Synthetic and natural antioxidants attenuate cisplatin-induced vomiting

The development of a novel antioxidant-based antiemetic drug to improve quality of life during anticancer therapy

Anticancer agents can effectively treat several types of cancers but are often limited in clinical settings due to various adverse effects. In particular, nausea and vomiting are serious side effects that markedly reduce the patients' quality of life. Accordingly, the development of novel antiemetic drugs that lack side effects is crucial, given that most conventional antiemetic drugs are known to possess side effects. In addition, reactive oxygen species generated by anticancer agents are involved in nausea and vomiting; hence, appropriate antioxidants might also be effective toward nausea and vomiting.

Silicon (Si)-based agents can abundantly generate antioxidant hydrogen in the intestine. Therefore, we assessed whether Si-based agents could be effective against nausea associated with anticancer agents in cisplatin-injected mice. We observed numerous neurons expressing c-Fos protein, a neuronal activity marker, in the nausea-associated regions of the dorsal medulla (area postrema, nuclei of the solitary tract, and dorsal vagal nuclei) 24 h after cisplatin injection. Conversely, mice fed a diet containing 2.5% Si-based agents showed a reduction in c-Fos-positive neurons.

These findings revealed that the Si-based agent alleviated cisplatin-induced nausea. Si-based agents demonstrate potent antioxidant effects by producing hydrogen, which has no known side effects and will be a safer antiemetic agent and greatly help improve the quality of life of patients undergoing anticancer drug treatment.

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Si-based agent can continuously generate a large amount of hydrogen, which has an antioxidant effect.

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Cisplatin was used at a concentration that is not nephrotoxic and induces only nausea and vomiting.

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Si-based agent alleviated nausea and vomiting associated with cisplatin administration.

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.

The antioxidant N-(2-mercaptopropionyl)-glycine (tiopronin) attenuates expression of neuropathic allodynia and hyperalgesia

The current pharmacotherapy of neuropathic pain is inadequate as neuropathic pain involves varied clinical manifestations with multifactorial etiology, modulated by a cascade of physical and molecular events leading to different clinical presentations of pain. There is an accumulating evidence of the involvement of oxidative stress in neuropathy, and antioxidants have shown promise in mitigating neuropathic pain syndromes. To explore the evidence supporting this beneficial proclivity of antioxidants, this study investigated the antinociceptive effectiveness of N-(2-mercaptopropionyl)glycine or tiopronin, a well-recognized aminothiol antioxidant, in a refined chronic constriction injury (CCI) rat model of neuropathic pain. Tiopronin (10, 30, and 90 mg/kg, i.p.) and pregabalin (30 mg/kg, i.p.) were administered daily after CCI surgery. The neuropathic paradigms of mechanical/cold allodynia and mechanical/heat hyperalgesia were assessed on days 3, 7, 14, and 21 post-nerve ligation. At the end of study, malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) levels were estimated in the sciatic nerve, dorsal root ganglion, and spinal cord for assessing the extent of oxidative stress. The expression of neuropathic nociception was attenuated by tiopronin which was observed as a significant attenuation of CCI-induced allodynia and hyperalgesia. Tiopronin reversed the neuronal oxidative stress by significantly reducing MDA, and increasing SOD, CAT, and GSH levels. Pregabalin also showed similar beneficial propensity on CCI-induced neuropathic aberrations. These findings suggest prospective neuropathic pain attenuating efficacy of tiopronin and further corroborated the notion that antioxidants are effective in mitigating the development and expression of neuropathic pain and underlying neuronal oxidative stress.

Impact of genetic factors on platinum-induced gastrointestinal toxicity

Severe gastrointestinal (GI) toxicity is a common side effect after platinum-based chemotherapy. The incidence and severity of GI toxicity vary among patients with the same chemotherapy. Genetic factors involved in platinum transport, metabolism, detoxification, DNA repair, cell cycle control, and apoptosis pathways may account for the interindividual difference in GI toxicity. The influence of gene polymorphisms in the platinum pathway on GI toxicity has been extensively analyzed. Variations in study sample size, ethnicity, design, treatment schedule, dosing, endpoint definition, and assessment of toxicity make it difficult to precisely interpret the results. Hence, we conducted a review to summarize the most recent pharmacogenomics studies of GI toxicity in platinum-based chemotherapy and identify the most promising avenues for further research.

Antibacterial, Antibiofilm and Antioxidant Activities of some Medicinal Plants from Pharmacopoeia of Tassili N’ajjer

Three plants adopted by nomads at Tassili n’ajjer (south Algeria) in traditional medicine namely, Cymbopogon schoenanthus, Anabasis articulata and Salvia chudaei, were analysed for theirs antibacterial, antibiofilm and antioxidant properties. Total flavonoid and phenolic contents were measured with 2% AlCl3 and Folin-Ciocalteu’s reagent method, respectively. The antibacterial propertie was investigated by measurement of MIC of plants extract inhibing bacterial proliferation. The antibiofilm propertie was calculated by fluorescent quantization of the DAPI labeled bacterial biomass fixed on the surface and by COMSTAT analysis of confocal scanning laser microscopy (CSLM) images. DPPH radical scavenging and β-carotene/linoleate bleaching methods were used to determine the antioxidant activities of the plants. Total phenolic content was ranged from 21.98 to 2.51 (gallic acid equivalents mg/g methanolic extracts) and the total flavonoid content ranged from 19.27 to 1.65 (catechin equivalent mg/g methanolic extracts). Antibacterial activity against four Gram positive bacteria was shown with plants extracts. The biofilm inhibition concentration of extracts decreasing 50% of biofilm cell density (BIC50) for Salvia chudaei and Cymbopogon schoenanthus extracts ranges from 1 to 10 µg/mL. CSLM images analysis revealed that both surface covering by germ and three dimensional development of the biofilm were reduced with plants extracts. For antioxidant activities, the methanol extracts of the plants evaluated showed low antioxidant activity, with a IC50 between 1.94 and 6.16 mg/ml. Thus, Our systematic research showed that this three common plants of Sahara desert has diversified phytochemicals possessing satisfying extent of antimicrobial, antibiofilm and antioxidant activities.

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.

D-methionine improves cisplatin-induced anorexia and dyspepsia syndrome by attenuating intestinal tryptophan hydroxylase 1 activity and increasing plasma leptin concentration

BACKGROUND

Cisplatin is a widely used antineoplastic drug. However, cisplatin-induced dyspepsia syndromes, including delayed gastric emptying, gastric distension, early satiety, nausea, and vomiting, often force patients to take doses lower than those prescribed or even refuse treatment. D-methionine has an appetite-enhancing effect and alleviates weight loss during cisplatin treatment.

METHODS

This work established a model of anorexia and dyspepsia symptoms with intraperitoneal injection of cisplatin (5 mg/kg) once a week for three cycles. Presupplementation with or without D-methionine (300 mg/kg) was performed. Orexigenic and anorexigenic hormones (ghrelin, leptin, and glucagon-like peptide-1), tryptophan hydroxylase 1 (TPH1), 5-hydroxytryptamine receptors (5-HT_2C and 5-HT₃ ), and hypothalamic feeding-related peptides were measured by immunohistochemistry staining, enzyme-linked immunosorbent assay, and real-time PCR assay.

KEY RESULTS

Cisplatin administration caused marked decrease in appetite and body weight, promoted adipose and fat tissue atrophy, and delayed gastric emptying and gastric distension, and D-methionine preadministration prior to cisplatin administration significantly ameliorated these side effects. Besides, cisplatin induced an evident increase in serum ghrelin level, TPH1 activity, and 5-HT₃ receptor expression in the intestine and decreased plasma leptin levels and gastric ghrelin mRNA gene expression levels. D-methionine supplementation recovered these changes. The expression of orexigenic neuropeptide Y/agouti-related peptide and anorexigenic cocaine- and amphetamine-regulated transcript proopiomelanocortin neurons were altered by D-methionine supplementation in cisplatin-induced anorexia rats.

CONCLUSIONS AND INFERENCES

D-methionine supplementation prevents cisplatin-induced anorexia and dyspepsia syndrome possibly by attenuating intestinal tryptophan hydroxylase 1 activity and increasing plasma leptin concentration. Therefore, D-methionine can be used as an adjuvant therapy for treating cisplatin-induced adverse effects.

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.

Comparative study between lutein and its liposomal form on cisplatin-induced retinal injury in rabbits

Aim: Lutein is a potent antioxidant that is found in ocular tissue. It protects retina against oxidative stress. We aimed to increase lutein efficiency by encapsulating it into liposome and testing its neuroprotective effect against cisplatin-induced retinal injury in rabbits. Materials and methods: Twenty-four male, New Zealand, rabbits weighing 1.5-2 kg were divided into four groups, as follows: group I as a control, group II received cisplatin, group III received free lutein + cisplatin and group IV received liposomal lutein + cisplatin. All treatments were administrated twice per week for 14 days. Electroretinogram (ERG) was recorded for all rabbits just before decapitation. Then, the retinae were subjected to histopathological evaluations and comet assay. Results: Results indicated significant decrease (p ˂ 0.01) in ERG waves, significant increase (p ˂ 0.01) in all parameters of comet assay (% tailed cells, tail length, DNA% in tail and tail moment), severe fragmentation in photoreceptors layer and changes in inner retina after the administration of cisplatin. There were some sort of improvement in ERG, comet assay and the histological results after the administration of lutein with cisplatin, whereas these tests yielded values comparable to control in the liposomal lutein group. Conclusions: Liposomal lutein administration could prevent the detrimental effects of cisplatin on the retina, while avoiding the use any artificial chemicals. The latter might be preferable but with possible highly toxic effects. Results were promising and worse further future investigations.

L. Ambrósio R, Calonga L, Curi SFBB, de T. Leme MF, Chone CT, Altemani JMC, Mazzola PG, Malaguti C, Vercesi AE, Lima CSP, Moriel P. Can acetylcysteine ameliorate cisplatin-induced toxicities and oxidative stress without decreasing antitumor efficacy? A randomized, double-blind, placebo-controlled trial involving patients with head and neck cancer

The protective antioxidant activity of acetylcysteine (NAC) against toxicity due to cisplatin has been reported in experimental models; however, its efficacy in patients has not been elucidated. The aim of this study was to investigate the possible protective effect of NAC on cisplatin-induced toxicity and the effect of NAC on clinical response and oxidative stress in patients treated for head and neck cancer. This was a randomized, double-blind, placebo-controlled trial conducted in patients receiving high-dose cisplatin chemotherapy concomitant to radiotherapy. Patients were randomly assigned to groups and received: (a) 600 mg NAC syrup, orally once daily at night for 7 consecutive days or (b) placebo, administered similarly to NAC. Nephro-, oto-, hepato-, myelo-, and gastrointestinal toxicities, clinical responses, and plasma and cellular markers of oxidative stress were evaluated. Fifty-seven patients were included (n = 28, NAC arm; and n = 29, placebo arm). A high prevalence of most types of toxicities was observed after cisplatin chemotherapy; however, the parameters were similar between the two groups. There was a predominance of partial response to treatment. In the cellular and plasmatic oxidative stress analyses, minor differences were observed. Overall, there was no statistically significant difference between the groups for all outcomes. These findings show that low-dose oral NAC does not protect patients with head and neck cancer from cisplatin-induced toxicities and oxidative stress. The antitumor efficacy of cisplatin was apparently not impaired by NAC.

Role of epigenetic mechanisms in cisplatin-induced toxicity

Cisplatin (CDDP) is a highly effective antineoplastic agent, widely used in the treatment of various malignant tumors. However, its major problems are side effects associated to toxicity. Considerable inter-individual differences have been reported for CDDP-induced toxicity due to genetic and epigenetic factors. Genetic causes are well described; however, epigenetic modifications are not fully addressed. In the last few years, many evidences were found linking microRNA to the development of CDDP-mediated toxicity, particularly nephrotoxicity. In this review, we described how genetic and epigenetic modifications can be important determinants for the development of toxicity in patients treated with CDDP, and how these alterations may be interesting biomarkers for monitoring toxicity induced by CDDP. Considering the validation in different studies, we suggest that miR-34a, -146b, -378a, -192, and -193 represent an attractive study group to evaluate potential biomarkers to detect CDDP-related nephrotoxicity.

Protective effect of rutin supplementation against cisplatin-induced Nephrotoxicity in rats

Background

Cisplatin (CP) is commonly used in the treatment of different types of cancer but nephrotoxicity has been a major limiting factor. Therefore, the present study aimed to study the possible protective effect of rutin against nephrotoxicity induced by cisplatin in rats.

Methods

Forty male Wistar albino rats were randomly divided into 4 groups. Rats of group 1 control group intraperitoneal (i.p.) received 2.5 ml/kg, group 2 CP group received single dose 5 mg/kg cisplatin i.p. group 3 rutin group orally received 30 mg/kg rutin group 4 (CP plus rutin) received CP and rutin as in group 2 and 3. Kidneys were harvested for histopathology and for the study the gene expression of c-Jun N-terminal kinases (JNK), Mitogen-activated protein kinase 4 (MKK4), MKK7, P38 mitogen-activated protein kinases (P38), tumor necrosis factors alpha (TNF-α), TNF Receptor-Associated Factor 2 (TRAF2), and interleukin-1 alpha (IL-1-α).

Results

The cisplatin single dose administration to rats induced nephrotoxicity associated with a significant increase in blood urea nitrogen (BUN) and serum creatinine and significantly increase Malondialdehyde (MDA) in kidney tissues by 230 ± 5.5 nmol/g compared to control group. The animal treated with cisplatin showed a significant increase in the expression levels of the IL-1α (260%), TRFA2 (491%), P38 (410%), MKK4 (263%), MKK7 (412%), JNK (680%) and TNF-α (300%) genes compared to control group. Additionally, histopathological examination showed that cisplatin-induced interstitial congestion, focal mononuclear cell inflammatory, cell infiltrate, acute tubular injury with reactive atypia and apoptotic cells. Rutin administration attenuated cisplatin-induced alteration in gene expression and structural and functional changes in the kidney. Additionally, histopathological examination of kidney tissues confirmed gene expression data.

Conclusion

The present study suggested that the anti-oxidant and anti-inflammatory effect of rutin may prevent CP-induced nephrotoxicity via decreasing the oxidative stress, inhibiting the interconnected ROS/JNK/TNF/P38 MAPK signaling pathways, and repairing the histopathological changes against cisplatin administration.

A bacosides containing Bacopa monnieri extract alleviates allodynia and hyperalgesia in the chronic constriction injury model of neuropathic pain in rats

BACKGROUND

The current therapy of neuropathic pain is inadequate and is limited by the extent of pain relief and the occurrence of dose dependant side effects. Insufficient control of pain with conventional medications prompts the use of complementary and alternative medicine therapies by patients with neuropathic pain. This study therefore investigated a standardized methanolic extract of Bacopa monnieri, a widely reputed nootropic plant, for prospective antinociceptive effect in the chronic constriction injury (CCI) model of neuropathic pain.

METHODS

Placement of four loose ligatures around the sciatic nerve produced partial denervation of the hindpaw in rats. Bacopa monnieri (40 and 80 mg/kg, p.o) and the positive control, gabapentin (75 mg/kg, i.p), were administered daily after CCI or sham surgery and the behavioral paradigms of static- and dynamic-allodynia (paw withdrawal threshold to von Frey filament stimulation [PWT] and paw withdrawal latency to light-brushing [PWL]), cold-allodynia (paw withdrawal duration [PWD] to acetone), heat- (PWL to heat-stimulus) and punctate-hyperalgesia (PWD to pin-prick) were assessed on days 3, 7, 14 and 21.

RESULTS

CCI consistently generated static- (days 3-21), dynamic- (days 14-21) and cold-allodynia (days 3-21) plus heat- and mechano-hyperalgesia (days 3-21). The tested doses of Bacopa monnieri significantly attenuated the CCI-induced allodynia and hyperalgesia, exemplified by increased PWT (days 7-21), PWL to light brushing (days 14-21) and heat (days 7-21) as well as decreased PWD to pin prick and cold stimuli (days 3-21). The extract also counterbalanced the CCI-induced aberrations in the nociceptive behaviors by increasing the pain threshold to that of pre-surgery baseline. Gabapentin also afforded analogous beneficial behavioral profile but of higher magnitude.

CONCLUSIONS

Our findings suggest that Bacopa monnieri can be used as adjuvant therapy for neuropathic pain conditions afflicted with allodynia and hyperalgesia.