Assessment of the antioxidant, cytotoxic, and genotoxic potential of the Annona muricata leaves and their influence on genomic stability

Ruthenium(II) complex with 2-mercaptothiazoline ligand induces selective cytotoxicity involving DNA damage and apoptosis in melanoma cells

Melanoma is the most aggressive and lethal type of skin cancer due to its characteristics such as high metastatic potential and low response rate to existing treatment modalities. In this way, new drug prototypes are being studied to solve the problem of treating patients with melanoma. Among these, ruthenium-based metallopharmaceuticals may be promising alternatives due to their antitumor characteristics and low systemic toxicity. In this context, the present study evaluated the antineoplastic effect of the ruthenium complex [Ru(mtz)(dppe)2]PF6-2-mercaptothiazoline-di-1,2-bis(diphenylphosphine) ethaneruthenium(II), namely RuMTZ, on human melanoma (A-375) and murine (B16-F10) cells, considering different approaches. Through XTT colorimetric and clonogenic efficiency assays, the complex revealed the selective cytotoxic activity, with the lowest IC50 (0.4 µM) observed for A375 cells. RuMTZ also induced changes in cell morphology, increased cell population in the sub-G0 phase and inhibiting cell migration. The levels of γH2AX and cleaved caspase 3 proteins were increased in both cell lines treated with RuMTZ. These findings indicated that the cytotoxic activity of RuMTZ on melanoma cells is related, at least in part, to the induction of DNA damage and apoptosis. Therefore, RuMTZ exhibited promising antineoplastic activity against melanoma cells.

Phytochemical characterization, isolation, antioxidant and cytogenotoxic activity of leaves of Heliotropium elongatum (Lehm) I.M. Johnst

Heliotropium elongatum is used to treat inflammation, cough, and flu. This study aimed to characterize the phytochemical profile and determine the total phenolic content (TPC), antioxidant and cytogenotoxic activity of the ethanolic extract (EE), and fractions of H. elongatum leaves. In the phytochemical profile analysis, organic acids, reducing sugars, flavonoids, saponins, anthraquinones, steroids/triterpenes, and depsides/depsidones were detected in the EE and/or fractions (hexanic/FH, chloroformic/FC, ethyl acetate/FAE, and hydromethanolic/FHM). The highest TPC and highest antioxidant activity (DPPH and ABTS) was detected in FHM. In FH, 16 compounds were identified by GC-MS, and ursolic acid was isolated by 1H NMR and 13C NMR. HPLC-DAD from EE, FAE, and FHM demonstrated characteristic wavelengths for flavonoids, flavonols, flavones, and anthraquinones. ESI-IT/MSn analysis of EE, FC, FAE, and FHM revealed alkaloids, steroids, terpenoids, flavonoids, and phenolic acids. In Allium cepa assay there was no significant cytotoxic effect initiated by EE (62.5 to 1,000 µg/ml), FHM (1,000 µg/ml), and FAE (62.5 µg/ml). Genotoxicity was evidenced only with EE at 500 and 1,000 µg/ml, and FHM (62.5 to 1,000 µg/ml) as evidenced by presence of micronuclei (MN) and nuclear buds (NB). Our results identified compounds of medicinal interest with antioxidant activity; however observed cytogenotoxic changes indicated the need for caution when using these compounds for therapeutic purposes.

Assessing the Acute Toxicological Effects of Annona muricata Leaf Ethanol Extract on Rats: Biochemical, Histopathological, and Metabolomics Analyses

Annona muricata is a common plant used in Africa and South America to manage various types of disease. However, there is insufficient toxicological information or published standard available regarding repeated dose animal toxicity data. As part of the safety assessment, we exposed Sprague Dawley rats to an acute oral toxicity of A. muricata. The intent of the current study was to use advanced proton nuclear magnetic resonance (1H NMR) in serum and urinary metabolomics evaluation techniques to provide the in vivo acute toxicological profile of A. muricata leaf ethanol extract in accordance with the Organization for Economic Co-operation and Development's (OECD) 423 guidelines. A single 2000 mg/kg dose of A. muricata leaf ethanol extract was administered to Sprague Dawley rats over an observational period of 14 days. The toxicity evaluation (physical and behavior observation, body weight, renal function test, liver function test and 1H NMR analysis) showed no abnormal toxicity. Histopathological analysis manifested mild changes, i.e., the treated kidney manifested mild hypercellularity of mesangial cells and mild red blood cell congestion. In addition, there was mild hemorrhage into tissue with scattered inflammatory cells and mild dilated central vein with fibrosis in the liver. However, the changes were very mild and not significant which correlate with other analyses conducted in this study (biochemical test and 1H NMR metabolomic analysis). On the other hand, urinary 1H NMR analysis collected on day 15 revealed high similarity on the metabolite variations for both untreated and treated groups. Importantly, the outcomes suggest that A. muricata leaf ethanol extract can be safely consumed at a dose of 2000 mg/kg and the LD50 must be more than 2000 mg/kg.

Altered hallmarks of DNA double-strand breaks, oxidative DNA damage and cytogenotoxicity by piperlongumine in hippocampus and hepatocytes of rats intoxicated with cyclophosphamide

AIM

Cyclophosphamide is an effective anti-tumor agent, however, it induces genomic instability and tissue toxicity in clinical application. This study aims to evaluate the action of piperlongumine against cyclophosphamide-induced toxicity.

MAIN METHODS

The action was investigated in rodent model of genomic instability, where piperlongumine (50 mg/kg) was orally co-administered with cyclophosphamide (5 mg/kg) for 28 days to Wistar albino rats. Further, piperlongumine was also examined for acute and sub-acute toxicity.

KEY FINDINGS

Piperlongumine significantly reversed genotoxicity in high-proliferation tissue (bone marrow: p < 0.05) as well as in vital tissues (hippocampus: p < 0.01 and hepatocytes: p < 0.05), calculated as micronuclei formation and %DNA fragmentation. It also restored the redox homeostasis, counteracted the formation of oxidative DNA damage product and DNA double-strand break in vital tissues, indicated by reduction of 8-OHdG and γH2AX. TUNEL assay revealed that piperlongumine diminished the cyclophosphamide-associated apoptotic cell death in hippocampus as well as in liver tissue and conferred cytoprotection to the host. These findings were finally corroborated with the histopathological findings, where piperlongumine treatment restored the cellular viability of liver and hippocampus. Further, piperlongumine did not produce any toxic effects to rats in systemic toxicity studies.

SIGNIFICANCE

Piperlongumine possesses genome stabilizing effect and reduces cyclophosphamide-associated DNA damage, oxidative stress, hepato-, and neurotoxicity, diminishes the DNA damage response pathway in the rat model, at the same time, conserves the micro-architectural details of liver and hippocampus. The findings are significant in terms of reducing genotoxic impact of chemotherapy-receiving patients.

Evaluation of Genotoxic Effect and Antigenotoxic Potential against DNA Damage of the Aqueous and Ethanolic Leaf Extracts of Annona muricata Using an In Vivo Erythrocyte Rodent Micronucleus Assay

Annona muricata have been extensively used in traditional medicine to treat multiple diseases, including cancers. This study evaluated the genotoxic potential and antigenotoxic activities of A. muricata aqueous and ethanolic leaf extracts by employing an in vivo erythrocyte rodent micronucleus assay. Different doses (187.5, 375, and 750 mg/kg) of both extracts were administered orally for 5 days alone and combined with cyclophosphamide (CP, 60 mg/kg) to BALB/c mice. Also, it was administered orally to Wistar rats for 5 days through the final stage of gestation. No genotoxic or cytotoxic effects were observed in the two adult rodent models when A. muricata was administered orally nor in newborn rats transplacentally exposed to the extracts. Moreover, A. muricata aqueous and ethanolic leaf extracts demonstrated a protective effect against CP-induced DNA damage. Due to its lack of genotoxic effect and its capacity to decrease DNA damage, A. muricata is likely to open an interest field regarding its potential safe use in clinical applications.

Evaluation of the cytotoxic, anticancer, and genotoxic activities of Acacia nilotica flowers and their effects on N-methyl-N-nitrosourea-induced genotoxicity in mice

Purpose

In this study, two main research objectives were examined: (1) the cytotoxic and anticancer activities of the aqueous methanol extract from Acacia nilotica flowers on three human cancer cells, namely lung A549, breast MCF-7, and leukemia THP-1 cells, and (2) the genotoxic effects of A. nilotica extract and its influence on DNA damage induced by N-methyl-N-nitrosourea (MNU) in mice.

Methods

Mice were orally treated with A. nilotica extract (200, 500, and 800 mg/kg for 4 days) with or without MNU (80 mg/kg intraperitoneally for 24 h).

Results

In vitro experiments showed that A549 cells were the most sensitive to A. nilotica extract among the tested cell lines. A. nilotica extract inhibited A549 cell proliferation by blocking the cell cycle at the G₂/M phase and accumulating apoptotic cells in the sub-G₀/G₁ phase in A549 cells. In vivo experiments showed that MNU induced positive and negative genotoxicity in bone marrow cells and spermatocytes, respectively. Negative genotoxicity was observed in A. nilotica extract-treated groups only. However, A. nilotica extract (800 mg/kg) remarkably increased comet tail formation in bone marrow cells. Unexpectedly, the absence of antigenotoxicity was observed in three cotreated groups with A. nilotica extract and MNU compared with the MNU-treated group. Astonishingly, cotreatment with MNU and A. nilotica extract at a dose above 200 mg/kg remarkably increased micronucleus and comet tail formation in bone marrow cells compared with the MNU-treated group.

Conclusions

A. nilotica extract possessed anticancer activity with relative genotoxic effects at high doses.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11033-022-07662-0.

Evaluation of the Modulatory Effect of Annona muricata Extracts on the Activity of Some Selected Antibiotics against Biofilm-Forming MRSA

The study investigated the influence of Annona muricata extracts on the action of selected antibiotics against biofilm-forming MRSA. The various parts of the plant were processed into powder and extracted with ethanol or hot water and then screened for the presence of phytochemicals. The modulatory effect of the Annona muricata extract was also tested on some antibiotics against Methicillin-resistant Staphylococcus aureus (MRSA). The findings from this study revealed that the various parts of the Annona muricata extract (ethanolic and aqueous) contained different proportions of secondary metabolites. Varied antimicrobial activities were observed when the extract of the A. muricata was exposed to MRSA strain at a concentration of 100 mg/mL. The stem recorded the highest (17.00 and 18.00 mm) inhibitory activity against MRSA for both the aqueous and the ethanolic extract, respectively, and this was not different from the control, tetracycline. Again, the results on the modulatory action indicated that out of the 10 extracts of A. muricata, 4 of them antagonized the activity of ampicillin against the tested MRSA by a factor of 0.5 folds and the rest potentiated the drug within 1-4 folds, respectively. On the other hand, the various test extracts significantly potentiated the efficacy of streptomycin and tetracycline against the MRSA by a range of 1-32 folds with the aqueous root extract recording the highest synergistic effect and ethanol seed extract with the least effect. The findings of this study support the antibacterial activities of the A. muricata plant parts.

Manool, a diterpene from Salvia officinalis, exerts preventive effects on chromosomal damage and preneoplastic lesions

The present study aimed to evaluate the effect of the manool diterpene on genomic integrity. For this purpose, we evaluated the influence of manool on genotoxicity induced by mutagens with different mechanisms of action, as well as on colon carcinogenesis. The results showed that manool (0.5 and 1.0 µg/ml) significantly reduced the frequency of micronuclei induced by doxorubicin (DXR) and hydrogen peroxide in V79 cells but did not influence genotoxicity induced by etoposide. Mice receiving manool (1.25 mg/kg) exhibited a significant reduction (79.5%) in DXR-induced chromosomal damage. The higher doses of manool (5.0 and 20 mg/kg) did not influence the genotoxicity induced by DXR. The anticarcinogenic effect of manool (0.3125, 1.25 and 5.0 mg/kg) was also observed against preneoplastic lesions chemically induced in rat colon. A gradual increase in manool doses did not cause a proportional reduction of preneoplastic lesions, thus demonstrating the absence of a dose-response relationship. The analysis of serum biochemical indicators revealed the absence of hepatotoxicity and nephrotoxicity of treatments. To explore the chemopreventive mechanisms of manool via anti-inflammatory pathways, we evaluated its effect on nitric oxide (NO) production and on the expression of the NF-kB gene. At the highest concentration tested (4 μg/ml), manool significantly increased NO production when compared to the negative control. On the other hand, in the prophylactic treatment model, manool (0.5 and 1.0 μg/ml) was able to significantly reduce NO levels produced by macrophages stimulated with lipopolysaccharide. Analysis of NF-kB in hepatic and renal tissues of mice treated with manool and DXR revealed that the mutagen was unable to stimulate expression of the gene. In conclusion, manool possesses antigenotoxic and anticarcinogenic effects and its anti-inflammatory potential might be related, at least in part, to its chemopreventive activity.

Influence of Asiatic acid on cell proliferation and DNA damage in vitro and in vivo systems

Asiatic acid (AA) is a triterpene with promising pharmacological activity. In the present study, in vitro and in vivo assays were conducted to understand the effect of AA on cell proliferation and genomic instability. AA was cytotoxic to human tumor cell lines (M059J, HeLa, and MCF-7), with IC₅₀ values ranging from 13.91 to 111.72 µM. In the case of M059J, AA exhibited selective cytotoxicity after 48 h of treatment (IC₅₀  = 24 µM), decreasing the percentage of cells in the G0/G1 phase, increasing the percentage of cells in the S phase, and inducing apoptosis. A significant increase in chromosomal damage was observed in V79 cell cultures treated with AA (40 µM), revealing genotoxic activity. In contrast, low concentrations (5, 10, and 20 µM) of AA significantly reduced the frequencies of micronuclei induced by the mutagens doxorubicin (DXR), methyl methanesulfonate, and hydrogen peroxide. A reduction of DXR-induced intracellular free radicals was found in V79 cells treated with AA (10 µM). The antigenotoxic effect of AA (30 mg/kg) was also observed against DXR-induced chromosomal damage in Swiss mice. Significant reductions in p53 levels were verified in the liver tissue of these animals. Taken together, the data indicate that AA exerted antiproliferative activity in M059J tumor cells, which is probably related to the induction of DNA damage, leading to cell cycle arrest and apoptosis. Additionally, low concentrations of AA exhibited antigenotoxic effects and its antioxidant activity may be responsible, at least in part, for chemoprevention.

Licochalcone A, a licorice flavonoid: antioxidant, cytotoxic, genotoxic, and chemopreventive potential

Licochalcone A (LicoA) is a flavonoid derived from Glycyrrhiza spp. plants. The present study aimed to investigate the antioxidant, cytotoxic, genotoxic, and chemopreventive effects of LicoA in in vitro and in vivo systems. The results showed that LicoA (197.1 μM) scavenged 77.92% of free radicals. Concentrations of 147.75 µM or higher LicoA produced cytotoxicity in Chinese hamster ovary (CHO) fibroblasts. LicoA treatments of 4.43 to 10.34 µM did not exert genotoxic activity, but at 11.8 µM significantly lowered nuclear division indexes, compared to negative control, revealing cytotoxicity. Lower concentrations (1.85 to 7.39 µM) exhibited protective activity against chromosomal damage induced by doxorubicin (DXR) or methyl methanesulfonate (MMS) in CHO cells. LicoA exerted no marked influence on DXR-induced genotoxicity in mouse erythrocytes, but reduced pre-neoplastic lesions induced by 1,2-dimethylhydrazine (DMH) in rat colon at 3.12 to 50 mg/kg b.w. Biochemical markers and body weight indicated no apparent toxicity. These findings contribute to better understanding the mechanisms underlying LicoA-initiated activity as a promising chemopreventive compound.

ABBREVIATIONS

AC, aberrant crypts; ACF, aberrant crypt foci; ALT, alanine aminotransferase; AST, aspartate aminotransferase; BOD, biochemical oxygen demand; CHO, Chinese hamster ovary fibroblast; DMH, 1,2-dimethylhydrazine; DMSO, dimethyl sulfoxide; DPPH, 2,2-diphenyl-1-picrylhydrazyl; DXR, doxorubicin hydrochloride; EDTA, ethylenediaminetetraacetic acid; GA, gallic acid; LicoA, licochalcone A; MMS, methyl methanesulfonate; MNBC, micronucleated binucleated cells; MNPCE, micronucleated polychromatic erythrocyte; NCE, normochromatic erythrocyte; NDI, nuclear division index; PBS, phosphate-buffered saline; PCE, polychromatic erythrocyte; XTT, 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide.

Antioxidant Properties and Protective Effects of Some Species of the Annonaceae, Lamiaceae, and Geraniaceae Families against Neuronal Damage Induced by Excitotoxicity and Cerebral Ischemia

This study aimed to compare the antioxidant activities of extracts obtained from three plant families and evaluate their therapeutic effect on strokes. Ethanol extracts were obtained from either the leaf or the aerial parts of plants of the families Annonaceae (Annona cherimola, A. diversifolia, A. muricata, A. purpurea, and A. reticulata), Lamiaceae (Salvia amaríssima and S. polystachya), and Geraniaceae (Geranium niveum and G. mexicanum). Extracts were analyzed in terms of hydroxyl radical (OH•), peroxyl radical (ROO•), and superoxide anion (O2•-). The efficiency of the extracts to prevent neuronal death induced by excitotoxicity was tested with the tetrazolium assay, the O2•- scavenging capacity was evaluated with the dihydroethidium dye, and the protective effect of the extracts with the highest antioxidant activity was tested on a stroke experimental model. The extracts' IC50 values (μg/mL) of scavenging varied from 98.9 to 155.04, 4.5 to 102.4, and 20.2 to 118.97 for OH•, ROO•, and O2•-, respectively. In the excitotoxicity model, Annonaceae extracts were highly cytotoxic while Lamiaceae and Geraniaceae reduced intracellular O2•- production and protect neurons against oxidative stress. Salvia polystachya reduced cerebral damage, as well as improved survival and behavior after ischemia. Our results encouraged the use of plant extracts as natural antioxidants to minimize neuronal injury following stroke.

The safety and tolerability of Annona muricata leaf extract: a systematic review

OBJECTIVES

Annona muricata, also known as graviola, soursop and guanabana, has been widely utilised for the treatment of a range of cancers. The mechanism of action and the efficacy of A. muricata and its constituents in the treatment of cancer have been comprehensively reviewed. The aim of this systematic review was to summarise the available literature that reports on factors related to the safety and tolerability of A. muricata leaf extract and its acetogenins.

METHODS

In-vitro, preclinical animal studies and human studies of any design written in any language were included. Studies that evaluated A. muricata leaf extract and its constituents were searched through the databases Pubmed, Medline and Embase from inception to April 2019. The elaborated item 4 of Consolidated Standards of Reporting Trials statement and Animals in Research: Reporting In vivo Experiments guidelines were used to evaluate the quality of the studies.

KEY FINDINGS

The results suggest that A. muricata and its constituents have hepatoprotective, neurotoxic, antinociceptive, anti-ulcerative and chemopreventive effects. The dose and duration used in animal studies demonstrating toxicity may not directly translate into the effects in humans. Studies included in this review were judged to be of medium to high quality.

CONCLUSIONS

The overall outcome of the current review suggests that A. muricata has a favourable safety and tolerability profile. Future studies investigating its use in people diagnosed with a range of cancers are warranted.

Usnic acid attenuates genomic instability in Chinese hamster ovary (CHO) cells as well as chemical-induced preneoplastic lesions in rat colon

Usnic acid (UA) is one of the pharmacologically most important compounds produced by several lichen species. To better understand the mechanism of action (MOA) of this important substance, this study examined the genotoxicity attributed to UA and its influence on mutagens with varying MOA using the micronucleus (MN) test in Chinese hamster ovary cells (CHO). Additional experiments were conducted to investigate the effect of UA on colon carcinogenesis in Wistar rats employing the aberrant crypt focus (ACF) assay. In vitro studies showed a significant increase in the frequency of MN in cultures treated with the highest UA concentration tested (87.13 µM). In contrast, UA concentrations of 10.89, 21.78, or 43.56 µM produced an approximate 60% reduction in chromosomal damage induced by doxorubicin, hydrogen peroxide, and etoposide, indicating an antigenotoxic effect. In the ACF assay, male Wistar rats treated with different UA doses (3.125, 12.5, or 50 mg/kg b.w.) and with the carcinogen 1,2-dimethylhydrazine exhibited a significantly lower incidence of neoplastic lesions in the colon than animals treated only with the carcinogen. Data suggest that the MOA responsible for the chemopreventive effect of UA may be related to interaction with DNA topoisomerase II and/or the antioxidant potential of the compound.

Ameliorative effects of Annona muricata Linn. (Annonaceae) against potassium dichromate-induced hypertension in vivo: involvement of Kim-1/p38 MAPK/Nrf2 signaling

Background Recently, the incidences of hypertension and environmental pollution have increased significantly. This study investigates the antihypertensive effect of Annona muricata extract against K2Cr2O7-induced hypertension. Methods Fifty rats were used for this study, which were divided into five groups of 10 rats each. Rats in Group A received normal saline, and those in Groups B, C, D, and E were treated with A. muricata extract alone at 250 mg/kg, K2Cr2O7 at 30 mg/kg, pretreated with the extract at 250 mg/kg, and pretreated with gallic acid at 60 mg/kg for 14 days, respectively, and thereafter administered with a single intraperitoneal injection of K2Cr2O7 at 30 mg/kg. Results Administration of K2Cr2O7 significantly increased systolic, diastolic, and mean arterial pressure and caused prolonged QT and QTc intervals. Further, pretreatment with the extract at 250 mg/kg and gallic acid at 60 mg/kg significantly reduced high blood pressure to near-normal values. K2Cr2O7 intoxication led to significant increases in serum advanced oxidative protein products, myeloperoxidase, and xanthine oxidase, while serum nitric oxide (NO) also reduced significantly. Immunohistochemistry of the renal kidney injury molecule (Kim-1) and p38 MAPK showed increased expressions following the administration of K2Cr2O7 together with the downregulation of nuclear factor erythroid 2-related factor 2 (Nrf2). Pretreatment with the extract at 250 mg/kg and gallic acid at 60 mg/kg also increased the expressions of Nrf2 and downregulated Kim-1 and p38. Conclusion Together, we found that pretreatment with the extract at 250 mg/kg and gallic acid at 60 mg/kg normalized the blood pressure, reduced the markers of oxidative stress, and improved the antioxidant defense system and serum NO bioavailability.

Mutagenic activity and chemical composition of phenolic-rich extracts of leaves from two species of Ficus medicinal plants

Plant species from the Ficus genus are widely used as food, and in folk medicine as anti-inflammatory, antioxidant and anticancer agents, although some of these species are known to produce adverse effects. The aim of this study was to determine and compare the chemical composition as well as in vitro antioxidant and mutagenic activity of the aqueous extracts of leaves from F. adhatodifolia and F. obtusiuscula. Phytochemical screening using thin-layer chromatography identified 6 classes of secondary metabolites in the extracts. Total phenolic content was estimated by the Folin-Ciocalteau method and the phenolic profile was determined by UPLC-DAD-ESI/MS/MS. Antioxidant activities were evaluated by the DPPH radical assay and by the β-carotene/linoleic acid system. Mutagenic activity was measured by the Salmonella typhimurium reverse mutation test with 4 strains, in both the presence and absence of metabolic activation. Flavonoids, coumarins, and tannins were detected in both extracts, and 6 major derivatives were identified as flavone compounds. Antioxidant activities were demonstrated for both extracts, while F. obtusiuscula contained higher concentrations of phenolic compounds. Mutagenic activity of the TA97 strain without metabolic activation was observed for both tested extracts, as well as the TA102 strain with metabolic activation. In addition, the extract of F. adhatodifolia was shown to be mutagenic to the TA102 strain without metabolic activation. Evidence indicates that the use of teas obtained from these two plant extracts in folk medicine may raise concerns and needs further investigation as a result of potential pro-oxidant mutagenic effects in the absence or presence of metabolic activation.

Pouteria ramiflora (Mart.) Radlk. extract: Flavonoids quantification and chemopreventive effect on HepG2 cells

Pouteria ramiflora (Mart.) Radlk., popularly known as curriola, is commonly used in Brazil as medicinal plant to treat worm infections, dysentery, pain, inflammation, hyperlipidemia, and obesity. At present the safety of this extract when used therapeutically in human remains to be determined. Thus, the aim of this study was to examine cytotoxicity, antiproliferative, and antimutagenic actions of this extract. The hydroalcoholic extract from P. ramiflora leaves consisted of flavonoids identified and quantified as myricetin-3-O-β-D-galactopyranoside (13.55 mg/g) and myricetin-3-O-α-L-rhamnopyranoside (9.61 mg/g). The extract exhibited cytotoxicity at concentrations higher than 1.5 µg/ml in human hepatocarcinoma (HepG2)and 2.5 µg/ml in non-tumoral primary gastric (GAS) cells using the MTT assay, and at concentrations higher than 3 µg/ml in HepG2 and 3.5 µg/ml in GAS cells by the neutral red assay. The extract did not show antiproliferative effect as evidenced by the nuclear division index (NDI). However, in the presence of benzo[a]pyrene (BaP) (positive control), an enhanced cytostatic effect in the NDI and flow cytometry was noted. It is of interest that when the extract was co-incubated with BaP a significant decrease in DNA damage was observed indicating an antimutagenic action. This protective effect might be attributed to myricetin and gallic acid found in P. ramiflora extract. The low cytotoxicity action and protective effect observed in the present study encourage further studies regarding other biological effects of P. ramiflora, as well as its potential use as a chemopreventive agent.

Phytochemical characterization and antioxidant, antibacterial and antimutagenic activities of aqueous extract from leaves of Alchornea glandulosa

Plant extracts exist as a complex matrix which serves as a source of numerous bioactive metabolites. The ultra performance liquid chromatography with diode-array detection-coupled electrospray ionization-mass spectrometry/mass spectrometry technique was used to characterize the aqueous extract from leaves of Alchornea glandulosa (EAG), a species popularly used to treat gastrointestinal problems as an antiulcer agent. Quantification of phenolic derivatives was determined using Folin-Ciocalteu and aluminum trichloride (AlCl₃) methods. In addition, antioxidant (2,2-diphenyl-1-picrylhydrazyl [DPPH^•] radical scavenging, β-carotene-linoleic acid, and lipid peroxidation), antibacterial (agar well diffusion method and minimum inhibitory concentration), antimutagenic (Ames test), and antigenotoxic (plasmid cleavage) assays were also performed on this plant extract. The ellagitannin tris-galloyl-hexahydroxydiphenic acid-glucose was identified as the predominant compound along with tannins as majority metabolites. EAG showed high antioxidant activity accompanied by moderate antibacterial activity against Staphylococcus aureus. The highest antimutagenic activity was observed for TA97 strain without metabolic activation (S9) and with metabolic activation, TA100 and TA102 were completely inhibited. In addition, EAG exhibited potential signs of antigenotoxic action. The high antioxidant and antimutagenic activity observed for EAG suggests important therapeutic uses that still need to be verified in future studies.

Hepatic damage exacerbates cisplatin-induced acute kidney injury in Sprague-Dawley rats

The objective of this study was to elucidate the effect of hepatic damage on cisplatin (CDDP)-induced acute kidney injury (AKI). Thioacetamide (TAA, 150 mg/kg), a hepatotoxicant, was intraperitoneally (i.p.) injected to male Sprague-Dawley rats for 3 d prior to CDDP (5 mg/kg, i.p.) injection. All animals were sacrificed 5 d after CDDP treatment, and urine or blood was obtained to measure various parameters. No significant changes in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity were observed after CDDP treatment. However, pretreatment with TAA significantly elevated ALT and AST activity. Serum blood urea nitrogen and creatinine levels significantly increased in CDDP-treated group compared to control. In addition, urinary excretion of novel protein-based biomarkers such as neutrophil gelatinase-associated lipocalin, vascular endothelial growth factor, kidney injury molecule-1, and tissue inhibitor of metalloproteinase-1 rose markedly in the CDDP-treated group. In particular, pretreatment with TAA markedly elevated CDDP-induced urinary excretion of protein-based nephrotoxic biomarkers compared with CDDP alone. Hematoxylin and eosin staining demonstrated that pretreatment with TAA following CDDP injection led to more severe tubular damage and apoptosis in rats compared with CDDP alone. Antioxidant status was significantly reduced in kidneys following pretreatment with TAA prior to CDDP. These findings indicate that liver injury enhanced the vulnerability of kidney to CDDP-induced AKI and this phenomenon may be associated with severe apoptotic damage.

Risk management of free radicals involved in air travel syndromes by antioxidants

Frequent air travelers and airplane pilots may develop various types of illnesses. The environmental risk factors associated with air travel syndromes (ATS) or air travel-related adverse health outcomes raised concerns and need to be assessed in the context of risk management and public health. Accordingly, the aim of the present review was to determine ATS, risk factors, and mechanisms underlying ATS using scientific data and information obtained from Medline, Toxline, and regulatory agencies. Additional information was also extracted from websites of organizations, such as the International Air Transport Association (IATA), International Association for Medical Assistance to Travelers (IAMAT), and International Civil Aviation Organization (ICAO). Air travelers are known to be exposed to environmental risk factors, including circadian rhythm disruption, poor cabin air quality, mental stress, high altitude conditions, hormonal dysregulation, physical inactivity, fatigue, biological infections, and alcoholic beverage consumption. Consequences of ATS attributed to air travel include sleep disturbances (e.g., insomnia), mental/physical stress, gastrointestinal disorders, respiratory diseases, circulatory-related dysfunction, such as cardiac arrest and thrombosis and, at worst, mechanical and terrorism-related airplane crashes. Thus safety measures in the cabin before or after takeoff are undertaken to prevent illnesses or accidents related to flight. In addition, airport quarantine systems are strongly recommended to prepare for any ultimate adverse circumstances. Routine monitoring of environmental risk factors also needs to be considered. Frequently, the mechanisms underlying these adverse manifestations involve free radical generation. Therefore, antioxidant supplementation may help to reduce or prevent adverse outcomes by mitigating health risk factors associated with free radical generation.