Antioxidant activity, antimicrobial and effects in the immune system of plants and fruits extracts

Potential of phenolic compounds from pomegranate (Punica granatum L.) by-product with significant antioxidant and therapeutic effects: A narrative review

The wealth of epidemiological evidence in the scientific world underscores the possibility that a plant-based diet can reduce the prevalence of common diseases such as diabetes, cardiovascular disease, cancer, and stroke. The therapeutic effects of plant sources are partly explained by phenolic secondary metabolites or polyphenolic compounds. Therefore, polyphenolic compounds, which are widely distributed in plants, are of great interest for the development of effective specific drugs with antioxidant and anti-inflammatory effects. Moreover, polyphenol compounds have no harmful effects due to their natural biocompatibility and safety. Numerous studies have highlighted the potential of some industrial food wastes from plant material processing, including apple peels and mashed potatoes, grape skins, tomato and carrot peels, pomegranate peels and seeds, and many others. These byproducts are considered low-cost sources of natural biological compounds, including antioxidants, which have beneficial effects on human health. The polyphenol complex of pomegranate peel (Punica granatum L.), which makes up half of the pomegranate fruit, has more pronounced antioxidant and anti-inflammatory properties than other parts. And the most important active components of pomegranate peel, which are found only in this plant, are punicalagin, followed by ellagic acid and gallic acid. It is known that these polyphenolic compounds of pomegranate peel have the most pronounced therapeutic effect. Several studies have shown the protective effect of ellagic acid, punicalagin, against oxidative stress damage caused by free radicals. The potential of pomegranate peel as an antioxidant and therapeutic component in various biological systems is high, according to scientific sources. However, despite extensive research in recent years, a review of sources has shown that there is insufficient evidence to support the therapeutic effects of polyphenolic compounds from pomegranate peels. The role of pomegranate peel polyphenolic compounds, including flavonoids, as antioxidants in various biological systems also requires further research. Of particular importance are the mechanisms by which antioxidants influence the cellular response against oxidative stress. The purpose of this review was to report our current knowledge of plant polyphenolic compounds and their classification, and to evaluate the potential of phenolic compounds from pomegranate peels with significant antioxidant and therapeutic effects.

Antioxidant, Anti-Cancer Activity and Phytochemicals Profiling of Kigelia pinnata Fruits

Over the past few years, research studies on the therapeutic benefits of medicinal plants with potent antioxidant activity and few side effects have grown significantly. This has sparked interest in determining whether naturally occurring antioxidants could take the place of synthetic antioxidants, which are currently being constricted because of their toxic and carcinogenic properties. The identification and quantification of phytochemicals in the methanolic extract of Kigelia pinnata fruits was measured using gas chromatography–mass spectrometry (GC-MS) and ultra-high-performance liquid chromatography–mass spectrometry (UPLC-MS/MS) techniques. Additionally, the methanolic extract of fruits was used to determine antioxidant activity. Free radical-scavenging (DPPH) and ferric ion-reducing antioxidant power were measured using spectrophotometry, and total antioxidant capacity (TAC) was compared with two common antioxidants, vitamin C and α-tocopherol. Moreover, mature fruits have high DDPH, ferric ion-reducing antioxidant power and total antioxidant capacity. Furthermore, mature fruits have high levels of total phenolic, flavonoid, and tannin content; these compounds are thought to be the sources of the antioxidant activity. The major constituents of the methanolic extracts from the mature fruits of K. pinnata were found to be larixinic acid, 3,5-Dihydroxy-6-methyl-2,3-dihydro-4H-pyran-4-one (DMDP), and 5-Hydrxoymethylfurfural. We performed the elemental analysis of the whole fruit. Huh-7 (liver cancer), PANC-1 (pancreatic cancer), Colo-205 (colorectal cancer), HT-29 (colorectal cancer), SNU-16 (gastric carcinoma), SW620 (colorectal adenocarcinoma) and HCT116 (colon carcinoma) were tested in vitro for anticancer activity. Both methanolic and ethyl acetate extracts of mature fruits had a positive effect on all cancer cell lines as compared to the doxorubicin drug. In addition, the methanolic extracts of mature fruits showed more potent cytotoxic effects than the ethyl acetate extracts. Moreover, the most pronounced cytotoxic effects of the methanolic extract were detected in SW620 (colorectal adenocarcinoma), with an IC50 value of 6.79 μg/mL, SNU-16 (gastric carcinoma), with and IC50 value of 8.69 μg/ ml, and in PANC-1 (pancreatic cancer) with an IC50 value of 10.34 μg/mL. Moreover, the results show that the water, ethyl acetate and methanolic extracts of mature fruits have antioxidant capacity, ferric ion-reducing antioxidant power, DPPH scavenging activity and also anticancer activity. Therefore, the present study suggests that the phytochemical profiles of mature fruits of K. pinnata may be used as potential natural antioxidants and anti-cancer cell lines.

Dietary inclusion of chestnut (Castanea sativa) polyphenols to Nile tilapia reared in biofloc technology: Impacts on growth, immunity, and disease resistance against Streptococcus agalactiae

A feeding trial was carried out to examine the effects of adding chestnut (Castanea sativa) polyphenols (CSP) on the growth, skin mucus and serum immune parameters of Nile tilapia (Oreochromis niloticus). Five experimental diets with inclusion levels of 0, 1, 2, 4, and 8 g kg^-1 of CSP were fed to Nile tilapia fingerlings (12.77 ± 0.17 g fish^-1) during an eight-week trial. Fish were analyzed on the fourth and eighth week to determine the influences of CSP on growth, skin mucus, and serum immune parameters. Challenging test versus Streptococcus agalactiae was evaluated at the end of the trial. Fish fed with CSP enriched diets displayed a significant increase (P ≤ 0.05) in growth and a decline in feed conversion ratio (P ≤ 0.05). Similarly, skin mucus and serum immune parameters were significantly increased (P ≤ 0.05) in fish fed CSP with respect to the control. The effects were already evident four weeks after the CSP administration. The disease protection test displayed that the fish's survival rate was significantly higher (P < 0.05) in CSP diets over the control. The relative percentage of survival (RSP) was 62.5, 75.0, 58.3, and 37.5 in fish fed diets contained 1, 2, 4, and 8 g kg^-1 CSP, respectively. The best effect on growth, immune response, and disease resistance were shown in Nile tilapia fed with a diet supplementation of 2 g kg^-1 CSP.

Immunomodulatory and Antioxidant Activities of a Polysaccharide from Ligustrum vicaryi L. Fruit

Ligustrum vicaryi L. is a hybrid of Ligustrum ovalifolium Hassk. var. aureo-marginatum and Ligustrum vulgale L., belonging to the Oleaceae family. It is often used as an ornamental shrub due to its golden leaves. However, its medical value is yet to be discovered. Recently, plant polysaccharides have attracted comprehensive attention owing to their biological properties, including immunomodulatory and antioxidant activities. This study aimed to extract, purify, and characterize the polysaccharide from the Ligustrum vicaryi L. fruit and investigate its immunomodulatory and antioxidant activities. The Ligustrum vicaryi L. fruit polysaccharide (LVFP) was obtained by ultrasonic extraction, ethanol precipitation, macroporous resin separation, and dialysis bag purification. The physicochemical properties of the LVFP were elucidated using Fourier-transform infrared spectrometry, high-performance ion chromatography, and high-performance gel filtration chromatography. The results indicated that the LVFP consisted of rhamnose, arabinose, galactose, and glucose in a ratio of 1.79 : 7.55 : 4.58 : 1.54, and its molecular weight was 88,949 Da. The immunomodulatory and antioxidant activities of the LVFP were investigated using a cyclophosphamide- (Cy-) induced immunosuppressed mouse model. The results demonstrated that the LVFP significantly increased spleen and thymus indexes, enhanced the phagocytic function of neutrophils, activated B and T lymphocytes, and upregulated serum levels of IL-10 and TNF-α. Moreover, we observed that the LVFP relieved Cy-induced liver damage by increasing superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) levels. These results suggested that the LVFP has the immunomodulatory and antioxidant activities, therefore laying a foundation for the application of the LVFP in the pharmaceutical and functional food industries.

Chemical characterization and evaluation of gastric antiulcer properties of the hydroethanolic extract of the stem bark of Virola elongata (Benth.) Warb

ETHNOPHARMACOLOGICAL RELEVANCE

Virola elongata is a tree species belonging to the Myristicaceae family, distributed in the North and Midwest regions of Brazil, in the phytogeographic domain of the Amazon. The aqueous infusion or the hydroethanolic macerate of the stem bark of V. elongata are used in Brazilian and Ecuadorian indigenous folk medicine for several ethnopharmacological purposes, principally, in the treatment of stomach pain, indigestions, and gastric ulcers. This study was aimed to investigate the gastroprotective activity of this plant in order to support its popular use with scientific evidence.

MATERIALS AND METHODS

The stem bark hydroethanolic extract of the plant (HEVe) was prepared by maceration. Its qualitative and quantitative phytochemical constituents were investigated by classical colorimetric techniques, HPLC, and electrospray ionization-multiple stage fragmentation (ESI-MSⁿ). The gastroprotective and antiulcer activity of HEVe at doses of 100, 300 and 900 mg/kg p.o. were tested using three acute (acidified ethanol, piroxicam, and in-water-restrain stress), and one chronic (acetic acid) animal ulcer models. The probable mode of action of the HEVe was evaluated by analyzing gastric acid secretion, mucus content, nitric oxide effect, and its antioxidant properties (on catalase, myeloperoxidase, and GSH content) in experimental rodents. The direct extract's activity on the growth of Helicobacter pylori was also investigated.

RESULTS

Total phenolic content in the HEVe was of 146.20 ± 1.07 mg, being flavonoids about 50% (71.79 ± 0.70 mg) of it. Comparative HPLC fingerprint analysis revealed the presence of known phenolic antiulcer compounds, such as gallic acid, catechin, and rutin. Also, methanol/water fractionation and ESI-MSⁿ analysis of the HEVe reveals the presence of quinic acid, 3,3',4-trihydroxystilbene, juruenolid D, one catechin dimer, one C-glycosyl flavonoid, one polyketide and two neolignans as the major components of the extract. The HEVe attenuated gastric ulceration in all the different models of acute gastric ulcer, by enhancing gastroprotection through its antioxidant properties in vivo, and reducing also considerably the gastric secretion and total acidity. The HEVe also presented healing properties against the induced chronic ulceration process. On the other hand, the HEVe did not exhibit direct activity against H. pylori.

CONCLUSION

The HEVe exhibited significant gastroprotective/antiulcer effects and contain a relative high proportion of phenolic compounds, especially flavonoids, that could likely account, at least in part, for its pharmacological properties. The results justify its traditional usage and provided scientific evidence for its potential as a new herbal medicine to treat gastric ulcers.