Evaluation of anti-amnesic effect of extracts of selected Ocimum species using in-vitro and in-vivo models

Dose-Dependent Attenuation of the Efficacy of Clitoria ternatea by Cobalt Oxide Nanoparticles Against Diabetes-Induced Cognitive Impairment

Diabetes mellitus is a metabolic disorder caused by insulin deficiency, insulin resistance, genetic alterations, and oxidative stress. The high glucose levels may impair the functioning of nerve cells, leading to neurodegenerative diseases, including cognitive impairment. Clitoria ternatea has various pharmacological activities, including antioxidant, anti-inflammatory, antidiabetic, and neuroprotective effects. The present study evaluates the efficacy of fresh flower aqueous extract of Clitoria ternatea against diabetes-induced cognitive impairment. The challenges in delivering drugs targeting the brain possess the limitations of crossing the blood-brain barrier. Metal nanoparticles are considered the most reliable brain drug delivery systems. Considering the neurotoxicity of cobalt oxide, whether it can be used to improve brain delivery is also evaluated. Cobalt oxide nanoparticles (Co3O4 NPs) of fresh flower aqueous extract of Clitoria ternatea are prepared by green synthesis and characterized. The effect of these nanoparticles is compared with Clitoria ternatea extract against Streptozotocin (STZ)-induced cognitive impairment. The behavioral, biochemical, in vivo antioxidant, total thiol content, estimation of proinflammatory cytokines, acetylcholine esterase, and nitrite levels in the brain of STZ-induced diabetic rats revealed that cobalt oxide nanoparticles showed neurotoxicity, whereas C. ternatea showed neuroprotective effect and also improved the cognitive function. The lower dose of cobalt oxide nanoparticles of C. ternatea (2 mg/kg) exhibited a neuroprotective and cognition improvement effect. However, the higher dose (4 mg/kg) of cobalt oxide nanoparticles of C. ternatea showed a neurotoxic effect. Since Co3O4 NPs are neuroprotective at low doses, they can be used for neuroprotective actions. However, dose optimization studies are required.

5,7-dihydroxy-3',4',5'-trimethoxyflavone mitigates lead induced neurotoxicity in rats via its chelating, antioxidant, anti-inflammatory and monoaminergic properties

Chronic exposure to lead (Pb) induces neurodegenerative changes in animals and humans. Drugs with strong antioxidant properties are effective against Pb-mediated neurotoxicity. In a prior study, we identified 5,7-dihydroxy-3',4',5'-trimethoxyflavone (TMF) from Ocimum basilicum L. leaves as a potent antioxidant and neuroprotective compound. This research explores TMF's neuroprotective effects against Pb-induced brain toxicity in rats to establish it as a therapeutic agent. Rats received lead acetate (100 mg/kg, orally, once daily) for 30 days to induce brain injury, followed by TMF treatment (5 and 10 mg/kg, oral, once daily) 30 min later. Cognitive and motor functions were assessed using Morris Water Maze and horizontal bar tests. Lead, monoamine oxidase (MAO) A and B enzymes, reduced glutathione (GSH), thiobarbituric acid reactive species (TBARS), Tumor necrosis factor-alpha (TNF-α), and IL-6 levels were measured in the hippocampus and cerebellum. Pb exposure impaired cognitive and motor functions, increased Pb, TBARS, TNF-α, and IL-6 levels, and compromised MAO A & B and GSH levels. TMF reversed Pb-induced memory and motor deficits and normalized biochemical anomalies. TMF's neuroprotective effects against lead involve chelating, antioxidant, anti-inflammatory, and monoaminergic properties, suggesting its potential as a treatment for metal-induced brain injury.

Effects of Ocimum basilicum L. Extract on Hippocampal Oxidative Stress, Inflammation, and BDNF Expression in Amnesic Aged Rats

The present study was conducted to investigate the effects of Ocimum basilicum L. (OB) extract on learning and memory impairment in aged rats. Male rats were divided into the following experimental groups: Group 1 (control): including 2 months old rats, Group 2 (aged) including 2 years old rats, Groups 3-5 (aged-OB): including 2 years old rats received 50, 100, and 150 mg/kg OB for 8 weeks by oral gavage. Aging increased the delay to find the platform but, however, decreased the time spent in the target quadrant when tested by Morris water maze (MWM). Aging also reduced the latency to enter the dark chamber in the passive avoidance (PA) test compared to the control group. Moreover, interleukin-6 (IL-6) and malondialdehyde (MDA) levels were raised in the hippocampus and cortex of aged rats. In contrast, thiol levels and enzymatic activity of superoxide dismutase (SOD) and catalase (CAT) significantly reduced. In addition, aging significantly reduced BDNF expression. Finally, OB administration reversed the mentioned effects. The current research showed that OB administration improves learning/memory impairment induced by aging. It also found that this plant extract protects the brain tissues from oxidative damage and neuroinflammation.

The effect of rosemary hydroalcoholic extract on cognitive function and activities of daily living of patients with chronic obstructive pulmonary disease (COPD): A clinical trial

BACKGROUND

In patients living with chronic obstructive pulmonary disease (COPD), cognitive impairment and reduced activities of daily living (ADLs) are associated with poor clinical outcomes.

AIM

The aim of the present study was to determine the effect of rosemary hydroalcoholic extract on cognitive function and ADLs in patients with COPD.

METHODS

A total of 77 COPD patients aged 40-80 years were assigned to two intervention and control groups by random stratified block method in the current tripleblind clinical trial. The intervention group received 500 mg rosemary capsules and the control group received oral capsules containing corn powder twice a day, one to two hours before breakfast and dinner, for two months. The Montreal Cognitive Assessment-Basic (MoCA-B), London Chest Activity of Daily Living scale (LCADL) and Lawton Instrumental Activities of Daily Living (IADL) were used to measure cognitive function and the measure of basic and instrumental daily life activities, before and after the intervention, respectively.

RESULTS

The mean total score of cognitive function (P = 0.022) and the two subscales of abstraction (P = 0.003) and naming (P = 0.034) significantly increased after the intervention in the intervention group. There was no significant difference between the intervention and control groups in terms of changes in the mean scores of IADL and LCADL (P < 0.05). The final statistical model showed that the changes in the total mean score of cognitive function (P = 0.014) and IADL (P = 0.047) in intervention group patients are significantly higher than in the control group after adjusting the effect of obstructive sleep apnea (OSA).

CONCLUSION

The rosemary hydroalcoholic extract can be effective in improving cognitive function and IADL in patients with COPD, but not LCADL.

CLINICAL TRIALS REGISTRATION NUMBER

IRCT20150919024080N16.

N-methylpiperazinyl and piperdinylalkyl-O-chalcone derivatives as potential polyfunctional agents against Alzheimer's disease: Design, synthesis and biological evaluation

The series of N-methylpiperazinyl and piperdinylalkyl-O-chalcone derivatives as potential polyfuctional agents against Alzheimer's disease that have been designed, synthesized and then evaluated biologically using in vitro assays for the inhibition of acetylcholinesterase (AChE) activity, AGEs, and free radical formation. The majority of synthesized compounds inhibited AChE & AGEs with additional free radical scavenging activities at nanomolar concentrations. Among these, compound 5k was found to have potent AChE inhibitory activity (IC50  = 11.6 nM), superior than the reference compound donepezil (15.68 nM) along with the good anti-AGEs and free radical formation effect. Its potency was justified by docking studies that revealed its dual binding characteristic with both catalytic active site and peripheral anionic site of AChE, simultaneously. Furthermore, the in vivo evaluation of 5k against streptozotocin (STZ)-induced dementia in rats also showed improvement of memory functions (Morris water maze test) in animals. Also, 5k inhibited STZ-inudced brain AChE activity and oxidative stress which further strengthen the observed in vitro effects. The stability of the ligand-protein complex was then analyzed using a simulation-based interaction protocol. The results revealed that these N-methylpiperazinyl and piperdinylalkyl-O-chalcone derivatives could be considered for potential polyfunctional anti-Alzheimer's molecules.

Hepatoprotective effects of bioactive compounds from traditional herb Tulsi (Ocimum sanctum Linn) against galactosamine-induced hepatotoxicity in rats

Ocimum sanctum L. (Tulsi; Family: libiaceae), also known as "The Queen of herbs" or "Holy Basil," is an omnipresent, multipurpose plant that has been used in folk medicine of many countries as a remedy against several pathological conditions, including anticancer, antidiabetic, cardio-protective, antispasmodic, diaphoretic, and adaptogenic actions. This study aims to assess O. sanctum L.'s hepatoprotective potential against galactosamine-induced toxicity, as well as investigate bioactive compounds in each extract and identify serum metabolites. The extraction of O. sanctum L as per Ayurveda was simultaneously standardized and quantified for biochemical markers: rutin, ellagic acid, kaempferol, caffeic acid, quercetin, and epicatechin by HPTLC. Hepatotoxicity was induced albino adult rats by intra-peritoneal injection of galactosamine (400 mg/kg). The quantified hydroalcoholic and alcoholic extract of O. sanctum L (100 and 200 mg/kg body weight/day) were compared for evaluation of hepatoprotective potential, which were assessed in terms of reduction in histological damage, change in serum enzymes such as AST, ALT, ALP and increase TBARS. Twenty chemical constituents of serum metabolites of O. sanctum were identified and characterized based on matching recorded mass spectra by GC-MS with those obtained from the library-Wiley/NIST. We evaluated the hepatoprotective activity of various fractions of hydroalcoholic extracts based on the polarity and investigated the activity at each phase (hexane, chloroform, and ethyl acetate) in vitro to determine how they affected the toxicity of CCL4 (40 mM) toward Chang liver cells. The ethyl acetate fraction of the selected plants had a higher hepatoprotective activity than the other fractions, so it was used in vacuum liquid chromatography (VLC). The ethyl acetate fraction contains high amounts of rutin (0.34% w/w), ellagic acid (2.32% w/w), kaempferol (0.017% w/w), caffeic acid (0.005% w/w), quercetin (0.038% w/w), and epicatechin (0.057% w/w) which are responsible for hepatoprotection. In comparison to standard silymarin, isolated bioactive molecules displayed the most significant hepatoprotective activity in Chang liver cells treated to CCl4 toxicity. The significant high hepatoprotection provided by standard silymarin ranged from 77.6% at 100 μg/ml to 83.95% at 200 μg/ml, purified ellagic acid ranged from 70% at 100 μg/ml to 81.33% at 200 μg/ml, purified rutin ranged from 63.4% at 100 μg/ml to 76.34% at 200 μg/ml purified quercetin ranged from 54.33% at 100 μg/ml to 60.64% at 200 μg/ml, purified epicatechin ranged from 53.22% at 100 μg/ml to 65.6% at 200 μg/ml, and purified kaempferol ranged from 52.17% at 100 μg/ml to 60.34% at 200 μg/ml. These findings suggest that the bioactive compounds in O. sanctum L. have significant protective effects against galactosamine-induced hepatotoxicity.

Bioprospecting of Five Ocimum sp. Cultivars from Croatia: New Potential for Dietary and Dermatological Application with Embryotoxicity Tests

Ocimum basilicum L. is the most common Ocimum species, and it is used as an ornamental plant and in food condiments. This unique study examined the chemical composition and biological activities of six extracts from five basil cultivars, including their antimicrobial, antidiabetic, antilipidemic, neuroprotective, and anticollagenase activity. Moreover, their toxicological effects were studied using the zebrafish Danio rerio. Volatile components were determined using HS-SPME and GC-MS, while total polyphenols were detected using HPLC and the spectrophotometric Folin-Ciocalteu method. Spectrophotometric assays (DPPH, ABTS, ORAC, FRAP) were performed to determine antioxidant activity, collagenase inhibition, acetylcholinesterase inhibition, and pancreatic lipase inhibition. Antimicrobial activity was determined using the broth microdilution test. The study found that the biological activities of different basil cultivars varied depending on the proportion of active compounds, as determined by chemical analyses. All six basil extracts significantly inhibited α-amylase, while Purple basil extract most significantly inhibited the activity of collagenase, acetylcholinesterase, and pancreatic lipase. Purple basil and Dark Opal basil I extracts exhibited the highest antimicrobial activity, while the Dark Opal basil II extract had the most significant antioxidant potential. The findings in this study suggest that ethanolic basil extracts have the potential to be used as dietary drugs and implemented in antiaging products. This study is unique in its aims to compare the chemical composition and biological activities of basil cultivars from Croatia and to evaluate potential toxicological effects through embryotoxicity tests on zebrafish Danio rerio embryos, and it reports the first evidence of anticollagenase, antidiabetic, and antilipidemic activities for these cultivars.

Exploring the Chemistry of Ocimum Species under Specific Extractions and Chromatographic Methods: A Systematic Review

Ocimum is considered the largest genus in the Lamiacea family. The genus includes basil, a group of aromatic plants with a wide range of culinary uses that nowadays draws attention for its medicinal and pharmaceutical potential. This systematic review intends to explore the chemical composition of nonessential oils and their variation across different Ocimum species. Moreover, we aimed to identify the state of knowledge regarding the molecular space in this genus as well as the different methods of extraction/identification and geographical location. Seventy-nine eligible articles were selected for the final analysis, from which we extracted more than 300 molecules. We found that the countries with the highest number of studies into Ocimum species are India, Nigeria, Brazil, and Egypt. However, from all known species of Ocimum, only 12 were found to have an extensive chemical characterization, particularly Ocimum basilicum and Ocimum tenuiflorum. Our study focused especially on alcoholic, hydroalcoholic, and water extracts, in which the main techniques for compound identifications are GC-MS, LC-MS, and LC-UV. Across the compiled molecules, we found a wide variety of compounds, especially flavonoids, phenolic acids, and terpenoids, suggesting that this genus could be a very useful source of possible bioactive compounds. The information collected in this review also emphasizes the huge gap between the vast number of Ocimum species discovered and the number of studies in each of them that determined the chemical characterization.

Morus alba fruit diet ameliorates cognitive deficit in mouse model of streptozotocin-induced memory impairment

Mounting evidence shows that dietary intake of fruits with polyphenols is beneficial to improve impaired memory functions. This study explored the preventive as well as therapeutic effects of diet enriched with Morus alba fruits extract (DEMA) in streptozotocin (STZ) induced mouse model of memory impairment. The study consisted of two facets: one aspect consisted of pretreatment of animals with DEMA for two weeks followed by STZ (i.c.v) intervention and the second phase involved induction of dementia with STZ (i.c.v) followed by treatment with DEMA for 14 days. Cognitive functions of animals were measured by Morris Water Maze test and to delineate the associated mechanism of action, brain biochemical estimations (acetyl-cholinesterase activity, myeloperoxidase activity, thiobarbituric acid reactive species, superoxide dismutase activity, reduced glutathione and nitrite/nitrate) and histopathological studies (haematoxylin and eosin staining) were performed. Pre- and post- treatment with DEMA significantly prevented and attenuated, respectively, the detrimental effects of STZ on mice brain. The results demonstrated that dietary modification, by incorporation of M. alba fruits, reduces the incidence and aids in treatment of memory disorder in mice by reducing central cholinergic activity, decreasing oxidative stress and preventing neurodegeneration.

Trimethoxyflavones from Ocimum basilicum L. leaves improve long term memory in mice by modulating multiple pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Traditionally, Ocimum basilicum L. leaves (OB) are recommended for various brain disorders.

AIM OF THE STUDY

Scientific evidence highlights the cognition improvement capacity of Ocimum basilicum L. leave extract (OBE), however, the compound(s) responsible for this effect and the associated mechanism was not reported. The present study was, thus, designed to isolate and identify the compound responsible for memory improvement effects of OB and to delineate the associated mechanism of action.

MATERIALS AND METHODS

In-vitro acetylcholinesterase (AChE) inhibitory (Ellman method) and antioxidant (DPPH scavenging) assays guided fractionation was employed to isolate the bioactive compounds from OBE. The isolated compounds were characterised using spectroscopic techniques (FTIR, NMR and MS). In-silico and in-vivo [mouse model of scopolamine (SCOP) induced amnesia] investigations were used to substantiate the memory improvement effects of isolated compounds and to understand their mechanism of action.

RESULTS

AChE and DPPH assays guided fractionation of OBE lead to isolation of two pure compounds namely, 5,7-dihydroxy-3',4',5'-trimethoxyflavone (S1) and 3-hydroxy-3',4',5'-trimethoxyflavone (S2). Both S1 and S2 mitigated the cognitive impairment due to SCOP in mice by reducing brain AChE activity, TBARS, TNF-α, IL-1β, IL-6 and caspase-3 concentrations and elevating reduced glutathione and IL-10 levels; together with amelioration of brain hippocampus histopathological aberration (H and E staining). Moreover, the molecular docking of S1 and S2 at the active pockets of AChE and caspase-3 has shown good interactions with vital amino acid residues.

CONCLUSIONS

Our findings show that trimethoxy flavones are responsible for the memory improvement effect of OBE due to their anticholinergic, antioxidant, anti-inflammatory and anti-apoptotic properties. These maybe developed as valuable alternatives for management of cognitive disorders.

Acetylcholinesterase inhibition and antioxidant activity properties of Petiveria alliacea L

ETHNOPHARMACOLOGICAL RELEVANCE

Petiveria alliacea L. is traditionally used as a folk medical herb in different regions of the world to treat different ailments including those related to the central nervous system. Previous studies have proved that extracts from P. alliacea show improvement in memory and learning process.

AIM OF THE STUDY

To study extracts, fractions, subfractions and isolated compounds from P. alliacea on acetylcholinesterase inhibition and antioxidant activity.

MATERIAL AND METHODS

Extracts obtained with different polarity solvents and fractions from P. alliacea were evaluated for their inhibitory activity on acetylcholinesterase by Ellman method. This screening allowed the selection of the methanol fraction as the most active and continued a bio-guided study. The compounds identified in methanol fraction were analyzed by high performance liquid chromatography-mass spectrometry (HPLC-MS). Identification of (E)-Tagetone was performed by ¹H and ¹³C NMR spectra. Moreover, the antioxidant activity was evaluated by DPPH and ABTS methods, and the cell viability was assessed by WST-1 method.

RESULTS

Two extracts of different polarity were obtained from P. alliacea. The methanol extract and its fraction showed an inhibitory activity on acetylcholinesterase; however, methanol fraction was found to be most potent with 86.5 % AChE inhibition. The methanol fraction also showed antioxidant activity and was not toxic on SH-SY5Y cells. Different compounds including capreoside, narcissin, indane, (-)-isocaryophyllene, (-)-β-pinene, (E)-tagetone and peonidin 3-O-sambubioside 5-O-glucoside were identified.

CONCLUSION

This is the first report indicating that P. alliacea methanol fraction and its subfractions bear acetylcholinesterase inhibition and antioxidant activity properties. This work establishes the basis for further studies in the development of new therapies for neurodegenerative disorders such as Alzheimer 's disease.

Isolation, characterization and biological activities of betulin from Acacia nilotica bark

Medicinal plants are in use of humankind since ancient and still they are playing an important role in effective and safer natural drug delivery systems. Acacia nilotica (native of Egypt) commonly known as babul belongs to family Fabaceae, widely spread in India, Sri Lanka and Sudan. Being a common and important plant, using in many ways from fodder (shoots and leaves to animals) to dyeing (leather coloration) to medicine (root, bark, leaves, flower, gum, pods). The present study is focused on investigating the natural chemistry and important biological activities of the plant. Employing bioassay guided fractionation coupled with TLC and column chromatography, a pure fraction named AN-10 was isolated from ethyl acetate fraction of crude methanol extract which identified as "Betulin (Lupan-3ß,28-diol)" by Liebermann-Burchard test and structure elucidation by UV-Vis, NMR and MS techniques. A battery of in vitro biological assays for antioxidant, anti-inflammatory and anticancer were performed and betulin showed excellent potential in all assays. It was found that the inhibitory potential in all assays were dose dependent manner and after a range of concentration, the activities get leveled off with no further increase in activity.

Attenuation of Scopolamine-Induced Amnesia via Cholinergic Modulation in Mice by Synthetic Curcumin Analogs

Alzheimer’s disease is an emerging health disorder associated with cognitive decline and memory loss. In this study, six curcumin analogs (1a−1f) were synthesized and screened for in vitro cholinesterase inhibitory potential. On the basis of promising results, they were further investigated for in vivo analysis using elevated plus maze (EPM), Y-maze, and novel object recognition (NOR) behavioral models. The binding mode of the synthesized compounds with the active sites of cholinesterases, and the involvement of the cholinergic system in brain hippocampus was determined. The synthesized curcumin analog 1d (p < 0.001, n = 6), and 1c (p < 0.01, n = 6) showed promising results by decreasing retention time in EPM, significantly increasing % SAP in Y-maze, while significantly (p < 0.001) enhancing the % discrimination index (DI) and the time exploring the novel objects in NORT mice behavioral models. A molecular docking study using MOE software was used for validation of the inhibition of cholinesterase(s). It has been indicated from the current research work that the synthesized curcumin analogs enhanced memory functions in mice models and could be used as valuable therapeutic molecules against neurodegenerative disorders. To determine their exact mechanism of action, further studies are suggested.

Neuroprotective Potential of Synthetic Mono-Carbonyl Curcumin Analogs Assessed by Molecular Docking Studies

Cognitive decline in dementia is associated with deficiency of the cholinergic system. In this study, five mono-carbonyl curcumin analogs were synthesized, and on the basis of their promising in vitro anticholinesterase activities, they were further investigated for in vivo neuroprotective and memory enhancing effects in scopolamine-induced amnesia using elevated plus maze (EPM) and novel object recognition (NOR) behavioral mice models. The effects of the synthesized compounds on the cholinergic system involvement in the brain hippocampus and their binding mode in the active site of cholinesterases were also determined. Compound h2 (p < 0.001) and h3 (p < 0.001) significantly inhibited the cholinesterases and reversed the effects of scopolamine by significantly reducing TLT (p < 0.001) in EPM, while (p < 0.001) increased the time exploring the novel object. The % discrimination index (DI) was significantly increased (p < 0.001) in the novel object recognition test. The mechanism of cholinesterase inhibition was further validated through molecular docking study using MOE software. The results obtained from the in vitro, in vivo and ex vivo studies showed that the synthesized curcumin analogs exhibited significantly higher memory-enhancing potential, and h3 could be an effective neuroprotective agent. However, more study is suggested to explore its exact mechanism of action.

The neuroprotective attribution of Ocimum basilicum: a review on the prevention and management of neurodegenerative disorders

Background

Bioactive principles from various natural resources including medicinal herbs have always played a crucial role in healthcare settings and increasingly became key players in drug discovery and development for many biopharmaceutical applications. Additionally, natural products (NPs) have immense arrangement of distinctive chemical structures with diverse functional groups that motivated numerous investigators including synthetic chemists to discover new therapeutic entities. Numerous pre-clinical investigations involving the animal models have evident the usefulness of these NPs against various human diseases including neurodegenerative disorders (NDs).

Main text

Ocimum basilicum Linn (O. basilicum L.), also known as sweet basil, is well practiced in traditional healthcare systems and has been used to treat various human illnesses, which include malaria, skin disease, diarrhea, bronchitis, dysentery, arthritis, eye diseases, and insect bites and emphasize the significance of the ethno-botanical approach as a potential source of novel drug leads With the growing interest in advanced techniques, herbal medicine and medicinal plants explorations are still considered to be a novel resource for new pharmacotherapeutic discovery and development. O. basilicum L and its bioactive principles including apigenin, eugenol, myretenal, β-sitosterol, luteolin, rosmarinic acid, carnosic acid, essential oil (EO)-rich phenolic compounds, and others like anthocyanins and flavones could be of therapeutic values in NDs by exhibiting their neuro-protective efficacy on various signaling pathways. The present comprehensive review collected various related information using the following searching engines such as PubMed, Science Direct, Google Scholar, etc. and focused mainly the English written documents. The search period comprised of last two decades until present.

Conclusion

Although these efficacious plant genera of prime importance and has potential medical and socioeconomic importance, yet the pivotal evidence for its neuroprotective potential in novel clinical trials remains lacking. However, with the available wealth of obtainable literature on this medicinal plant, which supports this review and concludes that O. basilicum L may function as a promising therapeutics for the treatment of NDs.

Quercetin: A Bioactive Compound Imparting Cardiovascular and Neuroprotective Benefits: Scope for Exploring Fresh Produce, Their Wastes, and By-Products

Quercetin, a bioactive secondary metabolite, holds incredible importance in terms of bioactivities, which has been proved by in vivo and in vitro studies. The treatment of cardiovascular and neurological diseases by quercetin has been extensively investigated over the past decade. Quercetin is present naturally in appreciable amounts in fresh produce (fruits and vegetables). However, today, corresponding to the growing population and global demand for fresh fruits and vegetables, a paradigm shift and focus is laid towards exploring industrial food wastes and/or byproducts as a new resource to obtain bioactive compounds such as quercetin. Based on the available research reports over the last decade, quercetin has been suggested as a reliable therapeutic candidate for either treating or alleviating health issues, mainly those of cardiovascular and neurological diseases. In the present review, we have summarized some of the critical findings and hypotheses of quercetin from the available databases foreseeing its future use as a potential therapeutic agent to treat cardiovascular and neurological diseases. It is anticipated that this review will be a potential reference material for future research activities to be undertaken on quercetin obtained from fresh produce as well as their respective processing wastes/byproducts that rely on the circular concept.

Improvement of cognitive function in mice by Citrus reticulata var. kinnow via modulation of central cholinergic system and oxidative stress

Memory disorders are a result of a number of factors, of which elevated brain oxidative stress and acetylcholinesterase (AChE) activity are significant hallmarks. A number of Citrus species have cognition-enhancing capacity mediated by their antioxidant and anti-cholinesterase activities. This study was designed to assess the cognitive-enhancing, antioxidant and anticholinesterase potentials of Citrus reticulata var. kinnow (CR) leaf extracts. CR extracts were examined by bioactivity guided fractionation using in-vitro DPPH and Ellman assays to determine antioxidant and AChE inhibitory capacity. The most active component was further evaluated for memory improvement effects using mouse model of scopolamine induced amnesia. Passive shock avoidance test and elevated plus maze test were employed to determine cognitive functions while brain biochemical parameters were measured to establish the neuroprotective mechanism. The methanol extract (ME) showed marked AChE inhibitory and antioxidant activities, therefore, it was fractionated. Comparative analysis of all obtained fractions revealed that ethylacetate fraction (EAF) was most active. Both ME and EAF improved cognitive dysfunction caused by scopolamine in mice by reducing TBARS levels and brain AChE activity. TLC densitometric studies showed appreciable levels of naringenin in ME (0.32 % w/w) and EAF (1.14 % w/w). The observed memory enhancement effects of ME and EAF could be attributed to their ability to inhibit AChE activity and antioxidant effects due to presence of flavonoids.

In Vitro Antioxidant Activities of the Aqueous and Methanolic Stem Bark Extracts of Piliostigma thonningii (Schum.)

Oxidative stress has been recognized as a key driver of many ailments affecting humankind. Free radicals attack biologically important biomolecules, impairing their functioning, thereby initiating and exacerbating diseases. As a comeback, antioxidant therapies have been proposed as novel approaches to ameliorating oxidative stress-associated diseases including chronic ones. Antioxidants are thought to employ multifaceted and multitargeted mechanisms that either restore oxidative homeostasis or prevent free radical buildup in the body, which overwhelm the endogenous defenses. Plants have been used for many ages across time to manage human diseases, and have a host of antioxidant phytocompounds. Piliostigma thonningii is traditionally used for the management of inflammation, malaria fever, rheumatism, and insanity, among other diseases caused by a disturbed redox state in the body. In this study, in vitro antioxidant activities of the methanolic and aqueous stem bark extracts of P. thonningii were evaluated using the in vitro antilipid peroxidation, the 1,1-diphenyl-2-picryhydrazyl (DPPH) free radical scavenging, and the ferric reducing antioxidant power assay methods. The obtained results revealed remarkable antioxidant activities of the studied plant extracts as evidenced by the low IC50 and EC50 values. These antioxidant activities could be due to the presence of antioxidant phytochemicals like flavonoids, carotenoids, tannins, and phenols, among others. Therefore, the therapeutic potency of this plant could be due to its antioxidant properties. This study recommends in vivo antioxidant efficacy testing of the studied plant extracts, as well as isolation and characterization of bioactive antioxidant compounds that are potent against oxidative stress.

Improvement of memory and neurological deficit with Ocimum basilicum L. extract after ischemia reperfusion induced cerebral injury in mice

Oxidative stress is strongly implicated in the pathogenesis of stroke. Strategies using antioxidants to improve neurological functions after stroke have, thus, gained significant attention. Ocimum basilicum L. is used traditionally to treat CNS disorders. Its antioxidant capacity is well established. Our laboratory has reported protective effects of pre-treatment with O. basilicum in experimental stroke, but its curative (post-treatment) effects in ischemic stroke have not been documented. Hence, the present study was aimed to evaluate the effect of O. basilicum leaf extract (OBLE) on functional outcomes following cerebral injury in mice. Cerebral injury was induced in the experimental animals by bilateral common carotid artery occlusion (BCCAO) followed by reperfusion. OBLE treatment (200 and 400 mg/kg; orally, once daily) was given for 7 days after BCCAO. Cognitive outcomes and sensorimotor disturbances were evaluated with Morris Water Maze, Elevated Plus Maze and neurological severity score, respectively. TTC (2,3,5-triphenyltetrazolium chloride) staining was used to measure cerebral infarct size. Thiobarbituric acid reactive substances, reduced glutathione levels and superoxide dismutase activity in mice brain homogenate were estimated to elucidate the neuroprotective mechanism of OBLE. Treatment with OBLE resulted in marked improvement in memory and motor coordination. OBLE also decreased cerebral infarct size and oxidative stress in mice. The extract was standardised with respect to total phenol content; an HPLC-PDA analysis showed the presence of eight phenolic acids in OBLE. It is concluded that treatment with OBLE improves functional outcomes after ischemic stroke and this may be developed as a neuroprotective drug.

Comparative Evaluation of Prosopis cineraria (L.) Druce and Its ZnO Nanoparticles on Scopolamine Induced Amnesia

Over recent years, utilization of green synthesized nanomaterials has been widely growing on human body because of its special properties. With the increasing acceptance of nanoparticle approach for various clinical treatments, the biosafety and toxicological effects on the vital organs such as central nervous system, have received more concern. Main focus of this study was to evaluate acute exposure of n-butanol fraction of Prosopis cineraria (L.) Druce hydroethanolic extract (BuPC) and green synthesized zinc oxide nanoparticles of BuPC (ZnOPC) on spatial cognition behavior, and to assess underlying mechanism by estimation of enzymatic antioxidative status along with acetylcholinesterase (AChE) activity in mice brain. Strongest in vitro antioxidant and AChE inhibitory activity exhibiting fraction, BuPC, was examined for inhibition kinetic study by Lineweaver-Burk and Dixon plots. BuPC was further used for fabrication ZnOPC and characterized by UV-visible spectroscopy, Fourier Transform Infrared (FTIR), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X ray (EDX), and Dynamic Light Scattering (DLS) analysis. Old male swiss albino mice were randomly divided into seven groups and treated for 21 days. Subsequently spatial memory was determined by two behavioral models [Elevated plus maze (EPM) and Hebbs William maze (HWM)] and supernatant of brain homogenate was analyzed for enzymatic antioxidant level and AChE inhibitory activity. Zinc content of blood plasma and brain was estimated. Results showed prolonged transfer latency (TL) and time taken to reach reward chamber (TRC) by scopolamine was not ameliorated by the ZnOPC group, whereas BuPC group showed significant reduction in scopolamine induced increase in TL and TRC compared to control and scopolamine treated groups. ZnOPC alleviated enzymatic antioxidant activity and AChE as compared to donepezil and BuPC treated groups. Study concludes that ZnOPC attenuated spatial learning and memory by increase in oxidative stress and decrease in AChE activity at both dose levels. Our results suggest that BuPC exhibited a strong neuroprotective effect on cognitive deficit mice and it may be employed as a strong substance for the treatment of dementia whereas the green synthesized ZnOPC was not proficient to reverse the memory impairment induced by scopolamine.

Beneficial Effect of Ocimum sanctum (Linn) against Monocrotaline-Induced Pulmonary Hypertension in Rats

Background: The study was designed to explore any beneficial effect of Ocimum sanctum (Linn) (OS) in experimental pulmonary hypertension (PH) in rats. OS is commonly known as “holy basil” and “Tulsi” and is used in the Indian System of Medicine as antidiabetic, antioxidant, hepatoprotective, adaptogenic, and cardioprotective. Methods: Monocrotaline (MCT) administration caused development of PH in rats after 28 days and rats were observed for 42 days. Treatments (sildenafil; 175 µg/kg, OS; 200 mg/kg) were started from day 29 after the development of PH and continued for 14 days. Parameters to assess the disease development and effectiveness of interventions were echocardiography, right and left ventricular systolic pressures, and right ventricular end diastolic pressure, percentage medial wall thickness (%MWT) of pulmonary artery, oxidative stress markers in lung tissue, NADPH oxidase (Nox-1) protein expression in lung, and mRNA expression of Bcl2 and Bax in right ventricular tissue. Results: OS (200 mg/kg) treatment ameliorated increased lung weight to body weight ratio, right ventricular hypertrophy, increased RVSP, and RVoTD/AoD ratio. Moreover, OS treatment decreases Nox-1 expression and increases expression of Bcl2/Bax ratio caused by MCT. Conclusion: The present study demonstrates that OS has therapeutic ability against MCT-induced PH in rat which are attributed to its antioxidant effect. The effect of OS was comparable with sildenafil.

Anti-amnesic effects of Ganoderma species: A possible cholinergic and antioxidant mechanism

Mushrooms are valued for their nutritional as well as medicinal properties. Ganoderma species are used traditionally to treat neurological disorders but scientific evidence for this is insufficient. The present study was designed to systematically evaluate the anti-amnesic effect of selected Ganoderma species i.e. G. mediosinense and G. ramosissimum. Extracts of selected mushroom species were evaluated for their antioxidant activity and acetylcholinesterase (AChE) inhibition using in-vitro assays (DPPH and Ellman tests respectively). The anti-amnesic potential of the most active extract (i.e. 70% methanol extract of G. mediosinense) was confirmed using mouse model of scopolamine-induced amnesia. Mice were treated with bioactive extract and donepezil once orally before the induction of amnesia. Cognitive functions were evaluated using passive shock avoidance (PSA) and novel object recognition (NOR) tests. The effect on brain AChE activity, brain oxidative stress (TBARS level) and neuronal damage (H & E staining) were also assessed. In-vitro results showed strong antioxidant and AChE inhibitory activities by G. mediosinense extract (GME). Therefore, it was selected for in-vivo studies. GME pre-treatment (800mg/kg, p.o.) reversed the effect of scopolamine in mice, evident by significant decrease (p <0.05) in the transfer latency time and increase in object recognition index in PSA and NOR, respectively. GME significantly reduced the brain AChE activity and oxidative stress. Histopathological examination of brain tissues showed decrease in vacuolated cytoplasm and increase in pyramidal cells in brain hippocampal and cortical regions. GME exerts anti-amnesic effect through AChE inhibition and antioxidant mechanisms.