Phenolic profiling and in vitro antioxidant, anticholinesterase, and antimonoamine oxidase properties of aqueous extract of African star apple (Chrysophyllum albidum) fruit parts

Chemical composition, antioxidant, and enzyme inhibitory properties of Rauwolfia vomitoria extract

OBJECTIVES

Rauwolfia vomitoria is one ethno-botanicals in Nigeria used by traditional health practitioners in managing several human diseases. However, necessary information regarding its effect on enzymes implicated in the development and progression of erectile dysfunction is missing in the literature. Thus, this study investigated the antioxidant property and impact of Rauwolfia vomitoria extract on erectile dysfunction-related enzymes in vitro.

METHODS

High performance liquid chromatography was used to identify and quantify Rauwolfia vomitoria's phenolic components. Then, utilizing common antioxidant assays, the extract's antioxidant properties were evaluated and finally the effect of the extract on some enzymes (AChE, arginase and ACE) implicated in erectile dysfunction was investigated in vitro.

RESULTS

The results showed that the extract inhibited AChE (IC50=388.72 μg/mL), arginase (IC50=40.06 μg/mL) and ACE (IC50=108.64 μg/mL) activities. In addition, phenolic rich extract of Rauvolfia vomitoria scavenged radicals and chelated Fe2+ in concentration dependent manner. Furthermore, rutin, chlorogenic acid, gallic acid, and kaempferol were found in large quantities by HPLC analysis.

CONCLUSIONS

Therefore, one of the potential reasons driving Rauwolfia vomitoria's use in folk medicine for the treatment of erectile dysfunction could be its antioxidant and inhibitory activities on several enzymes linked to erectile dysfunction in vitro.

Almond and date fruits enhance antioxidant status and have erectogenic effect: Evidence from in vitro and in vivo studies

This study was designed to investigate the efficacies of almond and date fruits on redox imbalance and enzymes relevant to the pathogenesis of erectile dysfunction. The total polyphenol contents, ferric reducing antioxidant power, and vitamin C content were determined spectrophotometrically. Phenolic and amino acid compositions were quantified using HPLC; meanwhile, the antioxidant activities were determined using DPPH, ABTS, FRAP, and metal chelation. Also, the effect of almond and date extract on advanced glycated end-products (AGEs) formation, arginase, and phosphodiesterase-5 activities was evaluated in vitro. Thereafter, the influence of almond and date supplemented diets on copulatory behaviors in normal rats was assessed, followed by arginase and phosphodiesterase-5 activities determination in vivo. The results revealed that date and almond extracts exerted antioxidant properties, prevented AGEs formation in vitro, and inhibited arginase and phosphodiesterase-5 activities in vitro and in vivo. Besides, almond and date supplemented diets significantly enhance sexual behaviors in normal rats when compared with the control. Among the active compounds identified were gallic acid, ellagic acid, quercetin, and rutin. All the 20 basic amino acids were identified. Given the aforementioned, date and almond could represent a reliable source of functional foods highly rich in compounds with antioxidant activity, and arginase and PDE-5 inhibitory properties. PRACTICAL APPLICATIONS: Fruits are essential part of the human diet that furnish the body with important nutrients. Despite the crucial roles of fruits in human diets, some fruits like almond and date are underutilized among Nigerians. However, we characterized the important compounds present in these fruits and how their presence contributes to the biological activities of the fruits. Finally, we relate the chemical composition and the observed biological activities to the overall health and wellness of the consumers.

Medicinal Plants for Anti-neurodegenerative diseases in West Africa

ETHNOPHARMACOLOGICAL RELEVANCE

Neurodegenerative diseases are neuronal diseases that affect the brain components by degenerating the structure and function of the central or peripheral nervous system progressively. It is a leading cause of death and affects huge amount of people worldwide. Plant-based medicines have been utilised in the therapies for many illnesses that have defied western treatments, including neurodegenerative diseases.

AIM OF THIS REVIEW

This review presents an overview of the major neurodegenerative diseases and reported prominent medicinal plants used in managing those diseases in West Africa.

METHODS

Scientific articles regarding medicinal plants and their usefulness in managing neurodegenerative diseases in West Africa were pooled from different scientific databases. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses to filter articles based on their relevance. Pharmacological activity, plant parts used, experimental models, and some isolated chemical compounds of those plants were summarised.

RESULTS

In the West Africa region, Fabaceae (19%) and Solanaceae (13%) have the highest representation of plant families used to treat neurological diseases, while Apocynaceae, Asteraceae, Euphorbiaceae have also been utilised. Flavonoids, alkaloids, phenolic compounds, terpenoids, coumarins present in those plants and their derivatives are reported to possess neuro-protective effects. Biochemical enzymes correlating to antioxidants, anti-inflammatory effects are the potential targets against neurodegenerative diseases.

CONCLUSION

Medicinal plants for anti-neurodegenerative diseases in West Africa have been documented with their neuropharmacological activities. Plant families such as Fabaceae, Solanaceae, Apocynaceae, Asteraceae, and Euphorbiaceae could be a major natural source for discovery of anti-neurodegenerative drugs, thus the metabolites from them should be given priority for neurological research. This review will provide clues for further investigations on the screening and development of anti-neurodegenerative natural products from West African medicinal plants.

Effect of Chrysophyllum albidum fruit pulp powder on antioxidant and proinflammatory genes in non-diabetic and type 2 diabetic rats

Background

Diabetes mellitus (DM) is a metabolic disorder characterized by chronic hyperglycemia resulting from insulin deficiency or dysfunction. The imbalance between free radicals and antioxidants known as oxidative stress has been implicated in the pathogenesis and complications associated with DM. Chrysophyllum albidum is a seasonal fruit found to be rich in natural antioxidants.

Methods

DM was induced by high-fat diet dietary supplementation for 14 days followed by intraperitoneal injection of streptozotocin (35 mg/kg). Thirty-five experimental rats were then divided into seven groups viz.: non-diabetic control; diabetic control; metformin; diabetic and non-diabetic fed with 5 and 10% C. albidum fruit pulp powder (CAFPP). Fasting blood glucose was done with an automatic auto-analyzer and weights were monitored at three-day intervals. The expressions of Nrf2, SOD, CAT, GST, TNF-α, DPP4, and insulin were investigated using RT-PCR. Schrödinger suites was used for docking of C. albidum phytocompounds with insulin.

Results

Diabetic rats fed with CAFPP for thirteen days have their blood glucose lowered significantly (p < 0.05) and gained weight compared to diabetic control. CAFPP significantly (p < 0.05) up-regulated Nrf2, CAT, GST, SOD, and insulin genes expression in the diabetic group relative to diabetic control with concomitant down-regulation of TNF-α and DPP4 genes expression. Molecular docking of compounds previously characterized from C. albidum revealed that they are potent ligands of insulin receptors.

Conclusion

The study revealed that CAFPP could be effective in the management of DM-related oxidative stress by up-regulating antioxidant and down-regulating pro-inflammatory genes expression. It also positively modulates genes associated with glucose metabolism.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-021-00921-0.

Effects of Chrysophyllum albidum fruit pulp on haemodynamic parameters, pro-inflammatory markers, antioxidant parameters and critical biomolecules associated with hypertension-in vivo

The effects of Chrysophyllum albidum fruit pulp on haemodynamic parameters, pro-inflammatory markers, antioxidant parameters and critical biomolecules associated with hypertension in vivo were determined. Feeding with supplemented diet with pulp reduced heart rate, mean arterial pressure, systolic and diastolic blood pressure levels of hypertensive-treated groups. Moreover, hypertensive-treated groups fed with fruit pulp supplemented diets had significantly (p < 0.05) lower level of serum pro-inflammatory markers when compared to untreated hypertensive group. Furthermore, feeding with supplemented diet with pulp and captopril administration reduced AChE, BChE, ACE, and arginase activities of hypertensive-treated groups. The fruit pulp supplemented diet also increased antioxidant status of hypertensive-treated groups. This was supported by the histopathological examination of the kidney and heart tissues. These beneficial effects could in part be the explanations of ethnomedicinal uses of the fruit pulp in the management of hypertension. Nevertheless, the higher percentage inclusion of the pulp showed higher antihypertensive effects.

Starch composition, glycemic indices, antioxidant properties and carbohydrate hydrolyzing enzymes activities of African star apple fruit parts

Background

African star apple (Chrysophyllum albidum) is a traditonal fruit, which is predominant in tropical regions with the fruit parts consumed by the populace and used in folklore to manage diabetes. However, the likely activity mechanism is still undetermined. The current study examined and compared the inhibitory abilities of African star apple fruit parts on selected key enzymes related to diabetes mellitus in the pancreas tissue of rat.

Methods

Inhibitory effect of aqueous extract (1:10 w/v) of African star apple fruit parts (pulp, cotyledon, seed coat and pulp coat) on the activities of α-amylase, α-glucosidase, as well as their starch composition, phenolic constituents, estimated glycemic index, and antioxidant properties were assessed.

Results

The fruit parts showed low sugar, eGI, amylose, and amylopectin contents. The analysis also showed that the fruit parts inhibited α-glucosidase and α-amylase activities and exhibited antioxidant properties. Furthermore, the fruit parts contain high concentrations of beta-amyrin acetate, eleagine, epicatechin, epigallocatechin, skatole, stigmasterol and tetrahydro − 2- methylharman as revealed by HPLC-DAD.

Conclusion

The fruit part low estimated glycemic indices, strong antioxidant properties, inhibition of α-amylase and α-glucosidase activities exhibited might be related to the bioactive compounds contained in the extract. This could also be a potential mechanism for the use in the prevention and management of type-2 diabetes. Nevertheless, the African star apple pulp coat displayed the highest property in comparison to other parts of the fruit.

Solanum leaves extracts exhibit antioxidant properties and inhibit monoamine oxidase and acetylcholinesterase activities (in vitro) in Drosophila melanogaster

Background This study sought to determine the in vitro antioxidant, anti-monoamine oxidase and anticholinesterase properties of extracts (aqueous and alkaloid) of two tropical vegetables from Solanum spp- African eggplant (Solanum macrocarpon L) and black nightshade (Solanum nigrum L) as indices of their neuroprotective properties. Methods Both aqueous and alkaloid extracts of African eggplant (AE) and black nightshade (BN) were prepared by solvent extraction according to standard methods. Thereafter, the inhibitory effects of the extracts on monoamine oxidase (MAO) and acetylcholinesterase (AChE) activities, as well as their free radical-scavenging and reducing abilities were assessed. Also, phytochemical analysis for phenols, flavonoids, and alkaloids were carried out. Results The results showed that the extracts inhibited MAO and AChE activities dose dependently, with aqueous extracts showing significantly higher MAO inhibition that the alkaloid extracts from both samples, but in all, BN showed higher MAO inhibitory effect compared to AE; the reverse was however, observed for AChE inhibition. Furthermore, the aqueous extracts showed significantly higher antioxidant properties than the alkaloid extracts, while BN had higher antioxidant properties compared to AN. The phytochemical analysis also showed that BN had significantly higher amount of phenols, flavonoids, and alkaloids than AE. Conclusions The anti-monoamine oxidase, anticholinesterase, and antioxidant properties exhibited by extracts from both samples could contribute to their neuroprotective abilities. Thus, these vegetables can be potential sources of functional foods and nutraceuticals in the management of neurodegenerative diseases, especially in the tropics.

Chrysophyllum albidum fruit peel attenuates nociceptive pain and inflammatory response in rodents by inhibition of pro-inflammatory cytokines and COX-2 expression through suppression of NF-κB activation

Chrysophyllum abidum fruit is a seasonal fruit commonly eaten as snacks with abundant health promoting phytochemicals in the fruit peels. The fruit peels have been reported to be rich in anti-inflammatory eleagnine, myricetin rhamnoside, quercetin, linoleic acid and oleic acid. We hypothesized that the anti-inflammatory effect of the peel extract involve suppression of pro-inflammatory cytokines, cyclooxygenase-2 and nuclear factor-kappa B (NF-κB). Hence, this study was designed to assess the anti-nociceptive and anti-inflammatory effects of fruit peel extract of Chrysophyllum albidum in animal models of nociception and inflammation. The anti-nociceptive activity of CAPEE (100 and 400 mg/kg) was evaluated in acetic acid-induced writhing and formalin-induced paw licking in mice. Formalin-induced paw edema and carrageenan-induced air pouch models of inflammation were used to evaluate the anti-inflammatory activity. CAPEE (100 and 400 mg/kg) significantly reduced abdominal writhing and paw licking in acetic acid and formalin tests in mice, respectively. CAPEE demonstrated significant inhibition of paw edema at 24 h (41.0% and 55.7%) and 72 h (52.3% and 86.6%) after formalin injection. CAPEE suppressed inflammatory responses in carrageenan-induced air pouch by reducing exudates, inflammatory cells infiltration, nitrites and myeloperoxidase activity. There was significant inhibition of tumor necrosis factor-alpha, interleukin-6 levels and reduced immunopositive expression of COX-2 and NF-κB. In conclusion, CAPEE has anti-nociceptive and anti-inflammatory potentials via mechanisms associated with inhibition of pro-inflammatory cytokines and cyclooxygenase-2 (COX-2) expression through suppression of nuclear factor kappa B (NF-κB) activation, and has potential as a functional food ingredient.

African star apple fruit pulp-supplemented diet modulates fertility-related biomolecules in the testis and epididymis of high-fat diet/streptozotocin-induced diabetic rats

This study evaluated the modulatory effect of African star apple fruit (ASAF) pulp inclusive diet on biomolecules associated with reproductive function in the testis and epididymis of high-fat diet/streptozotocin-induced diabetic male rats. The rats were divided into seven groups: control, diabetic control, diabetic rats treated with metformin, diabetic rats served with diet having 5 and 10% ASAF, respectively, and control rats served with diet containing 5%, and 10% ASAF respectively for 14 days. There were noticeable decrease in sperm parameters, reproductive hormone, glycogen, nitric oxide, total thiol, nonprotein thiol levels, and testicular 3β- and 17β-hydroxysteroid dehydrogenase activities and concomitant increase in cholesterol, reactive oxygen species, malondialdehyde levels, and arginase activity compared to the control. Nevertheless, ASAFs reversed all these parameters toward the control levels. Therefore, these findings suggest that ASAF pulp-supplemented diet might be an active approach in controlling male reproductive dysfunction induced by diabetes. PRACTICAL APPLICATIONS: The results suggest that ASAF pulp-supplemented diet might be an active approach in controlling male reproductive dysfunction induced by diabetes through alterations in the levels of blood glucose, glycogen, cholesterol, nitric oxide, reproductive hormones, activities of steroidogenic enzymes, arginase, and sperm characteristics as well as the antioxidant status in the testes and epididymis.

Natural antioxidants of plant origin

Interest in the content of natural antioxidants in plant-based foods can be from the human health perspective, in terms of how these compounds might help promote one's health and wellness, or from the storage point-of-view, as the endogenous antioxidant constituents aid to extend a foodstuff's shelf-life. This chapter reports essential information about the mechanism of antioxidant action and methods employed for determination of their activity, classes of phenolic compounds (phenolic acids, flavonoids, lignans, stilbenes, tannins), sources of plant antioxidants (oil seeds, cereals, legumes, plants of the Lamiaceae family, tea and coffee, tree nuts, fruits, and berries), extraction strategies of phenolic compounds from plant material, and the influence of processing and storage on the content of natural antioxidants in foods and their antioxidant activity. Thermal processing, if not releasing bound phenolics from the structural matrices of the food, tends to decrease the antioxidant potential or, in the best case scenario, has no significant negative impact. Gentler sterilization processes such as high-pressure processing tend to better retain the antioxidant potential of a foodstuff than thermal treatments such as steaming, boiling, or frying. The impact of processing can be assessed by determining the antioxidant potential of foodstuffs either at the point of formulation or after different periods of storage under specified conditions.

Phenolic distribution, antioxidant activity, and enzyme inhibitory properties of eggplant (Solanum aethiopicum) cultivated in two different locations within Nigeria

Solanum aethiopicum is commonly cultivated in Nigeria for its nutritional and medicinal properties. Although, information on the possible effect of location on the biological activities of S. aethiopicum has not been reported, however, present research work investigated the phenolic contents and distribution, antioxidative properties, and enzyme inhibitory activities of S. aethiopicum collected from two locations in Nigeria. HPLC phenolic profile, polyphenol contents, free radical scavenging activities, and inhibitory effect of eggplant extracts on carbohydrate metabolizing enzymes were carried out. Significant variations were observed in the phenolic profile, polyphenol contents, antioxidant activities, and enzymes inhibitory properties of the extracts from different locations. In most of the analyses carried out, extract of eggplant fruit collected from Uyo (UEF) showed higher activities than the one obtained from Ibadan (IEF). Thus, findings from this study revealed that geographical location may influence the phenolic contents, antioxidant, and enzymes inhibitory properties of eggplant fruits. PRACTICAL APPLICATIONS: The geographical location of a particular place determines the nature and biological activities of plants cultivated in the area. Hence, we presented the effect of location on the phenolic profile, antioxidant, and enzyme inhibitory properties of eggplant fruit (S. aethiopicum) cultivated in two different locations in Nigeria. However, data generated in this study showed the effect of location on phenolic composition and biological activities of eggplant fruit cultivated in Nigeria.