Protective effects of total alkaloidal extract from Murraya koenigii leaves on experimentally induced dementia

Phyto-Carbazole Alkaloids from the Rutaceae Family as Potential Protective Agents against Neurodegenerative Diseases

Plant-derived (phyto) carbazole alkaloids are an important class of compounds, presented in the family of Rutaceae (Genera Murraya, Clausena, Glycosmis, Micromelum and Zanthoxylum). Due to several significant biological activities, such as antitumor, antibacterial, antiviral, antidiabetic, anti-HIV and neuroprotective activities of the parent skeleton (3-methylcarbazole), carbazole alkaloids are recognized as an important class of potential therapeutic agents. Neurodegenerative diseases (NDs) may exhibit a vast range of conditions, affecting neurons primarily and leading ultimately to the progressive losses of normal motor and cognitive functions. The main pathophysiological indicators of NDs comprise increasing atypical protein folding, oxidative stresses, mitochondrial dysfunctions, deranged neurotransmissions and neuronal losses. Phyto-carbazole alkaloids can be investigated for exerting multitarget approaches to ameliorating NDs. This review presents a comprehensive evaluation of the available scientific literature on the neuroprotective mechanisms of phyto-carbazole alkaloids from the Rutaceae family in ameliorating NDs.

Multi-Target Approach of Murraya koenigii Leaves in Treating Neurodegenerative Diseases

Neurodegenerative diseases (NDs) mainly affect neurons and gradually lead to a loss of normal motor and cognitive functions. Atypical protein homeostasis-misfolding, aggregations and accumulations, oxidative stress, inflammation, and apoptosis-are common features in most NDs. To date, due to the complex etiology and pathogenesis of NDs, no defined treatment is available. There has been increasing interest in plant extracts as potential alternative medicines as the presence of various active components may exert synergistic and multi-pharmacological effects. Murraya koenigii (Rutaceae) is utilized in Ayurvedic medicine for various ailments. Pharmacological studies evidenced its potential antioxidant, anti-inflammatory, anticancer, hepatoprotective, immunomodulatory, antimicrobial, and neuroprotective activities, among others. In line with our interest in exploring natural agents for the treatment of neurodegenerative diseases, this review presents an overview of literature concerning the mechanisms of action and the safety profile of significant bioactive components present in M. koenigii leaves to support further investigations into their neuroprotective therapeutic potential.

Mahanimbine Improved Aging-Related Memory Deficits in Mice through Enhanced Cholinergic Transmission and Suppressed Oxidative Stress, Amyloid Levels, and Neuroinflammation

Murraya koenigii leaves contain mahanimbine, a carbazole alkaloid, reported with improving cholinergic neuronal transmission and reducing neuroinflammation in the CNS. The current research investigated the effects of mahanimbine on age-related memory deficits, oxidative stress, cholinergic dysfunction, amyloid formation, and neuroinflammation in aged mice (16 months old). Mahanimbine was administered (1 and 2 mg/kg, p.o.) daily to groups of aged mice for 30 days. The Morris water maze (MWM) task was performed to study spatial learning (escape latency (EL) and swimming distance (SD)) and memory (probe test). The levels of malondialdehyde (MDA), glutathione (GSH), acetylcholine (ACh), acetylcholinesterase (AChE), β-amyloid (Aβ1-40 and Aβ1-42), β-secretase (BACE-1), as well as neuroinflammation markers (total cyclooxygenase (COX) and COX-2 expression), were measured from the isolated brain. Mahanimbine reduced the EL time and SD in the MWM test. From the probe trial, the mahanimbine-treated group spent more time in the targeted quadrant related to the age-matched control, which indicated the enhancement of memory retention. From the biochemical tests, the treatment decreased MDA, AChE, Aβ1-40, and Aβ1-42, BACE-1, total COX activity, and COX-2 expression. It also raised the brain GSH and ACh levels in aged mice compared to age-matched control. These results have supported the reversal of memory dysfunctions by mahanimbine in aged mice and hypothesized that it could be a potential target to treat age-related neurodegenerative disease.

Evaluation of nootropic activity of telmisartan and metformin on diazepam-induced cognitive dysfunction in mice through AMPK pathway and amelioration of hippocampal morphological alterations

Cognitive impairments such as dementia are considered the biggest challenges for public health. Benzodiazepines are often prescribed for treatment of anxiety disorder but they are associated with elevated risk of dementia. The present study has been designed to evaluate the neuroprotective effect of telmisartan and metformin on diazepam-induced cognitive dysfunction in mice. Piracetam was used as an established nootropic agent. Mice were divided into 8 groups, group1; control group which received normal saline. groups 2, 3 and 4 were received telmisartan 0.3 mg/kg/day, metformin 100 mg/kg/day and piracetam 200 mg/kg/day respectively. group 5; DZP group that injected with diazepam 2.5 mg/kg, groups 6, 7 and 8 were received diazepam 2.5 mg/kg + telmisartan 0.3 mg/kg/day, metformin 100 mg/kg/day and piracetam 200 mg/kg/day respectively. All drugs were administrated for 15 successive days. Cognitive skills of the animals were examined with Elevated plus maze and Passive Shock Avoidance tests. Investigations of oxidative stress markers were performed. Gene expression levels of TNF-α, NFκB, Caspase 3 and AMPK were analyzed using RT-PCR. Histological and immunohistochemical techniques were performed in hippocampus using H&E, cresyl violet stain, anti GFAP and anti COX-2 immunostain. The study revealed that administration of diazepam increased initial and retention transfer latency as well as it decreased step down latency that means it caused memory impairment. There was a significant increase in hippocampal expression levels of TNF-α, NFκB, and Caspase 3 and downregulation of AMPK expression levels associated with increased neurodegeneration, astrocytes activation and COX-2 immunohistochemical staining. This study indicates that diazepam caused a decline in cognitive function depending on hippocampal activity. Telmisartan, a common antihypertensive agent and metformin, a traditional antidiabetic drug improved this cognitive dysfunction through their anti-oxidant and anti-inflammatory effect as they decreased initial and retention transfer latency as well as it increased step down latency. Also they decreased TNF-α, NFκB, and Caspase 3 and upregulated AMPK expression, moreover they ameliorated the hippocampal morphological alterations, GFAP and COX-2 immunoexpression.

Zanthoxylum zanthoxyloides Alkaloidal Extract Improves CCl4-Induced Hepatocellular Carcinoma-Like Phenotypes in Rats

Background

Despite the enrollment of new small molecules such as Sorafenib for the treatment of hepatocellular carcinoma (HCC), HCC still remains a significant contributor to cancer-related mortality and morbidity globally. Zanthoxylum zanthoxyloides is long suspected of possessing anticancer bioactive compounds that may hold the prospect of adjunctive therapy against inflammation-related cancers such as HCC.

Objective

This study assessed the effects of an alkaloidal extract of the leaves of Zanthoxylum zanthoxyloides on CCl₄/olive oil (1 : 1 v/v)-induced HCC-like phenotypes in rats.

Materials and Methods

Zanthoxylum zanthoxyloides alkaloidal extract (ZZAE) was prepared using Soxhlet and liquid-liquid extraction methods. Subsequently, ZZAE was characterized phytochemically. In the curative method, experimental HCC was established in adult (8-10 weeks old) male Sprague-Dawley rats weighing 150-300 g by twice-daily administration of CCl₄/olive oil (1 : 1 v/v) (2 mL/kg ip). After confirmation of experimental HCC in rats, the rats were randomly reassigned into seven (7) groups of seven (7) rats each and treated daily for 12 weeks as follows: control (normal saline, 5 ml/kg po), model (CCl₄, 5 ml/kg, ip), ZZAE (50, 100, and 200 mg/kg po), carvedilol (6.25 mg/kg po), and 20% Tween20 (1 mL/rat, po). To assess whether ZZAE has a prophylactic (preventive) effect, rats were first treated with ZZAE and later exposed to CCl₄ reconstituted in olive oil.

Results

ZZAE (100 and 200 mg/kg) and carvedilol decreased tumor incidence compared to that of control. Compared to control, ZZAE (100 and 200 mg/kg) significantly (P < 0.05) improved serum GGT. Compared to control, ZZAE improved hepatohistological distortions induced by CCl₄/olive oil and also improved liver/body weight ratio. Compared to water, ZZAE arrested mitosis in the Allium cepa assay.

Conclusion

ZZAE ameliorated CCl₄/olive oil-induced HCC-like phenotype in rats and demonstrated general hepatoprotective effects by improving liver and kidney function markers. This finding rationalizes the need for further studies on ZZAE as a potential source of bioactive anti-HCC compounds.

Alkaloidal extract from Zanthoxylum zanthoxyloides stimulates insulin secretion in normoglycemic and nicotinamide/streptozotocin-induced diabetic rats

Introduction

Increase in the prevalence of type-2 diabetes in Sub-Sahara Africa has created the need for robust treatment and management programs. However, an effective diabetes management program requires a high annual budget that most countries in this region cannot afford. That said, various plants and plant products in this region have either been confirmed and/or ethnopharmacologically used for the management of type-2 diabetes.

Aim

To investigate the antidiabetic and insulin secretory effects of an alkaloidal extract derived from Zanthoxylum zanthoxyloides in normoglycemic and experimental diabetic rats.

Materials and methods

Alkaloidal extract was prepared from leaves of Zanthoxylum zanthoxyloides (ZZAE). Nicotinamide/streptozotocin-induced type-2 diabetes was modeled in male Sprague Dawley rats weighing between 130 to 150 g. The experimental diabetic rats were grouped into six treatment groups [Model, 20% Tween20, chlorpropamide, and ZZAE (50, 100, and 150 mg/kg)], and one control group. Fasting blood glucose (FBG), and body weight were measured weekly. Rats were sacrificed 2 days after treatment under chloroform anesthesia to collect blood samples and to isolate major organs for biochemical, and histological analyses respectively. Islets of Langerhans were isolated from normoglycemic rats and co-cultured with ZZAE and chlorpropamide (10 μg/mL) to assess the insulin secretory effect of ZZAE.

Results

ZZAE improved glucose kinetics curve in normoglycemic (p < 0.001) and experimental diabetic rats (p < 0.05) compared to the model. ZZAE (100 and 150 mg/kg) restored islets population, and improved kidney, and liver, histoarchitecture. ZZAE (150 mg/kg) improved post-treatment serum insulin levels compared to the model group (p < 0.001) and the Chlorpropamide group (p < 0.05). ZZAE also restored glycogen synthesis in skeletal muscles of experimental diabetic rats and stimulated insulin secretion in pancreatic islets of Langerhans isolated from normoglycemic rats.

Conclusion

These results showed that ZZAE has active alkaloids that can be explored for diabetes management.

Chemopreventive activity of hydroethanolic Murraya koenigii leaves extract (HEMKLE) against chemically induced skin carcinogenesis in mice

The present study aimed to examine the chemoprotective effect of Hydroethanolic Murraya koenigii leaves extract (HEMKLE) on murine skin carcinogenesis model. For the study, male LACA mice divided into four groups (n = 15 per group). Group I (Control), Group II (DMBA/TPA), Group III (HEMKLE), and Group IV (HEMKLE + DMBA/TPA). Skin tumors were induced in Group II (DMBA/TPA) and Group IV (HEMKLE + DMBA/TPA) by topical application of 7, 12 dimethylbenz[a]anthracene (DMBA) [500 nmol/100 μL of acetone, twice a week for two weeks] and 12-O-tetradecanoyl phorbol-13-acetate (TPA) [1.7 nmol/100 μL of acetone, twice a week for eighteen weeks] and HEMKLE (200 mg/kg b. w.) was administered orally (instilled by oral gavage). The chemoprotective response of HEMKLE was evident by inhibition in tumor incidence, mean tumor volume, mean tumor burden, total number of tumors, and tumor size in Group IV (HEMKLE + DMBA/TPA) when compared to Group II (DMBA/TPA). HEMKLE administration also decreased the reactive oxygen species (ROS) and lipid peroxidation (LPO) levels and increased the antioxidants enzyme activities in Group IV (HEMKLE + DMBA/TPA) when compared to Group II (DMBA/TPA) that suggests its antioxidant potential. HEMKLE administration also increased the mRNA and protein expression of caspase-9 and caspase-3 and decreased the mRNA and protein expression of Bcl-2 in Group IV (HEMKLE + DMBA/TPA) when compared to Group II (DMBA/TPA) that suggest its apoptosis-inducing effect on DMBA/TPA induced skin carcinogenesis.

Medicinal Profile, Phytochemistry, and Pharmacological Activities of Murraya koenigii and its Primary Bioactive Compounds

The discovery of several revitalizing molecules that can stop or reduce the pathology of a wide range of diseases will be considered a major breakthrough of the present time. Available synthetic compounds may provoke side effects and health issues, which heightens the need for molecules from plants and other natural resources under discovery as potential methods of replacing synthetic compounds. In traditional medicinal therapies, several plant extracts and phytochemicals have been reported to impart remedial effects as better alternatives. Murraya koenigii (M. koenigii) belongs to the Rutaceae family, which is commonly used as a medicinally important herb of Indian origin in the Ayurvedic system of medicine. Previous reports have demonstrated that the leaves, roots, and bark of this plant are rich sources of carbazole alkaloids, which produce potent biological activities and pharmacological effects. These include antioxidant, antidiabetic, anti-inflammatory, antitumor, and neuroprotective activities. The present review provides insight into the major components of M. koenigii and their pharmacological activities against different pathological conditions. The review also emphasizes the need for more research on the molecular basis of such activity in various cellular and animal models to validate the efficacy of M. koenigii and its derivatives as potent therapeutic agents.

Spices: Potential Therapeutics for Alzheimer's Disease

India has traditionally been known to all over the world for spices and medicinal plants. Spices exhibit a wide range of pharmacological activities. In contemporary, Indian spices are used to rustle up delicious delicacies. However, the Indian spices are more than just adjuvant which adds aroma and fragrance to foods. A few spices are very widely used and grown commercially in many countries, contain many important chemical constituents in the form of essential oil, oleoresin, oleogum, and resins, which impart flavor, pungency, and color to the prepared dishes, simultaneously exerts diverse therapeutic benefits. Ayurveda, the traditional systems of medicine in India has many evidences for the utilization of spices to cure various diseases. Some of the activities have been scientifically proven. Among various indications central nervous system disorders are of prime importance and it has been evident in traditional books and published reports that spices in fact protect and cure neuronal ailments. Likewise there are many spices found in India used for culinary purpose and have been found to have reported specific activities against brain disorders. About 400 B.C., Hippocrates rightly said "Let food be thy medicine and medicine thy food." This review focuses on the importance of spices in therapeutics and the till date scientific findings of Indian spices in CNS pharmacology and explores the potential of Indian spices to cure CNS disorders.

Taraxerol as a possible therapeutic agent on memory impairments and Alzheimer's disease: Effects against scopolamine and streptozotocin-induced cognitive dysfunctions

Alzheimer's disease (AD) is a neurodegenerative disorder associated with cognitive impairment and cholinergic neuronal death, characteristic of the effect of time on biochemical neuronal function. The use of medicinal plants as an alternative form of prevention, or even as a possible treatment of AD, is therefore interesting areas of research, since the standard drugs have many side effects. Taraxerol (TRX) is a triterpene that has been isolated from several plant species, and its various pharmacological properties have already been identified, such the acetylcholinesterase (AChE) inhibition activity in vitro. There is a lack of information in literature that confirms the effect of TRX in an animal AD-like model. Seeking to fill this gap in the literature, in the present work we assessed the effect of TRX on AChE activity in the animals' encephalon and hippocampus. We also investigated the effect of TRX (1.77 µM/side, 0.5 μL) isolated from leaves of Eugenia umbelliflora Berg. on aversive memory impairments induced by scopolamine (2 µg/side, 0.5 µL) infused into rat hippocampus, and the effect of TRX (0.89 and 1.77 µM/side, 0.5 μL) on aversive memory impairments induced by streptozotocin (STZ) (2.5 mg/mL, 2.0 µL) infused i.c.v. into mice, using the step-down inhibitory avoidance task. We found that TRX significantly inhibited AChE activity in the animal's hippocampus. Furthermore, TRX significantly improved scopolamine and STZ-induced memory impairment. Taking together, these results confirms its AChE activity inhibition in animals and indicate that TRX has anti-amnesic activity that may hold significant therapeutic value in alleviating certain memory impairments observed in AD.

Cytotoxicity and Proteasome Inhibition by Alkaloid Extract from Murraya koenigii Leaves in Breast Cancer Cells-Molecular Docking Studies

Murraya koenigii (curry tree) leaves are rich in bioactive compounds such as flavonoids, alkaloids, and coumarins. Alkaloids from M. koenigii leaves have antianalgesic, antiulcerogenic, antiobesity, and antitumor activities. In this study, we tested the cytotoxic and proteasome-inhibitory potential of a total alkaloid extract (TAE) from M. koenigii leaves in the breast cancer cell line MDA-MB-231. The TAE decreased cell viability with an IC₅₀ of 14.4 μg/mL and altered growth kinetics of breast cancer cells. TAE (32 μg/mL) arrested cells (35%) in the "S" phase of the cell cycle and induced apoptosis. The 26S proteasome, a multicatalytic protease complex, promotes tumor cell proliferation and protects tumor cells from apoptosis. The TAE and mahanine, a carbazole alkaloid present in M. koenigii leaves, preferentially inhibited the trypsin-like, but not the chymotrypsin-like proteolytic activity of the proteasome with an IC₅₀ of 162 μg/mL and 287 μM, respectively. In silico analysis of 26 compounds from M. koenigii leaves revealed significant docking scores for mahanine and two other carbazole alkaloids with the β2 and β5 subunits of the catalytic 20S proteasome. Taken together, this study demonstrates that inhibition of the proteasome is an important biological activity of M. koenigii alkaloids, which may lead to cancer cell death.

Development and Structural Modification of BACE1 Inhibitors

Alzheimer's disease (AD) is a progressive neurodegenerative disorder which usually occurs in the elderly. The accumulation of β-amyloid and the formation of neurofibrillary tangles are considered as the main pathogenies of AD. Research suggests that β-secretase 1 (BACE1) plays an important role in the formation of β-amyloid. Discovery of new BACE1 inhibitors has become a significant method to slow down the progression of AD or even cure this kind of disease. This review summarizes the different types and the structural modification of these new BACE1 inhibitors.

Enhancement of β-secretase inhibition and antioxidant activities of tempeh, a fermented soybean cake through enrichment of bioactive aglycones

CONTEXT

Soybean and its fermented products are the most common source of isoflavones in human food.

OBJECTIVE

The present study quantifies the major glycosides and aglycones in soybean and its fermented product tempeh isoflavone extracts. The comparision of antioxidant effects and BACE1 inhibitory activity between the isoflavones of soybean and tempeh were also established.

MATERIALS AND METHODS

The major isoflavones such as daidzein and genistein (aglycones), and their sugar conjugates (glycosides) daidzin and genistin in soybean and tempeh isoflavones were quantified using HPLC analysis. Comparative studies on BACE 1 (β-site amyloid precursor protein cleaving enzyme 1 or β-secretase 1) inhibition and free-radical scavenging activities (diphenyl-1-picrylhydrazyl (DPPH) and ferrous ion chelating ability) were conducted.

RESULTS

The amount of actives (mg/100 g) in soybean isoflavone compared with tempeh isoflavone is as follows: daidzein 16.72 mg/100 g versus 38.91 mg/100 g, genistein 11.10 mg/100 g versus 24.03 mg/100 g, daidzin 6.16 mg/100 g versus 0.69 mg/100 g, and genistin 24.61 mg/100 g versus 6.57 mg/100 g. The IC50 values of soybean and tempeh isoflavones against BACE1 were 10.87 and 5.47 mg/ml, respectively. The tempeh isoflavone had a more potent DPPH free-radical scavenging activity (IC50 = 2.67 mg/ml) than the soybean isoflavone (IC50 = 10 mg/ml). The ferrous ion chelating ability of the isoflavones was practically similar (IC50 = 10.40 mg/ml, soybean and 11.13 mg/ml, tempeh).

DISCUSSION AND CONCLUSION

The present study indicates that tempeh is a healthy supplement to alleviate oxidative stress through the enrichment of aglycones.

Total isoflavones from soybean and tempeh reversed scopolamine-induced amnesia, improved cholinergic activities and reduced neuroinflammation in brain

The present study was undertaken to compare the neuroprotective effects between total isoflavones from soybean and tempeh against scopolamine-induced cognitive dysfunction. Total isoflavones (10, 20 and 40mg/kg) from soybean (SI) and tempeh (TI) were administered orally to different groups of rats (n=6) for 15days. Piracetam (400mg/kg, p.o.) was used as a standard drug while scopolamine (1mg/kg, i.p.) was used to induce amnesia in the animals. Radial arm and elevated plus mazes served as exteroceptive behavioural models to measure memory. Brain cholinergic activities (acetylcholine and acetylcholinesterase) and neuroinflammatory activities (COX-1, COX-2, IL-1β and IL10) were also assessed. Treatment with SI and TI significantly reversed the scopolamine effect and improved memory with TI group at 40mg/kg, p.o. exhibiting the best improvement (p<0.001) in rats. The TI (10, 20 and 40mg/kg, p.o.) significantly increased (p<0.001) acetylcholine and reduced acetylcholinesterase levels. Meanwhile, only a high dose (40mg/kg, p.o.) of SI showed significant improvement (p<0.05) in the cholinergic activities. Neuroinflammation study also showed that TI (40mg/kg, p.o.) was able to reduce inflammation better than SI. The TI ameliorates scopolamine-induced memory in rats through the cholinergic neuronal pathway and by prevention of neuroinflammation.

Effects of SuperUlam on Supporting Concentration and Mood: A Randomized, Double-Blind, Placebo-Controlled Crossover Study

Background. SuperUlam is a proprietary blend of natural ingredients aimed at supporting brain health. We aimed to evaluate the effect of SuperUlam on attention and mood in healthy adults. Methods. Twenty healthy individuals aged 35–65 were enrolled in this randomized, double-blind, placebo-controlled, crossover study. Study duration was 3 weeks and consisted of 3 visits. Measurement of cognitive function included computer-based testing of reaction time, complex attention, working memory, sustained attention, and executive functioning. Mood testing was performed via the profile of mood states (POMS) survey and the Chalder fatigue scale. Results. Cognitive function testing demonstrated a significant improvement from baseline in executive functioning, cognitive flexibility, reaction time, and working memory in the product group only (P < 0.05). When comparing the study product to placebo, the data demonstrated a significant decrease in tension, depression, and anger (P < 0.05). There was no significant difference between the product and placebo in the other measures of mood, including vigor, fatigue, confusion, and total mood disturbance. No adverse events were reported. Conclusions. Supplementation with SuperUlam is safe to consume with potential benefits to cognitive function and mood.