Suppression of Cisplatin-Induced Vomiting by Cannabis sativa in Pigeons: Neurochemical Evidences

A re-consideration of neural/receptor mechanisms in chemotherapy-induced nausea and vomiting: current scenario and future perspective

The neural mechanisms and the receptors behind the course of chemotherapy-induced nausea and vomiting (CINV) are well described and considered mechanistically multifactorial, whereas the neurobiology of nausea is not completely understood yet. Some of the anti-neoplastic medications like cisplatin result in biphasic vomiting response. The acute phase of vomiting is triggered mainly via the release of serotonin from the enterochromaffin (EC) cells in the gastrointestinal tract (GIT) and results in stimulation of dorsal vagal complex (DVC) of the vomiting center and the vomiting is initiated by downward communication to the gut via vagal efferents. Agonism of 5HT3 receptors is majorly involved in the mediation of the acute phase. Therefore, antagonists at 5HT3 receptors are effective in the management of acute-phase vomiting episodes. Likewise, Dopamine type 2 (D2) receptors, dopamine neurotransmitter, Muscarinic receptors (M3), GLP1 receptors, and histaminergic receptors (H1) are also implicated in the vomiting act as well. In continuation, Cannabinoid type 1 (CB1) receptors are also recommended and included in the guidelines as agonism of presynaptically located CB1 receptors inhibits the release of excitatory neurotransmitters responsible for vomiting initiation. The delayed phase involves the release of "Substance P" in the gut and results in the stimulation of neurokinin-1 (NK1) receptors centrally in the area postrema (AP) and nucleus tractus solitarius (NTS), subsequently the vomiting response. The current understanding is the existence of overlapping mechanisms of neurotransmitters, serotonin, dopamine, and substance P throughout the time course of CINV. Furthermore, the emetic neurotransmitters are released via calcium ion (Ca++)-dependent mechanisms, implicating the molecular targets of intracellular Ca++ signaling in emetic circuitry. The current review entails the neurobiology of nausea and vomiting induced by cancer chemotherapeutic agents and the recent approaches in the management.

Phytotherapeutic Approach in the Management of Cisplatin Induced Vomiting; Neurochemical Considerations in Pigeon Vomit Model

Cisplatin induced vomiting involves multiple mechanisms in its genesis and a single antiemetic agent do not cover both the phases (acute & delayed) of vomiting in clinics; necessitating the use of antiemetics in combination. Cannabis sativa and other selected plants have ethnopharmacological significance in relieving emesis. The aim of the present study was to investigate the intrinsic antiemetic profile of Cannabis sativa (CS), Bacopa monniera (BM, family Scrophulariaceae), and Zingiber officinale (ZO, family Zingiberaceae) in combinations against vomiting induced by highly emetogenic anticancer drug-cisplatin in pigeons. We have analysed the neurotransmitters which trigger the vomiting response centrally and peripherally. Electrochemical detector (ECD) was used for the quantification of neurotransmitters and their respective metabolites by high performance liquid chromatography in the brain stem (BS) and area postrema (AP) while peripherally in the small intestine. Cisplatin (7 mg/kg i.v.) induced reliable vomiting throughout the observation period (24 hrs). CS-HexFr (10 mg) + BM-MetFr (10 mg)–Combination 1, BM-ButFr (5 mg) + ZO-ActFr (25 mg)–Combination 2, ZO-ActFr (25 mg) + CS-HexFr (10 mg)–Combination 3, and CS-HexFr (10 mg) + BM-ButFr (5 mg)–Combination 4; provided ~30% (30 ± 1.1), 70% (12 ± 0.4; P < 0.01), 60% (19 ± 0.2; P < 0.05) and 90% (05 ± 0.1; P < 0.001) protection, respectively, against cisplatin induced vomiting as compared to cisplatin control. Standard MCP (30 mg) provided ~50% (23 ± 0.3) protection (P > 0.05). CS Hexane fraction (10 mg/kg), BM methanolic (10 mg/kg) and bacoside rich n-butanol fraction (5 mg/kg) and ZO acetone fraction (25 mg/kg) alone provided ~62%, 36%, 71%, and 44% protection, respectively, as compared to cisplatin control. The most effective and synergistic combination 4 was found to reduce 5HT and 5HIAA (P < 0.05–0.001) in all the brain areas area postrema (AP)+brain stem (BS) and intestine at the 3^rd hour of cisplatin administration. In continuation, at the 18^th of cisplatin administration reduction in dopamine (P < 0.001) in the AP and 5HT in the brain stem and intestine (P < 0.001) was observed. The said combination did not change the neurotransmitters basal levels and their respective metabolites any significantly. In conclusion, all the tested combinations offered protection against cisplatin induced vomiting to variable degrees, where combination 4 provided enhanced attenuation by antiserotonergic mechanism at the 3^rd hour while a blended antidopaminergic and antiserotonergic mechanism at the 18^th hour after cisplatin administration.

Casticin and chrysosplenol D from Artemisia annua L. induce apoptosis by inhibiting topoisomerase IIα in human non-small-cell lung cancer cells

BACKGROUND

Artemisia annua L. (A. annua) and its active components exhibit antitumour effects in many cancer cells. However, the biological processes and mechanisms involved are not well understood, especially for the treatment of non-small-cell lung cancer (NSCLC).

PURPOSE

This study aimed to comprehensively explore the biological processes of A. annua and its active components in NSCLC cells and to identify the mechanism by which these compounds induce apoptosis.

STUDY DESIGNS/METHODS

Cell viability and flow cytometry assays were used to evaluate the cytotoxicity of A. annua active components casticin (CAS) and chrysosplenol D (CHD) in A. annua in NSCLC cells. After treatment with CAS and CHD, A549 cells were subjected to RNA sequencing (RNA-seq) analysis, differentially expressed genes (DEGs) were screened and subjected to functional enrichment analysis (KEGG and GO analysis) as well as protein interaction network analysis. The key targets associated with apoptosis induction in A549 cells were screened by Cytoscape, and the screened DEGs were validated by qRT-PCR. Immunoblotting, immunofluorescence, and molecular docking assays were used to determine whether CAS and/or CHD could induce apoptosis in NSCLC cells by inducing DNA damage through down-regulation of topoisomerase IIα (topo IIα) expression. The same experiments were verified again in the H1299 lung cancer cell line.

RESULTS

CAS and CHD inhibited NSCLC cells proliferation in a time- and dose-dependent manner, and significantly induced apoptosis. A total of 115 co-upregulated DEGs and 277 co-downregulated DEGs were identified in A549 cells following treatment with CAS and CHD. Comprehensive and systematic data about biological processes and mechanisms were obtained. DNA damage pathways and topo IIα targets were screened to study the apoptosis effects of CAS and CHD on NSCLC cells. CAS and CHD may be able to induce DNA damage by binding to topo IIα-DNA and reducing topo IIα activity.

CONCLUSION

This study suggested that CAS and CHD may reduce topo IIα activity by binding to topo IIα-DNA, affecting the replication of DNA, triggering DNA damage, and inducing apoptosis. It described a novel mechanism associated with topo IIα inhibition to reveal a novel role for CAS and CHD in A. annua as potential anticancer agents and/or adjuvants in NSCLC cells.

Cannabinoid drugs against chemotherapy-induced adverse effects: focus on nausea/vomiting, peripheral neuropathy and chemofog in animal models

Although new drugs are being developed for cancer treatment, classical chemotherapeutic agents are still front-line therapies, despite their frequent association with severe side effects that can hamper their use. Cannabinoids may prevent or palliate some of these side effects. The aim of the present study is to review the basic research which has been conducted evaluating the effects of cannabinoid drugs in the treatment of three important side effects induced by classical chemotherapeutic agents: nausea and vomiting, neuropathic pain and cognitive impairment. Several published studies have demonstrated that cannabinoids are useful in preventing and reducing the nausea, vomits and neuropathy induced by different chemotherapy regimens, though other side effects can occur, such as a reduction of gastrointestinal motility, along with psychotropic effects when using centrally-acting cannabinoids. Thus, peripherally-acting cannabinoids and new pharmacological options are being investigated, such as allosteric or biased agonists. Additionally, due to the increase in the survival of cancer patients, there are emerging data that demonstrate an important cognitive deterioration due to chemotherapy, and because the cannabinoid drugs have a neuroprotective effect, they could be useful in preventing chemotherapy-induced cognitive impairment (as demonstrated through studies in other neurological disorders), but this has not yet been tested. Thus, although cannabinoids seem a promising therapeutic approach in the treatment of different side effects induced by chemotherapeutic agents, future research will be necessary to find pharmacological options with a safer profile. Moreover, a new line of research awaits to be opened to elucidate their possible usefulness in preventing cognitive impairment.

Phytochemical Analysis, α-Glucosidase and Amylase Inhibitory, and Molecular Docking Studies on Persicaria hydropiper L. Leaves Essential Oils

Objective

Medicinal plants and essentials oils are well known for diverse biological activities including antidiabetic potential. This study was designed to isolate essential oils from the leaves of Persicaria hydropiper L. (P. hydropiper), perform its phytochemical analysis, and explore its in vitro antidiabetic effects.

Materials and Methods

P. hydropiper leaves essential oils (Ph.Los) were extracted using a hydrodistillation apparatus and were subjected to phytochemical analysis using the gas chromatography mass spectrometry (GC-MS) technique. Ph.Lo was tested against two vital enzymes including α-glucosidase and α-amylase which are important targets in type-2 diabetes. The identified compounds were tested using in silico approaches for their binding affinities against the enzyme targets using MOE-Dock software.

Results

GC-MS analysis revealed the presence of 141 compounds among which dihydro-alpha-ionone, cis-geranylacetone, α-bulnesene, nerolidol, β-caryophyllene epoxide, and decahydronaphthalene were the most abundant compounds. Ph.Lo exhibited considerable inhibitory potential against α-glucosidase enzyme with 70% inhibition at 1000 μg mL⁻¹ which was the highest tested concentration. The inhibitory activity of positive control acarbose was 77.30 ± 0.61% at the same tested concentration. Ph.Lo and acarbose exhibited IC₅₀ of 170 and 18 µg mL⁻¹ correspondingly. Furthermore, dose-dependent inhibitions were observed for Ph.Lo against α-amylase enzyme with an IC₅₀ of 890 μg mL⁻¹. The top-ranked docking conformation was observed for β-caryophyllene epoxide with a docking score of -8.3182 against α-glucosidase, and it has established seven hydrogen bonds and one H-pi interaction at the active site residues (Phe 177, Glu 276, Arg 312, Asp 349, Gln 350, Asp 408, and Arg 439). Majority of the identified compounds fit well in the binding pocket of Tyr 62, Asp 197, Glu 233, Asp 300, His 305, and Ala 307 active residues of α-amylase. β-Caryophyllene epoxide was found to be the most active inhibitor with a docking score of -8.3050 and formed five hydrogen bonds at the active site residues of α-amylase. Asp 197, Glu 233, and Asp 300 active residues were observed to be making polar interactions with the ligand.

Conclusions

The current study revealed that Ph.Lo is rich in bioactive metabolites which might contribute to its enzyme inhibitory potential. Inhibition of these enzymes is the key target in reducing postprandial hyperglycemia. However, further detailed in vivo studies are required for their biological and therapeutic activities.

HPLC-DAD phenolics analysis, α-glucosidase, α-amylase inhibitory, molecular docking and nutritional profiles of Persicaria hydropiper L

BACKGROUND

Natural phenolic compounds and Phenolics-rich medicinal plants are also of great interest in the management of diabetes. The current study was aimed to analyze phenolics in P. hydropiepr L extracts via HPLC-DAD analysis and assess their anti-diabetic potentials using in-vitro and in-silico approaches.

METHODS

Plant crude methanolic extract (Ph.Cme) was evaluated for the presence of phenolic compounds using HPLC-DAD analysis. Subsequently, samples including crude (Ph.Cr), hexane (Ph.Hex), chloroform (Ph.Chf), ethyl acetate (Ph.EtAc), butanol (Ph.Bt), aqueous (Ph.Aq) and saponins (Ph.Sp) were tested for α-glucsidase and α-amylase inhibitory potentials and identified compounds were docked against these target enzymes using Molecular Operating Environment (MOE) software. Fractions were also analyzed for the nutritional contents and acute toxicity was performed in animals.

RESULTS

In HPLC-DAD analysis of Ph.Cme, 24 compounds were indentfied and quantified. Among these, Kaemferol-3-(p-coumaroyl-diglucoside)-7-glucoside (275.4 mg g- 1), p-Coumaroylhexose-4-hexoside (96.5 mg g- 1), Quercetin-3-glucoronide (76.0 mg g- 1), 4-Caffeoylquinic acid (58.1 mg g- 1), Quercetin (57.9 mg g- 1), 5,7,3'-Trihydroxy-3,6,4',5'-tetramethoxyflavone (55.5 mg g- 1), 5-Feruloylquinic acid (45.8 mg g- 1), Cyanidin-3-glucoside (26.8 mg g- 1), Delphinidin-3-glucoside (24 mg g- 1), Quercetin-3-hexoside (20.7 mg g- 1) were highly abundant compounds. In α-glucosidase inhibition assay, Ph.Sp were most effective with IC50 value of 100 μg mL-1. Likewise in α-amylase inhibition assay, Ph.Chf, Ph.Sp and Ph.Cme were most potent fractions displayed IC50 values of 90, 100 and 200 μg mL-1 respectively. Docking with the α-glucosidase enzyme revealed top ranked conformations for majority of the compounds with Kaemferol-3-(p-coumaroyl-diglucoside)-7-glucoside as the most active compound with docking score of - 19.80899, forming 14 hydrogen bonds, two pi-H and two pi-pi linkages with the Tyr 71, Phe 158, Phe 177, Gln 181, Arg 212, Asp 214, Glu 276, Phe 300, Val 303, Tyr 344, Asp 349, Gln 350, Arg 439, and Asp 408 residues of the enzyme. Likewise, docking with α-amylase revealed that most of the compounds are well accommodated in the active site residues (Trp 59, Tyr 62, Thr 163, Leu 165, Arg 195, Asp 197, Glu 240, Asp 300, His 305, Asp 356) of the enzyme and Cyanidin-3-rutinoside displayed most active compound with docking score of - 15.03757.

CONCLUSIONS

Phytochemical studies revealed the presence of highly valuable phenolic compounds, which might be responsible for the anti-diabetic potentials of the plant samples.

Flavonoids containing Vitex negundo extract displayed calcium channels blocking property underlying its anti-diarrheal and anti-spasmodic activities

Diarrhea is a major health problem and despite of interventions, it remains a substantial cause of mortality and morbidity. In this study, a flavonoids-rich Vitex negundo extract was mechanistically evaluated for its effectiveness in diarrheal diseases. The Vitex negundo ethanolic extract was subjected to extraction for isolation of total flavonoids and qualitative phytochemical analysis. The acute toxicity of flavonoids-extract was done in mice to assess its safety and tolerability. The anti-diarrhoeal activity was determined using the castor oil induced diarrhea mouse model at doses of 10, 30 and 100 mg/kg in relation to loperamide (10 mg/kg, oral). The antispasmodic profile was determined by using cut pieces of rabbit’s jejunum in Tyrode’s solutions, employing acetylcholine (0.03μM) as a tissue stabilizer and verapamil, as a calcium channel blocker. The preliminary qualitative analysis of extract revealed different phytochemicals, in addition to flavonoids. The acute toxicity profile showed that the flavonoids-extract is safe and tolerable (LD50 = 1678 mg/kg). In the tissue experiments, the total flavonoids exhibited an EC50 of 1.52 mg/mL and showed maximum relaxation of spontaneous contractions at 5.0 mg/mL and against high-K + induced contractions at 3 mg/mL (EC50 = 0.43 mg/mL). The spasmolytic activity of total flavonoids was comparable to verapamil which suggests that the activity might be due to the blockade of calcium channels. The flavonoids extract (0.1, 0.3 and 1.0 mg/mL) produced an adequate right shift in the calcium concentration response curve as compared to the control (EC50 value = –2.67 mg/mL), which confirmed that the extract has calcium channel blocking activity.

Clinical Investigation on the Impact of Cannabis Abuse on Thyroid Hormones and Associated Psychiatric Manifestations in the Male Population

Cannabis abuse is a common public health issue and may lead to considerable adverse effects. Along with other effects, the dependence on cannabis consumption is a serious problem which has significant consequences on biochemical and clinical symptoms. This study intends to evaluate the harmful effects of the use of cannabis on thyroid hormonal levels, cardiovascular indicators, and psychotic symptoms in the included patients. This prospective multicenter study was conducted on cannabis-dependent patients with psychotic symptoms (n = 40) vs. healthy control subjects (n = 40). All participants were evaluated for psychiatric, biochemical, and cardiovascular physiological effects. Patients were selected through Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV criteria and urine samples, exclusively for the evaluation of cannabis presence. Serum thyroid stimulating hormone (TSH), T3, and T4 levels were measured using the immunoassay technique. Patients were assessed for severity of depressive, schizophrenic, and manic symptoms using international ranking scales. Various quantifiable factors were also measured for the development of tolerance by cannabis. Among the patients of cannabis abuse, 47.5% were found with schizophrenia, 20% with schizoaffective symptoms, 10% with manic symptoms, and 22.5% with both manic and psychotic symptoms. In the group-group and within-group statistical analysis, the results of thyroid hormones and cardiovascular parameters were non-significant. The psychiatric assessment has shown highly significant (p < 0.001) difference of positive, negative, general psychopathology, and total scores [through Positive and Negative Syndrome Scale (PANSS) rating scales] in patients vs. the healthy control subjects. The study revealed that cannabis abuse did not significantly alter thyroid hormones and cardiovascular parameters due to the development of tolerance. However, the cannabis abuse might have a significant contributing role in the positive, negative, and manic symptoms in different psychiatric disorders.

The flavonoid 6-hydroxyflavone prevention of cisplatin-induced nephrotoxicity

In this study, the flavonoid, 6-hydroxyflavone was investigated for its renal protective activity in the cisplatin rat model of nephrotoxicity. Male Sprague-Dawley rats weighing 200-250 g were included in the study. 6-Hydroxyflavone was daily administered at 25 and 50 mg/kg (i.p.), while ascorbic acid was used as a positive control and injected (i.p.) at 50 mg/kg for 15 days. The nephrotoxicity was evoked with a single cisplatin injection at 7.5 mg/kg on the tenth day of treatment. The renal function and levels of oxidative stress markers were assessed. Each tissue slide of different groups was observed under a compound microscope attached with a digital camera. Cisplatin significantly decreased the overall body weight with an increase in serum creatinine and urea and production of severe histopathological and oxidative stress in the kidneys. The daily treatment with 6-hydroxyflavone significantly attenuated the cisplatin associated detrimental changes in the body weight, and serum levels of creatinine and urea at both 25 mg/kg (P<0.05) and 50 mg/kg (P<0.01). The 6-hydroxyflavone treatment also preserved the renal histoarchitecture from the toxicological influence of cisplatin as evident from a significant reduction in the severity of histopathological changes in the renal tissues. Moreover, 6-hydroxyflavone also reduced the cisplatin-induced lipid peroxidation and corrected the renal antioxidant status. A similar protective effect was observed with the positive control, ascorbic acid (50 mg/kg). These findings show that the flavonoid 6-hydroxyflavone has potential nephroprotective properties and can be used for the management of chemotherapy associated renal disturbances.

Potential Role of Plant Extracts and Phytochemicals Against Foodborne Pathogens

Foodborne diseases are one of the major causes of morbidity and mortality, especially in low-income countries with poor sanitation and inadequate healthcare facilities. The foremost bacterial pathogens responsible for global outbreaks include Salmonella species, Campylobacter jejuni, Escherichia coli, Shigella sp., Vibrio, Listeria monocytogenes and Clostridium botulinum. Among the viral and parasitic pathogens, norovirus, hepatitis A virus, Giardia lamblia, Trichinella spiralis, Toxoplasma and Entamoeba histolytica are commonly associated with foodborne diseases. The toxins produced by Staphylococcus aureus, Bacillus cereus and Clostridium perfringens also cause these infections. The currently available therapies for these infections are associated with various limited efficacy, high cost and side-effects. There is an urgent need for effective alternative therapies for the prevention and treatment of foodborne diseases. Several plant extracts and phytochemicals were found to be highly effective to control the growth of these pathogens causing foodborne infections in in vitro systems. The present review attempts to provide comprehensive scientific information on major foodborne pathogens and the potential role of phytochemicals in the prevention and treatment of these infections. Further detailed studies are necessary to evaluate the activities of these extracts and phytochemicals along with their mechanism of action using in vivo models.

Pharmacological Evaluation of Aldehydic-Pyrrolidinedione Against HCT-116, MDA-MB231, NIH/3T3, MCF-7 Cancer Cell Lines, Antioxidant and Enzyme Inhibition Studies

Purpose

The current work was designed to synthesize a bioactive derivative of succinimide and evaluate it for anti-Alzheimer, anticancer and anti-diabetic potentials.

Methods

The compound was synthesized by Michael addition of butyraldehyde with N-phenylmaleimide. The synthesized compound was screened for biological potentials including anti-cholinesterase, in-vitro anti-diabetic, antioxidant and anthelmintic potentials. The anti-cholinesterase potential was evaluated against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), anti-diabetic potential against α-glucosidase, antioxidant potential against ABTS, DPPH and H₂O₂ and anthelmintic potential against Perethima posthuma and Ascaridia galli respectively.

Results

The compound demonstrated significant AChE and BChE inhibition i.e., 71.34±1.92 and 73.42 ±1.92 at the concentration of 1000 µg/mL respectively. Other dilutions exhibited concentration-dependent inhibitory activity against both enzymes. In the MTT assay, the newly synthesized compound was found active against all of the cell lines viz, HCT-116, MDA-MB231, NIH/3T3 and MCF-7 and the highest cytotoxicity potential was observed against the colon cancer cell line (HCT-116) with an IC₅₀ value of 78 µg/mL exhibiting its highest potential. Moreover, the compound exhibited prominent α-glucosidase inhibitory potentials (79.86±2.54% at 1000 µg/mL) with IC₅₀ value of 156.23 µg/mL. Further, our test compound exhibited considerable scavenging activity against DPPH, ABTS and H₂O₂ free radicals with percent inhibitions of 75.84±1.58, 72.85±1.17 and 54.82±1.82 and IC₅₀ values of 84.36, 139.74 and 752.21 µg/mL respectively. Our test sample exhibited significant anthelmintic potentials. It demonstrated significant paralysis and death of the test worms in an unbelievably short time in comparison with albendazole.

Conclusion

Going into the detail of all observations, it may be deduced that the newly synthesized succinimide derivative could be an important drug candidate against neurodegenerative disorders like Alzheimer's disease, cancer, diabetes mellitus and worms. Further detailed studies in animal models are required for in-vivo analysis of the compound.

Gingerol inhibits cisplatin-induced acute and delayed emesis in rats and minks by regulating the central and peripheral 5-HT, SP, and DA systems

Abstract

Gingerol, a biologically active component in ginger, has shown antiemetic properties. Our study aimed to explore the underlying mechanisms of gingerol on protecting rats and minks from chemotherapy-induced nausea and vomiting. The preventive impact of gingerol was evaluated in the pica model of rats and the vomiting model of minks induced by cisplatin at every 6 h continuously for a duration of 72 h. Animals were arbitrarily separated into blank control group, simple gingerol control group, cisplatin control group, cisplatin + metoclopramide group, cisplatin + three different doses gingerol group (low-dose; middle-dose; high-dose). The area postrema as well as ileum damage were assessed using H&E stain. The levels of 5-TH, 5-HT₃ receptor, TPH, SERT, SP, NK₁ receptor, PPT, NEP, DA, D2R, TH, and DAT were determined using immunohistochemistry or qRT-PCR in rats and minks. All indicators were measured in the area postrema along with ileum. The kaolin intake by rats and the incidence of CINV of minks were significantly decreased after pretreatment with gingerol in a dosage-dependent way for the duration of 0–24-h and 24–72-h. Gingerol markedly decreased the levels of 5-TH, 5-HT₃ receptor, TPH, SP, NK₁ receptor, PPT, DA, D2R, TH, alleviated area postrema as well as ileum damage, and increased the accumulation of SERT, NEP, DAT in the area postrema along with ileum of rats and minks. Gingerol alleviates cisplatin-induced kaolin intake of rats and emesis of minks possibly by regulating central and peripheral 5-HT system, SP system and DA system.

Graphic abstract

Efficacy of a topical gabapentin gel in a cisplatin paradigm of chemotherapy-induced peripheral neuropathy

BACKGROUND

Chemotherapy induced peripheral neuropathy (CIPN) has been attributed to chemotherapeutic agents such as cisplatin which adversely affect disease outcome leading to increased cancer related morbidity. The clinical efficacy of systemic gabapentin in neuropathic pain management is limited by central side-effects in addition to a scarceness of conclusive evidence of its efficacy in CIPN management. The topical route therefore may provide a relatively safe alternative for neuropathic pain treatment in general and CIPN in particular.

METHODS

Cisplatin induced neuropathic nociception was established in rats after a single weekly cisplatin injection (3.0 mg/kg, intraperitoneally) for 4 weeks. The evoked neuropathic sensation of allodynia was assessed by plantar application of von Frey monofilaments as the paw withdrawal threshold (PWT), whereas the expression of heat-hypoalgesia was determined on a hot-plate as paw withdrawal latency (PWL). Gabapentin gel (10% w/w) was applied three-times daily on the hind paws while in a concurrent systemic study, gabapentin was administered daily (75 mg/kg, intraperitoneally) for 4 weeks. To assess any evidence of neurological adverse symptoms of cisplatin and the central side-effect propensity of systemic or topical gabapentin, evaluation of motor coordination (rotarod test) and gait (footprint analysis) were performed.

RESULTS

Cisplatin invoked a progressive development of neuropathic hind paw allodynia (decreased PWT, days 7-28) and heat hypoalgesia (increased PWL, days 21-28). Topical gabapentin significantly delayed the expression of both allodynia on protocol days 21 and 28 and heat-hypoalgesia (day 28). Systemic gabapentin displayed a comparative anti-neuropathic predisposition through a sustained suppression of tactile allodynia on days 14 and 21-28 as well as thermal hypoalgesia (days 21 and 28). Systemic gabapentin also impaired motor coordination and gait thus affirming its clinically documented central side effects, but these outcomes were not evident after topical treatment.

CONCLUSIONS

Both topical and systemic gabapentin exhibit a propensity to attenuate CIPN in a cisplatin paradigm. Gabapentin applied topically may therefore provide an adjunctive or alternative route for CIPN management upon cessation of systemic medications due to intolerable side-effects.

Synergistic interactions of phytochemicals with antimicrobial agents: Potential strategy to counteract drug resistance

The emergence of multidrug resistant (MDR) pathogens is a global threat and has created problems in providing adequate treatment of many infectious diseases. Although the conventional antimicrobial agents are quite effective against several pathogens, yet there is a need for more effective antimicrobial agents against MDR pathogens. Herbal drugs and phytochemicals have been used for their effective antimicrobial activity from ancient times and there is an increasing trend for development of plant based natural products for the prevention and treatment of pathogenic diseases. One of the strategies for effective resistance modification is the use of antimicrobial agent-phytochemical combinations that will neutralize the resistance mechanism, enabling the drug to still be effective against resistant microbes. These phytochemicals can work by several strategies, such as inhibition of target modifying and drug degrading enzymes or as efflux pumps inhibitors. A plethora of herbal extracts, essential oils and isolated pure compounds have been reported to act synergistically with existing antibiotics, antifungals and chemotherapeutics and augment the activity of these drugs. Considerable increases in the susceptibility pattern of several microbes towards the natural antimicrobials and their combinations were observed as indicated by significant decline in minimum inhibitory concentrations. This review paper summarizes the current developments regarding synergistic interactions of plant extracts and isolated pure compounds in combination with existing antibacterial, antifungal agents and chemotherapeutics. The effect of these agents on the susceptibility patterns of these pathogens and possible mechanisms of action are described in detail. In conclusion, many phytochemicals in combination with existing drugs were found to act as resistance modifying agents and proper combinations may rescue the efficacy of important lifesaving antimicrobial agents.

Bio-guided profiling and HPLC-DAD finger printing of Atriplex lasiantha Boiss

BACKGROUND

Plants represent an intricate and innovative source for the discovery of novel therapeutic remedies for the management of various ailments. The current study has been aimed to validate the therapeutic potential of ethnomedicinally significant plant Atriplex lasiantha Boiss.

METHODS

The polarity based extraction process was carried out using fourteen solvents to figure out best extraction solvent and bioactive fractions. Total phenolic-flavonoids contents were quantified colorimetrically and polyphenolics were measured using HPLC-DAD analysis. Moreover, the test samples were tested against several diseases targets following various assays including free radicals scavenging, antibacterial, antifungal, cytotoxic and antileishmanial assay.

RESULTS

Among the solvent fractions, maximum yield was obtained with methanol-water extract i.e., 11 ± 0.49%. Maximum quantity of gallic acid equivalent phenolic content and quercetin equivalent flavonoid content were quantified in methanol-ethyl acetate extract of A. lasiantha. Significant quantity of rutin i.e., 0.3 μg/mg was quantified by HPLC analysis. The methanol-ethyl acetate extract of A. lasiantha exhibited maximum total antioxidant and total reducing power with 64.8 ± 1.16 AAE/mg extract respectively, while showing 59.8 ± 1.07% free radical scavenging potential. A significant antibacterial potential was exhibited by acetone-distilled water extract of A. lasiantha with 11 ± 0.65 mm zone of inhibition against B. subtilis. Considerable antifungal activity was exhibited by ethyl acetate-n-hexane extract of aerial part of A. lasiantha with 14 ± 1.94 mm zone of inhibition against A. fumigatus. Highest percentage of α-amylase inhibition (41.8 ± 1.09%) was observed in ethyl acetate-n-hexane extract. Methanol-acetone extract of A. lasiantha demonstrated significant inhibition of hyphae formation with 11 ± 0.49 mm bald zone of inhibition. Significant in-vitro cytotoxicity against Hep G2 cell line has been exhibited by methanol-chloroforms extract of A. lasiantha.

CONCLUSION

The current study reveals the prospective potential of Atriplex lasiantha Boiss. for the discovery of biologically active compounds through bioassay guided isolation against various diseases.