Sanjeev Acharya

Novel anticancer agents from plant sources

Plants remain an important source of new drugs, new drug leads and new chemical entities. Plant based drug discovery resulted mainly in the development of anticancer and anti-infectious agents, and continues to contribute to the new leads in clinical trials. Natural product drugs play a dominant role in pharmaceutical care. Several plant-derived compounds are currently successfully employed in cancer treatment. There are many classes of plant-derived cytotoxic natural products studied for further improvement and development of drugs. New anticancer drugs derived from research on plant antitumor agents will be continuously discovered. The basic aim of this review is to explore the potential of newly discovered anticancer compounds from medicinal plants, as a lead for anticancer drug development. It will be helpful to explore the medicinal value of plants and for new drug discovery from them for the researchers and scientists around the globe.

Development of glutathione‐conjugated asiatic acid‐loaded bovine serum albumin nanoparticles for brain‐targeted drug delivery

Asiatic acid, a well‐known plant‐based neuroprotective pentacyclic triterpenoid, has major limitation for its bioavailability in the brain. The objective of this study is to develop novel bovine serum albumin (BSA) nanoparticles coupled with glutathione (natural tripeptide) to enhance drug delivery to brain.

Phytopharmacological evaluation and anti-asthmatic activity of Ficus religiosa leaves

OBJECTIVE To discuss phytopharmacological potential and anti-asthmatic activity of Ficus religiosa (F. religiosa) (L.). METHODS Fresh leaves of F. religiosa were obtained from Vastrapur Lake, Ahmedabad, and dried to obtain powder. Histamine and acetylcholine were used to guinea pigs to establish bronchospasm model. In in vivo study, the aqueous extract of F. religiosa leaves (AEFR) at doses of 150 and 300 mg/kg was administrated to guinea pigs, and the broncho-protective activity of AEFR was compared with aminophylline at 25 mg/kg. While in in vitro study, and 10 g/mL, 20 g/mL, 30 g/mL of AEFRL was administrated to guinea pigs, respectively, and mast cell stabilizing activity of AEFR was compared with ketotifen at 10 g/mL. RESULTS In the in-vivo model, pre-treatment with aminophylline (25 mg/kg, ip.) could significantly delay the onset of histamine induced pre-convulsive dyspnea, compared with vehicle control. Administration of AEFRL (150 and 300 mg/kg, ip.) also produced significant effect on latency to develop histamine & acetylcholine induced pre-convulsive dyspnea. In the mast cell stabilizing model, AEFRL at 10, 20 and 30 μg/mL could significantly increase the number of intact cells. CONCLUSIONS It can be concluded that AEFRL is effective on histamine & acetylcholine induced bronchospasm in guinea pigs. In addition, AEFRL can potentiate the number of intact cells in the mast cell stabilizing model.

Development and characterization of glutathione-conjugated albumin nanoparticles for improved brain delivery of hydrophilic fluorescent marker

Abstract The glutathione-conjugated bovine serum albumin (BSA) nanoparticles were constructed in the present exploration as a novel biodegradable carrier for brain-specific drug delivery with evaluation of its in vitro and in vivo delivery properties. BSA nanocarriers were activated and conjugated to the distal amine functions of the glutathione via carbodiimide chemistry using EDAC as a mediator. These nanoparticles were characterized for particle shape, average size, SPAN value, drug entrapment and in vitro drug release. Further, presence of glutathione on the surface of BSA nanoparticles was confirmed by Ellman’s assay, which has suggested that approximately 750 units of glutathione were conjugated per BSA nanoparticle. To evaluate the brain delivery properties of the glutathione-conjugated BSA nanoparticles fluorescein sodium was used as a model hydrophilic compound. Permeability and neuronal uptake properties of developed formulations were evaluated against the MDCK-MDR1 endothelial and neuro-glial cells, respectively. The permeability of glutathione-conjugated BSA nanoparticles across the monolayer of MDCK-MDR1 endothelial tight junction was shown significantly higher than that of unconjugated nanoparticles and fluorescein sodium solution. Similarly, glutathione-conjugated nanoparticles exhibited considerably higher uptake by neuro-glial cells which was inferred by high fluorescence intensity under microscope in comparison to unconjugated nanoparticles and fluorescein sodium solution. Following an intravenous administration, nearly three folds higher fluorescein sodium was carried to the rat brain by glutathione-conjugated nanoparticles as compared to unconjugated nanoparticles. The significant in vitro and in vivo results suggest that glutathione-conjugated BSA nanoparticles is a promising brain drug delivery system with low toxicity.

Anti-Parkinson Activity of Petroleum Ether Extract of Ficus religiosa (L.) Leaves

In the present study, we evaluated anti-Parkinsons activity of petroleum ether extract of Ficus religiosa (PEFRE) leaves in haloperidol and 6 hydroxydopamine (6-OHDA) induced experimental animal models. In this study, effects of Ficus religiosa (100, 200, and 400 mg/kg, p.o.) were studied using in vivo behavioral parameters like catalepsy, muscle rigidity, and locomotor activity and its effects on neurochemical parameters (MDA, CAT, SOD, and GSH) in rats. The experiment was designed by giving haloperidol to induce catalepsy and 6-OHDA to induce Parkinsons disease-like symptoms. The increased cataleptic scores (induced by haloperidol) were significantly (p < 0.001) found to be reduced, with the PEFRE at a dose of 200 and 400 mg/kg (p.o.). 6-OHDA significantly induced motor dysfunction (muscle rigidity and hypolocomotion). 6-OHDA administration showed significant increase in lipid peroxidation level and depleted superoxide dismutase, catalase, and reduced glutathione level. Daily administration of PEFRE (400 mg/kg) significantly improved motor performance and also significantly attenuated oxidative damage. Thus, the study proved that Ficus religiosa treatment significantly attenuated the motor defects and also protected the brain from oxidative stress.

Exploration of statistical experimental design to improve entrapment efficiency of acyclovir in poly (d, l) lactide nanoparticles.

Abstract Objective: In current exploration, systematic attempts have been made to improve the entrapment efficiency of a model hydrophilic drug substance, i.e. acyclovir, in poly (d, l) lactide (PLA) nanoparticles (NPs) using a modified nanoprecipitation technique. Methods: Formulation parameters such as drug to polymer ratio, antisolvent selection, electrolyte (NaCl) addition, pH alteration and temperature were screened to improve the entrapment efficiency of acyclovir in PLA NPs. The temperature of the system (0–5 °C), phase volume ratio (1:2), stirring speed (2000 rpm), sonication time (5 min), etc. were kept constant during the preparation of NPs. Drug to polymer ratio and electrolyte addition emerged as critical formulation parameters affecting particle size as well as entrapment efficiency. Hence, in the present investigation a 32 full factorial design was used to investigate the combined influence of two factors, i.e. drug to polymer ratio (X1) and the amount of electrolyte, i.e. NaCl (X2) on particle size (Y1) and entrapment efficiency (Y2). The NPs were also evaluated for drug-excipient compatibility study by employing DSC and FT-IR analysis, whereas in vitro drug release studies were performed using dialysis bag technique in phosphate buffer pH 7.4. Results: Statistically significant models were evolved to predict entrapment efficiency and particle size. The effect of factors X1, X2 and was found to be statistically significant in nature. Response variables, i.e. entrapment efficiency and particle size, were simultaneously optimized using desirability function using Design Expert software. This process allowed the selection of most suitable level of factors to achieve desired level of particle size and entrapment efficiency. The results of multiple linear regression analysis revealed that for obtaining desirable particle size (less than 250 nm) and entrapment efficiency (more than 17%), the NPs should be prepared using 1:3 drug to polymer ratio and 0.04 M NaCl. Acyclovir was found to be compatible with PLA as indicated by DSC and FT-IR studies. The experimental values obtained from the optimized formulation highly agreed with the predicted values. The drug release from the optimized formulation exhibited biphasic pattern and the drug release kinetics was best explained by Weibull model. Conclusion: In conclusion, results of the present study demonstrated that PLA NPs with expected particle size and entrapment efficiency can be obtained by adopting the concept of quality by design.

Bergenia ciliata ameliorates streptozotocin-induced spatial memory deficits through dual cholinesterase inhibition and attenuation of oxidative stress in rats

Bergenia ciliata (Haw.) Sternb. rhizomes, family Saxifragaceae, are claimed to possess an array of beneficial effects like antioxidant, anti-inflammatory, immunomodulatory, antibacterial and anticancer activities. The plant has also been reported to be used by Nepalese folk to alleviate symptoms related to Parkinsons disease. Oxidative stress is one of the major reasons for cognitive decline observed in sporadic Alzheimers disease (AD). Bergenia ciliata rhizomes have depicted potent antioxidant properties, but their role in the treatment of Alzheimers disease is yet unexplored. Therefore, the present study was intended to explore the beneficial effects of methanolic extracts of rhizomes of B. ciliata (BM) in a streptozotocin-induced model of Alzheimers disease in Wistar rats. Streptozotocin (STZ) was injected intracerebroventricularly (ICV) on day 1 (3 mg/kg, unilaterally) in Wistar rats. BM was thereafter administered (125, 250 and 500 mg/kg b.w./day p.o.), daily for 28 days. Morris water maze and Y maze test were used to evaluate learning and memory in rats on 7th, 14th, 21st and 28th days following initiation of dosing. Terminally, acetylcholinesterase activity, butyrylcholinesterase, and levels of oxidative stress markers were assessed in the serum as well as in brain homogenates of rats. Additionally, histopathological studies were carried out to observe effects in brain tissues at the cellular level. STZ produced significant (p < 0.001) learning and memory impairment, oxidative stress as well as a cholinergic deficit in rats. Whereas, BM treatment at various dose levels was able to significantly and dose-dependently diminish STZ induced behavioral deficits and biochemical anomalies in rats. The observed cognitive improvement following BM administration in STZ injected rats may be accredited to its antioxidant activity and refurbishment of cholinergic functions. The results of the study are indicative of the therapeutic potential of Bergenia ciliata in cognitive disorders such as AD as well as other such neurodegenerative disorders.

Neuroprotective effects of bergenin in Alzheimer’s disease: Investigation through molecular docking, in vitro and in vivo studies

&NA; Alzheimers disease (AD) is an enervating and chronic progressive neurodegenerative disorder, occurring frequently in the elderly and adversely affecting intellectual capabilities and the cognitive processes. Bergenin possesses efficacious antioxidant, antiulcerogenic, anti‐HIV, hepatoprotective, neuroprotective, anti‐inflammatory and immunomodulatory activity along with antinociceptive effect and wound healing properties. Previous studies have shown that bergenin has in vitro bovine adrenal tyrosine hydroxylase inhibitory activity, mushroom tyrosinase inhibitory activities, &bgr;‐secretase (BACE‐1) enzyme inhibitory activity and prevented neuronal death in the primary culture of rat cortical neurons. Protein tyrosine phosphatase‐1B (PTP1B) is an intriguing target for anticancer and antidiabetic drugs and has recently been implicated to act as a positive regulator of neuroinflammation. Bergenin is also found to inhibit human protein tyrosine phosphatase‐1B (hPTP1B) in vitro. Thus, bergenin was screened by molecular docking study using GOLD suite (version 5.2), CCDC for predicting its activity against targets of AD management like acetylcholinesterase (AChE) (1B41), butyrylcholinesterase (BuChE) (1P0I), Tau protein kinase 1 (GSK‐3&bgr;) (1J1B), BACE‐1 (1FKN) wherein the GOLD score and fitness of bergenin were comparable to those of standard drugs like donepezil, galanthamine, physostigmine, etc. Bergenin demonstrated dose‐dependent inhibition of both AChE and BuChE in vitro and found to be safe up to 50 &mgr;M when screened in vitro on SH‐SY5Y cell lines by cytotoxicity studies using MTT and Alamar blue assays. It also led to dose‐dependent prevention of NMDA induced toxicity in these cells. Pretreatment with bergenin (14 days) in rats at three dose levels (20, 40 and 80 mg/kg; p.o.) significantly (p < 0.01) and dose‐dependently alleviated amnesia induced by scopolamine (2 mg/kg, i.p.). The therapeutic effect of bergenin supplementation for 28 days, at three dose levels, was also evaluated in streptozotocin (3 mg/kg, ICV, unilateral) induced AD model in Wistar rats using Morris water maze and Y maze on 7th, 14th, 21st and 28th days. STZ caused significant (p < 0.001) cognitive impairment and cholinergic deficit and increased oxidative stress in rats. Bergenin could significantly ameliorate STZ induced behavioral deficits, inhibit the AChE and BuChE activity in parallel with an increase in the diminished GSH levels in a dose‐dependent fashion. The histopathological investigations were also supportive of this datum. The bergenin treatment at 80 mg/kg led to significant (p < 0.05) abatement of the raised A&bgr;‐1‐42 levels and alleviated the perturbed p‐ tau levels leading to significantly low (p < 0.01) levels of p‐tau in brain homogenates of rats as compared to ICV STZ injected rats. In conclusion, the observed effects might be attributed to the cholinesterase inhibitory activity of bergenin coupled with its antioxidant effect, anti‐inflammatory activity and reduction of A&bgr;‐1‐42 and p‐tau levels which could have collectively helped in the attenuation of cognitive deficits. The current findings of the study are indicative of the promising preventive and ameliorative potential of bergenin in the management of AD through multiple targets. Graphical abstract Figure. No caption available. HighlightsDocking of bergenin into AChE, BuChE, BACE‐1 and tau protein kinase‐ I (GSK‐3&bgr;) showed high GOLD fitness and internal GOLD scores.Bergenin was safe up to 50 &mgr;M in MTT and Resazurin reduction‐based assay and prevented NMDA induced cytotoxicity in SH‐SY5Y cells.It reduced MEL in MWM and MPA in Y maze when evaluated in scopolamine induced amnesia and ICV STZ induced model of AD in rats.It inhibited AChE and BuChE, attenuated oxidative stress through increased GSH levels and caused restoration of hippocampal cytoarchitecture.ELISA assays showed a significant reduction in A&bgr;1‐42 levels and phosphorylated tau protein levels in brain homogenates of rats.

Core–shell nanoparticles as a drug delivery platform for tumor targeting

Abstract In last few decades, nanoparticle-based drug delivery platforms gained a lot of attention for the treatment of various disease, owing to their unique properties at the nanometer scale. Core–shell nanoparticles are composed of a hollow/matrix core surrounded by a shell. Such unique architecture can offer advantages such as biocompatibility, tunable physicochemical properties, improved biopermeability, target-specific drug delivery, and multidrug delivery. This chapter has included detail about core–shell nanoparticles and their various applications as a drug delivery system for targeting tumor. Furthermore, core–shell nanoparticles are classified on the basis of types of material used for the preparation of core as well as shell, along with their method of preparation and characterization. Details about target-specific surface modification of core–shell nanoparticles are also described. Lastly, factors affecting the pharmacokinetic and biodistribution profile of core–shell nanoparticles, along with biomedical applications and their future prospectives are describe in detail. It can be concluded that core–shell nanoparticles show potential as a multidrug delivery platform for tumor targeting.

Neuroprotective effects of Bergenia ciliata on NMDA induced injury in SH-SY5Y cells and attenuation of cognitive deficits in scopolamine induced amnesia in rats

Bergenia ciliata (Haw) Sternb. possess immunomodulatory, anti-inflammatory, antioxidant, anti-urolithiatic, wound healing, anti-malarial, anti-diabetic and anti-cancer properties. Moreover, the methanolic extracts of the rhizomes of the plant were found to demonstrate beneficial neuroprotective effects in the intracerebroventricular streptozotocin-induced model in rats. Thus, the present study was undertaken to further explore the neuroprotective potential of the aqueous (BA) and methanolic extracts (BM) of B. ciliata through various in-vitro and in-vivo studies. Both the extracts at all tested concentrations i.e. 50-50,000 ng/mL did not cause any significant reduction of cell viability of SH-SY5Y cells when tested for 48 h when assessed through MTT and resazurin metabolism- based cell viability assays. The pre-treatment with the extracts could confer significant (p < 0.001) and dose-dependent protective effects against NMDA induced injury in SH-SY5Y cells. BM [IC50: 5.7 and 5.19 μg/mL for acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) respectively] led to more potent inhibition of both the enzymes as compared to BA (IC50: 227.12 and 23.25 μg/mL for AChE and BuChE respectively). BM also proved to be a 1.85-fold better scavenger of the DPPH free radicals as compared to BA. Thus, BM was taken further for the evaluation of the beneficial effects of 14-day pre-treatment in rats in the scopolamine (2 mg/kg, i.p.) induced amnesia model at 125, 250 and 500 mg/kg, p.o. BM pre-treatment at 250 and 500 mg/kg could significantly ameliorate the cognitive impairment (p < 0.001), inhibit AChE (p < 0.001) and BuChE (p < 0.05) activity, restore GSH levels (p < 0.05) in serum and brain homogenates and recover the morphology of hippocampal neurons back to normal. Moreover, the BM administration at 500 mg/kg also showed beneficial effects through the significant (p < 0.05) reduction of Aβ1-42, phosphorylated tau (p-tau) and GSK-3β immunoreactivity in the brain homogenates of the intracerebroventricularly streptozotocin (ICV STZ) injected rats as observed from the results of the ELISA assays. The outcomes of the study unveiled that BM exerts its beneficial effects through prevention of NMDA induced excitotoxic cell death, dual cholinesterase inhibition, antioxidant activity coupled with the reduction of the immunoreactivity for the Aβ1-42, p-tau and GSK-3β indicating its potential to be screened further for various other models to determine the exact mechanism of action.