Bioconjugate based on cisplatin and bacterial exopolysaccharide with reduced side effects: A novel proposal for cancer treatment

BACKGROUND

In the search for alternatives that attenuate the toxicity associated to oncologic treatment with cisplatin (CDDP) and considering the potential health-beneficial properties of exopolysaccharides (EPS) produced by lactic acid bacteria, it was aimed on this study to evaluate the cytotoxic, toxicologic and antitumoral efficacy of a bioconjugate based on CDDP and EPS, on the experimental tumor of sarcoma 180.

METHODS

After the synthesis of the cis-[Pt(NH3)2(Cl)2] complex and of the conjugate containing Lactobacillus fermentum exopolysaccharide was tested both in vitro and in vivo for evaluating the acute toxicity.

RESULTS

The antitumoral study was performed using mice transplanted with sarcoma 180. The bioconjugate showed low to medium cytotoxicity for the cell lines tested, as well moderated acute toxicity. After determining the LD50, the following experimental groups were established for the antitumor assay: Control (NaCl 0,9%), CDDP (1 mg/kg), EPS and bioconjugate composition (200 mg/kg). The bioconjugate promoted a 38% regression in tumor mass when compared to the control, and a regression of 41% when compared to CDDP. Liver histopathological analysis revealed discrete alterations in animals treated with (CDDP + EPS) when compared to control. The bioconjugate also minimized changes in the renal parenchyma resulting from the tumor.

CONCLUSION

Our results indicate that when CDDP is associated with EPS, this composition was more biocompatible, showing itself as a potent chemotherapeutic agent and lower tissue toxicity.

Ent-kaurenoic acid-enriched Mikania glomerata leaves-complexed β-cyclodextrin: Pharmaceutical development and in vivo antitumor activity in a sarcoma 180 mouse model

The extract obtained from Mikania glomerata leaves rich in ent-kaurenoic acid (ERKA) shows cytotoxic activity in vitro, but its hydrophobic nature and thermosensitivity are issues to be solved prior to in vivo antitumor studies. The purpose of this study was to investigate the antitumor activity of inclusion complexes formed between ERKA and β-cyclodextrin (ERKA:β-CD) in rodents. ERKA:β-CD complexes obtained by malaxation (MX) and co-evaporation (CE) methods were firstly characterized regarding their physical properties, encapsulation efficiency, and cytotoxicity againts L929 cells. The antitumor activity study was then performed in mice with sarcoma 180 treated with saline, 5-fluouracil (5FU) and ERKA:β-CD at 30, 100 and 300 µg/kg. The weight, volume, percentage of inhibition growth, gross and pathological features and positivity for TUNEL, ki67, NFκB and NRF2 in the tumors were assessed. Serum lactate-dehydrogenase activity (LDH), white blood cells count (WBC) and both gross and pathological features of the liver, kidneys and spleen were also evaluated. The formation of the inclusion complexes was confirmed by thermal analysis and FTIR, and they were non-toxic for L929 cells. The MX provided a better complexation efficiency. ERKA:β-CD300 promoted significant tumor growth inhibition, and attenuated the tumor mitotic activity and necrosis content, comparable to 5-fluorouracil. ERKA:β-CD300 also increased TUNEL-detected cell death, reduced Ki67 and NF-kB immunoexpression, and partially inhibited the serum LDH activity. No side effect was observed in ERKA:β-CD300-treated animals. The ERKA:β-CD inclusion complexes at 300 µg/kg displays antitumour activity in mice with low systemic toxicity, likely due to inhibition on the NF-kB signaling pathway and LDH activity.

α-Phellandrene exhibits antinociceptive and tumor-reducing effects in a mouse model of oncologic pain

Medical reports indicate a prevalence of pain in 50% of patients with cancer. In this context, this article investigated the antinociceptive activity of α-PHE using in vivo Sarcoma-180-induced hypernociception in mice to detail its mechanism(s) of antinociception under different conditions of treatment and tumor progression. Firsty, in vitro cytotoxic action was assessed using melanoma B-16/F-10 and S-180 murine cells and colorimetric MTT assays. For in vivo studies, acute treatment with α-PHE (6.25, 12.5, 25 and 50 mg/kg orally by gavage) was performed on the 1st day after S-180 inoculation. Subacute treatments were performed for 8 days starting on the next day (early protocol) or on day 8 after S-180 inoculation (late protocol). For all procedures, mechanical nociceptive evaluations were carried out by von Frey's technique in the subaxillary region peritumoral tissue (direct nociception) and in right legs of S-180-bearing mice (indirect nociception). α-PHE showed in vitro cytotoxic action on B-16/F-10 and S-180 (CI₅₀ values of 436.0 and 217.9 μg/mL), inhibition of in vivo tumor growth (ranging from 47.3 to 82.7%) and decreased direct (peritumoral tissue in subaxillary region) and indirect (right leg) mechanical nociception in Sarcoma 180-bearing mice with early and advanced tumors under acute or subacute conditions of treatment especially at doses of 25 and 50 mg/kg. It improved serum levels of GSH as well as diminished systemic lipid peroxidation, blood cytokines (interleukin-1β, -4, -6, and tumor necrosis factor-α). Such outcomes highlight α-PHE as a promising lead compound that combines antinociceptive and antineoplasic properties. Its structural simplicity make it a cost-effective alternative, justifying further mechanistic investigations and the development of pharmaceutical formulations. Moreover, the protocols developed and standardized here make it possible to use Sarcoma-180 hypernociception model to evaluate the capacity of new antinociceptive molecules under conditions of cancer-related allodynia.

Antitumor effects of citrinin in an animal model of Sarcoma 180 via cytogenetic mechanisms

Citrinin (CIT) is a cytotoxic, hepatotoxic, nephrotoxic and cardiotoxic metabolite obtained from Penicillium citrinum, that has been increasingly searched as an anticancer drug candidate. In this study, we assessed the antitumor effects of citrinin, using cytogenetic biomarkers for genotoxicity in Sarcoma 180 (S-180) ascitic fluid cells of mice. Citrinin, extracted from P. citrinum acetonitrile extract, was characterized by LC-MS. Cytotoxic assessment was done through using comet (alkaline version) and micronucleus assays. In S-180 cells, CI50 of CIT was 3.77 μg/mL, while at 12.5 and 100 μg/mL, CIT was as cytotoxic as doxorubicin (2 μg/mL). At 0.5, 1.0 and 2.0 μg/mL, it induced genotoxicity and mutagenicity in S-180 cells, especially at 2 μg/mL, triggering oxidative damage similar to hydrogen peroxide (10 mM). The antitumor effects were evidenced by a marked increase in S-180 cells apoptosis and necrosis due to clastogenic and/or aneugenic cytogenetic effects (micronucleus formation), as well as by induction of nucleoplasm bridges and nuclear buds, culminating in S-180 apoptosis and necrosis. CIT has potential as drug candidate for antitumor purposesbyinvolving cytogenetic mechanisms.

Antitumoral effects of [6]-gingerol [(S)-5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-3-decanone] in sarcoma 180 cells through cytogenetic mechanisms

BACKGROUND

[6]-Gingerol [(S)-5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-3-decanone] is a phenolic substance reported for several ethnopharmacological usage by virtue of its antioxidant, antiemetic, anti-inflammatory and anticancer properties. This study assessed the antitumoral effects of [6]-Gingerol in primary cells of Sarcoma 180 as well as in peripheral blood lymphocytes of mice.

METHODS

The effect of [6]-Gingerol was assessed by applying cytogenetic biomarkers as indicative of genotoxicity, mutagenicity and apoptosis. Ascitic liquid cells were treated with [6]-Gingerol at concentrations of 21.33, 42.66 and 85.33 μM and subjected to the cytotoxicity assays using Trypan blue test and the comet assay, as well as the cytokinesis-block micronucleus assay. Doxorubicin (6 μM) and hydrogen peroxide (85.33 μM) were used as positive controls.

RESULTS

[6]-Gingerol, especially at concentrations of 42.66 and 85.33 μM, showed notable cytotoxicity in Sarcoma 180 cells by reducing cell viability and cell division rates via induction of apoptosis. Genotoxicity at the concentrations used was punctuated by the increase in the index and frequency of DNA damage in tested groups. [6]-Gingerol, at all concentrations tested, did not induce significant aneugenic and/or clastogenic effects. It did, however, induced other nuclear abnormalities, such as nucleoplasmic bridges, nuclear buds and apoptosis. The genotoxic effects observed in the cotreatment with H₂O₂ (challenge assay) employing neoplastic and healthy cells, indicated that [6]-Gingerol may induce oxidative stress.

CONCLUSIONS

Observations suggest that [6]-Gingerol may be a candidate for pharmaceutical antitumoral formulations due to its cytotoxicity and to mechanisms associated with genetic instability generated by nuclear alterations especially by apoptosis.

In vivo antitumor effect, induction of apoptosis and safety of Remirea maritima Aubl. (Cyperaceae) extracts

BACKGROUND

Remirea maritima has been widely used in the treatment of diarrhea, kidney disease, and high fever and for therapeutic purposes, such as an analgesic and anti-inflammatory. However, few scientific research studies on its medicinal properties have been reported.

PURPOSE

The present study aimed to investigate the anticancer potential of aqueous extract (AE), 40% hydroalcoholic extracts (40HA) and 70% (70HA) from R. maritima in experimental models and to identify its phytochemical compounds.

METHODS

The chemical composition of AE, 40HA and 70HA was assessed by HPLC-DAD and ESI-IT-MS/MS. In vitro activity was determined on cultured tumor cell, NCI-H385N (Broncho-alveolar carcinoma), OVCAR-8 (Ovarian carcinoma) and PC-3M (prostate carcinoma) by the MTT assay, and the in vivo antitumor activity was assessed in Sarcoma 180-bearing mice. Toxicological parameters were also evaluated as well as the humoral immune response.

RESULTS

Among the aqueous and hydroalcoholic extracts of R. maritima, only 40HA showed in vitro biological effect potential, presenting IC50 values of 27.08, 46.62 and >50µg/ml for OVCAR-8, NCI-H385M and PC-3M cells lines, respectively. Regarding chemical composition, a mixture of isovitexin-2''-O-β-D-glucopyranoside, vitexin-2''-O-β-D-glucopyranoside, luteolin-7-O-glucuronide and 1-O-(E)-caffeoyl-β-D-glucose were identified as the major phytochemical compounds of the extracts. In the in vivo study, the tumor inhibition rates were 57.16-62.57% at doses of 25mg/kg and 50mg/kg, respectively, and the tumor morphology presented increasing numbers of apoptotic cells. Additionally, 40HA also demonstrated significantly increased of OVA-specific total Ig.

CONCLUSIONS

40HA exhibited in vitro and in vivo anticancer properties without substantial toxicity that could be associated with its immunostimulating properties.

Preclinical anticancer effectiveness of a fraction from Casearia sylvestris and its component Casearin X: in vivo and ex vivo methods and microscopy examinations

ETHNOPHARMACOLOGICAL RELEVANCE

Casearia sylvestris (Salicaceae) is found in South America and presents antiulcerogenic, cytotoxic, antimicrobial, anti-inflammatory and antihypertensive activities.

AIM OF THE STUDY

To assess the in vivo and ex vivo antitumor action of a fraction with casearins (FC) and its main component - Casearin X-isolated from C. sylvestris leaves.

MATERIALS AND METHODS

Firstly, Sarcoma 180 bearing Swiss mice were treated with FC and Cas X for 7 days. Secondly, BALB/c nude animals received hollow fibers with colon carcinoma (HCT-116) or glioblastoma (SF-295) cells and were treated with FC for 4 days. On 5th day, proliferation was determined by MTT assay.

RESULTS

FC 10 and 25mg/kg/day i.p. and 50mg/kg/day oral and Cas X 25mg/kg/day i.p. and 50mg/kg/day oral revealed tumor growth inhibition rates of 35.8, 86.2, 53.7, 90.0 and 65.5% and such tumors demonstrated rare mitoses and coagulation necrosis areas. Similarly, FC reduced multiplying of HCT-116 and SF-295 cells when evaluated by the Hollow Fiber Assay (2.5 and 5mg/kg/day i.p. and 25 and 50mg/kg/day oral), with cell growth inhibition rates ranging from 33.3 to 67.4% (p<0.05). Flow cytometry experiments revealed that FC reduced membrane integrity and induced DNA fragmentation and mitochondrial depolarization (p<0.05).

CONCLUSIONS

FC and Cas X were efficient antitumor substances against murine and human cancer cells and caused reversible morphological changes in liver, kidneys and spleens, emphasizing clerodane diterpenes as an emerging class of anticancer molecules.

Cis-[RuCl(BzCN)(N-N)(P-P)]PF6 complexes: Synthesis and in vitro antitumor activity: (BzCN=benzonitrile; N-N=2,2'-bipyridine; 1,10-phenanthroline; P-P=1,4-bis(diphenylphosphino) butane, 1,2-bis(diphenylphosphino)ethane, or 1,1'-(diphenylphosphino)ferrocene)

The motivation to use ruthenium complexes in cancer treatment has led our research group to synthesize complexes with this metal and test them against several types of tumor cells, yielding promising results. In this paper the results of biological tests, assessed by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, were carried out on the complexes cis-[RuCl(BzCN)(bipy)(dppe)]PF6 (1), cis-[RuCl(BzCN)(bipy)(dppb)]PF6 (2), cis-[RuCl(BzCN)(bipy)(dppf)]PF6 (3) and cis-[RuCl(BzCN)(phen)(dppb)]PF6 (4) which are described [BzCN = b enzonitrile; bipy = 2,2'-bipyridine; phen = 1,10-phenanthroline; dppe = 1,2-bis(diphenylphosphino) ethane; dppb = 1,4-bis-(diphenylphosphino)butane; dppf = 1,1'-bis(diphenylphosphino)ferrocene]. The present study is focused on the cytotoxic activity of complexes (1)-(4) against four tumor cell lines and on the apoptosis and changes in the cell cycle and gene expression observed in the sarcoma 180 (S180) tumor cell line treated with complex (1). The results demonstrated that this complex inhibits S180 cell growth, with an IC50 of 17.02 ± 8.21 μM, while exhibiting lower cytotoxicity (IC50 = 53.73 ± 5.71 μM) towards lymphocytes (normal cells). Flow cytometry revealed that the complex inhibits the growth of tumor cells by inducing apoptosis as evidenced by an increase in the proportion of cells positive for annexin V staining and G0/G1 phase cell-cycle arrest. Further investigation showed that complex (1) induces a drop in the mitochondrial membrane potential and provokes a decrease in Bcl-2 protein expression and increase in caspase 3 activation, while the increased activation of caspase 8 caused a decrease in the gene expression in caspases 3 and 9. Increases in Tp53 and Bax expressions were also observed.

Polysaccharides from Cymbopogon citratus with antitumor and immunomodulatory activity

Abstract Context: Most of the present studies on the antitumor efficiency of Cymbopogon citratus (DC.) Stapf (Gramineae) are limited to its low-mass compounds, and little information about the antitumor activity of polysaccharides from this plant is available.

OBJECTIVES

This study focused on the potential antitumor and immunomodulatory activities of polysaccharides (CCPS) from C. citratus.

MATERIALS AND METHODS

CCPS was isolated using the water extraction-ethanol precipitation method. The sarcoma 180 (S180) cells-inoculated mice were intraperitoneally administrated with CCPS (30-200 mg/kg/d) for seven consecutive days. The effects of CCPS on tumor growth, thymus and spleen weights, splenocyte proliferation, and cytokine secretion in the tumor-bearing mice were measured. The cytotoxicity of CCPS (50-800 μg/mL) towards S180 cells was also studied.

RESULTS

CCPS significantly inhibited the growth of the transplanted S180 tumors, with the inhibition rates ranging from 14.8 to 37.8%. Simultaneously, CCPS dose-dependently improved the immunity of the tumor-bearing mice. With the highest dose of 200 mg/kg/d, the thymus and spleen indices were increased by 21.9 and 91.9%, respectively; ConA- and LSP-induced splenocyte proliferations were increased by 32.7 and 35.3%, respectively. The secretions of interleukin 2 (IL-2), interleukin 6 (IL-6), interleukin 2 (IL-12), and tumor necrosis factor-α (TNF-α) were increased by 103.2, 40.2, 23.6, and 26.3%, respectively. Nevertheless, almost no toxicity of CCPS towards S180 cells was observed, with the maximal inhibition rate less than 15% at the CCPS concentration of 800 μg/mL.

CONCLUSION

CCPS exhibited antitumor activity in vivo, and this activity might be achieved by immunoenhancement rather than direct cytotoxicity.

A Comparative Study of the effects of Vitamins C and E in the Development of Sarcoma 180 in Mice

In this work we have investigated the effects of vitamins C and E on tumors via the mice xenotransplant model of sarcoma 180 (S180) in vivo. The experimental results suggest that dosages of 100 mg/kg vitamin C and 400 mg/kg vitamin E yields a great inhibitory behavior on tumors.

Anticancer effect of Jinlongshe granules on in situ-transplanted human MKN-45 gastric cancer in nude mice and xenografted sarcoma 180 in Kunming mice and its mechanism

AIM: To study the antitumor effect of Chinese compound Jinlongshe (JLS) granules on sarcoma 180 and MKN-45 human gastric cancer cell lines in vivo and its mechanism.

METHODS: After establishment of S180 sarcoma (S180) and MKN-45 gastric cancer model of nude mice, the tumor-bearing mice were divided into 5 groups at random. Three experimental groups were respectively given the aqueous extract of JLS granules at doses of 120 g, 60 g and 20 g /(kg per 6/wk, i.g) for 3 wk in S180 and 6 wk in nude mice model. Positive control was given cyclophosphamide (Cy) at a dose of 50 mg/(kg per 3 /wk, i.g) for 3 wk in S180 models and 5- Fluorouracil (5-FU) 20 mg/(kg per 3 /wk, i.g) for 3 wk in nude mice model. Negative control was given normal saline (NS) at a dose of 0.18 g/(kg per 6/wk, i.g) respectively. After 3 wk in mice bearing S180 tumor and 6 wk in nude mice model, the experimental animals were sacrificed and the masses of tumor were weighed, and the rates of tumor inhibition of each treated group were calculated respectively. To determine the antitumor mechanisms, the morphological changes, cell cycle and apoptosis were observed in MKN-45 nude mice model. Annexin V-FITC/PI double staining FCM assay was used to further determine the live cells, apoptotic cells, necrotic cells and debris.

RESULTS: The inhibitory rates of JLS granules at the doses of 20 g/kg, 60 g/kg and 120 g/kg were 50.31%, 55.94% and 68.13% (P < 0.01) in nude mice models and 40.90%, 50.32% and 58.46% (P < 0.01) in S180 model. The inhibitory rate of Cy was 85.22% in S180 models and the inhibitory rate of 5-FU was 53.43% in nude mice model (P < 0.01). Nuclear chromatin and margination were observed under a transmission electron microscope (TEM). The G0/G1 phase was arrested, typical apoptotic peak appeared, the apoptotic rate was 22.81%-38.54% in three JLS granule-treated groups. Annexin V-FITC/PI double staining FCM assay showed that the apoptotic cells were 4.36%, 3.08%and 7.08% in three dosages, most cells were localized in the low right quadrant.

CONCLUSION: Jinlongshe granules possess anti-tumor effects on experimental tumor models in vivo, and apoptosis induction is one of its anti-tumor mechanisms.