Capsaicin alleviates the imbalance in xenobiotic metabolizing enzymes and tumor markers during experimental lung tumorigenesis

Associations between urinary concentrations of benzothiazole, benzotriazole, and their derivatives and lung cancer: A nested case-control study

Benzothiazole (BTH), benzotriazole (BTR), and their respective derivatives (BTHs and BTRs) are emerging environmental pollutants with widespread human exposure and oncogenic potential. Studies have demonstrated adverse effects of exposure to certain BTHs and BTRs on the respiratory system. However, no study has examined the associations between exposure to BTHs and BTRs and lung cancer risk. We aimed to examine the associations between urinary concentrations of BTHs and BTRs and the risk of lung cancer in the general population from Quzhou, China. We conducted a nested case-control study in an ongoing prospective Quzhou Environmental Exposure and Human Health (QEEHH) cohort, involving 20, 694 participants who provided urine samples during April 2019-July 2020. With monthly follow-up until November 2022, 212 lung cancer cases were recruited and 1:1 matched with healthy controls based on age and sex. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) of lung cancer risk associated with urinary BTHs and BTRs concentrations using conditional logistic regression models after controlling for potential covariates. We also examined effect modification by several covariates, including sex, socioeconomic status, smoking status, alcohol consumption, and dietary habit. Creatinine-corrected urinary BTH and 2-hydroxy-benzothiazole (2-OH-BTH) levels were significantly associated with the risk of lung cancer, after adjusting for a variety of covariates. Participants in the highest quartile of BTH had a 95% higher risk of lung cancer, compared with those in the lowest quartile (adjusted OR = 1.95, 95% CI: 1.08-3.49; p for trend = 0.01). Participants with higher levels of urinary 2-OH-BTH had an 83% higher risk of lung cancer than those with lower levels (adjusted OR = 1.83, 95% CI: 1.16-2.88; p for trend = 0.01). Exposure to elevated levels of BTH and 2-OH-BTH may be associated with an increased risk of lung cancer. These associations were not modified by socio-demographic characteristics.

Baicalein: A review on its anti-cancer effects and mechanisms in lung carcinoma

Plant-derived flavonoids are reported to function as potential anti-cancer agents against different types of cancer. Baicalein (BE) is an important flavonoid found in the roots of Scutellaria baicalensis that is popularly used in Chinese medicine as an ingredient in herbal tea preparations to promote wellness. BE has been studied for its several biological effects including antioxidant, anti-inflammatory, anti-hepatotoxic, antiviral, and anti-tumor properties. BE has now been discovered to be an effective agent against lung neoplasm. The molecular factors supporting baicalein's anti-cancer activity against lung cancer and its value to human health are discussed in this article. This would help in identifying BE as a promising competent drug against lung carcinoma. PRACTICAL APPLICATIONS: Baicalein is a flavonoid obtained from the roots of Scutellaria baicalensis. It has been widely used as an antioxidant, anti-inflam5matory, anti-hepatotoxic, antiviral, and anti-cancer agent. Lung cancer is one of the most common malignancies in the world with a high fatality rate. Several studies have found that Baicalein is an important candidate for treating lung cancer. Its mechanism of action includes regulation of cell proliferation, metastasis, apoptosis, autophagy, and so on. Baicalein could be used as a novel anti-cancer drug for the treatment of lung carcinoma.

Anticancer and immunomodulatory effect of rhaponticin on Benzo(a)Pyrene-induced lung carcinogenesis and induction of apoptosis in A549 cells

In worldwide, one of the most important cancer-related death is lung cancer. Also has the highest mortality rate between various cancer types. The count of lung cancer occurrence is increasing with an increased frequency by smoking. Proficient chemoprevention approaches are needed to prevent the occurrence of lung cancer. Therefore, the aim of this exploration is to determine the therapeutic impact on the immune modulatory effect of rhaponticin on lung tumorigenesis in vivo and in vitro cytotoxicity effect in A549 cells of human lung cancer. Lung cancer tumorigenesis in mice was challenged with benzo(a)pyrene (BaP) with 50 mg/kg bodyweight (b.wt) as oral administration for 6 weeks (two times/week). Rhaponticin were given orally 30 mg/kg b.wt (two times/week) in BaP induced mice from 12 weeks to 18 weeks. After treatment completes, the body weight was measured and then blood, lung tissue was collected for various parameters detection. The results evidenced that BaP induced mice decreased the bodyweight, increased lung weight, increased tumor markers (AHH, CEA and LDH), and increased the proinflammatory cytokines. The enzyme catalase, superoxide dismutase activity was decreased and increased lipid peroxidation in immune comprising cells compared with the control cells. Moreover, rhaponticin treatment improves in chemical assays and also the histopathological alteration of lung tissues. The present findings provide evidence about the therapeutic potentials of rhaponticin against BaP triggered lung tumorigenesis.

Citral inhibits N-nitrosodiethylamine-induced hepatocellular carcinoma via modulation of antioxidants and xenobiotic-metabolizing enzymes

Hepatocellular carcinoma (HCC) ranks the sixth position among various cancers worldwide. Recent research shows that natural and dietary compounds possess many therapeutic effects. Citral is a monoterpene aldehyde that contains geranial and neral. The present study was considered to study the role of citral against N-nitrosodiethylamine (NDEA)-induced HCC via modulation of antioxidants and xenobiotic-metabolizing enzymes in vivo. NDEA-alone-administered group II animals profoundly showed increased tumor incidence, reactive oxygen species, liver marker enzyme levels, serum bilirubin levels, tumor markers of carcinoembryonic antigen, α-fetoprotein, proliferative markers of argyrophilic nucleolar organizing regions, proliferating cell nuclear antigen (PCNA) expressions, phase I xenobiotic-metabolic enzymes and simultaneously decreased antioxidants, and phase II enzymes levels. Citral (100 mg/kg b.w.) treatment significantly reverted the levels in group III cancer-bearing animals when compared to group II cancer-bearing animals. In group IV animals, citral-alone administration did not produce any adverse effect during the experimental condition. Based on the results, citral significantly inhibits the hepatocellular carcinogenesis through restoring the antioxidants and phase II xenobiotic-enzyme levels; thereby, it strongly proves as an antiproliferative agent against rat HCC.

Antitumor activity of Cuphea ignea extract against benzo(a)pyrene-induced lung tumorigenesis in Swiss Albino mice

Lung cancer has one of the highest mortality rates among various types of cancer and is the most frequent cancer in the world. The incidence of lung cancer is increasing rapidly, in parallel with an increased incidence of smoking. Effective chemoprevention may be an alternative strategy to control the incidence of lung cancer. Thus, the objective of current work was to ascertain the possible preventive and therapeutic efficacies of Cuphea ignea extract in a mouse model of lung tumorigenesis and its cytotoxicity toward the A549 human lung cancer cell line. Lung tumorigenesis was induced by the oral administration of benzo(a)pyrene (50 mg/kg b.w.) twice per week to Swiss albino mice for 4 weeks. Benzo(a)pyrene-treated mice were orally administered C. ignea (300 mg/kg body weight, 5 days/week) for 2 weeks before or 9 weeks after the first benzo(a)pyrene dose, for a total of 21 weeks. At the end of the administration period, various parameters were measured in the serum and lung tissues. The results revealed that the oral administration of benzo(a)pyrene resulted in increases in relative lung weight, serum levels of tumor markers (ADA, AHH, and LDH), and the inflammatory marker NF-κB, and a decreased total antioxidant capacity compared with the control. In addition, decreased levels of enzymatic and non-enzymatic antioxidants, with a concomitant increase in lipid peroxidation, metalloproteinases (MMP-2 and MMP-12), and the angiogenic marker VEGF were detected in lung tissues. Moreover, benzo(a)pyrene administration induced the upregulation of PKCα, COX-2, and Bcl-2 expression, with the downregulation of BAX and caspase-3 expression. C. ignea treatment alleviated all alterations in these parameters, which was further confirmed by the histopathological analysis of lung tissues. The findings of the current work provide the first verification of the preventive and therapeutic potentials of C. ignea extract against benzo(a)pyrene-induced lung tumorigenesis in mice.

Protective effect of vanillic acid against benzo(a)pyrene induced lung cancer in Swiss albino mice

Vanillic acid (VA) is found in high concentrations in various plants and used as traditional medicine for various diseases. The aim of the existing study is to illustrate the protective effects of VA against benzo(a)pyrene (B(a)P)-induced lung cancer in Swiss albino mice. B(a)P (50 mg/kg b.wt.) was given orally to induce lung cancer in mice. The body weight, tumor incidence, carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), and enzymatic/nonenzymatic antioxidants (superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase, and glutathione) were estimated. Further histochemical investigation through hematoxylin and eosin staining was also carried out. B(a)P administered groups showed increased levels of serum pathological markers CEA, NSE along with reduced final body weight as well as decreased tissue enzymatic and nonenzymatic antioxidants activities, whereas VA treatment (200mg/kg/b.wt) along with B(a)P showed significantly reverted the above changes, which proves as prominent anticancer effects in experimentally induced lung cancer. Overall, these results suggest that VA has an efficient preventive action against B(a)P-induced lung cancer, and this is attributed to its free-radical scavenging antioxidant activities.

Assessment of Pharmacology, Safety, and Metabolic activity of Capsaicin Feeding in Mice

Capsaicin (CAP) activates transient receptor potential vanilloid subfamily 1 (TRPV1) to counter high-fat diet (HFD)-induced obesity. Several studies suggest that CAP induces the browning of white adipocytes in vitro or inguinal white adipose tissue (iWAT) in vivo. However, there is a lack of data on the dose-response for CAP to inhibit HFD-induced obesity. Therefore, we first performed experiments to correlate the effect of various doses of CAP to prevent HFD-induced weight gain in wild-type (WT) mice. Next, we performed a subchronic safety study in WT mice fed a normal chow diet (NCD ± CAP, 0.01% in NCD) or HFD ± CAP (0.01% in HFD) for eight months. We analyzed the expression of adipogenic and thermogenic genes and proteins in the iWAT from these mice, conducted histological studies of vital organs, measured the inflammatory cytokines in plasma and iWAT, and evaluated liver and kidney functions. The dose-response study showed that CAP, at doses above 0.001% in HFD, countered HFD-induced obesity in mice. However, no difference in the anti-obesity effect of CAP was observed at doses above 0.003% in HFD. Also, CAP, above 0.001%, enhanced the expression of sirtuin-1 and thermogenic uncoupling protein 1 (UCP-1) in the iWAT. Safety analyses suggest that CAP did not cause inflammation. However, HFD elevated plasma alanine aminotransferase and creatinine, caused iWAT hypertrophy and hepatic steatosis, and CAP reversed these. Our data suggest that CAP antagonizes HFD-induced metabolic stress and inflammation, while it does not cause any systemic toxicities and is well tolerated by mice.

Methanolic bark extract of Acacia catechu ameliorates benzo(a)pyrene induced lung toxicity by abrogation of oxidative stress, inflammation, and apoptosis in mice

Benzo(a)pyrene [B(a)P] is a well-known carcinogen present in the environment. In this study, we evaluated the protective potential of methanolic bark extract of Acacia catechu Willd. (MEBA) against the lung toxicity induced by B(a)P in Swiss albino mice. To determine the protective efficacy of MEBA, it was orally administered to the mice at two doses (200 and 400 mg/kg body weight) once daily for 7 days. Mice were also exposed (orally) to B(a)P at a dose of 125 mg/kg body weight on 7th day. Administration of B(a)P increased the activities of toxicity markers such as LDH, LPO, and XO with a subsequent decrease in the activities of tissue anti-oxidant armory (CAT, SOD, GST, GPx, GR, QR, and GSH). It also caused activation of the apoptotic and inflammatory pathway by upregulation of TNF-α, NF-kB, COX-2, p53, bax, caspase-3, and downregulating Bcl-2. Pretreatment with MEBA at two different doses (200 and 400 mg/kg body weight) significantly ameliorates B(a)P-induced increased toxicity markers and activities of detoxifying enzymes along with the levels of glutathione content. It also significantly attenuated expression of apoptotic and inflammatory markers in the lungs. Histological results further confirmed the protective role of MEBA against B(a)P-induced lung toxicity. The results indicate that MEBA may be beneficial in ameliorating the B(a)P-induced oxidative stress, inflammation, and apoptosis in the lungs of mice. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1566-1577, 2017.

The Anticancer Role of Capsaicin in Experimentallyinduced Lung Carcinogenesis

OBJECTIVES

Capsaicin (CAP) is the chief pungent principle found in the hot red peppers and the chili peppers that have long been used as spices, food additives and drugs. This study investigated the anticancer potential of CAP through its ability to modify extracellular matrix components and proteases during mice lung carcinogenesis.

METHODS

Swiss albino mice were treated with benzo(a) pyrene (50 mg/kg body weight dissolved in olive oil) orally twice a week for four successive weeks to induce lung cancer at the end of 14(th) week. CAP was administrated (10 mg/kg body weight dissolved in olive oil) intraperitoneally. Extracellular matrix components were assayed; Masson's trichome staining of lung tissues was performed. Western blot analyses of matrix metalloproteases 2 and 9 were also carried out.

RESULTS

In comparison with the control animals, animals in which benzo(a)pyrene had induced lung cancer showed significant increases in extracellular matrix components such as collagen (hydroxy proline), elastin, uronic acid and hexosamine and in glycosaminoglycans such as hyaluronate, chondroitin sulfate, keratan sulfate and dermatan sulfate. The above alterations in extracellular matrix components were effectively counteracted in benzo(a)pyrene along with CAP supplemented animals when compared to benzo(a) pyrene alone supplemented animals. The results of Masson's trichome staining for collagen and of, immunoblotting analyses of matrix metalloproteases 2 and 9 further supported the biochemical findings.

CONCLUSION

The apparent potential of CAP in modulating extracellular matrix components and proteases suggests that CAP plays a chemomodulatory and anti- cancer role working against experimentally induced lung carcinogenesis.

Carvacrol modulates instability of xenobiotic metabolizing enzymes and downregulates the expressions of PCNA, MMP-2, and MMP-9 during diethylnitrosamine-induced hepatocarcinogenesis in rats

Hepatocellular carcinoma is the fifth most common malignant tumor in the world, both in terms of incidence and mortality in Asian and Western countries. There are currently limited therapeutic regimens available for effective treatment of this cancer. Carvacrol is a predominant monoterpenoic phenol believed to impede cancer promotion and progression. The present study was conducted to decipher the role of carvacrol during diethylnitrosamine (DEN)-induced hepatocarcinogenesis in male wistar albino rats. Carvacrol (15 mg/kg body weight) suppressed the elevation of serum tumor marker enzymes, carcinoembryonic antigen, and α-feto protein induced by DEN. The activities of phase I enzymes increased markedly during DEN induction, but was found to be significantly lowered upon carvacrol treatment. On the contrary, the phase II enzymes decreased in DEN-administered animals, which was improved normalcy upon carvacrol-treated animals. DEN-administered animals showed increased mast cell counts, argyrophilic nucleolar organizing regions, proliferating cell nuclear antigen, and matrix metalloproteinases (MMPs-2/9), whereas carvacrol supplementation considerably suppressed all the above abnormalities. The results suggest that the carvacrol exhibited the potential anticancer activity by inhibiting cell proliferation and preventing metastasis in DEN-induced hepatocellular carcinogenesis.

Mitigating role of baicalein on lysosomal enzymes and xenobiotic metabolizing enzyme status during lung carcinogenesis of Swiss albino mice induced by benzo(a)pyrene

The lungs mainly serve as a primary site for xenobiotic metabolism and constitute an important defense mechanism against inhalation of carcinogens. Our current study aimed to evaluate the chemotherapeutic efficacy of baicalein (BE) in Swiss albino mice exposed to tobacco-specific carcinogen benzo(a)pyrene [B(a)P] for its ability to mitigate pulmonary carcinogenesis. Here, we report that altered activities/levels of lysosomal enzymes (cathepsin-D, cathepsin-B, acid phosphatase, β-D-galactosidase, β-D-glucuronidase, and β-D-N-acetyl glucosaminidase), phase I biotransformation enzymes (cytochrome P450, cytochrome b5, NADPH-cytochrome P450 reductase, and NADH-cytochrome b5 reductase), and phase II enzymes (glutathione S-transferase, UDP-glucuronyl transferase, and DT-diaphorase) were observed in the B(a)P-induced mice. Treatment with BE significantly restored back the activities/levels of lysosomal enzymes, phase I and phase II biotransformation enzymes. Moreover, assessment of lysosomal abnormalities by transmission electron microscopic examination revealed that BE treatment effectively counteract B(a)P-induced oxidative damages. Protein expression levels studied by immunohistochemistry, immunofluorescence, and immunoblot analysis of CYP1A1 revealed that BE treatment effectively negate B(a)P-induced upregulated expression of CYP1A1. Further analysis of scanning electron microscopic studies in lung was carried out to substantiate the anticarcinogenic effect of BE. The overall data suggest that BE treatment significantly inhibits lysosomal and microsomal dysfunction, thus revealing its potent anticarcinogenic effect.

Geraniol modulates tongue and hepatic phase I and phase II conjugation activities and may contribute directly to the chemopreventive activity against experimental oral carcinogenesis

Xenobiotic metabolizing enzymes are chief determinants in both the susceptibility to mutagenic effect of chemical carcinogens and in the response of tumors to chemotherapy. The present study was aimed to analyze the effect of geraniol administration on the activity of phase I and phase II carcinogen metabolizing enzymes through the nuclear factor erythroid 2-related factor-2 (Nrf2) activation against 4-niroquinoline-1-oxide (4NQO) induced oral carcinogenesis. The well-known chemical carcinogen 4NQO (50 ppm) was used to induce oral carcinogenesis through drinking water for 4, 12, and 20 weeks. The degree of cancer progression at each stage was confirmed by histological examination. At the end of the experimental period, 100% tumor formation was observed in the oral cavity of 4NQO induced animals with significant (P<0.05) alteration in the status of tumor markers, tongue and liver phase I and phase II drug metabolizing enzymes indicating progression of disease. Oral administration of geraniol at the dose of 200 mg/kg b.wt., thrice a week to 4NQO induced animals was able to inhibit tumor formation and thereby delayed the progression of oral carcinogenesis by modulating tongue and liver phase I and phase II drug metabolizing enzymes, as substantiated further by the histological and transmission electron microscopic studies. Our results demonstrate that geraniol exerts its chemopreventive potential by altering activities of phases I and II drug metabolizing enzymes to achieve minimum bioactivation of carcinogen and maximum detoxification.

Baicalein abrogates reactive oxygen species (ROS)-mediated mitochondrial dysfunction during experimental pulmonary carcinogenesis in vivo

Our current study aimed to evaluate the chemotherapeutic efficacy of baicalein (BE) in Swiss albino mice, which is exposed to benzo(a)pyrene [B(a)P] for its ability to alleviate mitochondrial dysfunction and systolic failure. Here, we report that oral administration of B(a)P (50 mg/kg body weight)-induced pulmonary genotoxicities in mice was assessed in terms of elevation in reactive oxygen species (ROS) generation and DNA damage in lung mitochondria. MDA-DNA adducts were formed in immunohistochemical analysis, which confirmed nuclear DNA damage. mRNA expression levels studied by RT-PCR analysis of voltage-dependent anion channel (VDAC) and adenine nucleotide translocase (ANT) were found to be significantly decreased and showed a marked increase in membrane permeability transition pore (MPTP) opening. Accompanied by up-regulated Bcl-xL and down-regulated Bid, Bim and Cyt-c proteins studied by immunoblot were observed in B(a)P-induced lung cancer-bearing animals. Administration of BE (12 mg/kg body weight) significantly reversed all the above deleterious changes. Moreover, assessment of mitochondrial enzyme system revealed that BE treatment effectively counteracts B(a)P-induced down-regulated levels/activities of isocitrate dehydrogenase, α-ketoglutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, NADH dehydrogenase, cytochrome-C-oxidase and ATP levels. Restoration of mitochondria from oxidative damage was further confirmed by transmission electron microscopic examination. Further analysis of lipid peroxidation, superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase, glutathione reductase, reduced glutathione, vitamin E and vitamin C in lung mitochondria was carried out to substantiate the antioxidant effect of BE. The overall data conclude that chemotherapeutic efficacy of BE might have strong mitochondria protective and restoration capacity in sub-cellular level against lung carcinogenesis in Swiss albino mice.

A Comprehensive Review of the Carcinogenic and Anticarcinogenic Potential of Capsaicin

Human exposure to capsaicin, the most abundant pungent chili pepper component, is ubiquitous. Evaluation of capsaicin’s carcinogenic potential has produced variable results in in vitro and in vivo genotoxicity and carcinogenicity assays. The capsaicin tested in older studies was often from pepper plant extracts and included other capsaicinoids and diverse impurities. Recent studies utilizing high-purity capsaicin and standardized protocols provide evidence that the genotoxic and carcinogenic potential of capsaicin is quite low and that the purity of capsaicin is important. Several small epidemiological studies suggest a link between capsaicin consumption and stomach or gall bladder cancer, but contamination of capsaicin-containing foods with known carcinogens renders their interpretation problematic. The postulated ability of capsaicin metabolites to damage DNA and promote carcinogenesis remains unsupported. Anticancer activities of capsaicin have been widely reported, as it inhibits the activity of carcinogens and induces apoptosis in numerous cancer cell lines in vitro and explanted into rodents. Diverse mechanisms have been postulated for capsaicin’s anticancer properties. One hypothesis is that inhibition of cytochrome P450 enzymes—particularly CYP2E1—retards carcinogen activation but is contradicted by the low potency of capsaicin for CYP inhibition. The potential for dietary capsaicin to act as a chemopreventative is now widely postulated.

Individual variability in the detoxification of carcinogenic arylhydroxylamines in human breast

Cytochrome b(5) (b5) and NADH cytochrome b(5) reductase (b5R) detoxify reactive hydroxylamine (NHOH) metabolites of known arylamine and heterocyclic amine mammary carcinogens. The aim of this study was to determine whether NHOH reduction for the prototypic arylamine 4-aminobiphenyl (4-ABP) was present in human breast and to determine whether variability in activity was associated with single nucleotide polymorphisms (SNPs) in the coding, promoter, and 3'untranslated region (UTR) regions of the genes encoding b5 (CYB5A) and b5R (CYB5R3). 4-ABP-NHOH reduction was readily detected in pooled human breast microsomes, with a K(m) (280μM) similar to that found with recombinant b5 and b5R, and a V(max) of 1.12 ± 0.19 nmol/min/mg protein 4-ABP-NHOH reduction varied 75-fold across 70 individual breast samples and correlated significantly with both b5 (80-fold variability) and b5R (14-fold) immunoreactive protein. In addition, wide variability in b5 protein expression was significantly associated with variability in CYB5A transcript levels, with a trend toward the same association between b5R and CYB5R3. Although a sample with a novel coding SNP in CYB5A, His22Arg, was found with low reduction and b5 expression, no other SNPs in either gene were associated with outlier activity or protein expression. We conclude that b5 and b5R catalyze the reduction of 4-ABP-NHOH in breast tissue, with very low activity, protein, and messenger RNA expression in some samples, which cannot be attributed to promoter, coding, or 3'UTR SNPs. Further studies are underway to characterize the transcriptional regulation of CYB5A and CYB5R3 and begin to understand the mechanisms of individual variability in this detoxification pathway.