In vitro enhancement effect of humic acid on the progression of lung cancer cells

Flow photocatalysis system-based functionalized graphene oxide-ZnO nanoflowers for degradation of a natural humic acid

The functionalized graphene oxide-ZnO (fGO/ZnO) nanoflower composites have been studied as a photocatalyst material for flow photodegradation of humic acid (HA) in real samples. The fGO/ZnO nanoflower was prepared via hydrothermal methods. The chemical and physical properties of the synthesized photocatalyst have been carried out by several techniques, including X-ray diffraction (XRD), scanning electron microscope-energy-dispersive spectrometer (SEM-EDS), Fourier transform infrared (FTIR), and UV-Vis spectrophotometer. The photocatalytic study of degradation of HA by flow system is reported. The optimum condition for degradation was found at pH 4.0, a flow rate of 1 mL min^-1, and a light intensity of 400 mW cm^-2. The degradation efficiency of HA also was influenced by several anion or cation concentration ratios on the system. This method was applied for the degradation of HA in extracted natural HA from the soil, and the efficiency achieved at 98.5%. Therefore, this research provides a low-cost, fast, and reusability method for HA degradation in the environment.

Deciphering the antitumoral potential of the bioactive metabolites from medicinal mushroom Inonotus obliquus

ETHNOPHARMACOLOGICAL RELEVANCE

The crude extracts of the medicinal mushroom Inonotus obliquus have been used as an effective traditional medicine to treat malicious tumors, gastritis, gastric ulcers, and other inflammatory conditions in Russia and most Baltic countries.

AIM OF THIS REVIEW

Deciphering the antitumoral potential of the bioactive metabolites from I. obliquus and addressing its possibility to be used as effective agents for tumor treatment, restoration of compromised immunity and protection of gastrointestinal damage caused by chemotherapy.

MATERIALS AND METHODS

We analysed the current achievements and dilemma in tumor chemo- or immunotherapy. In this context, we searched the published literatures on I. obliquus covering from 1990 to 2020, and summarized the activities of antitumor, antioxidation, and immunomodulation by the polysaccharides, triterpenoids, small phenolic compounds, and hispidin polyphenols. By comparing the merits and shortcomings of current and traditional methodology for tumor treatment, we further addressed feasibility for the use of I. obliquus as an effective natural drug for tumor treatment and prevention.

RESULTS

The diverse bioactive metabolites confer I. obliquus great potential to inhibit tumor growth and metastasis. Its antitumor activities are achieved either through suppressing multiple oncogenic signals including but not limited to the activation of NF-κB and FAK, and the expression of RhoA/MMP-9 via ERK1/2 and PI3K/Akt signaling pathway. The antitumor activities can also be achieved by inhibiting tyrosinase activity via PAK1-dependent signaling pathway or altering lysosomal membrane permeabilization through blocking tubulin polymerization and/or disturbing energy metabolism through LKB1/AMPK pathway. In addition, the metabolites from I. obliquus also harbour the potentials to reverse MDR either through selective inhibition on P-gp/ABCB1 or MRP1/ABCC1 proteins or the induction of G2/M checkpoint arrest in tumor cells of chemoresistant phenotypes mediated by Nox/ROS/NF-kB/STAT3 signaling pathway. In addition to the eminent effects in tumor inhibition, the metabolites in I. obliquus also exhibit immunomodulatory potential to restore the compromised immunity and protect against ulcerative damage of GI tract caused by chemotherapy.

CONCLUSIONS

I. obliquus possesses the potential to reduce incidence of tumorigenesis in healthy people. For those whose complete remission has been achieved by chemotherapy, administration of the fungus will inhibit the activation of upstream oncogenic signals and thereby prevent metastasis; for those who are in the process of chemotherapy administration of the fungus will not only chemosensitize the tumor cells and thereby increasing the chemotherapeutic effects, but also help to restore the compromised immunity and protect against ulcerative GI tract damage and other side-effects induced by chemotherapy.

Detection of DNA damage formation by natural organic matter using EGFP-fused MDC1-expressing cells

Studies have been conducted on the genotoxicity and carcinogenicity of disinfection by-products formed from natural organic matter (NOM) and mitigation effect for mutagens and clastogens by NOM. Whereas, reportedly, synthetic humic acid in high concentration has induced genotoxicity in human cells, and NOM samples have provoked mild oxidative and other physiological responses in aquatic organisms. Our group developed a novel detection method for DNA damage formation, namely enhanced green fluorescent protein (EGFP)-fused mediator of DNA damage checkpoint 1 (MDC1)-expressing human cells as simple and high-sensitive system. By using this method, a significant increase in the foci area was observed after 3 h, but not 24 h for 130 mgC L^-1 Suwannee River fulvic acid (SRFA), 38 mgC L^-1 humic acid (SRHA), and 19 mgC L^-1 NOM (SRNOM). The SRNOM concentration is the original environmental one; therefore, it was suggested that the formation and repair of DNA damage associated with γ-H2AX, a biomarker for DNA double-strand breaks by mild oxidative stress, in Suwannee River (SR) were detected for the first time. The increase in the foci area was not observed for 18 mgC L^-1 Lake Biwa fulvic acid (LBFA) and 50 mg L^-1 catechin after both 3 h and 24 h. The difference between the SR and Lake Biwa (LB) samples may result from the differences in their electron-accepting capacity. The application of this methodology is expected to elucidate oxidative stress and toxicological effects shortly and in detail for many water samples.

Environmentally relevant concentration of arsenic trioxide and humic acid promoted tumor progression of human cervical cancer cells: In vivo and in vitro studies

In a previous study, treatment at higher concentrations of arsenic trioxide or co-exposure to arsenic trioxide and humic acid was found to be inhibited cell growth of cervical cancer cells (SiHa cells) by reactive oxygen species generation. However, treatment at lower concentrations slightly increased cell viability. Here, we investigate the enhancement of progression effects of environmentally relevant concentration of humic acid and arsenic trioxide in SiHa cell lines in vitro and in vivo by measuring cell proliferation, migration, invasion, and the carcinogenesis-related protein (MMP-2, MMP-9, and VEGF-A) expressions. SiHa cells treated with low concentrations of humic acid and arsenic trioxide alone or in co-exposure significantly increased reactive oxygen species, glutathione levels, cell proliferation, scratch wound-healing activities, migration abilities, and MMP-2 expression as compared to the untreated control. In vivo the tumor volume of either single drug (humic acid or arsenic trioxide) or combined drug-treated group was significantly larger than that of the control for an additional 45 days after tumor cell injection on the back of NOD/SCID mice. Levels of MMP-2, MMP-9, and VEGF-A, also significantly increased compared to the control. Histopathologic effects of all tumor cells appeared round in cell shape with high mitosis, focal hyperkeratosis and epidermal hyperplasia in the skin, and some tumor growth in the muscle were observed. Our results may indicate that exposure to low concentrations of arsenic trioxide and humic acid is associated with the progression of cervical cancer. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1121-1132, 2016.

Humic acids: Structural properties and multiple functionalities for novel technological developments

Humic acids (HAs) are macromolecules that comprise humic substances (HS), which are organic matter distributed in terrestrial soil, natural water, and sediment. HAs differ from the other HS fractions (fulvic acid and humins) in that they are soluble in alkaline media, partially soluble in water, and insoluble in acidic media. Due to their amphiphilic character, HAs form micelle-like structures in neutral to acidic conditions, which are useful in agriculture, pollution remediation, medicine and pharmaceuticals. HAs have undefined compositions that vary according to the origin, process of obtainment, and functional groups present in their structures, such as quinones, phenols, and carboxylic acids. Quinones are responsible for the formation of reactive oxygen species (ROS) in HAs, which are useful for wound healing and have fungicidal/bactericidal properties. Phenols and carboxylic acids deprotonate in neutral and alkaline media and are responsible for various other functions, such as the antioxidant and anti-inflammatory properties of HAs. In particular, the presence of phenolic groups in HAs provides antioxidant properties due to their free radical scavenging capacity. This paper describes the main multifunctionalities of HAs associated with their structures and properties, focusing on human health applications, and we note perspectives that may lead to novel technological developments. To the best of our knowledge, this is the first review to address this topic from this approach.

Humic acid enhances cigarette smoke-induced lung emphysema in mice and IL-8 release of human monocytes

Tobacco smoke is the main factor in the etiology of lung emphysema. Generally prolonged, substantial exposure is required to develop the disease. Humic acid is a major component of cigarette smoke that accumulates in smokers' lungs over time and induces tissue damage.

OBJECTIVES

To investigate whether humic acid pre-loading potentiates the development of cigarette smoke-induced lung emphysema in mice and increases IL-8 release by human monocytes.

METHODS

C57BL/6J mice received humic acid or aqueous vehicle by tracheal installation on day 0 and day 7. From day 21 to day 84, the mice were exposed to cigarette smoke or clean air for 5 days/week. Twenty-four hours after the last exposure we determined leukocytes in lung lavage, heart hypertrophy and alveolar wall destruction. Human monocytes were incubated with cigarette smoke extract (CSE), humic acid or the combination overnight.

RESULTS

Humic acid nor cigarette smoke caused alveolar wall destruction within two months. Interestingly, the combination did induce lung emphysema. Humic acid, cigarette smoke or the combination did not change leukocyte types and numbers in lung lavage fluid, but the combination caused peribronchiolar and perivascular lymphocyte infiltration. Humic acid treatment resulted in a high proportion of alveolar macrophages heavily loaded with intracellular granula. Humic acid also induces the release of IL-8 from human monocytes and enhances the CSE-induced IL-8 release.

CONCLUSIONS

Humic acid deposition in the lungs potentiates the development of cigarette smoke-induced interstitial inflammation and lung emphysema. Moreover, humic acid promotes IL-8 release from human monocytes. Since humic acid accumulates steadily in the lungs of smokers, this may provide an explanation for the natural history on late onset of this disease. The model described here offers a novel way to study emphysema and may direct the search for new therapeutic approaches.

High-density lipoprotein of patients with type 2 diabetes mellitus elevates the capability of promoting migration and invasion of breast cancer cells

Epidemiological studies suggested complicated associations between type 2 diabetes mellitus and breast cancer. There is a significant inverse association between high-density lipoprotein (HDL) and the risk and mortality of breast cancer. However, HDL could be modified in various ways in diabetes patients, and this may lead to the altered effects on many different types of cells. In our study, we found that glycation and oxidation levels are significantly higher in HDL from type 2 diabetes mellitus patients compared to that from healthy subjects. Diabetic HDL dramatically had a stronger capability to promote cell proliferation, migration and invasion of breast cancer (as examined both on hormone-independent cells and on hormone-dependent cells). In addition, glycated and oxidized HDL, which were produced in vitro, acted in similar way as diabetic HDL. Diabetic HDL, glycated HDL and oxidized HDL also induced higher synthesis and secretion of VEGF-C, MMP-2 and MMP-9 from malondialdehyde (MDA)-MB-231 cells. It was indicated that diabetic, glycated and oxidized HDL promote MDA-MB-231 cell migration and invasion through ERK and p38 MAPK pathways, and Akt pathway plays an important role as well in MDA-MB-231 cell invasion. The Akt, ERK and p38 MAPK pathways are also involved in VEGF-C and MMP-9 secretion induced by diabetic, glycated and oxidized HDL. Our study demonstrated that glycation and oxidation of HDL in diabetic patients could lead to abnormal actions on MDA-MB-231 cell proliferation, migration and invasion, thereby promoting the progression of breast cancer. This will largely draw the attention of HDL-based treatments in diabetic patients especially those with breast cancer.

Korean Scutellaria baicalensis water extract inhibits cell cycle G1/S transition by suppressing cyclin D1 expression and matrix-metalloproteinase-2 activity in human lung cancer cells

AIM OF THE STUDY

Scutellaria baicalensis Georgi is a widely used medicinal herb in several Asian countries including Korea. The various medicinal properties attributed to Scutellaria baicalensis include anti-bacterial, anti-viral, anti-inflammatory and anti-cancer effects. The present study investigated the cytotoxicity of Scutellaria baicalensis water extract (SBWE) on A549 non-small-cell-lung cancer cells and the A549 expression of cyclin D1, cyclin-dependent kinase 4 (CDK4) and matrix metalloproteinase-2 (MMP-2), and the effects of SBWE on cell cycle progression, especially the G1/S phase, and on cell motility.

MATERIALS AND METHODS

SBWE cytotoxicity was assessed by a standard colorimetric assay utilizing 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and expression of cyclin D1 and CDK4 protein in SBWE-treated A549 cells was assessed by Western blot analysis. Flow cytometry analysis was performed to determine the effect of SBWE on A549 cell cycle progression. A549 cell MMP-2 activity was examined by zymography. Cell motility and migration was assessed by a scratch wound healing assay.

RESULTS

SBWE was not cytotoxic. The production of Cyclin D1, CDK4 and MMP-2 activity were significantly decreased in a SBWE dose-dependent manner, with maximum inhibition occurring at SBWE concentrations of 250 μg/ml and 500 μg/ml. SBWE inhibited cell cycle progression in the G1/S phase and significantly inhibited the motility of A549 cells.

CONCLUSIONS

Cyclin D1 protein may be associated with MMP-2 activity and cell motility. Thus, SBWE promotes a strong protective effect against MMP-2 mediated metastasis and cell proliferation through the down-regulation of cyclin D1. SBWE may be a useful chemotherapeutic agent for lung cancer.