Caffeine – rich infusion from Cola nitida (kola nut) inhibits major carbohydrate catabolic enzymes; abates redox imbalance; and modulates oxidative dysregulated metabolic pathways and metabolites in Fe2+-induced hepatic toxicity

Dynamic changes in the hippocampal memory index and biochemical indices in Sprague Dawley rats exposed to intrauterine kola nut

Kola nut is commonly consumed by pregnant women to suppress symptoms of morning sickness. This study investigated the effects of kola nut on the biochemical indices of the hippocampus and its dependent memory. Kola nut extract was fed to pregnant dams from the first day of their pregnancy until parturition. The following behavioral function tests were conducted: surface righting (SR); cliff avoidance (post-natal day [PND] 4, 5, 6 & 7); open field; novel object recognition and location; and radial-arm maze (PND 21 and 56). The levels of brain-derived neurotrophic factor (BDNF), acetylcholine (ACh), and malondialdehyde (MDA) of the matched hippocampal tissues were also checked in the pups. The kola nut-treated pups showed significantly reduced behavioral indices compared to the pups in the control group: lower postural balance, higher risk avoidance memory, and lower frequency in pivoting and rearing compared to that in the control group. However, the frequency of urine and fecal bolus was significantly lower in the pups in the control group than that in the treated pups. The discrimination ratio of the control group pups in novel object recognition (NOR) and novel object location (NOL) was significantly higher than that in the treated pups, and the time taken by the treated pups to complete RAM was significantly higher. The levels of ACh and BDNF in the treated pups were increased compared to that in control pups. A positive correlation was found between MDA and SR (r = 0.7207; p = 0.0437), grooming (r = 0.7707; p = 0.0252), and fecal bolus (r = 0.7606; p = 0.0284), as well as with the BDNF level in those treated with grooming (r = 0.7570; p = 0.0297). However, negative correlations between ACh and rearing (r = -0.8261; p = 0.0115) and fecal bolus (r = -0.8066; p = 0.0156) and a positive correlation with NOL (r = 0.8358; p = 0.0098) were observed. Based on these observations, the study concluded that Kola nut affects both biochemical and hippocampal memory profiles.

Inhibitory effect of extracts from edible parts of nuts on α-amylase activity: a systematic review

Elevated blood glucose concentration is a risk factor for developing metabolic dysfunction and insulin resistance, leading to type 2 diabetes and cardiovascular diseases. Nuts have the potential to inhibit α-amylase activity, and so lower postprandial glucose, due to their content of polyphenols and other bioactive compounds. We conducted a systematic literature review to assess the ability of extracts from commonly consumed edible parts of nuts to inhibit α-amylase. Among the 31 included papers, only four utilised human α-amylases. These papers indicated that polyphenol-rich chestnut skin extracts exhibited strong inhibition of both human salivary and pancreatic α-amylases, and that a polyphenol-rich almond skin extract was a potent inhibitor of human salivary α-amylase. The majority of the reviewed studies utilised porcine pancreatic α-amylase, which has ∼86% sequence homology with the corresponding human enzyme but with some key amino acid variations located within the active site. Polyphenol-rich extracts from chestnut, almond, kola nut, pecan and walnut, and peptides isolated from cashew, inhibited porcine pancreatic α-amylase. Some studies used α-amylases sourced from fungi or bacteria, outcomes from which are entirely irrelevant to human health, as they have no sequence homology with the human enzyme. Given the limited research involving human α-amylases, and the differences in inhibition compared to porcine enzymes and especially enzymes from microorganisms, it is recommended that future in vitro experiments place greater emphasis on utilising enzymes sourced from humans to facilitate a reliable prediction of effects in intervention studies.

Coconut (Cocos nucifera (L.)) Water Improves Glucose Uptake with Concomitant Modulation of Antioxidant and Purinergic Activities in Isolated Rat Psoas Muscles

The present study investigated the effect of coconut water on glucose uptake and utilization, and metabolic activities linked to hyperglycemia in isolated rat psoas muscles. Coconut water was subjected to in vitro antioxidant and antidiabetic assays, which cover 2,2'-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, ferric reducing antioxidant power (FRAP), and inhibition of α-glucosidase and α-amylase activities. Psoas muscles were isolated from male Sprague Dawley rats and incubated with coconut water in the presence of glucose. Control consisted of muscles incubated with glucose only, while normal control consisted of muscles not incubated in coconut water and/or glucose. The standard antidiabetic drug was metformin. Incubation with coconut water led to a significant increase in muscle glucose uptake, with concomitant exacerbation of glutathione level, and SOD and catalase activities, while suppressing malondialdehyde level, and ATPase and E-NTDase activities. Coconut water showed significant scavenging activity against DPPH, and significantly inhibited α-glucosidase and α-amylase activities. LC-MS analysis of coconut water revealed the presence of ellagic acid, butin, quercetin, protocatechuic acid, baicalin, and silibinin. Molecular docking analysis revealed potent molecular interactions between the LC-MS-identified compounds, and AKT-2 serine and PI-3 kinase. These results indicate the potential of coconut water to enhance glucose uptake, while concomitantly improving antioxidative and purinergic activities. They also indicate the potential of coconut water to suppress postprandial hyperglycemia. These activities may be attributed to the synergistic effects of the LC-MS-identified compounds.

Potential molecular mechanisms underlying the ameliorative effect of Cola nitida (Vent.) Schott & Endl. on insulin resistance in rat skeletal muscles

ETHNOPHARMACOLOGICAL RELEVANCE

Cola nitida (Vent.) Schott & Endl. are among the common medicinal plants employed in traditional medicine for treating diabetes and its complications.

AIM OF THE STUDY

The present study investigated the effect of Cola nitida infusion on the expression of key genes involved in insulin signaling vis-à-vis Insulin receptor substrate 1 (IRS-1), tumor protein P53 gene, glucose transporter type 4 (GLUT4), phosphoinositide 3-kinases (PI3K) and B-cell lymphoma-2 (BCL2) in skeletal muscles of type 2 diabetic (T2D) rats.

METHODS

Type 2 diabetic rats were administered C. nitida infusion at low and high doses (150 and 300 mg/kg bodyweight, respectively), while a high dose of the infusion was also administered to a normal toxicological group. Metformin served as the standard antidiabetic drug. The rats were sacrificed at the end of the experimental period. Their psoas muscles were harvested and assayed for the expressions of IRS1, p53, GLUT4, PI3K and BCL2. The studied genes were further subjected to enrichment analysis using the ShinyGO 0.76 online software.

RESULTS

Induction of T2D upregulated the expressions of IRS-1, p53, PI3K and BCL2 in psoas muscles, while concomitantly downregulating GLUT4 expression. These expressions were significantly reversed in type 2 diabetic rats treated with C. nitida infusion, and the results were statistically significant compared to metformin. Gene enrichment analysis revealed that the genes were linked to intrinsic pathways and biological processes involved in insulin resistance. The infusion further improved muscle glucose uptake, ex vivo. Molecular docking and molecular dynamics stimulation of C. nitida infusion phytoconstituents, caffeine and theobromine with IRS-1, p53, GLUT4, PI3K and BCL2 revealed a strong binding affinity as evident by the RMSD and RMSF values.

CONCLUSION

These results indicate the potentials of C. nitida infusion to improve glucose homeostasis in skeletal muscles of type 2 diabetic rats.

Butanol fraction of Alstonia boonei De Wild. leaves ameliorate oxidative stress and modulate key hypoglycaemic processes in diabetic rats

OBJECTIVE

The effect of Alstonia boonei fractions on glucose homeostasis was investigated via in vitro enzyme inhibition activity, ex vivo glucose uptake assay, and in vivo methods in diabetic rats.

METHODOLOGY

A. boonei fractions were subjected to in vitro α-glucosidase inhibitory assay and then ex vivo glucose uptake activity. The butanol fraction of the leaves (ABBF) was picked for the in vivo assay since it showed more activity in the initial tests conducted. ABBF was administrated via oral dosing to six-weeks old fructose-fed STZ-induced type 2 diabetic rats over a 5-week experimental period.

RESULTS

ABBF treatment at a low dose of 150 mg/kg bw, significantly (p < .05) reduced blood glucose level, enhanced oral glucose tolerance ability, restored insulin secretion and hepatic glycogen synthesis as well as promoted islet regeneration than the high dose (300 mg/kg bw).

CONCLUSION

These results suggest that ABBF could be exploited as a therapeutic potential for treating T2D.

A Tiered Ecological Risk Assessment of Caffeine by Using Species Sensitivity Distribution Method in the Nansi Lake Basin

Caffeine has been reported toxic to aquatic organisms, and it frequently occurs at relatively high concentrations in most of surface waters. However, it is difficult to control caffeine pollution because of the lack of Water Quality Criteria (WQC). In this study, species sensitivity distribution method and Log-normal model were applied to derive caffeine WQC as 83.7 ng/L. Meanwhile, concentrations of caffeine in the Nansi Lake basin were detected in 29 sampling sites, with the mean of 99.3 ng/L. The levels of caffeine in tributaries were higher than those in the lakes. In addition, a tied ecological risk assessment method was applied to assess the adverse effect of caffeine on aquatic system. The joint probability curve indicated that ecological risk might exist 3.1% of surface water in the study area, while 5% threshold (HC₅) was set up to protect aquatic species. Generally, caffeine posted a low risk to aquatic organisms in the Nansi Lake basin.

Kolaviron modulates dysregulated metabolism in oxidative pancreatic injury and inhibits intestinal glucose absorption with concomitant stimulation of muscle glucose uptake

This present study investigated the antioxidative and antidiabetic properties of kolaviron by analysing its inhibitory effect on key metabolic activities linked to T2D, in vitro and ex vivo. Kolaviron significantly inhibited α-glucosidase and α-amylase activities, and intestinal glucose absorption dose-dependently, while promoting muscle glucose uptake. Induction of oxidative pancreatic injury significantly depleted glutathione level, superoxide dismutase, catalase, and ATPase activities, while elevating malondialdehyde and nitric oxide levels, acetylcholinesterase and chymotrypsin activities. These levels and activities were significantly reversed in tissues treated with kolaviron. Kolaviron depleted oxidative-induced metabolites, with concomitant restoration of oxidative-depleted metabolites. It also inactivated oxidative-induced ascorbate and aldarate metabolism, pentose and glucuronate interconversions, fructose and mannose metabolism, amino sugar and nucleotide sugar metabolism, and arginine and proline metabolism, while reactivating selenocompound metabolism. These results depict the antidiabetic properties of kolaviron as indicated by its ability to attenuate oxidative-induced enzyme activities and dysregulated metabolisms, and modulated the enzyme activities linked to hyperglycaemia.

Indigenous Nigeria medicinal herbal remedies: A potential source for therapeutic against rheumatoid arthritis

Rheumatoid arthritis (RA) is a debilitating disease associated with locomotion impairment, and conventional therapeutic drugs are not optimal for managing RA. There is an avalanche of medications used for the management of RA. Still, studies have shown that they are associated with severe side effects, including hepatotoxicity, retinopathy, and cardiotoxicity disorders of the central nervous system (CNS), skin, blood, and infections. Complementary and alternative medicine (CAM) is currently gaining attention as a novel panacea for managing debilitating diseases, such as RA. Nigerian folk herbal remedies are replete with a plethora of curative medicine, albeit unvalidated scientifically but with seemingly miraculous provenance. Studies of the identification of bioactive compounds present in these botanicals using advanced spectral analytical techniques have enhanced our understanding of the role of Nigerian herbal remedies in the treatment and management of RA. Interestingly, experimental studies abound that the bioactive compounds present in the extracts of plant botanicals protected animals from the development of RA in different experimental models and reduced the toxicity associated with conventional therapeutics. Validated mechanisms of RA amelioration in human and animal models include suppression of the expression of NF-κB, IL-1β, TNF-α, IL-6, IL-8, IL-17, IL-23, chemokines, TGF-β, RANKL, RANK, iNOS, arginase, COX-2, VEGFA, VEGFR, NFATC1, and TRAP in the synoviocytes. Decreased ROS, NO, MDA, carbonyl groups, and PGE₂ in the synovial fluid increased the expression of PPARα/γ; antioxidant and anti-inflammatory molecules also improve RA etiology. In this mini-review, we discuss the global burden of RA, the novel role of plant-based botanicals as potential therapeutics against signaling pathways in RA. Also addressed is the possible repurposing/reprofiling of plant botanicals to increase their therapeutic index among RA patients that patronize traditional healers in Nigeria with a global projection.

Dietary sources, health benefits, and risks of caffeine

Dietary intake of caffeine has significantly increased in recent years, and beneficial and harmful effects of caffeine have been extensively studied. This paper reviews antioxidant and anti-inflammatory activities of caffeine as well as its protective effects on cardiovascular diseases, obesity, diabetes mellitus, cancers, and neurodegenerative and liver diseases. In addition, we summarize the side effects of long-term or excessive caffeine consumption on sleep, migraine, intraocular pressure, pregnant women, children, and adolescents. The health benefits of caffeine depend on the amount of caffeine intake and the physical condition of consumers. Moderate intake of caffeine helps to prevent and modulate several diseases. However, the long-term or over-consumption of caffeine can lead to addiction, insomnia, migraine, and other side effects. In addition, children, adolescents, pregnant women, and people who are sensitive to caffeine should be recommended to restrict/reduce their intake to avoid potential adverse effects.

Antidiabetic Medicinal Plants Used in Democratic Republic of Congo: A Critical Review of Ethnopharmacology and Bioactivity Data

Several studies have been conducted and published on medicinal plants used to manage Diabetes Mellitus worldwide. It is of great interest to review available studies from a country or a region to resort to similarities/discrepancies and data quality. Here, we examined data related to ethnopharmacology and bioactivity of antidiabetic plants used in the Democratic Republic of Congo. Data were extracted from Google Scholar, Medline/PubMed, Scopus, ScienceDirect, the Wiley Online Library, Web of Science, and other documents focusing on ethnopharmacology, pharmacology, and phytochemistry antidiabetic plants used in the Democratic Republic of Congo from 2005 to September 2021. The Kew Botanic Royal Garden and Plants of the World Online web databases were consulted to verify the taxonomic information. CAMARADES checklist was used to assess the quality of animal studies and Jadad scores for clinical trials. In total, 213 plant species belonging to 72 botanical families were reported. Only one plant, Droogmansia munamensis, is typically native to the DRC flora; 117 species are growing in the DRC and neighboring countries; 31 species are either introduced from other regions, and 64 are not specified. Alongside the treatment of Diabetes, about 78.13% of plants have multiple therapeutic uses, depending on the study sites. Experimental studies explored the antidiabetic activity of 133 plants, mainly in mice, rats, guinea pigs, and rabbits. Several chemical classes of antidiabetic compounds isolated from 67 plant species have been documented. Rare phase II clinical trials have been conducted. Critical issues included poor quality methodological protocols, author name incorrectly written (16.16%) or absent (14.25%) or confused with a synonym (4.69%), family name revised (17.26%) or missing (1.10%), voucher number not available 336(92.05%), ecological information not reported (49.59%). Most plant species have been identified and authenticated (89.32%). Hundreds of plants are used to treat Diabetes by traditional healers in DRC. However, most plants are not exclusively native to the local flora and have multiple therapeutic uses. The analysis showed the scarcity or absence of high-quality, in-depth pharmacological studies. There is a need to conduct further studies of locally specific species to fill the gap before their introduction into the national pharmacopeia.

Microbial Degradation of Caffeine Using Himalayan Psychrotolerant Pseudomonas sp.GBPI_Hb5 (MCC 3295)

Caffeine, a xenobiotic compound, is continuously released into the environment. Fifteen psychrotolerant bacterial strains, isolated from the Indian Himalayan region, were screened for their caffeine degradation capacity. The medium for the growth of bacteria was optimized using Box-Behnken method. Among these bacteria, Pseudomonassp. (GBPI_Hb5), showing the best response, was further used for caffeine degradation in batch mode. The culture medium, having caffeine as a sole source of carbon, was used for analyzing the effect of pH, agitation speed, temperature, inoculum volume, and caffeine concentration on bacterial growth and its caffeine degradation potential. The bacterium GBPI_Hb5 showed approx. 93% caffeine degradation up to 96 h under controlled conditions. The compounds produced during the degradation of caffeine were also studied. The study is likely to have implications in the bioremediation of caffeine from polluted environments.

Cola nitida infusion modulates cardiometabolic activities linked to cardiomyopathy in diabetic rats

This study investigated the therapeutic mechanism of Cola nitida seeds on diabetic cardiomyopathy in hearts of diabetic rats. Type 2 diabetic (T2D) rats were treated with C. nitida infusion at 150 or 300 mg/kg body weight (bw). The rats were sacrificed after 6 weeks of treatment, and their hearts harvested. There was an upsurge in oxidative stress on induction of T2D as depicted by the depleted levels of glutathione, superoxide dismutase and catalase activities, and elevated malondialdehyde level. The activities of acetylcholinesterase, and ATPase were significantly elevated, with suppressed ENTPDase and 5'nucleotodase activities in hearts of T2D rats depicting cholinergic and purinergic dysfunctions. Induction of T2D further led to elevated activity of ACE and altered myocardial morphology. Treatment with C. nitida infusion led to reversal of these biomarkers' activities and levels, while maintaining an intact morphology. The infusion caused decreased lipase activity and depletion of diabetes-generated cardiac lipid metabolites, while concomitantly generating saturated and unsaturated fatty acids, fatty esters and alcohols. There was also an inactivation of plasmalogen synthesis and mitochondrial beta-oxidation of long chain saturated fatty acids pathways in T2D rats treated with C. nitida infusion. These results indicate the therapeutic effect of C. nitida infusion against diabetic cardiomyopathy.

Vernonia amygdalina stimulates muscle glucose uptake and modulates redox activities and functional chemistry in oxidative hepatic injury

The ethyl acetate, ethanol, and aqueous extracts sequentially obtained from the leaves of Vernonia amygdalina were investigated for their antidiabetic and antioxidant protective effect in oxidative hepatic injury. The extracts showed significant (p < .05) free radical scavenging and reducing power activities. They significantly (p < .05) elevated reduced glutathione level, superoxide dismutase, and catalase activities, with concomitant depletion of malondialdehyde level. The ethanol and aqueous extracts caused a removal of oxidative-included chemical functional group at 1,500-1,200 (amide II)/cm region, with the inclusion of a functional group at 3,000-2,800 (carboxylic acid)/cm region. The extracts significantly (p < .05) inhibited the activities of α-glucosidase and α-amylase and stimulated glucose uptake in rat muscles. Gas chromatography-mass spectrometric (GC-MS) analysis revealed phytol as the predominant compound, with ethanol having the highest concentration. Based on the IC₅₀ values, the ethanol extract exhibited the best activities, followed by the ethyl acetate extract, while the aqueous extract was the least. These results suggest the antioxidative and antidiabetic properties of V. amygdalina as evident by their modulation of antioxidant biomarkers and oxidative-induced chemistry changes and stimulate muscle glucose uptake. PRACTICAL APPLICATIONS: Vernonia amygdalina (bitter leaf) is amongst the common leafy vegetables in West Africa reported for its various medicinal and nutritional properties. It is utilized as a food ingredient as well as supplement for the treatment and management of type 2 diabetes. The ability of its extracts to stimulate glucose uptake and protect against diabetic-induced changes in the chemical functional groups of the liver gives more credence to its reported antidiabetic properties. Being a common leafy vegetable, V. amygdalina can be a cheap source of nutraceutical for the treatment and management of type 2 diabetes and its complications.

Caffeic Acid Protects against Iron-Induced Cardiotoxicity by Suppressing Angiotensin-Converting Enzyme Activity and Modulating Lipid Spectrum, Gluconeogenesis and Nucleotide Hydrolyzing Enzyme Activities

The protective effects of caffeic acid on angiotensin-converting enzyme (ACE) and purinergic enzyme activities, as well as gluconeogenesis was investigated in iron-induced cardiotoxicity. Cardiotoxicity was induced in heart tissues harvested from healthy male SD rats by 0.1 mM FeSO₄. Treatment was carried out by co-incubating hearts tissues with caffeic acid and 0.1 mM FeSO₄. Cardiotoxicity induction significantly (p < 0.05) depleted GSH level, SOD, catalase, and ENTPDase activities, with concomitant elevation of the levels of malondialdehyde (MDA), nitric oxide, ACE, ATPase, glycogen phosphorylase, glucose 6-phosphatase, fructose 6-biphsophatase, and lipase activities. There was significant (p < 0.05) reversion in these levels and activities on treatment with caffeic acid. Caffeic acid also caused depletion in cardiac levels of cholesterol, triglyceride, LDL-c, while elevating HDL-c level. Our results suggest the protective effect of caffeic acid against iron-mediated cardiotoxicity as indicated by its ability to suppress oxidative imbalance and ACE activity, while concomitantly modulating nucleotide hydrolysis and metabolic switch.

Ferulic acid promotes muscle glucose uptake and modulate dysregulated redox balance and metabolic pathways in ferric-induced pancreatic oxidative injury

The antidiabetic properties of ferulic acid and its protective role against Fe²⁺ -induced oxidative pancreatic injury were investigated in this study using in vitro and ex vivo models. Induction of oxidative injury in the pancreas was achieved by incubating normal pancreatic tissue with 0.1 mM FeSO₄ and treated by co-incubating with different concentrations of ferulic acid for 30 min at 37°C. Ferulic acid inhibited the activities of α-glucosidase, α-amylase, and pancreatic lipase significantly (p < .05) and promoted glucose uptake in isolated rat psoas muscles. Induction of oxidative pancreatic injury caused significant (p < .05) depletion of glutathione (GSH) level, superoxide dismutase (SOD), and catalase activities, as well as elevation of malondialdehyde (MDA) and nitric oxide (NO) levels, acetylcholinesterase and chymotrypsin activities. Treatment of tissues with ferulic acid significantly (p < .05) reversed these levels and activities. LC-MS analysis of the extracted metabolites revealed 25% depletion of the normal metabolites with concomitant generation of m-Chlorohippuric acid, triglyceride, fructose 1,6-bisphosphate, and ganglioside GM1 in oxidative-injured pancreatic tissues. Treatment with ferulic acid restored uridine diphosphate glucuronic acid and adenosine tetraphosphate and generated P1,P4-Bis(5'-uridyl) tetraphosphate and L-Homocysteic acid, while totally inactivating oxidative-generated metabolites. Ferulic acid also inactivated oxidative-activated pathways, with concomitant reactivation of nucleotide sugars metabolism, starch and sucrose metabolism, and rostenedione metabolism, estrone metabolism, androgen and estrogen metabolism, porphyrin metabolism, and purine metabolism pathways. Taken together, our results indicate the antidiabetic and protective potential of ferulic acid as depicted by its ability to facilitate muscle glucose uptake, inhibit carbohydrate and lipid hydrolyzing enzymes, and modulate oxidative-mediated dysregulated metabolisms. PRACTICAL APPLICATIONS: There have been increasing concerns on the side effects associated with the use of synthetic antidiabetic drug, coupled with their expenses particularly in developing countries. This has necessitated continuous search for alternative treatments especially from natural products having less or no side effects and are readily available. Ferulic acid is among the common phenolics commonly found in fruits and vegetables. In this present study, ferulic acid was able to attenuate oxidative stress, cholinergic dysfunction, and proteolysis in oxidative pancreatic injury, as well as inhibit carbohydrate digesting enzymes. Thus, indicating the ability of the phenolic to protect against complications linked to diabetes. Crops rich in ferulic acid maybe beneficial in managing this disease.

Modulatory effect of ursolic acid on neurodegenerative activities in oxidative brain injury: An ex vivo study

Natural products-based antioxidants have been well reported for their therapeutic benefits in the treatment and management of neurodegenerative diseases. The neuroprotective effect of ursolic acid (UA) against oxidative injury was investigated in isolated rat brain. Induction of oxidative injury in isolated rat brains with 0.1 mM FeSO4 led to depleted levels of glutathione, superoxide dismutase, catalase, and ENTPDase activities, with concomitant exacerbation of malondialdehyde and nitric oxide levels, α-chymotrypsin, ATPase, and acetylcholinesterase activities. These levels and activities were significantly reversed following treatment of the brain tissues with UA. Molecular docking studies revealed strong molecular interactions between UA, catalase, and ATPase. Overall, these results indicate the neuroprotective effect of UA against oxidative injury in isolated rat brains as depicted by their ability to mitigate oxidative stress, purinergic, and cholinergic dysfunctions, with concomitant suppression of proteolytic activity. PRACTICAL APPLICATIONS: Neurodegenerative diseases are among the common diseases associated with aging and has been implicated as oxidative mediated. Natural products have received increasing recognition in their use as treatment remedy for various oxidative-mediated diseases including neurodegeneration. These natural products include plant secondary metabolites commonly known as phytochemicals. Ursolic acid is a phytochemical usually present in leafy vegetables and fruits. The present study describes the possible therapeutic mechanism of ursolic acid in the amelioration of complications linked to neurodegeneration in oxidative-mediated brain injury. These findings thus give insights into the use of natural products of plant origin in treating and managing neurodegenerative diseases, which may have little or no side effects.

Bioactive compounds of African star apple (Chrysophyllum albidum G. Don) and its modulatory effect on metabolic activities linked to type 2 diabetes in isolated rat psoas muscle

The infusion of Chrysophyllum albidum was investigated for its antidiabetic mechanism by studying its ability to promote glucose uptake and utilization as well as its modulatory effect on metabolic activities linked to type 2 diabetes in isolated psoas muscle. Isolated psoas muscle was incubated with different concentrations of the infusion in the presence of glucose at 37°C for 2 hr. The infusion improved muscle glucose uptake, with concomitant elevated muscular levels of glutathione, superoxide dismutase, catalase, and ectonucleotidase activities, while depleting malondialdehyde, nitric oxide, adenosine triphosphatase, acetylcholinesterase, glycogen phosphorylase, glucose 6-phosphatase, fructose-1,6-biphosphatase, and lipase activities. It also maintained muscular morphology, while increasing magnesium, calcium, and iron levels. The infusion inhibited α-glucosidase and α-amylase activities in vitro. LC-MS analysis of the infusion revealed the presence of phenolics. These results indicate that C. albidum may mediate antidiabetic activities by stimulating muscle glucose uptake and modulation of key metabolisms linked to diabetes. PRACTICAL APPLICATIONS: The African star apple is among the underutilized fruits consumed for nutritional and medicinal purposes in Western Africa. The fruits are usually wasted during its season leading to postharvest loss owing to poor utilization. The present study gives credence to its use in treating diabetes and its complications. Thus, the fruits can be utilized in the development of cheap and affordable nutraceuticals for the management of diabetes which has been reported for its high-cost treatment. Utilization of the fruits will also reduce its postharvest loss and improve its economic values.

Occurrence, fate, persistence and remediation of caffeine: a review

Pharmaceutical and personal care products (PPCPs) have gained attention in recent years due to their continuous discharge in natural waters. Their persistence in the environment has impacted flora, fauna and human being worldwide. One of the most common PPCPs is caffeine (1, 3, 7-trimethylxanthine) which acts as a stimulant to the central nervous system in humans and is found in nature in about 60 plant species, especially in coffee, tea and cacao plants. Here we discuss the evidence with respect to caffeine occurrence, its persistence and remediation in light of increasing knowledge and the impact of caffeine on the environment. Daily intake of caffeine around the world is found to increase due to the frequent introduction of new caffeinated beverages as well as increased consumption of coffee, tea and carbonated soft drinks, which has led to increase in its concentration in water bodies including agricultural soil. The caffeine concentration in different water system, studied by various authors is also described. Diverse effects of the use of caffeine on several organisms including humans are also briefly presented. Therefore, urgent attention for the removal of caffeine and its derivatives is the need of the hour. Various methods described in literature for caffeine degradation/removal is also presented. Another widely used technique in environmental remediation is molecular imprinting (MIP); however, only few MIPs have been demonstrated for caffeine which is also discussed. Regular monitoring can be useful to control toxic effects of caffeine. Graphical abstract.

Catechol protects against iron-mediated oxidative brain injury by restoring antioxidative metabolic pathways; and modulation of purinergic and cholinergic enzymes activities

OBJECTIVES

This study was aimed at investigating neuroprotective effect of catechol on redox imbalance, cholinergic dysfunctions, nucleotide hydrolysing enzymes activities, and dysregulated metabolic pathways in iron-mediated oxidative brain injury.

METHODS

Oxidative injury was induced in brain tissues by incubating with 0.1 mm FeSO₄ and treated with different concentrations of catechol.

KEY FINDINGS

Catechol significantly elevated glutathione level, superoxide dismutase and catalase activities, while depleting malondialdehyde and nitric oxide levels. It also inhibited the activities of acetylcholinesterase, butyrylcholinesterase, and ATPase, with concomitant elevation of ENTPDase activity. GC-MS analysis revealed that treatment with catechol completely depleted oxidative-generated lipid metabolites. While LC-MS analysis revealed depletion of oxidative-generated metabolites in brain tissues treated with catechol, with concomitant restoration of oxidative-depleted metabolites. Catechol also led to reactivation of oxidative-inactivated taurine and hypotaurine, purine, glutathione, glycerophospholipid, nicotinate and nicotinamide, fructose and mannose, pyrimidine metabolisms and pentose phosphate pathways. Catechol was predicted in silico to be permeable across the blood-brain barrier with a predicted oral LD₅₀ value of 100 mg/kg and a toxicity class of 3.

CONCLUSION

These results suggest the neuroprotective effects of catechol in iron-mediated oxidative brain injury.

Multifunctional titanium dioxide nanoparticles biofabricated via phytosynthetic route using extracts of Cola nitida: antimicrobial, dye degradation, antioxidant and anticoagulant activities

First study of phytosynthesis of TiO₂ NPs using the leaf (KL), pod (KP), seed (KS) and seed shell (KSS) extracts of kola nut tree (Cola nitida) is herein reported. The TiO₂ NPs were characterized and evaluated for their antimicrobial, dye degradation, antioxidant and anticoagulant activities. The nearly spherical-shaped particles had λmax of 272.5–275.0 nm with size range of 25.00–191.41 nm. FTIR analysis displayed prominent peaks at 3446.79, 1639.49 and 1382.96 cm⁻¹, indicating the involvement of phenolic compounds and proteins in the phytosynthesis of TiO₂ NPs. Both SAED and XRD showed bioformation of crystalline anatase TiO₂ NPs which inhibited multidrug-drug resistant bacteria and toxigenic fungi. The catalytic activities of the particles were profound, with degradation of malachite green by 83.48–86.28 % without exposure to UV-irradiation, scavenging of DPPH and H₂O₂by 51.19–60.08 %, and 78.45–99.23 % respectively. The particles as well prevented the coagulation of human blood. In addition to the antimicrobial and dye-degrading activities, we report for the first time the H₂O₂ scavenging and anticoagulant activities of TiO₂ NPs, showing that the particles can be useful for catalytic and biomedical applications.

Ferric-Induced Pancreatic Injury Involves Exacerbation of Cholinergic and Proteolytic Activities, and Dysregulation of Metabolic Pathways: Protective Effect of Caffeic Acid

The protective effect of caffeic acid on ferric-induced pancreatic injury was investigated using ex vivo and in silico models. Incubation of pancreatic tissues with Fe²⁺ led to significant depleted levels of glutathione (GSH) and SOD and catalase activities, with concomitant elevated levels of malondialdehyde (MDA) and nitric oxide (NO) and acetylcholinesterase and α-chymotrypsin activities. Treatment with caffeic acid led to significant reversion of these levels and activities. Molecular docking revealed a higher binding affinity of caffeic acid with acetylcholinesterase via hydrogen bonding, Pi-Pi stacking, and Van der Waals interactions. FTIR spectroscopy of pancreatic metabolite revealed little or no effect by caffeic acid on functional groups in ferric-induced injured pancreas. The LC-MS analysis of the metabolites revealed Fe²⁺ caused a 20% depletion of the normal metabolites, with concomitant generation of glyceraldehyde and 3,4-dihydroxymandelaldehyde. Treatment with caffeic acid led to the restoration of TG(22:4(7Z,10Z,13Z,16Z)/24:0/22:5(7Z,10Z,13Z,16Z,19Z)) and dTDP-D-glucose, while depleting glyceraldehyde as well as activating gluconeogenesis. These results indicate the ability of caffeic acid to protect against ferric toxicity by exacerbating antioxidative activities, with concomitant inhibition of MDA and NO levels while deactivating metabolic pathways linked to oxidative stress.

Cola Nitida (Kola Nuts) Attenuates Hepatic Injury in Type 2 Diabetes by Improving Antioxidant and Cholinergic Dysfunctions and Dysregulated Lipid Metabolism

BACKGROUND

The therapeutic effect of Cola nitida hot infusion against diabetes hepatic injury was investigated in livers of diabetic rats. Cola nitida was infused in boiling water and concentrated.

METHODS

The concentrated infusion was administered to T2D rats at low and high doses (150 and 300 mg/kg body weight (bw), respectively). The normal group (positive control) and another diabetic group (negative control) were administered distilled water, while metformin served as the standard drug. A toxic group that consists of normal rats administered a high dose of C. nitida. After 6 weeks, the rats were sacrificed, and their livers were collected. They were assayed for oxidative stress markers, myeloperoxidase, acetylcholinesterase and ATPase activities. Hepatic lipid metabolites were profiled with GC-MS and their metabolic pathways were analyzed using the MetaboAnalyst 4.0 online server.

RESULTS

Treatment with C. nitida caused a significant elevation of glutathione level and SOD activity, while concomitantly inhibiting lipid peroxidation, myeloperoxidase, acetylcholinesterase and ATPase activities in hepatic tissues of the rats. Treatment with C. nitida also caused significant depletion of diabetes-generated lipid metabolites, with concomitant generation of fatty esters and steroids as well as inactivation of diabetes-activated pathways.

CONCLUSION

These data demonstrate the therapeutic effect of C. nitida against diabetic hepatotoxicity in diabetic rats.

Vanillin and vanillic acid modulate antioxidant defense system via amelioration of metabolic complications linked to Fe2+-induced brain tissues damage

The therapeutic effect of phenolics on neurodegenerative diseases has been attributed to their potent antioxidant properties. In the present study, the neuroprotective activities of vanillin and vanillic acid were investigated in Fe²⁺- induced oxidative toxicity in brain tissues by investigating their therapeutic effects on oxidative imbalance, cholinergic and nucleotide-hydrolyzing enzymes activities, dysregulated metabolic pathways. Their cytotoxicity was investigated in hippocampal neuronal cell lines (HT22). The reduced glutathione level, SOD and catalase activities were ameliorated in tissues treated with the phenolics, with concomitant depletion of malondialdehyde and nitric oxide levels. They inhibited acetylcholinesterase and butyrylcholinesterase activities, while concomitantly elevated ATPase activity. Treatment with vanillin led to restoration of oxidative-depleted metabolites and reactivation of the pentose phosphate and purine metabolism pathways, with concomitant activation of pathways for histidine and selenoamino metabolisms. While vanillic acid restored and reactivated oxidative-depleted metabolites and pathways but did not activate any additional pathway. Both phenolics portrayed good binding affinity for catalase, with vanillic acid having the higher binding energy of -7.0 kcal/mol. Both phenolics were not cytotoxic on HT22 cells, and their toxicity class were predicted to be 4. Only vanillin was predicted to be permeable across the blood brain barrier (BBB). These results insinuate that vanillin and vanillic acid confer a neuroprotective effect on oxidative brain damage, when vanillin being the most potent.

Buddleja saligna Willd (Loganiaceae) inhibits angiotensin-converting enzyme activity in oxidative cardiopathy with concomitant modulation of nucleotide hydrolyzing enzymatic activities and dysregulated lipid metabolic pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Buddleja saligna Willd (Loganiaceae), mostly indigenous to South Africa is traditionally used in the treatment cardio-dysfunctional related ailments amongst other diseases.

AIMS

The cardio-protective effect of B. saligna was investigated in ferric-induced oxidative cardiopathy.

METHODS

Hearts harvested from healthy male SD rats were incubated with 0.1 mM FeSO₄ to induce oxidative damage and co-incubated with B. saligna extract. Reaction mixtures without the extract served as negative control, while tissues without the extract or standard antioxidant (gallic acid) and pro-oxidant served as the normal control. The tissues were analyzed for levels of glutathione, malondialdehyde, and nitric oxide as well as cholinergic, angiotensin-converting enzyme (ACE), lipase, and purinergic enzymes activities, lipid profiles, fatty acid metabolic pathways and metabolites.

RESULTS

Induction of oxidative damage significantly (p < 0.05) depleted the levels of GSH, SOD, catalase, and ENTPDase activities, while concomitantly elevating the levels of MDA, NO, ACE, acetylcholinesterase, lipase and ATPase activities. These levels and activities were significantly reversed on treatment with B. saligna. Treatment with B. saligna also led to depletion of cardiac cholesterol and LDL-c levels, while elevating triglyceride and HDL-c level. It also depleted oxidative-induced lipid metabolites with concomitant generation of thirteen other metabolites. B. saligna also inactivated oxidative-induced pathways for beta oxidation of very long chain fatty acids, glycerolipid metabolism, and fatty acid elongation in mitochondria.

CONCLUSION

These results suggest that B. saligna protects against ferric-induced oxidative cardiopathy by mitigating oxidative stress, while concomitantly inhibiting ACE, acetylcholinesterase and lipase activities, and modulating lipid spectrum and dysregulated metabolic pathways.

The antidiabetic properties of the hot water extract of kola nut (Cola nitida (Vent.) Schott & Endl.) in type 2 diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Cola nitida is amongst the evergreen plants native to West Africa used in the treatment of various ailments including diabetes.

AIM OF THE STUDY

This study aims to investigate the antidiabetic effects of the hot water extract of C. nitida seeds in type 2 diabetic rats.

METHODS

Type 2 diabetic rats were orally administered with low (150 mg/kg bw) and high (300 mg/kg bw) doses of the hot water extract for 6 wk and thereafter, blood glucose, insulin level, lipid profile, pancreatic β-cell function, perfusion and morphology, redox imbalance, glycolytic and cholinergic enzymes, as well as of caspase-3 and Nrf2 expressions were measured.

RESULTS

Treatment with the extract led to significant depletion of blood glucose, serum triglycerides, LDL-cholesterol, fructosamine, ALT, and uric acids, while elevating serum insulin and HDL-cholesterol levels. The infusion also significantly (p < 0.05) elevated GSH level, SOD, catalase, α-amylase, and ATPase activities, with concomitant depletion of myeloperoxidase enzyme activity, and NO and MDA levels in the serum and pancreas. Significantly (p < 0.05) improved pancreatic β-cell function and morphology were observed in rats treated with C. nitida, with restored pancreatic capillary networks. C. nitida inhibited the activities of glycogen phosphorylase, fructose 1,6 biphosphatase, glucose 6 phosphatase, and acetylcholinesterase while downregulated the Nrf2 expression. NMR analysis of the extract revealed the presence of caffeine and theobromine. The molecular docking studies indicated that identified compounds displayed strong molecular interactions with caspase-3 and Nrf2.

CONCLUSION

These results insinuate the antidiabetic activities of C. nitida hot water extract and may be attributed to the NMR-identified compounds.

Vernonia Amygdalina Del. stimulated glucose uptake in brain tissues enhances antioxidative activities; and modulates functional chemistry and dysregulated metabolic pathways

Brain glucose uptake is usually reduced in type 2 diabetes owing to downregulation of brain glucose transporters. The ability of Vernonia amygdalina to stimulate glucose uptake as well as ameliorate glucose-induced oxidative stress and proinflammation were investigated in rat brain. Hot infusion of V. amygdalina leaves was incubated with rat brain tissues for 2 h in the presence of glucose. Another incubation with glucose only, served as negative control while metformin served as positive control. Incubation of brain tissues with V. amygdalina led to significant (p < 0.05) increase in glucose uptake, reduced glutathione, nitric oxide and non-thiol proteins levels, superoxide dismutase, catalase and ATPase activities, while concomitantly decrease in myeloperoxidase activity and malondialdehyde level compared to the negative control. Incubation with glucose only, led to the development of nitrate, amide II and amide I functional groups which were removed on incubation with the infusion. LC-MS analysis revealed depletion of oxidative stress-induced 2-keto-glutaramic acid and cysteinyl-tyrosine metabolites in brain tissues, with concomitant generation of S-formylglutathione and adenosine tetraphosphate by the infusion. Pathway analysis of the metabolites revealed an activation of pyruvate metabolism pathway in the negative control, with the infusion reducing the intensity fold. LC-MS analysis of the infusion revealed the presence of l-serine, l-cysteine, l-proline, nicotinic acid, cumidine, salicylic acid, isoquinoline, 3-methyl-, and γ-octalactone. Except for l-serine, l-cysteine and l-proline, the other compounds were predicted to be permeable across the blood brain barrier. These results indicate the brain glucose uptake stimulatory and neuroprotective effect of V. amygdalina.

Hyperglycemia-induced oxidative brain injury: Therapeutic effects of Cola nitida infusion against redox imbalance, cerebellar neuronal insults, and upregulated Nrf2 expression in type 2 diabetic rats

The therapeutic effect of the hot water infusion of Cola nitida against hyperglycemia-induced neurotoxicity, cerebellar neurodegeneration and elemental deregulations was investigated in fructose-streptozotocin induced rat model of type 2 diabetes (T2D). A diabetic group was administered drinking water, two other diabetic groups were treated with C. nitida at 150 and 300 mg/kg bodyweight respectively, while another group was administered metformin (200 mg/kg bodyweight). Two other groups consisting of normal rats, were administered drinking water and C. nitida (300 mg/kg bodyweight). After 6 weeks of treatment, their brains were collected. Treatment with C. nitida led to suppression of oxidative stress, significantly elevating reduced glutathione (GSH) levels, superoxide dismutase and catalase activities, concomitant with depletion of malondialdehyde (MDA) levels. Acetylcholinesterase and ATPase activities were significantly inhibited in C. nitida-treated diabetic rats. Histological and microscopic analysis also revealed a restorative effect of C. nitida on T2D-altered distribution of elements, neurons and axonal nodes. Treatment with C. nitida also led to significant inhibition of Nrf2 expression in the cerebellar cortex. These results suggest the therapeutic effects of C. nitida in maintenance of the neuronal integrity and antioxidant status of the brain in T2D. These neuroprotective activities can be attributed to the identified alkaloid, caffeine in the infusion.

Histochemistry, phenolic content, antioxidant, and anti-diabetic activities of Vernonia amygdalina leaf extract

Vernonia amygdalina leaves were investigated for their histochemical properties and antidiabetic activities. Histochemical analysis of the leaf revealed distributions of acidic lipid, mucilage, and pectin, lipids, polyphenols, and alkaloids at the mid rib, glandular trichome, and epidermis. HPLC analysis of the leaves hot water infusion revealed the presence of quercetin and (-)-epi-catechin. The infusion had significant (p < 0.05) 2,2'-diphenyl-1-picrylhydrazyl scavenging activity and ferric reducing antioxidant power. Ex vivo antioxidative analysis revealed the ability of the infusion to increase glutathione level, superoxide dismutase, and catalase activities, while concomitantly depleting malondialdehyde level and DNA fragmentation in Fe²⁺ -induced hepatic injury. The infusion showed significant (p < 0.05) inhibitory activity against α-glucosidase and pancreatic lipase. It also inhibited intestinal glucose absorption and enhanced muscle glucose uptake, respectively. The ability of the infusion to abate oxidative stress, DNA fragmentation and stimulate muscle glucose uptake may suggest the antioxidative, anti-apoptotic, and insulin-sensitizing activity of V. amygdalina. PRACTICAL APPLICATIONS: Vernonia amygdalina (bitter leaf) is among the common leafy vegetables in West Africa reported for its various medicinal and nutritional properties. It is utilized as a food ingredient as well as supplement for the treatment and management of type 2 diabetes (T2D). Its ability to inhibit intestinal glucose absorption, enhance muscle glucose uptake, and protect against hepatic oxidative stress gives more credence to its reported antidiabetic properties. Being a common leafy vegetable, V. amygdalina can be a cheap source of nutraceutical for the treatment and management of T2D and its complications.