by principal component analysis to explore and visualise correlation and discrimination among collections of C. spinosa samples. Copyright © 2016 John Wiley & Sons, Ltd.