Centella asiatica improves memory and executive function in middle-aged rats by controlling oxidative stress and cholinergic transmission.

ETHNOPHARMACOLOGICAL RELEVANCE: Centella asiatica (L.) Urban, is a medicinal herb with rich history of traditional use in Indian subcontinent. This herb has been valued for its diverse range of medicinal properties including memory booster, and also as a folk treatment for skin diseases, wound healing and mild diuretic. AIM OF STUDY: Aging is a gradual and continuous process of natural decay in the biological systems, including the brain. This work aims to evaluate the effectiveness of ethanolic extract of Centella asiatica (CAE) on age-associated cognitive impairments in rats, as well as the underlying mechanism. MATERIAL AND METHODS: Rats were allocated into five distinct groups of 5 animals each: Young rats (3 months old rats), middle-aged (m-aged) rats (13-14 months old), and the remaining three groups were comprised of m-aged rats treated with different concentrations of CAE, viz., 150, 300, and 450 mg/kg b. w., orally for 42 days. Y-maze, open field, novel object recognition, and elevated plus maze tests were used to assess animal behavior. The malondialdehyde (MDA), superoxide dismutase (SOD), and acetylcholinesterase (AChE) assays; and H&E staining were done in the rat brain to assess the biochemical and structural changes. CAE was also subjected to HPLC analysis, in vitro antioxidant and anti-cholinergic activity. The active compounds of CAE were docked with AChE and BuChE in molecular docking study. RESULTS: The results showed that CAE treatment improves behavioral performance; attenuates the age-associated increase in MDA content, SOD, and AChE activity; and reduces neuronal loss. In vitro study showed that CAE has concentration-dependent antioxidant and anti-AChE activity. Furthermore, the presence of Asiatic acid and Madecassic acid in CAE and their good binding with cholinergic enzymes (in silico) also suggest the anticholinergic effect of CAE. CONCLUSION: The findings of the current study show that the anticholinergic and antioxidant effects of CAE are attributable to the presence of Asiatic acid and Madecassic acid, which not only provide neuroprotection against age-associated cognitive decline but also reverse it.

First report of association of 'Candidatus Phytoplasma asteris' with Moringa oleifera leaf yellowing and stunting disease in India.

Moringa oleifera (family Moringaceae) also known as the 'drumstick tree' is a significant nutritious and medicinal plant that is commonly grown in India and contains a variety of vital phytochemicals. M. oleifera is used in several Indian herbal medicine formulations to treat a variety of illnesses (Kumar and Rao 2021). Typical phytoplasma symptoms of leaf yellowing and stunting were observed in M. oleifera trees up to 10% incidence at Acharya Narendra Dev University of Agriculture & Technology, Ayodhya, Uttar Pradesh, India in November 2021 and stunting with less fruit bearings symptoms with 8% incidence in October 2021 at Jonnalakothapalle village of Mudigubba mandal of Ananthapuramu district in Andhra Pradesh, India (Fig.1a, b). To investigate the possibility of a phytoplasma association with the symptoms, total DNA was isolated from the leaf samples collected from two diseased and two healthy plants from both the locations using CTAB method. The DNAs isolated were analysed by nested polymerase chain reaction (PCR) with universal phytoplasma primer pairs P1/P7 and R16F2n/R16R2 for the 16S rRNA gene (Deng and Hiruki 1991; Gundersen and Lee 1996) and secAfor1/sArev3 and SecAfor2/ SecArev3 for secA gene (Hodgetts et al. 2008). Amplicons of the expected size (~1.25kb from 16S rRNA gene and ~480bp from secA gene) were obtained from symptomatic plants only. The nested PCR products were cloned (pGEM-T Easy Vector, Promega), sequenced (ABA Biotech, India) and the sequences were deposited in GenBank with accession numbers OP358449, OP358450, OP358451, OP358452 for the 16SrRNA gene (~1.25 kb) and OP358443, OP358444, OP358445, OP358446 for the secA gene (~480 bp). BLASTn analysis revealed that the partial 16S rRNA gene sequences of M. oleifera phytoplasma isolate shared up to 99.9% sequence identity with the strain 'Candidatus Phytoplasma asteris' (Accession numbers MN909051, MN909047) and secA gene sequences shared up to 100% sequence identity with 'Ca. Phytoplasma asteris' (Accession numbers KJ434315, KJ462009) belonging to 16SrI group. The 16S rRNA and secA genes sequence-based phylogenetic analysis (Figure 1d,e) showed that the phytoplasma strain associated with M. oleifera leaf yellowing and stunting clustered within the 16SrI phytoplasma group closest to 16SrI-B ('Ca. P. asteris') subgroup strains. Furthermore, the virtual RFLP pattern derived from the query 16S rDNA F2nR2 fragment is identical (similarity coefficient 1.00) to the reference pattern of 16Sr group I, subgroup B (GenBank accession: AP006628). To the best of our knowledge, this is the first report of the 16SrI-B subgroup of the phytoplasma strains with M. oleifera in the world. 'Candidatus Phytoplasma asteris' (16SrI-B subgroup) strains have been reported from several other commercial crops and weed hosts in India and efficient leafhopper vectors have been identified (Rao 2021; Reddy 2021). This indicates that the 'Ca. P. asteris'-related strains (16SrI-B) are widespread and infecting several plant species in India. The increasing incidence of the 16SrI-B strain and its wide host range in India strongly suggests further research into the epidemiology involved in the dynamic spread of the disease in order to recommend a suitable management approach.

The Potential of Low Phytic Acid1-1 Mutant in Maize (Zea mays L.): A Sustainable Solution to Non-Renewable Phosphorus.

BACKGROUND: Phosphorus is an essential component of fertilizers and feed and in recent decades has become one of the main sustainability issues as a non-renewable resource. In plant seeds, the main reserve of phosphorus is phytic acid, a strong anti-nutritional factor for monogastrics and a pollutant of cultivated lands. The reduction of phytic acid in cereal seeds has become a major challenge in breeding programs to increase the nutritional quality of foods and feeds and to improve the environmental phosphorus sustainability in agriculture. In maize (Zea mays L.), four low phytic acid (lpa) mutations have been isolated and lpa1-1 is the most promising. However, the reduction of phytic acid in lpa1-1 leads to many adverse pleiotropic effects on the seed and in general on plant performance. A seed weight reduction and a consequent yield loss were previously described in this mutant. METHOD: In this work, a field experiment to study seed weight and yield was conducted for two years in two different genetic backgrounds (B73 and B73/Mo17). Furthermore, the greater susceptibility of lpa1-1 to drought stress was also investigated: a dedicated field experiment was set up and measurements were carried out under optimal water conditions and moderate drought stress. RESULTS: From the first experiment it emerges that under high-input conditions, lpa1-1 seems to have comparable or even better yield than the relative control. The main problem of this mutant remains the reduced field emergence (~40%). In the study of drought stress it was found that the increased sensitivity in the mutant is mainly caused by an altered stomatal regulation, but not by a less developed root system, as previously reported. When the stress occurred, the parameters measured did not significantly change in the wild-type, while they dropped in the mutant: the net photosynthesis decreased by 58%, the transpiration rate by 63% and the stomatal conductance by 67%. CONCLUSIONS: Some possible solutions have been proposed, with the aim of developing a commercial variety, which remains the main goal to exploit the nutritional benefits of low phytic acid mutants.

Ultrasound-assisted rapid biological synthesis and characterization of silver nanoparticles using pomelo peel waste.

Synthesis of silver nanoparticles by green route is an emerging technique drawing more attention recently because of several advantages over the conventional chemical ways. The overall objective of the research was focused on the green synthesis of silver nanoparticles using pomelo peel waste via a rapid and eco-friendly ultrasonic-assisted technique and their characterization. Different factors affecting the synthesis, like methodology for the preparation of extract and various treatment conditions for the synthesis, were also studied. The developed nanoparticles were characterized for their optical, molecular, microstructural, and physical properties by UV-visible spectroscopy, dynamic light scattering (DLS), zeta-potential measurements, scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FT-IR). The green synthesized nanoparticles were found almost spherical when treated at room and high temperatures and cubical when treated with ultrasonication. As obtained from the XRD studies, the size of crystallitenanoparticles was 35 to 40 nm in diameter. The EDX, FT-IR, and zeta potential analysis corroborated the role of phenolic compounds in capping and reduction of the metal ion. The capping ability of the polyphenolic component in the extract was used to achieve size stability. The nanoparticles also showed antibacterial activity against gram-negative and gram-positive bacteria, owing to the inherent antibacterial capability of silver nanoparticles.

Centella asiatica Alleviates AlCl3-induced Cognitive Impairment, Oxidative Stress, and Neurodegeneration by Modulating Cholinergic Activity and Oxidative Burden in Rat Brain.

Aluminum (Al) is linked to the development of many neurological disorders such as Alzheimer's disease (AD), Parkinson's disease, and autism. Centella asiatica (CA) is a regenerating herb traditionally used to stimulate memory. This study was designed to assess the neuroprotective role of ethanolic extract of CA (CAE) in AlCl3-induced neurological conditions in rats. Adult rats were chronically treated with AlCl3 (100 mg/kg b.w./day) for 60 days to establish the dementia model, and co-administration of CAE was evaluated for its ability to attenuate the toxic effect of AlCl3. CAE was given orally at a dose of 150 and 300 mg/kg b.w./day, for 60 days. The behavioral performances of rats were tested through Y-maze and open field tests. Lipid peroxidation, superoxide dismutase, and catalase activity were evaluated to measure oxidative stress; and acetylcholinesterase (AChE) activity was assessed to evaluate cholinergic dysfunction in the rat brain. H&E staining was used to assess structural abnormalities in the cortex and hippocampus. The result showed that AlCl3 induces cognitive dysfunction (impaired learning and memory, anxiety, diminished locomotor activity), oxidative stress, cholinergic impairment, and histopathological alteration in the rat brain. Co-administration of CAE with AlCl3 markedly protects the brain from AlCl3-induced cognitive dysfunction, oxidative stress, AChE activity, and cytoarchitectural alterations. Furthermore, 15 days CAE treatment after 45 days AlCl3 administration markedly ameliorates the AlCl3-induced neurotoxicity indicating its potential for therapeutic use.

Phytoremedial effect of Tinospora cordifolia against arsenic induced toxicity in Charles Foster rats.

Arsenic poisoning is one of the most serious health hazards of recent times. It has been estimated that more than 200 million people of about 105 countries in the world are affected due to arsenic poisoning. Except mitigation, there is no such mode by which the population can be prevented from being exposed to arsenic. Tinospora cordifolia (T. cordifolia) is widely used in the folk medicine system for the treatment of various diseases. Hence, the aim of the present study was to investigate the antidote effects of ethanolic extract of T. cordifolia stem against arsenic induced hepato-renal toxicity in rat model. Twenty-four male Charles Foster rats (weighing 160-180 g) were randomly divided into two groups, where six rats were used as control group. Eighteen rats were orally treated with arsenic at the dose of 8 mg/kg body weight for 90 days daily and then further divided into three sub groups (n = 6 each). Sub group I-arsenic treated rats, were sacrificed after treatment; sub group II rats were used as arsenic control and the sub group III rats were administrated with T. cordifolia at the dose of 400 mg/kg body weight/day for 90 days. After the completion of dose duration, all the control and treatment group rats were sacrificed to evaluate the various parameters. Arsenic induced rats had significantly (p < 0.0001) altered biochemical serum levels of SGPT, SGOT, ALP, total bilirubin, urea, uric acid, creatinine and albumin; But, after the administration of T. cordifolia there was significant (p < 0.0001) restoration observed in these liver and kidney function parameters. The T. cordifolia administration also significantly (p < 0.0001) restored the serum MDA levels and arsenic concentration in blood, liver and kidney tissues, as well as significant (p < 0.0001) improvement in haematological variables. In histopathological study, the arsenic treated rats showed degenerative changes in the liver and kidney tissues such as lesions and vacuolizations in hepatocytes and nephrocytes respectively. However, after the administration with T. cordifolia rats, there was considerably significant restoration in liver and kidney tissues. The entire study suggests that arsenic caused severe damage to the liver and kidney at haematological, biochemical and histopathological levels in rats. However, T. cordifolia played the vital role to combat the arsenic induced toxicity in rats. Hence, T. cordifolia might be used as a nutritional supplement to combat the arsenic led toxicity among the exposed population.

Identification of human tau-tubulin kinase 1 inhibitors: an integrated e-pharmacophore-based virtual screening and molecular dynamics simulation.

Tau-tubulin kinase 1 inhibitors inhibit tau protein phosphorylation on Ser198, Ser199, Ser202, Ser422, and also in paired helical filaments. We developed receptor-based pharmacophore models by exploiting three TTBK1 protein structures, i.e., 4NFN, 4BTM, and 4BTK. The integrated e-pharmacophore based virtual screening and molecular dynamics simulation recognized four hits viz. ZINC14644839, ZINC00012956, ZINC91332506, and ZINC69775110 as TTBK1 inhibitors. The Glide XP docking energies (-8.48 to -10.71 kcal.mol-1) of hits were better than cocrystal ligand of 4NFN protein structure (-8.37 kcal.mol-1). Among the hits, ZINC14644839 possessed best binding energy with four hydrogen bonding interactions. The inhibitors showed acceptable calculated ADME and blood-brain barrier permeability properties and could be potential TTBK1 inhibitors for neurodegenerative diseases.Communicated by Ramaswamy H. Sarma.

Secretase inhibitors for the treatment of Alzheimer's disease: Long road ahead.

Alzheimer's disease (AD) is a neurodegenerative disease, characterized by progressive loss of memory which is associated with other cognitive deficits. The two protein structures in the brain i.e. neurofibrillary tangles and senile plaques are considered to hamper the normal cognitive activity of the brain. There are various therapeutic interpolations under investigation to thwart and treat AD. Secretases inhibitors are important agents that inhibit the development of senile plaques. ß-secretase (BACE) inhibitors are in lime light for the drug development of AD. BACE initiates the production of Aß, so its inhibition provides a valid target for the AD. BACE inhibitors viz. LY2811376, LY2886721, E2609 are in different phases of clinical trials. However, chemical study of MK8931 was discontinued due to lack of chances of finding a positive clinical effect. AREAS COVERED: The review incorporates exhaustive literature reports on secretase inhibitors, γ-secretase modulators (GSMs) and α-secretase enhancers. The recent studies on the natural products as GSMs have also been included.

Chalcone and curcumin derivatives: a way ahead for malarial treatment.

Malaria has been a major cause of morbidity and mortality in developing countries, particularly in Sub-Saharan Africa and South Asia. The global malaria situation is increasingly being challenging owing to lack of credible malaria vaccine and the emergence of drug resistance to most of the available antimalarials. They demand search for novel generation of drugs. Versatility and flexibility for structural modification of natural and synthetic analogues of curcumin and chalcone have been explored extensively for designing new antimalarial agent. Recent advances to our knowledge of parasite biology as well as the availability of the genome sequence, have opened up new vista in the firmament of antimalarial drug designing for identifying novel molecular targets. Curcumin and chalcones has been reported to exert anti-malarial effect by binding directly to numerous signaling molecules, such as histone acetyltransferase, histone deacetylase, sarco (endo) plasmic reticulum Ca(2+)-ATPase, cysteine proteases etc. This review highlights insights the more recent antimalarial activities of these compounds, their mechanisms of action, molecular targets and relevant structureactivity relationship studies. Natural lead compounds like chalcone and curcumin have shown good and optimal binding to many enzymes present in parasite and can be explored as molecular targets for in silico studies to develop new, affordable and effective antimalarial drugs. With no credible malaria vaccine in sight, there is an imperative need to develop new drugs with different mechanisms of action to help preclude issues of cross-resistance.

Effect of standardized extract of Marsilea minuta on learning and memory performance in rat amnesic models.

CONTEXT: Marsilea minuta Linn (Marsileaceae) is a common Indian hydrophytic plant. Traditionally, the plant has been used as a sedative for the treatment of insomnia and other mental disorders. Background information of this plant has encouraged us to investigate its antiamnesic activity in rat. OBJECTIVE: Standardized ethanol extract of M. minuta was investigated for their putative role in learning and memory performance in normal and amnesic rats. MATERIALS AND METHODS: Ethanol extract of M. minuta (EMM) was standardized for marsiline using HPLC. The effect of standardized extract of M. minuta (1.15% w/w marsiline) was tested in amnesic rat using elevated plus maze (EPM) and passive avoidance (PA) test. Amnesia was induced after scopolamine (1 mg/kg, s.c.) and electroconvulsive shock (150 mA, 0.2 s) treatment. Behavioral studies were further substantiated with acetylcholinesterase (AChE) activity and radioligand muscarinic receptor binding studies in rat brain regions. RESULTS: Oral administration of EMM at 200 and 400 mg/kg/day for 3 days significantly reversed the amnesia whereas, no per se effect was observed. In comparison to control, AChE activity in frontal cortex and hippocampus was found to be significantly (P < 0.05) inhibited by EMM. EMM at doses 200 and 400 mg/kg has significantly (P < 0.05) increased (+34 % and +40 % change in affinity, respectively) the binding of 3H-QNB in frontal cortex indicating the up regulation of the muscarinic receptors. DISCUSSION AND CONCLUSION: These findings suggest that standardized extract of M. minuta have excellent antiamnesic activity, probably mediating through central cholinergic system.

Anti-inflammatory activity of ethanol extract of Vitex glabrata leaves.

Vitex glabrata (Verbenaceae) is commonly employed for the treatment of various ailments in traditional medicine. In this study, ethanol extract of Vitex glabrata (EEVG) was evaluated for the anti-inflammatory activity using carrageenan-induced paw edema and cotton pellet induced granuloma formation in rat models. EEVG showed significant anti-inflammatory activity in rats in dose dependant manner. At a dose of 400 mg/kg, p.o. maximum effect was observed and was comparable (p<0.05) to that of diclofenac sodium (standard, 50 mg/kg, p.o.). Results of the study suggested that the anti-inflammatory activity of EEVG may be due to inhibition of prostaglandins synthesis and cessation of inflammatory events like fibroblast cell formation, neutrophils infiltration, and accumulation of fluids. Therefore, this study provides a support for the plant in the management of inflammatory related disorders.

Status of research on MMPs in India.

INTRODUCTION: MMPs are metal-dependant endopeptidases capable of degrading any one of the components of the extracellular matrix. In normal physiological conditions it is regulated by tissue inhibitors of metalloproteinases, and any alteration in this regulatory process leads to pathological conditions. AREAS COVERED: This review discusses the status of MMP research in India. The first research paper was published in 1998; the subsequent developments in this field led to an increase in the number of publications. This review highlights the growth of MMP research in India based on the research papers published from 1998 to 2010. We identify four major subject areas: cancer, arthritis, ulcer and quantitative structure-activity relationship. The diseases involved are discussed along with the required steps for improving treatments. EXPERT OPINION: Indian researchers need to work on new molecules with specific MMP inhibitory activity for cancer and communicable and geriatric diseases. Although several publications on natural products have appeared from India, they are very few considering the number of medicinal plants available in the country. Inhibiting MMPs could be both beneficial and detrimental to cells, owing to the inter-relationship between normal physiology and pathology; thus, targeting MMPs with broad MMP inhibitors can have mixed blessings.

Antidiabetic and antioxidant effect of various fractions of Phyllanthus simplex in alloxan diabetic rats.

AIM OF THE STUDY: To evaluate the antidiabetic and antioxidant effects of various fractions of Phyllanthus simplex on alloxan induced diabetes in rats. MATERIALS AND METHODS: Hypoglycemic effect of Phyllanthus simplex fractions was evaluated in normal and diabetic rats. Diabetes was induced by intraperitoneal injection of alloxan monohydrate (120 mg/kg). Normal and diabetic rats were divided into different groups (six rats each group) and orally administered with petroleum ether (P.E.) (200 and 400 mg/kg), ethyl acetate (EtOAc) (100 and 200 mg/kg), methanol (125 and 250 mg/kg), water fraction (150 and 300 mg/kg) and glibenclamide (10 mg/kg) for 21 days. Blood samples were collected from overnight fasted normal rats on day 21, from overnight fasted diabetic rats at 7, 14 and 21 days of treatment and analyzed for blood glucose level. On day 22 blood samples were collected from diabetic rats to estimate biochemical parameters, rats were sacrificed by single stunning and tissues were excised to measure their antioxidant and glycogen status. RESULTS: In the normoglycemic rats, MeOH (125 and 250 mg/kg) and aqueous fractions (150 and 300 mg/kg) showed a significant (P<0.05) hypoglycemic effect on day 21. In diabetic control rats, MeOH (125 and 250 mg/kg) and aqueous fractions (150 and 300 mg/kg) showed significant antihyperglycemic effect (P<0.001). The active fractions (MeOH and aqueous) of Phyllanthus simplex also increased the body weight of diabetic rats significantly compared to the control group. The active fractions were able to normalize the marked alterations in antioxidant enzymes and antioxidant parameters levels in liver and kidney. Treatment with the active fractions also normalized the diabetic induced hyperlipidemia and liver glycogen. CONCLUSIONS: These results demonstrate the antidiabetic and antioxidant potential of fractions of Phyllanthus simplex and suggests that the plant may have therapeutic value in diabetes and related complications.

Antidepressant activity of standardised extract of Marsilea minuta Linn.

AIM OF THE STUDY: Marsilea minuta Linn. (Marsileaceae) has been referred in Indian traditional medicine system (Ayurveda) for the treatment of insomnia and other mental disorders. Marsiline isolated from Marsilea minuta was reported to have sedative and anticonvulsant property. The ethanol extract of Marsilea minuta was standardised for marsiline (1.15%, w/w) and studied for its antidepressant activity. MATERIALS AND METHODS: Antidepressant activity was studied using forced swimming test (FST), tail suspension test (TST), learned helplessness test (LHT) and 5-hydroxytryptophan (5-HTP) induced head twitches response in rodents. Standardised extract of Marsilea minuta in doses of 100, 200 and 400 mg/kg/day were administered orally for three consecutive days and evaluated on day 3, 1h after the last dose treatment. Imipramine (15 mg/kg/day, i.p.) was used as the standard drug. Neurochemical mechanism of antidepressant activity was elucidated by using radioligand receptor binding assays for 5-HT2A and benzodiazepine receptors in rat frontal cortex. RESULTS: Immobility time in FST and TST was significantly (P<0.05) reduced by ethanol extract of Marsilea minuta treated animals. A decrease in number of escape failures in LHT was also observed in Marsilea minuta treated rats. Head twitch response induced by 5-HTP was significantly attenuated by Marsilea minuta (400 mg/kg, p.o.) and imipramine showing the involvement of serotonergic system. This effect was corroborated with radioligand receptor binding study where Marsilea minuta (400 mg/kg, p.o.) significantly (P<0.05) down regulated 5-HT2A receptor in frontal cortex, whereas, no marked effect was observed for benzodiazepine receptor. CONCLUSION: The antidepressant effect exhibited by Marsilea minuta extract may be due to its effect on 5-HT2A density in rat frontal cortex.