Garcinia kola seed biflavonoid fraction (Kolaviron), increases longevity and attenuates rotenone-induced toxicity in Drosophila melanogaster

Ameliorative role of Tetrapleura tetraptera (Schum. & Thonn.) taub in cadmium chloride-induced oxidative stress in Drosophila melanogaster using in vivo and computational approaches

BACKGROUND

Cadmium (Cd) is a naturally occurring transition metal associated with oxidative stress in living organisms. Whereas Tetrapleura tetraptera (Tt), an ethnomedicinal plant is said to possess high antioxidant activity and used to treat various human diseases locally. Therefore, the study aimed to investigate the biological activity of the ethanolic pod extract of T. tetraptera in cadmium chloride-induced toxicity in Drosophila melanogaster.

METHODS

Six groups of adults (1-3 days old) D. melanogaster as shown: Control, Tt 2.5 mg/10 g diet, Tt 5 mg/10 g diet, CdCl2, CdCl2+ Tt 2.5 mg/10 diet and CdCl2+Tt 5 mg/10 g diet were exposed via diet for 7 days consisting of 50 flies per vial and 5 replicate per group. Thereafter, we evaluated markers for free radical generation, antioxidant, non-antioxidant activities, and emergence rates of the flies. The active compounds of Tt extract were molecularly docked against glutathione-S-transferase II.

RESULTS

The results indicated that CdCl2 significantly induced oxidative stress by increasing the levels of lipid peroxidation (LPO), hydrogen peroxide (H2O2), nitric oxide (NO) and decreasing the activity of GST without an effect on total thiol (T-SH) and non-protein thiols (NP-SHs) levels. However, co-treatment with T. tetraptera (2.5 mg/10 g diet) significantly decreased levels of LPO, H2O2, but increased GST activity. Also, co-treatment with T. tetraptera (5 mg/10 g diet) increased NPSH and T-SH levels by 18.6 % and 35.8 %. Furthermore, Co-treatment (5 mg/10 g diet) increased the rate of offspring emergence.

CONCLUSION

T. tetraptera ameliorated cadmium chloride-induced oxidative stress in Drosophila melanogaster and increased offspring hatching rate. T. tetraptera may therefore serve as a good regimen for the treatment of oxidative stress-related diseases induced by cadmium.

Brown rice attenuates iron-induced Parkinson's disease phenotypes in male wild-type drosophila: insights into antioxidant and iron metabolism modulation

Parkinson's disease (PD) is a progressive movement disorder associated with brain iron (Fe) accumulation and free radicals. Brown rice (BR) is antioxidant-rich and has been shown to ameliorate oxidative stress-induced damage. The aim of this study was to investigate the effects of BR compared to white rice (WR) on Fe-induced PD in a fruit fly model. Three-day-old male adult flies were divided into two groups: one on a normal diet and the other on Fe-diet (1 mmol/L) for 10 days to induce PD. After 10 days, the Fe-fed flies were redistributed into four groups: one on normal diet (Fe group), while the others were treated with BR (Fe + BR group), WR (Fe + WR group), or L-3,4-dihydroxyphenylalanine (L-dopa) (Fe + L-dopa group) for 5 days. Similarly, the flies initially on a normal diet were separated into four groups: one on normal diet (Control group), while the others were treated with BR (BR group), WR (WR group), or L-dopa (L-dopa group) for 5 days. Finally, Fe levels, dopamine, malonaldehyde (MDA), and antioxidant enzymes were measured, and the mRNA levels of antioxidant and Fe metabolism genes were assessed. BR significantly improved motor and cognitive functions, decreased fly head MDA and Fe levels, and increased antioxidant enzyme levels in comparison to the Fe and WR groups. Similarly, BR upregulated the mRNA levels of antioxidant genes: catalase, GPx, Nrf2, and DJ-1. The results suggest that BR could potentially reduce morbidities associated with PD possibly due to its bioactive compounds compared to WR.

Rotenone exposure causes features of Parkinson`s disease pathology linked with muscle atrophy in developing zebrafish embryo

Parkinson's disease (PD) is associated with both genetic and environmental factors; however, sporadic forms of PD account for > 90 % of cases, and PD prevalence has doubled in the past 25 years. Depending on the importance of the environmental factors, various neurotoxins are used to induce PD both in vivo and in vitro. Unlike other neurodegenerative diseases, PD can be induced in vivo using specific neurotoxic chemicals. However, no chemically induced PD model is available because of the sporadic nature of PD. Rotenone is a pesticide that accelerates the induction of PD and exhibits the highest toxicity in fish, unlike other pesticides. Therefore, in this study, we aimed to establish a model exhibiting PD pathologies such as dysfunction of DArgic neuron, aggregation of ɑ-synuclein, and behavioral abnormalities, which are known features of PD pathology, by rotenone exposure at an environmentally relevant concentration (30 nM) in developing zebrafish embryos. Our results provide direct evidence for the association between PD and muscle degeneration by confirming rotenone-induced muscle atrophy. Therefore, we conclude that the rotenone-induced model presents non-motor and motor defects with extensive studies related to muscle atrophy.

Ribose-cysteine and levodopa abrogate Parkinsonism via the regulation of neurochemical and redox activities in alpha-synuclein transgenic Drosophila melanogaster models

Parkinson's disease (PD), the most prevalent type of parkinsonism, is a progressive neurodegenerative condition marked by several non-motor and motor symptoms. PD is thought to have a complex aetiology that includes a combination of age, genetic predisposition, and environmental factors. Increased expression of α-synuclein (α-Syn) protein is central to the evolvement of neuropathology in this devastating disorder, but the potential of ribose-cysteine and levodopa in abating pathophysiologic changes in PD model is unknown. Crosses were set up between flies conditionally expressing a pathological variant of human α-Syn (UAS-α-Syn) and those expressing GAL4 in neurons (elav-GAL4) to generate offspring referred to as PD flies. Flies were randomly assigned to five groups (n = 40) from the total population of flies, with each group having five replicates. Groups of PD flies were treated with either 500 mg/kg ribose-cysteine diet, 250 mg/kg levodopa diet, or a combination of the two compounds for 21 days, whereas the control group (w1118) and the PD group were exposed to a diet without ribose-cysteine or levodopa. In addition to various biochemical and neurochemical assays, longevity, larval motility, and gravitaxis assays were carried out. Locomotive capability, lifespan, fecundity, antioxidant state, and neurotransmitter systems were all significantly (p < 0.05) compromised by overexpression of α-Syn. However, flies treated both ribose cysteine and levodopa showed an overall marked improvement in motor functions, lifespan, fecundity, antioxidant status, and neurotransmitter system functions. In conclusion, ribose-cysteine and levodopa, both singly and in combination, potentiated a therapeutic effect on alpha-synuclein transgenic Drosophila melanogaster models of Parkinsonism.

Kolaviron: a Bioflavonoid from Seed Extract of Garcinia kola Attenuates Chromium (VI)-Induced Gut Dysfunction and Oxidative Damage in Drosophila melanogaster

Hexavalent chromium [Cr(VI)] is of public health significance due to its toxicity and carcinogenic effects. Kolaviron, a bio-flavonoid fraction from Garcinia kola seed, has been reported to possess gastroprotective and antioxidative properties. We hypothesize that Kolaviron-fortified diet will attenuate chromium (VI)-induced gut dysfunction and oxidative damage in Drosophila melanogaster. We exposed D. melanogaster (Oregon strain of 1-3 days old of both male and female) to a 1.0 mg/kg diet of chromium (VI), with or without Kolaviron (100 mg/kg diet) orally for 5 days. We evaluated markers of oxidative stress (total peroxide and protein carbonyl), antioxidative status (total thiols (T-SH), non-protein thiols (NP-SH), and catalase), and inflammatory (nitric oxide (nitrite and nitrate) and gut's morphology. The data indicated that Kolaviron ameliorated chromium (VI)-induced reduction in the levels of T-SH, NP-SH, and catalase activity (p < 0.05). In addition, Kolaviron attenuated chromium (VI)-induced elevation of total peroxide, protein carbonyl, and nitric oxide (p < 0.05). Kolaviron offered a protective role in chromium VI-induced toxicity in the gut of D. melanogaster. This study provided further insights into the protective mechanisms of Kolaviron against chromium (VI)-induced toxicity in D. melanogaster by maintaining epithelial integrity of the gut and oxidative stress-antioxidant balance.

Magainin-AM2 inhibits sucrose-induced hyperglycaemia, oxidative stress, and cognitive dysfunction in Drosophila melanogaster

Hyperglycaemia-induced oxidative stress plays significant roles in the development of type 2 diabetes and its complications. This study investigates effects of magainin-AM2 on high-sucrose diet induced redox imbalance and cognitive impairment in Drosophila melanogaster. Effects of various concentrations of sucrose, magainin-AM2 or a combination of both agents on mortality, eclosion rate, generation of reactive oxygen and nitrogen species, activities of antioxidant enzymes, thiol system, and markers of cognitive functions in control and treated flies were examined. Results showed that the exposure of flies to high sucrose (30 %-60 % w/w) diet increased mortality rate (38-67 %, P < 0.001) and levels of glucose (1.8-1.9-fold, P < 0.001), hydrogen peroxide (1.4-1.5-fold, P < 0.01) and nitrite/nitrate (1.2-fold, P < 0.01). Decreased levels of total thiol (53-59 %, P < 0.01), non-protein thiols (59-63 %, P < 0.01), catalase activities (39-47 %, P < 0.01-0.05) and glutathione-s-transferase activities (31-43 %, P < 0.01-0.05) were also observed. Magainin-AM2 (0-10 μM/kg diet) did not affect fly mortality rate, levels of hydrogen peroxide and nitrite/nitrate, and activities of catalase and glutathione-s-transferase. However, the peptide produced a dose-dependent increase in total thiol 1.2-1.6-fold, P < 0.001-0.01)and increases non-protein thiol levels at 10 μM/kg diet (2.0-fold, P < 0.01). Magainin-AM2 inhibited sucrose-induced elevation of glucose (55-70 %, P < 0.001), hydrogen peroxide (11-12 %, P < 0.01) and nitrite/nitrate (20-34 %, P < 0.01-0.05). The peptide prevented sucrose-induced reduction in total and non-protein thiols (1.9-2.0-fold, P < 0.05) levels and activities of catalase (2.3-3.1-fold, P < 0.001) and glutathione-s-transferase (1.8-2.8-fold, P < 0.001-0.05). Magainin-AM2 inhibited sucrose-induced reduction in acetylcholinesterase activities (3.6-4.0-fold, P < 0.001), eclosion rate (18 %, P < 0.001) and negative geotaxis (1.3-14-fold, P < 0.001). These results indicate that beneficial actions of magainin-AM2 may also involve the prevention of hyperglycaemia-induced oxidative damage and encourage its further development as an anti-diabetic agent.

Lauric acid with or without levodopa ameliorates Parkinsonism in genetically modified model of Drosophila melanogaster via the oxidative-inflammatory-apoptotic pathway

BACKGROUND

Parkinson's disease (PD), the most prevalent type of Parkinsonism, is a progressive neurological condition characterized by a range of motor and non-motor symptoms. The complicated etiology of PD is thought to involve a summation of aging, genetic predisposition, and environmental variables. However, the α-synuclein protein plays a significant role in the disease's pathophysiology.

MATERIALS AND METHODS

The UAS-α-Syn and Ddc-Gal4 strains were crossed to produce offspring referred to as PD flies. The entire population of flies was divided into five groups, each having about 100 flies and five replicates. The control group (w1118) and the PD group not receiving treatment were exposed to lauric acid (LA)/levodopa (LD)-free diet, while the PD groups that received treatments were fed with either a 250 mg/kg LA diet, a 250 mg/kg LD diet, or a combination of the two for 21 days. Longevity, geotaxis, and olfactory assays were performed in addition to other biochemical tests.

RESULTS

As a result of the overexpression of α-synuclein, the locomotive capacity, lifespan, and antioxidant status were all significantly (p < .05) reduced, and the apoptotic and neuroinflammatory activities were increased. Nevertheless, the majority of the treated flies improved significantly (p < .05).

CONCLUSION

LA, whether combined with LD or not, elicited a significant response in α-synuclein/dopa decarboxylase genetically modified Drosophila melanogaster Parkinsonism models.

Exploring the Efficient Natural Products for the Therapy of Parkinson's Disease via Drosophila Melanogaster (Fruit Fly) Models

Parkinson's disease (PD) is a severe neurodegenerative disorder, partly attributed to mutations, environmental toxins, oxidative stress, abnormal protein aggregation, and mitochondrial dysfunction. However, the precise pathogenesis of PD and its treatment strategy still require investigation. Fortunately, natural products have demonstrated potential as therapeutic agents for alleviating PD symptoms due to their neuroprotective properties. To identify promising lead compounds from herbal medicines' natural products for PD management and understand their modes of action, suitable animal models are necessary. Drosophila melanogaster (fruit fly) serves as an essential model for studying genetic and cellular pathways in complex biological processes. Diverse Drosophila PD models have been extensively utilized in PD research, particularly for discovering neuroprotective natural products. This review emphasizes the research progress of natural products in PD using the fruit fly PD model, offering valuable insights into utilizing invertebrate models for developing novel anti-PD drugs.

Toxicological assessment of sodium benzoate in Drosophila melanogaster

Sodium benzoate (SB), the sodium salt of benzoic acid, is a food preservative with wide applications in the food, cosmetic and pharmaceutical industries due to its ability to kill many microorganisms effectively. Experimental evidence however suggests that excessive intake of SB poses detrimental health risks among consumers in the population. The present study investigated the toxic effects of various concentrations of SB using Drosophila melanogaster as a model. Adult wild-type flies of Canton S strain (1- to 3-days old) was orally exposed to SB (0, 0.5, 1.0, 2.0 and 5.0 mg/5 g diet) to evaluate survival rates for 21 days. Thereafter, we evaluated markers of oxidative stress, antioxidant status and behavioral activity in D. melanogaster exposed to SB for seven (7) days. We observed that SB (2.0 and 5.0 mg/5 g diet) decreased the survival of D. melanogaster. Also, SB inhibited glutathione-S-transferase activity and depleted total thiols and nonprotein thiols contents. Moreover, SB (5 mg/5 g diet) increased nitric oxide (nitrite/nitrate) level and reduced flies' emergence rate. Conclusively, findings from this study revealed that exposure to high concentrations of SB reduced survival rate and induced toxicity via the induction of oxidative stress and inhibition of antioxidant enzymes in D. melanogaster.

Vitellaria paradoxa Inhibits Arsenic-induced Toxicity in Drosophila melanogaster Via the Augmentation of Antioxidant System

The Ethyl Acetate Fraction (EACF) of Ethanol Leaf Extract of Vitellaria paradoxa (ELVp) was assessed against Sodium Arsenite (SA)-induced toxicity in Drosophila melanogaster. The Gas Chromatography-Mass Spectrometry (GC-MS) analysis of EACF was carried out. The molecular docking of the compounds obtained from GC-MS was performed against D. melanogaster glutathione-S-transferase-2 (GST-2). Firstly, D. melanogaster (Harwich strain) was treated with EACF to determine its effect on longevity. Secondly, D. melanogaster was fed with EACF (1.0 and 3.0 mg/5 g diet) and/or SA (0.0625 mM) for 5 days. Thereafter, the ameliorative role of EACF in SA-induced toxicity was evaluated using the fly's emergence rate, locomotor activity, oxidative stress and antioxidant biomarkers. The in-silico study revealed varying degrees of binding affinity of the twelve active compounds of EACF against GST-2 which was comparable with the co-crystalized ligand (glutathione). The EACF increased the longevity of D. melanogaster by 20.0% compared with control and ameliorated SA-induced reduction of emergence rate and locomotor performance by 178.2 and 20.5%, respectively. Additionally, EACF ameliorated SA-induced reduction of total thiol and non-protein thiols and inhibition of catalase and GST activities (p < 0.05). These results corroborated with histological data obtained in the fat body of D. melanogaster. Overall, EACF augmented the antioxidant system of D. melanogaster and prevented sodium arsenite-induced oxidative stress due to its high antioxidant property.

Garcinia kola: a critical review on chemistry and pharmacology of an important West African medicinal plant

Garcinia kola Heckel (Clusiaceae) is a tree indigenous to West and Central Africa. All plant parts, but especially the seeds, are of value in local folklore medicine. Garcinia kola is used in treatment of numerous diseases, including gastric disorders, bronchial diseases, fever, malaria and is used to induce a stimulating and aphrodisiac effect. The plant is now attracting considerable interest as a possible source of pharmaceutically important drugs. Several different classes of compounds such as biflavonoids, benzophenones, benzofurans, benzopyran, vitamin E derivatives, xanthones, and phytosterols, have been isolated from G. kola, of which many appears to be found only in this species, such as garcinianin (found in seeds and roots), kolanone (fruit pulp, seeds, roots), gakolanone (stem bark), garcinoic acid, garcinal (both in seeds), garcifuran A and B, and garcipyran (all in roots). They showed a wide range of pharmacological activities (e.g. analgesic, anticancer, antidiabetic, anti-inflammatory, antimalarial, antimicrobial, hepatoprotective and neuroprotective effects), though this has only been confirmed in animal models. Kolaviron is the most studied compound and is perceived by many studies as the active principle of G. kola. However, its research is associated with significant flaws (e.g. too high doses tested, inappropriate positive control). Garcinol has been tested under better conditions and is perhaps showing more promising results and should attract deeper research interest (especially in the area of anticancer, antimicrobial, and neuroprotective activity). Human clinical trials and mechanism-of-action studies must be carried out to verify whether any of the compounds present in G. kola may be used as a lead in the drug development.

Impact of age on the rotenone-induced sporadic Parkinson's disease model using Drosophila melanogaster

Rotenone, a naturally occurring toxin, has been used to induce sporadic Parkinson's disease (PD) in Drosophila melanogaster for decades. However, the age of flies varies considerably between studies in this model. To investigate the impact of age on the rotenone-induced PD model, we collected male flies at the age of 1, 5, 7, and 10 days post-eclosion, respectively. Then, flies were immediately exposed to a feeding medium supplemented with 250 μM rotenone for seven days. The motor ability of Drosophila was detected by negative geotaxis assay, and the number of dopamine (DA) neurons and tyrosine hydroxylase (TH) expression levels were evaluated. The results showed that both the motor deficits and mortality increased with age. The flies older than five days showed typical PD features, including the loss of DA neurons, decreased TH expression levels, and decreased locomotive ability. However, 1-day-old flies displayed an unstable motor deficit and little TH expression changes after seven days of rotenone exposure. Lastly, after 7 days of exposure to rotenone, the death rate of flies rapidly increased with increasing starting age. The death rates of 1-, 5-, 7-, and 10-days old flies were 10.0%, 22.8%, 41.5%, and 50.4%, respectively. The findings of this study suggest that age is a crucial factor impacting the Drosophila PD model. This information provides a reference for the age selection to use this model for future studies.

An assessment of the ameliorative role of hesperidin in Drosophila melanogaster model of cadmium chloride-induced toxicity

Cadmium chloride (CdCl₂) is an important heavy metal widely regarded as an environmental contaminant. Hesperidin, a flavanone glycoside found in citrus fruits, has an established properties against free radicals, apoptosis, and inflammation. The present study investigated the protective actions of hesperidin on CdCl₂-induced oxidative damage and inflammation in Drosophila melanogaster. For 7 consecutive days via their diet regimen, the flies were exposed to CdCl₂ alone (0.05 mM) or in combination with hesperidin (50 and 100 μM). Exposure to CdCl₂ significantly (p < 0.05) increased mortality rate of flies, whereas the survived flies demonstrated significant oxidative toxicity from decreased activities of catalase and Glutathione S-transferase (GST) and Total Thiol (T-SH) and Non-Protein Thiols (NPSH) levels as well as accumulation of Nitric Oxide (NO (nitrite/nitrate)), protein carbonyl and Hydrogen Peroxide (H₂O₂). However, hesperidin-supplemented diet improved Acetylcholinesterase (AChE) activity, mitochondrial metabolic rate (cell viability), locomotor activity, and amelioration of oxidative damage and lipid peroxidation induced by CdCl₂. The hesperidin diet supplement boosted the antioxidant milieu and ameliorated the oxidative damage in the treated flies. Overall, the findings revealed that hesperidin improved antioxidative protective capacity in Drosophila melanogaster model of CdCl₂-induced toxicity. This suggests hesperidin as a potential therapeutic agent against oxidative stress disorders due to exposure to CdCl₂ and or related toxicants.

Drosophila as an Animal Model for Testing Plant-Based Immunomodulators

Allopathic medicines play a key role in the prevention and treatment of diseases. However, long-term consumption of these medicines may cause serious undesirable effects that harm human health. Plant-based medicines have emerged as alternatives to allopathic medicines because of their rare side effects. They contain several compounds that have the potential to improve health and treat diseases in humans, including their function as immunomodulators to treat immune-related diseases. Thus, the discovery of potent and safe immunomodulators from plants is gaining considerable research interest. Recently, Drosophila has gained prominence as a model organism in evaluating the efficacy of plant and plant-derived substances. Drosophila melanogaster "fruit fly" is a well-known, high-throughput model organism that has been used to study different biological aspects of development and diseases for more than 110 years. Most developmental and cell signaling pathways and 75% of human disease-related genes are conserved between humans and Drosophila. Using Drosophila, one can easily examine the pharmacological effects of plants/plant-derived components by employing a variety of tests in flies, such as survival, anti-inflammatory, antioxidant, and cell death tests. This review focused on D. melanogaster's potential for identifying immunomodulatory features associated with plants/plant-derived components.

Sex-specific changes in oxidative stress parameters and longevity produced by Bisphenol F and S compared to Bisphenol A in Drosophila melanogaster

Female and male Drosophila melanogaster were exposed separately for seven days to Bisphenol A (BPA), Bisphenol F (BPF), and Bisphenol S (BPS) at concentrations of 0.25, 0.5, and 1 mM. We observed that males exposed to 0.5 and 1 mM BPS showed lower catalase (CAT) activity and higher superoxide dismutase (SOD) and reactive species (RS); CAT activity decreased for BPF 0.5 and 1 mM. Nevertheless, BPA 0.5 and 1 mM decreased CAT activity, increased RS and lipid peroxidation (LPO), and reduced mitochondrial viability. None of the bisphenols altered the cell viability of male flies, although BPA 0.5 and 1 mM reduced longevity. In female flies, BPA and BPS 0.5 and 1 mM increased RS and LPO levels and decreased CAT activity and glutathione-S-transferase (GST), which may have contributed to lower mitochondrial and cell viability. Furthermore, BPS decreased SOD activity at the 1 mM concentration, and BPA reduced the SOD activity at concentrations of 0.5 and 1 mM. In the BPF 1 mM group, there was a reduction in GST activity and an increase in RS and LPO levels. The toxicological effects were different between sexes, and BPA was more harmful than BPF and BPS in male flies. Thus, our findings showed that females were more susceptible to oxidative cell damage when exposed to BPA and BPS than to BPF, and daily exposure to BPA and BPS at all concentrations reduced female longevity, as well as in BPF 1 mM.

Is Turkish coffee protects Drosophila melanogaster on cadmium acetate toxicity by promoting antioxidant enzymes?

With their increasing use in today's industry, heavy metals cause biochemical and biophysical changes by affecting the control and regulatory systems of living things. Cadmium (Cd), a heavy metal, spreads to the environment through both natural sources and industrial activities. It is taken into the organism through water, food, skin contact or smoke. Systems and organs of living things are directly or indirectly affected by Cd toxicity. Besides their recreational usage, herbal products such as coffee are preferred in alternative medicine because of their antioxidant, anti-inflammatory, anticancer and antidiabetic effects. Turkish coffee (TK) is a drink rich in flavorings, phenolic compounds and antioxidant compounds. The study evaluated the possible antioxidant role of TK against oxidative stress induced by Cadmium acetate (CdA) in the fat tissues of old-young female individuals of Drosophila melanogaster. The female flies were fed with either a standard diet, or CdA (10-30 mg), or TK (2%), or both (CdA + TK) for 3 and 10 days. Following the completion of the feeding period, the amounts of fatbody and oxidative stress markers (oxidative stress index, malondialdehyde), activities of antioxidant enzymes (Glutathione-S-transferase, Catalase, and Superoxide dismutase) and their levels were measured. Fat body lipid droplets were high in the individuals exposed to high concentrations of CdA. It was determined that lipid droplets decreased but did not significantly alter oxidative stress in the individuals treated with TK (p = 0.05). This article may be of help in terms of the use of TK compounds as antioxidants to evaluate their effects in preventing heavy metal accumulation and stress in the aging process.

Chemically induced models of Parkinson's disease

Environmental toxins are harmful substances detrimental to humans. Constant exposure to these fatal neurotoxins can cause various neurodegenerative disorders. Although poisonous, specific neurotoxins at optimal concentrations mimic the clinical features of neurodegenerative diseases in several animal models. Such chemically-induced model systems are beneficial in deciphering the molecular mechanisms of neurodegeneration and drug screening for these disorders. One such neurotoxin is 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), a widely used chemical that recapitulates Parkinsonian features in various animal models. Apart from MPTP, other neurotoxins like 6-hydroxydopamine (6-OHDA), paraquat, rotenone also induce specific clinical features of Parkinson's disease in animal models. These chemically-induced Parkinson's disease models are playing a crucial role in understanding Parkinson's disease onset, pathology, and novel therapeutics. In this review, we provide a concise overview of various neurotoxins that can recapitulate Parkinsonian features in different in vivo and in vitro model systems specifically focusing on the different treatment methodologies of neurotoxins.

Beneficial actions of esculentin-2CHa(GA30) on high sucrose-induced oxidative stress in Drosophila melanogaster

Hyperglycaemia-induced oxidative stress plays a critical role in the development of diabetes and its complications. This study investigated actions of esculentin-2CHa(GA30) on high sucrose-induced oxidative stress in adult Drosophila melanogaster. Adult flies were exposed to diets containing graded concentrations of sucrose in the presence or absence of esculentin-2CHa(GA30) (5.0-10 μmol/kg diet) for 7 days. Effects of high sucrose diet and/or esculentin-2CHa(GA30) on survival and longevity of flies, and markers of oxidative stress, antioxidant status and glucose were assessed. High-sucrose diet (15-30%) and esculentin-2CHa(GA30) (5-10 μmol/kg diet) enhanced the percentage of surviving flies by 33.5%-46.2% (P < 0.01) and 7.4%-26.9% (P < 0.01) respectively. Concentration-dependent reduction in total thiol (19.3-51.3%, P < 0.01), reduced glutathione (22.6-54.9%, P < 0.05-0.01), catalase activity (36.8-57.3%, P < 0.05-0.01) and elevated glucose concentration (1.8-2.9-fold, P < 0.001) were observed in high sucrose-fed flies. Esculentin-2CHa(GA30) alone did not affect levels of total thiol, reduced glutathione, glucose and catalase activity. Improved survival (1.2-1.3-fold, P < 0.05-0.01) and longevity (1.3-fold) were observed in flies treated with the peptide (5.0 and 7.5 μmol/kg diet). Feeding on sucrose and esculentin-2CHa(1-30) (5.0 and 7.0 μmol/kg diet) for 7 days increased total thiol (2 - 3-fold, P < 0.001) and reduced glutathione (1.6-1.8-fold, P < 0.05) levels. Reduced catalase activity (21.4-36.4%, P < 0.01) and reduced glucose level (38.6-49.4%, P < 0.01) were observed in peptide-treated flies. Esculentin-2CHa(1-30) inhibited sucrose-induced generation of hydrogen peroxide (7.5-13.7%, P < 0.05) and nitric oxide (22.3-42.9%, P < 0.01) in adult flies. Overall, findings from this study offered further insights into the anti-oxidative properties of esculentin-2CHa(GA30).

Methanol fraction of Ficus mucoso (welw) prevents iron-induced oxidative damage and alters mitochondrial dysfunction in Drosophila melanogaster

The present study investigated the antioxidant and cyto-/mito-protective roles of Methanol Fraction of Ficus mucoso (MFFM) in iron-induced oxidative damage in Drosophila melanogaster. At first, 10-day survival rates were carried out separately on FeSO₄ and MFFM, respectively, after which ameliorative effects of MFFM were investigated on FeSO₄-induced toxicity for 5 days using biochemical and behavioral markers. Additionally, mitochondria were isolated from treated D. melanogaster to assess mitochondrial Permeability Transition (mPT) pore opening. The results showed that FeSO₄ significantly reduced survival rate, total thiol level and activities of catalase and glutathione-S-transferase in D. melanogaster. In addition, treatment with FeSO₄ caused increased generation of H₂O₂, NO (nitrite/nitrates) and acetylcholinesterase (AChE) activity compared with control (p < 0.05). Conversely, MFFM restored FeSO₄-induced inhibition of glutathione-S-transferase and catalase activities, as well as glutathione and total thiol levels. FeSO₄-induced elevation of AChE activity as well as H₂O₂ and NO (nitrites/nitrates) levels were ameliorated by MFFM with improved climbing activity. Interestingly, MFFM prevented FeSO₄-induced mitochondrial Permeability Transition (mPT) pore opening, and elevated mitochondrial ATPase activity and mitochondrial lipid peroxides generation in D. melanogaster. Taken together, our results demonstrated that iron impaired anti-stress defence capacity, altered behavioral functions, increased generation of mitochondrial malondialdehyde and activated opening of the mPT pore in D. melanogaster. Conversely, methanol fraction of F. mucoso protected against iron-induced cyto-/mito-toxic effects. F. mucoso possibly contain bioactive agents which might be useful in the management of disorders associated with oxidative stress induced by iron and or related metals.

Garcinia kola improves cognitive and motor function of a rat model of acute radiation syndrome in the elevated plus maze

We reported recently that the elevated plus maze is a good tool for evaluating cognitive and motor functional changes in gamma-irradiated rats as a model for new drug evaluation and monitoring. The capacity of Garcinia kola to mitigate radiation-induced brain injury is currently unknown. We therefore assessed the effects of the neuroprotective medicinal plant Garcinia kola, on the cognitive and motor changes in this murine model of acute radiation syndrome. Wistar rats exposed once to an ionizing dose of Tc99m-generated Gamma radiation were treated with an ethyl acetate fraction of methanolic extract of Garcinia kola seeds (content of 100 mg/kg of extract) for 9 weeks. Cognitive and motor function indicators were assessed in the elevated plus maze in these animals and compared with irradiated control groups (vitamin C- and vehicle-treated groups) and the non-irradiated control rats. The irradiated control group displayed cachexia, shaggy and dirty fur, porphyrin deposits around eyes, decreased exploratory activity, reduced social interactions and a loss of thigmotaxis revealed by a marked decrease in rearing episodes and stretch attend posture episodes close to the walls of elevated plus maze closed arm, an increased central platform time, and decreases in open arm time and entries. This group further displayed a decrease in head dips and grooming episodes. Treatment with Garcinia kola, and in a lesser extent vitamin C, significantly prevented the body weight loss (P < 0.001) and mitigated the development of elevated plus maze signs of cognitive and motor affections observed in the irradiated control group (P < 0.05). Altogether, our data suggest for the first time that Garcinia kola seeds have protective properties against the development of cognitive and motor decline in the acute radiation syndrome-like context. Future studies are warranted to characterize the molecular mechanisms and neuronal networks of this action.

Alternative model organisms for toxicological fingerprinting of relevant parameters in food and nutrition

In the field of (food) toxicology, there is a strong trend of replacing animal trials with alternative methods for the assessment of adverse health effects in humans. The replacement of animal trials is not only driven by ethical concerns but also by the number of potential testing substances (food additives, packaging material, contaminants, and toxicants), which is steadily increasing. In vitro 2D cell culture applications in combination with in silico modeling might provide an applicable first response. However, those systems lack accurate predictions of metabolic actions. Thus, alternative in vivo models could fill the gap between cell culture and animal trials. In this review, we highlight relevant studies in the field and spotlight the applicability of alternative models, including C. elegans, D. rerio, Drosophila, HET-CAM and Lab-on-a-chip.

Ameliorative effects of flavonoids and polyketides on the rotenone induced Drosophila model of Parkinson's disease

Parkinson's disease (PD) is a movement disorder associated with the progressive loss of dopaminergic neurons (DA). PD treatment remains unsatisfactory as the current synthetic drugs in clinical use relies on managing only motor symptoms. This study investigated antioxidant potentials of selected compounds namely, 5,6,7,4'-tetramethoxyflavone (1), 6-hydroxy-2,3,4,4'-tetramethoxychalcone (2), 6-methoxyhamiltone A (3), diosquinone (4) and toussantine D (5) against rotenone (6) induced PD in Drosophila melanogaster. Toxicity of these compounds was conducted by monitoring flies' survival for seven days and determining the lethal concentrations (LC₅₀). Whereas compound 1 had LC₅₀ value of 91.3 μM within three days, compounds 2, 3, 4, and 5 had LC₅₀ values of 87.2, 58.0, 64.0 and > 1000 μM, respectively on the seventh day of the experiment. We exposed flies (1-4 days old) to 500 μM rotenone and co-treated with different doses of the test compounds in the diet for seven days at final concentrations of 11.0, 43.6 and 87.2 μM for compounds 2 and 3. The concentrations used for compound 4 were 8.0, 32.0 and 64.0 μM, while 250, 500 and 1000 μM were used for compound 5. Rotenone fed flies showed impaired climbing ability compared to control flies, the phenotype that was rescued by the treatment of tested phytochemicals. Rotenone toxicity also increased malondialdehyde levels assayed by lipid peroxidation in the brain tissues relative to control flies. This effect was reduced in flies exposed to rotenone and co-treated with the phytochemicals. Moreover, expression levels of mRNA of antioxidant enzymes; superoxide dismutase and catalase were elevated in flies exposed to rotenone and normalized in flies that were co-treated with tested compounds. Besides compound 1, this study provides overall evidence that the tested flavonoids and polyketides ameliorated the rotenone provoked neurotoxicity in D. melanogaster by battling the induced oxidative stress in brain cells including DA neurons and hence rescue the locomotor behaviour deficits.

D-Penicillamine prolongs survival and lessens copper-induced toxicity in Drosophila melanogaster

D-penicillamine (DPA) is an amino-thiol that has been established as a copper chelating agent for the treatment of Wilson's disease. DPA reacts with metals to form complexes and/or chelates. Here, we investigated the survival rate extension capacity and modulatory role of DPA on Cu²⁺-induced toxicity in Drosophila melanogaster. Adult Wild type (Harwich strain) flies were exposed to Cu²⁺ (1 mM) and/or DPA (50 μM) in the diet for 7 days. Additionally, flies were exposed to acute Cu²⁺ (10 mM) for 24 h, followed by DPA (50 μM) treatment for 4 days. Thereafter, the antioxidant status [total thiol (T-SH) and glutathione (GSH) levels and glutathione S-transferase and catalase activities] as well as hydrogen peroxide (H₂O₂) level and acetylcholinesterase activity were evaluated. The results showed that DPA treatment prolongs the survival rate of D. melanogaster by protecting against Cu²⁺-induced lethality. Further, DPA restored Cu²⁺-induced depletion of T-SH level compared to the control (P < 0.05). DPA also protected against Cu²⁺ (1 mM)-induced inhibition of catalase activity. In addition, DPA ameliorated Cu²⁺-induced elevation of acetylcholinesterase activity in the flies. The study may therefore have health implications in neurodegenerative diseases involving oxidative stress such as Alzheimer's disease.

Effects of pyriproxyfen exposure on immune signaling pathway and transcription of detoxification enzyme genes in fat body of silkworm, Bombyx mori

Sericulture is a very important and flourishing industry in developing countries. Bombyx mori is a kind of important and well-studied economic insects in the whole world. In China, applying of pyriproxyfen pesticide often resulted in non-cocooning and silk yield reduction. However, the effects of pyriproxyfen exposure on immune signaling pathway in fat body of silkworm has not been reported yet now. In the present study, we found that the growth and development of silkworm were significantly affected by pyriproxyfen exposure and the fat body tissues were injured after treatment. It was also showed that the expressions of key genes of PI3K/Akt and CncC/Keap1 pathway can be elevated at 24-96 h after pyriproxyfen exposure. Furtherly, the relative expression levels of detoxification enzyme genes and the activities of detoxification enzymes were both increased by pyriproxyfen exposure. These results provided comprehensive view of fat body injury and gene expression changes in silkworm after pyriproxyfen exposure.

Effect of kaempferol on the transgenic Drosophila model of Parkinson's disease

The present study was aimed to study the effect of kaempferol, on the transgenic Drosophila model of Parkinson's disease. Kaempferol was added in the diet at final concentration of 10, 20, 30 and 40 µM and the effect was studied on various cognitive and oxidative stress markers. The results of the study showed that kaempferol, delayed the loss of climbing ability as well as the activity of PD flies in a dose dependent manner compared to unexposed PD flies. A dose-dependent reduction in oxidative stress markers was also observed. Histopathological examination of fly brains using anti-tyrosine hydroxylase immunostaining has revealed a significant dose-dependent increase in the expression of tyrosine hydroxylase in PD flies exposed to kaempferol. Molecular docking results revealed that kaempferol binds to human alpha synuclein at specific sites that might results in the inhibition of alpha synuclein aggregation and prevents the formation of Lewy bodies.

Kolaviron ameliorates behavioural deficit and injury to striatal dopaminergic terminals via modulation of oxidative burden, DJ-1 depletion and CD45R+ cells infiltration in MPTP-model of Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disease. Currently, the precise pathogenic detail of PD is not entirely clear and first line therapeutics fail to attenuate the progress of the disease. In this study, we examined the neuroprotective effect of kolaviron, a natural antioxidant and anti-inflammatory biflavonoid from Garcinia kola seed, on behavioural impairment, neurodegeneration, oxidative stress and neuroinflammation in an acute MPTP-induced PD model. Kolaviron mitigated the frequently interrupted MPTP-associated hyperkinesia, inefficient gait, immobility, inability to pay attention to sizable holes on walking path, habitual clockwise rotations characterized with minimal diversion of movements and impaired balance. Also, kolaviron suppressed MPTP-mediated striatal oxidative stress, depletion as well as degeneration of dopaminergic terminals, reduced DJ-1 secretion and upregulated expression of caspase-3. Kolaviron facilitated cytoprotective antioxidant response and prevented MPTP-mediated neuroinflammation by blocking striatal infiltration of peripheral CD45R positive cells. Additionally, kolaviron reversed MPTP-induced inhibition of acetylcholinesterase activity. Together, our study provides evidence that the neuroprotective capacity of kolaviron to modulate striatal degeneration, behavioural impairment, antioxidant/redox imbalance and neuroinflammation implicated in the pathogenesis of PD may involve upregulation of DJ-1 secretion and inhibition of CD45R cells infiltration. Our data recommend kolaviron as a possible neuroprotective strategy in the management of Parkinson's disease and the associated behavioural complications, albeit the identity of MPTP-associated striatal CD45R infiltrate needs to be further characterized.

Luteolin-Supplemented diets ameliorates Bisphenol A-Induced toxicity in Drosophila melanogaster

Bisphenol A (BPA) is an industrial chemical used in the production of various plastic materials. It is associated with reproductive, immunological and neurological disorders. Luteolin, a flavonoid found in fruits and vegetables, possesses anti-oxidative, anti-inflammatory and free radical scavenging properties. Here, we carried out studies to ascertain if Luteolin would ameliorate BPA-induced toxicity in Drosophila melanogaster. Firstly, flies were treated separately with Luteolin (0, 50, 100, 150 and 300 mg/kg diet) and BPA (0, 0.01, 0.05 and 0.1 mM) for 28 days survival assessments. Consequently, Luteolin (150 and 300 mg/kg diet) and/or BPA (0.05 mM) were exposed to D. melanogaster for 7 days for the evaluation of nitric oxide level, eclosion rate, viability assay, histology of fat body, antioxidant (Glutathione-S-transferase, catalase and total thiol), oxidative stress (hydrogen peroxide) and behavioural (negative geotaxis and acetylcholinesterase) markers. The results showed that BPA induced antioxidant-oxidative stress imbalance and behavioural deficit in flies. Luteolin increased survival rate and augmented antioxidant markers in flies. Importantly, Luteolin ameliorated BPA-induced degeneration in the fat body around the rostral, thorax and abdominal regions, oxidative stress, behavioural deficit, reduction in cell viability and eclosion rate of D. melanogaster (p < 0.05). Overall, this study offered further insights on the antioxidative and chemopreventive properties of Luteolin against BPA-induced toxicity.

Curcumin attenuates copper-induced oxidative stress and neurotoxicity in Drosophila melanogaster

Curcumin is a hydrophobic polyphenol derived from the rhizome of the Herb Curcuma longa belonging to the family Zingiberaceae. Curcumin possesses antioxidative, anti-inflammatory and anti-depressant-like properties. In this study, we evaluated the rescue role of Curcumin in Copper²⁺-induced toxicity in D. melanogaster. Adult, wild type flies were exposed to Cu²⁺ (1 mM) and/or Curcumin (0.2 and 0.5 mg/kg diet) in the diet for 7 days. The results indicated that Cu²⁺- fed flies had reduced survival compared to the control group. Copper toxicity was also associated with a marked decrease in total thiol (T-SH), as well as catalase and glutathione S-transferase activities, contemporaneous with increased acetylcholinesterase (AChE) activity, nitric oxide (nitrate and nitrite) and dopamine levels. Co-exposure of flies to Cu²⁺ and Curcumin prevented mortality, inhibited AChE activity and restored dopamine to normal levels (p < 0.05). Moreover, Curcumin restored eclosion rates, and the cellular antioxidant status, as well as alleviated the accumulation of nitric oxide level in the flies. Curcumin ameliorated oxidative damage in the flies as evidenced by the survival rates, longevity assay as well as the restoration of antioxidant status. Our findings thus suggest that Curcumin ameliorated Cu²⁺-induced neurotoxicity in D. melanogaster and as such could be considered an effective therapeutic agent in the prevention and treatment of disorders, where oxidative stress is implicated.

Ameliorative effect of quercetin, catechin, and taxifolin on rotenone-induced testicular and splenic weight gain and oxidative stress in rats

Background The physiological functions of the testis and spleen can be affected through several cellular and molecular mechanisms such as the generation of reactive oxygen species (ROS) that causes oxidative stress. This study aimed at investigating the protective effect of catechin, quercetin, and taxifolin in rotenone-induced testicular and splenetic toxicity. Methods Male Wistar rats were administered with 1.5 mg/kg rotenone (s.c.) for 10 days followed by post-treatment with catechin (5, 10, or 20 mg/kg), quercetin (5, 10, or 20 mg/kg), and taxifolin (0.25, 0.5, or 1.0 mg/kg) for 3 days (s.c.), followed by estimation of biochemical markers of oxidative stress, inflammatory activities, and tissue damage in testes and spleen. Results Exposure of rats to rotenone caused reduced body weight gain, increased organ weight, decreased glutathione level and activities of glutathione transferase and superoxide dismutase, enhanced lipid peroxidation, and increased activities of prooxidant/proinflammatory enzymes and lactate dehydrogenase, which were mitigated by post-treatment with flavonoids. In general, quercetin and taxifolin showed better activity than catechin. Conclusions Catechin, quercetin, and taxifolin ameliorated rotenone-induced weight disturbances and oxidative damage in rats, indicating their potential relevance in toxicant and pesticide-induced tissue injury.

Protective role of resveratrol, a natural polyphenol, in sodium fluoride-induced toxicity in Drosophila melanogaster

Sodium fluoride (NaF) is used in water fluoridation and dental products such as mouth rinses and toothpastes. Resveratrol is a natural polyphenol with antioxidant and anti-inflammatory properties. The present study was carried out to evaluate the toxicity of NaF and the protective role of resveratrol in Drosophila melanogaster. For longevity assay, Harwich strain of D. melanogaster was treated with NaF (0, 10, 30, 50, 70 and 90 mg/kg diet) throughout the lifespan and daily mortality recorded. Then, flies were again treated with similar doses of NaF for seven days to evaluate survival rate and oxidative stress markers. Thereafter, 60 mg resveratrol/kg diet was selected to determine its ameliorative role in NaF (70 mg/kg)-induced toxicity in flies: Group A (control), Group B (60 mg resveratrol/kg diet), Group C (70 mg NaF/kg diet), and Group D (resveratrol, 60 mg/kg diet) + NaF, 70 mg/kg diet). Thereafter, Glutathione-S-transferase (GST), catalase and acetylcholinesterase (AchE) activities, as well as total thiol (T-SH), nitrites/nitrates and hydrogen peroxide (H2O2) levels were determined. The results showed that resveratrol prevented NaF-induced elevation of H2O2and nitrites/nitrates levels, as well as catalase activity. In addition, resveratrol restored NaF-induced inhibition of GST and AChE activities and depletion of T-SH content ( P < 0.05). Conclusively, resveratrol offered protective benefit against NaF-mediated toxicity in flies due to its antioxidant and anti-inflammatory properties.

Impact statement

D. melanogaster was used to understand the impact of NaF on lifespan and emergence rate as well as the rescue role of resveratrol. These parameters are difficult to carry out in previously used models such as rodents. This further enforces in part, the suitability of D. melanogaster in studying NaF-induced toxicity and the therapeutic effects of drugs. Additionally, we found that resveratrol rescued D. melanogaster from oxidative stress-induced by sodium fluoride (NaF) administration. This study is of public health significance as it indicated that the consumption of fruits rich in resveratrol such as grapes may offer protective role against inadvertent exposure to NaF and related chemicals.

Effects of chlorantraniliprole exposure on detoxification enzyme activities and detoxification-related gene expression in the fat body of the silkworm, Bombyx mori

Chlorantraniliprole (CAP) can induce excessive calcium release from muscle of insects, causing muscle paralysis until death, and its residues in farmland can cause poisoning in Bombyx mori (B. mori), resulting in the failure of cocooning. No reports have investigated the effects of CAP exposure on detoxification enzyme activities and detoxification-related gene expression in B. mori. In the present study, we treated mulberry leaves with CAP by the leaf-dipping method, and then B. mori larvae were continuously fed with the polluted mulberry leaves. Moreover, the detoxification enzyme activities and the expressions of detoxification-related genes in the fat body of B. mori were examined. The results showed that at 24 h after CAP exposure, the activities of P450 and GST enzymes were all significantly increased, with P450 enzymes responding fastest. CarE enzyme activity was up-regulated in 24 h, and then it was decreased compared with the control group. Furthermore, the expressions of the key genes in the PI3K/Akt/CncC signaling pathway (PI3K, PDK, Akt, CncC and Keap1) at the mRNA were significantly increased. Western blotting analysis revealed that Akt was inhibited at the protein level, resulting in decreased expression of Keap1 and increased expression of CncC. These results indicated that the PI3K/Akt/CncC signaling pathway in the fat body of B. mori responded to CAP exposure and regulated the expressions of downstream detoxification enzymes, thus enhancing the detoxifying capability of B. mori.

Cuprizone toxicity and Garcinia kola biflavonoid complex activity on hippocampal morphology and neurobehaviour

Cuprizone-induced neurotoxicity has been employed to study the biology of remyelination in experimental models of multiple sclerosis. This study was aimed at determining the role of kolaviron, a biflavonoid from Garcinia kola, in mitigating the damaging effects of cuprizone on behaviour and the hippocampus. Twenty-four male albino mice aged 6–8 weeks were categorised into 4 equal groups: Group A (Control) received regular diet; Group B received 200 mg/kg/d of kolaviron in addition to their regular diet; Group C received 0.2% cuprizone diet only, while Group D received both kolaviron and cuprizone diet. The treatment lasted for 35 days after which behavioural tests (Morris water maze, Y maze and open field tests) were conducted and brain tissues were processed for histology, histochemistry (Nissl staining), immunohistochemistry (glial fibrillary acidic protein) and biochemistry (malondialdehyde, superoxide dismutase and glutathione peroxidase). Results showed that cuprizone toxicity led to weight loss, impairment in memory and exploratory drive, oxidative stress, chromatolysis and reactive astrocytosis; meanwhile administration of kolaviron prevented cuprizone-induced weight loss, memory decline, oxidative stress and neuromorphological alterations. In conclusion, administration of kolaviron might be useful in limiting the effects of cuprizone toxicity on the morphology and functions of the hippocampus.

Possible involvement of transcriptional activation of nuclear factor erythroid 2-related factor 2 (Nrf2) in the protective effect of caffeic acid on paraquat-induced oxidative damage in Drosophila melanogaster

Paraquat (PQ) is a widely used herbicide with no antidote which is implicated in the pathogenesis of the Parkinson's disease. The present study then investigated the potential of caffeic acid (CA), a known antioxidant, cardioprotective and neuroprotective molecule to counteract oxidative stress mediated by PQ. In addition, molecular docking was performed to understand the mechanism underlying the inhibitory effect of CA against PQ poisoning. The fruit fly, Drosophila melanogaster, was exposed to PQ (0.44 mg/g of diet) in the absence or presence of CA (0.25, 0.5, 1 and 2 mg/g of died) for 7 days. Data showed that PQ-fed flies had higher incidence of mortality which was associated with mitochondrial dysfunction, increased free Fe(II) content and lipid peroxidation when compared to the control. Co-exposure with CA reduced mortality and markedly attenuated biochemical changes induced by PQ. The mechanism investigated using molecular docking revealed a strong interaction (-6.2 Kcal/mol) of CA with D. melanogaster transcriptional activation of nuclear factor erythroid 2-related factor 2 (Nrf2). This was characterized by the binding of CA to keap-1 domain of Nrf2. Taking together these results indicate the protective effect of CA against PQ-induced oxidative damage in D. melanogaster was likely through its coordination which hinders Nrf2-keap-1 binding leading to an increase of the antioxidant defense system.

Neuroprotective role of kolaviron in striatal redo-inflammation associated with rotenone model of Parkinson's disease

Parkinson's disease is the most prevalent movement disorder. Currently, therapies are palliative with associated irreversible behavioural incompetence. Here, we investigated the ability of kolaviron (KV), an anti-inflammatory biflavonoid isolated form Garcinia kola seeds, to rescue striatal neuronal damage and redo-inflammation in rats exposed to rotenone (ROT). Aged rats exposed to 11 days of rotenone intoxication were treated with KV either concurrently or for 18 days. The 18-day regimen included 7 days of pre-treatment prior 11-day concurrent ROT-KV treatment. Rotenone-exposed rats lost weight appreciably and travelled less distance with reduced speed, decline efficiency to maintain a straight path, enhanced freezing, increased immobile episodes and poor hole recognition. The motor incompetence was attributed to enhanced striatal neurodegeneration, increased alpha synuclein formation and reduced tyrosine hydroxylase expression. ROT intoxication significantly increased reactive species production, which co-existed with induction of striatal antioxidant system and damage to biomolecules. ROT additionally upregulated COX-2 expression, enhanced myeloperoxidase activity and increased concentration of striatal inteleukine-6 (IL-6), IL-1β and tumour necrosis factor (TNF-α). Treatment with kolaviron reversed the rotenone-associated locomotor impairment and exploratory deficits, motor/neuromuscular incompetence, striatal neurodegeneration, neurobiochemical imbalance, altered antioxidant defence system and neuroinflammation. KV-treated rats showed improved capacity to maintain efficient gait with minimal rigidity and enhanced coordination. Taken together, kolaviron exhibited neuroprotective properties, which may be beneficial for the prevention and management of Parkinson's disease, via antioxidant, anti-inflammatory and anti-apoptotic mechanisms.

Medicinal Potential, Utilization and Domestication Status of Bitter Kola (Garcinia kola Heckel) in West and Central Africa

Garcinia kola Heckel (Clusiaceae), known as bitter kola, is a multipurpose tree indigenous to West and Central Africa. This highly preferred species is called “wonder plant” because all of its parts can be used as medicine. Its seeds, the most valued product of the tree, are commonly eaten to prevent/cure gastric disorders and for their typical astringent taste. There is a vast evidence that bioactive components of the seeds can serve as alternative medicine to treat/prevent severe illnesses such as malaria, hepatitis and immune-destructive diseases. Despite the species’ pharmaceutical potential and its high preference by West and Central African communities, G. kola is still at the beginning of its domestication process. Even though, there are numerous scientific articles published on species‘ biological activities, it is a difficult task to find basic information on its diversity, distribution, genetics, silvicultural management or botany. Therefore, in this very first review published on G. kola, we summarize all relevant information known about the species, target some of the challenges connected with its cultivation and propose a leading direction for future research and domestication process.

Effect of Alkaloid Extract from African Jointfir (Gnetum africanum) Leaves on Manganese-Induced Toxicity in Drosophila melanogaster

Metal-induced toxicity in fruit fly (Drosophila melanogaster) is one of the established models for studying neurotoxicity and neurodegenerative diseases. Phytochemicals, especially alkaloids, have been reported to exhibit neuroprotection. Here, we assessed the protective effect of alkaloid extract from African Jointfir (Gnetum africanum) leaf on manganese- (Mn-) induced toxicity in wild type fruit fly. Flies were exposed to 10 mM Mn, the alkaloid extract and cotreatment of Mn plus extract, respectively. The survival rate and locomotor performance of the flies were assessed 5 days posttreatment, at which point the flies were homogenized and assayed for acetylcholinesterase (AChE) activity, nitric oxide (NO), and reactive oxygen species (ROS) levels. Results showed that the extract significantly reverted Mn-induced reduction in the survival rate and locomotor performance of the flies. Furthermore, the extract counteracted the Mn-induced elevation in AChE activity, NO, and ROS levels. The alkaloid extract of the African Jointfir leaf may hence be a source of useful phytochemicals for the development of novel therapies for the management of neurodegeneration.