1. Introduction
As part of the immune system, inflammation can be caused by a variety of factors, such as pathogens, damaged cells, and toxins [
1,
2]. To stop the spread of diseases, the body naturally uses inflammation as a defense mechanism [
3]. A local immune, vascular, and inflammatory cell response to infection or injury leads to inflammation at the tissue level. These cells cause redness, swelling, heat, pain, and loss of tissue function [
4]. There are different mediators and cytokines involved in inflammation. When inflammatory mediators and cytokines are released, the immune system's other cells are activated and go toward the area of inflammation, starting an inflammatory response [
5]. The activation and production of free radicals like reactive oxygen and nitric oxide from various immune system cells including neutrophils and macrophages may result in tissue damage and lipid peroxidation [
6]. The release of mediators and lytic enzymes from macrophages results in tissue damage and lipid peroxidation due to the produced reactive oxygen species and nitric oxide [
7,
8]. Uncontrolled inflammation leads to DNA damage and mutations, which in turn promote the growth of malignant cells. Numerous inflammatory mediators, including interferons, interleukins, tissue necrosis factor that promote tumor [
9]. Globally, cancer accounts for the first leading cause of death, caused by a variety of factors, including genetics and the environment [
10]. Almost 20% of the all cancer patients die of lung cancer all over the world [
11]. There are multiple mutations associated with lung cancer, which is a complex and highly aggressive disease. Small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) are the two primary subtypes of lung cancer. SCLC accounts for 15% of total cases, while NSCLC accounts for 85% [
12]. Lung cancer was the second-most prevalent cancer diagnosed by 2020 (11.4% of all cases), and it was also the major cause of cancer death (18%, 1.8 million fatalities) [
13]. Radiation therapy, chemotherapy, hormone therapy, and surgery are used together to treat and manage the majority of cancers. Nevertheless, there are a number of disadvantages to using these strategies despite their historic success. Additionally, radiation or chemotherapy have severe negative effects on cancerous patients [
14,
15,
16]. Therefore, it is urgently necessary to discover alternative methods of treating these deficiencies in modern cancer research [
17].
Recently, bioengineered nanomaterials more specifically, nanotechnology has gained popularity as a superior form of biodegradable material for a variety of medical uses, including the diagnosis and treatment of various illnesses [
18,
19]. Recently, researchers have been studying green chemistry methods for synthesizing metal nanoparticles in order to design and develop the most efficient and eco-friendly methods [
20,
21]. Different approaches, including chemical, physical, and biological methods, can generate nanoparticles. The use of bio-resources (plants, fungi, algae, and microorganisms) that can act as reducing, stabilizing, and capping agents makes the green synthesis approach for the synthesis of metal nanoparticles one of many methods available in the literature that has several advantages over conventional methods such as biocompatibility, low toxicity, ease of manufacturing, cost-effectiveness, and the ability to control the synthesis process [
22]. As a result of its exceptional physical and chemical properties, zinc oxide nanoparticles (ZnO NPs) are also widely employed in a variety of fields [
23]. ZnONPs offer a wide range of medical applications compared to other metal oxide nanoparticles, including drug delivery, anti-cancer, antibacterial, anti-inflammation, diabetic treatment, wound healing, and bioimaging [
24,
25,
26,
27,
28]. ZnO NPs that are 100 nm in size are regarded as biocompatible and substantial. ZnONPs are generally regarded as safe (GRAS) and have been given the thumbs-up by the US Food and medication Administration (FDA), making them potential medication delivery alternatives [
29].
Natural remedies have been used by people as their main source of medicine throughout civilization [
30]. Since prehistoric times, plant-based medications have served as the foundation of traditional medical practices used in many nations, including Egypt, India, and China [
31]. Due to their unique effectiveness, safety, and economical impact on cancer, natural products today play an important role in cancer prevention and therapy[
32,
33]. With approximately 300 species dispersed over all of the major tropical zones, Cissus is the biggest genus in the Vitaceae family of grapes [
34]. One of the most well-known species of the genus Cissus in the family Vitaceae is
Cissus Antarctica, sometimes known as "kangaroo vine" [
35].
Cissus Antarctica is a yellowish leaf, lamina ovate to ovate-oblong, mostly 4–12 cm long, 20–50 mm wide used traditionally used as a vine in subtropical climates as an
ornamental plant in
gardens. Cissus species contains saponins, triterpenoids, terpenoids, alcohols, phenols, alkanes, carboxylic acids, alkenes, aliphatic amines and aromatics [
34,
36,
37]. Cissus species has been reported on human health as an antioxidant, antimicrobial, anti-nociceptive, antibacterial, analgesic, anti-inflammatory, antipyretic activity and anti-cancer [
38,
39,
40,
41,
42] but there is no scientific evidence that
Cissus antractica pharmacologically efficacious against lung cancer and inflammation.
The morphological and chemical composition of nanoparticles were clarified by the greenery synthesis of nanoparticles, which was studied by Physicochemical methods. On the contrary, reactive oxygen species are external mediators that support several signaling pathways, including those that contribute to the development and spread of cancer [
43]. Previous studies showed that the p53 signaling pathway might be used by ROS to control cancer growth and apoptosis [
44,
45,
46]. As a result, numerous pro-inflammatory cytokines, including interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-8 (IL-8), and interleukin-10 (IL-10), signal to the NF-κB signaling pathway. Therefore, the apoptosis and reduced proinflammatory cytokines of the aforementioned targets play important roles in inflammation and lung cancer therapy.
More study is now required on the relevance of biologically active compounds obtained from natural resources with nanoparticles, such as chemicals with qualities that may reduce cancer risk and inflammation. Therefore, this study was planned to formulate the zinc oxide nanoparticles from the extract of Cissus antractica and their in vitro anticancer and anti-inflammatory actions were examined against the lung cancer macrophage cells.
2. Materials and Methods
2.1. Chemicals
The dried leaves of Cissus antractica were used from Nature Garden, South Korea, South Korea. Samchun Pure Chemical Co. Ltd. (Gyeonggi-do, South Korea) provided the absolute alcohol, sodium hydroxide (>98.0%), and zinc nitrate hexahydrate (Zn (NO3)26H2O; >98.0%) for the experiment. Lung cancer cell line (A549) and Raw 264.7 murine macrophage cells were donated by the Korean Cell Line Bank (KCLB, South Korea), which was used in this experiment. In addition to 10% fetal bovine serum (FBS) and 1% penicillin/streptomycin, the Roswell Park Memorial Institute (RPMI) 1640 Dulbecco's Modified Eagle Medium (DMEM) culture medium was sold by Welgene Inc. in Gyeongsan-si, South Korea. We purchased MTT reagent from Life Technologies in Eugene, Oregon, USA. reader for ELISA. The remaining compounds were of analytical quality and were utilized exactly as they were given to us for this investigation.
2.2. Preparation of Cissus antractica water extract
The water extract was prepared sonication and water evaporation method by using sonicator (30 min) and hot extraction evaporator (8h). The collected dried leaves was grounded and 10 g powder was added with 100 ml water for complete the extraction process. Further, the extract was collected and freeze dried for further experiment (
Figure 1).
2.3. ZnO NPs using co-precipitation method
The zinc oxide nanoparticles were synthesized by co-precipitation method using zinc nitrate salt and sodium hydroxide as precursors. Aqueous solution of zinc nitrate (0.1 M) and 10% extract were mixed under constant stirring using a magnetic stirrer heated up to 50ºC, sodium hydroxide (0.2 M) was added drop by drop and kept undisturbed for 2 h. After the synthesis, nanoparticles were purified and collected by centrifugation at 5,000 rpm for 10 min, washed thoroughly with sterile water. The washed nanoparticles were kept for 4 hours in 60°C oven and used further for characterization and applications (
Figure 2).
2.4. Cell culture
Human lung cancer (A549) was created using a growth medium that contained 89% RPMI 1640, 10% FBS, and 1% P/S. The standard culture medium for murine macrophage (RAW 264.7) cells was DMEM with 10% FBS and 1% penicillin-streptomycin. A549 and RAW 264.7 cell lines were allowed to adhere and grow for one day in a humid incubator at 37 degrees with 5% CO2 before being exposed to different substances.
2.5. Cytotoxicity Assay
The cytotoxicity of cisplatin, zinc salt, CA-Ex, and CA-ZnO-Nps was examined in A549 and RAW 264.7 cell lines employing a cytotoxicity assay. The toxicity of cisplatin (10 μg/mL) was tested in only A549 cells, and the results were compared to zinc salt, CA-Ex, and CA-ZnO-Nps after one day. Both cancer cells and healthy cells were first plated in a 96-well plate at a decided-on density of 1×10^4 cells/well. Cells were then exposed to a range of concentrations (0, 5, 10, 15, 20, 25, and 30) μg/mL and allowed to incubate for 24 hours. Cells were subjected to a treatment of 20 μL of 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl tetrazolium bromide solution (MTT; 5 mg/mL, in PBS) after 24 hours for 3–4 h at 37 °C. Additionally, the presence of MTT reagents leads live cells to produce a purple formazan. 100 μL of DMSO were added to each well in order to dissolve the insoluble formazan agents. The 570 nm ELISA was used to collect the data.
2.6. Reactive Oxygen Species (ROS) Assay
In order to quantify ROS, 2′,7′dichlorodihydrofluorescein diacetate (DCFH-DA) was used on human lung carcinoma (A549). At a density of 1104 cells per well, we seeded the cells in 96-well cell culture plates and allowed them to attain 100% growth confluency the next day. At a density of 1×104 cells per well, we seeded the cells in 96-well cell culture plates and allowed them to attain 100% growth confluency the next day. The cells were stained with 100 μL of DCFH-DA (10 μM) solution in each well after 24 hours of treatment, and they were then let to sit in the dark for 30 minutes. The cells were then washed twice with PBS (100 μL/well) and the old medium was discarded. The fluorescence intensity of ROS generation was measured using a multi-model plate reader with an excitation wavelength of 485 nm and an emission wavelength of 528 nm. The DCFH-DA reagent was used to measure the increase in ROS.
2.7. Wound-Healing Assay
The ability of the A549 cancer cells to migrate was examined in an experiment on wound healing. A549 lung cancer cells were seeded in 6-well plates at a density of 2×104 cells/well, and the plates were then left to incubate at 37 °C for twenty-four hours. A 200 µL sterile pipette tip was used to scrape the monolayer vertically, and any isolated cells were removed with PBS. After 72 hours of treatment, cells were then exposed to varied doses of CA-Ex, CA-ZnO-Nps (15 and 20) µg/mL, and cisplatin (20 µM). 5.0-megapixel MC 170 HD camera (Wetzlar, Germany) embedded within the device was used to take pictures.
2.8. Hoechst staining
A Hoechst-33342 staining kit was utilized to evaluate the induction of cisplatin, CA-Ex, and CA-ZnO-Nps during apoptosis in the A549 cancer cell line. In this instance, cells were placed into a 6-well plate at a frequency of 1×10^4 cells/well, followed by the addition of 2 mL of culture medium and a 24-hour incubation period. Agents containing 4% paraformaldehyde were administered for 10 minutes (twice) after the treated cell had been cleaned with a 1 X PBS solution. After adding the Hoechst dye, the mixture was maintained at 37°C for 10 minutes. After three PBS solution washes, the labeled cell was examined under a fluorescence microscope (Leica DMLB, Wetzlar, Germany) to capture images of the dying cells.
2.9. PI staining
Cisplatin (20 µM), CA-Ex, and CA-ZnO-Nps (15 or 20) μg/mL were applied to seeded cells. Cells were treated for 24 hours before being rinsed with 1 mL of PBS and stained for 10 minutes at room temperature with 500 μL of propidium iodide reagent (5 μg/mL) solution. A fluorescent microscope (Leica DMLB, Wetzlar, Germany) was used to see the cells.
2.10. Quantitative Reverse Transcription (qRT-PCR)
To isolate total RNA, QIAzol lysis reagents (QIAGEN, Germantown, MD, USA) were used. Then, using the amfiRivert reverse transcription kit (GenDepot, Barker, TX, USA), 1 μg of total RNA was added to the 20 μL reaction buffer as directed by the manufacturer. The procedure was carried out at the following temperatures: 25 °C for five minutes, 42 °C for sixty minutes, and 70 °C for fifteen minutes. At 95 °C, 60 °C, and 72 °C, the reaction was conducted 35 times in RT-PCR for 30 s each. On 1% agarose gels, the amplified RT-PCR data were analyzed, stained with Safe Pinky DNA Gel Staining (GenDepot, Barker, TX, USA), and photographed under UV light. SYBR TOPreal qPCR2X Premix (Enzynomics, Daejeon, Republic of Korea) was used to conduct qRT-PCR. In a nutshell, the reactions were carried out in triplicate and contained 10 μL of final solution, 2x Master Mix, 1 μL of template cDNA, and 1 μL of forward and reverse primers. The aCFX Connect Real-Time PCR (Bio Rad, Hercules, CA, USA) was used for all real-time measurements. The following conditions were used to amplify reactions: 95 °C for 10 min, then 40 cycles of 95 °C for 20 s and 55–60 °C for 30 s, followed by 15 s at 72 °C. Using the comparative 2−∆∆Ct technique, the relative amounts of mRNAs were determined and normalized using the GAPDH gene. The primer sequences (GenoTech, Daejeon, Republic of Korea) are shown in
Table 1.
Author Contributions
Conceptualization, D.C.Y., D.U.Y. and S.-K.J.; methodology, J.N., E.J.R., M.A., M.M., M.A.; J.K.P, software, J.N., E.J.R., M.M., M.A. validation, E.J.R.,D.C.Y. and D.U.Y.; formal analysis, J.N., E.J.R., M.A.; and J.K.P, resources, D.U.Y., I.M.K and S.J.L, data curation, E.J.R., J.N. and M.A.; writing—original draft preparation, J.N., E.J.R. and M.A,.; writing—review and editing, J.N., E.J.R., and D.U.Y.; supervision, D.C.Y.,D.U.Y. and S.-K.J.; project administration, D.C.Y., D.U.Y. and S.-K.J.; All authors have read and agreed to the published version of the manuscript.
Figure 1.
Cissus antractica plant extract preparation.
Figure 1.
Cissus antractica plant extract preparation.
Figure 2.
Synthesis of CA-ZnO NPs.
Figure 2.
Synthesis of CA-ZnO NPs.
Figure 3.
UV-Vis analysis of CA-ZnO NPs.
Figure 3.
UV-Vis analysis of CA-ZnO NPs.
Figure 4.
FE-TEM (a, b and d) Image indifferent scale bar, (c) SAED of CA-ZnO NPs, (e,f) elemental analysis (g) EDX analysis and (h) XRD analysis of CA-ZnO NPs.
Figure 4.
FE-TEM (a, b and d) Image indifferent scale bar, (c) SAED of CA-ZnO NPs, (e,f) elemental analysis (g) EDX analysis and (h) XRD analysis of CA-ZnO NPs.
Figure 5.
Functional group analysis of CA ZnO NPs By FT-IR.
Figure 5.
Functional group analysis of CA ZnO NPs By FT-IR.
Figure 6.
Size distribution of CA-ZnO-NPs by DLS analysis (A) Volume Distribution; (B) Number distribution.
Figure 6.
Size distribution of CA-ZnO-NPs by DLS analysis (A) Volume Distribution; (B) Number distribution.
Figure 7.
Percent cell viability was determined by MTT assay. Graphs representing percent cell viability of (A) Raw 264.7 and (B) A549 cells upon treatment with Cisplatin, Zinc Salt, CA-Extract, CA-ZnO-NPs. Graph shows mean ± SD values of four replicates. ** p < 0.01; *** p < 0.001 indicates significant differences from control groups.
Figure 7.
Percent cell viability was determined by MTT assay. Graphs representing percent cell viability of (A) Raw 264.7 and (B) A549 cells upon treatment with Cisplatin, Zinc Salt, CA-Extract, CA-ZnO-NPs. Graph shows mean ± SD values of four replicates. ** p < 0.01; *** p < 0.001 indicates significant differences from control groups.
Figure 8.
ROS determination by DCFDA staining in A549 cells when treated with Zinc Salt, CA-Extract, CA-ZnO-NPs for 24 h· Cisplatin (10 µM) was used as a positive control.
Figure 8.
ROS determination by DCFDA staining in A549 cells when treated with Zinc Salt, CA-Extract, CA-ZnO-NPs for 24 h· Cisplatin (10 µM) was used as a positive control.
Figure 9.
Colony formation assay in A549 cells at 15 and 20 µg/mL concentration of Cisplatin, CA-Extract and CA-ZnO-NPs. Corresponding bar graph of colony formation assay showing the number of colonies/ dish when A549 cells were treated Cisplatin, CA-Extract and CA-ZnO-NPs.
Figure 9.
Colony formation assay in A549 cells at 15 and 20 µg/mL concentration of Cisplatin, CA-Extract and CA-ZnO-NPs. Corresponding bar graph of colony formation assay showing the number of colonies/ dish when A549 cells were treated Cisplatin, CA-Extract and CA-ZnO-NPs.
Figure 10.
(A) The cell-free area of the scratched region was measured with ImageJ soft-ware. (B) The extent of cell migration is presented as the percentage of scratch cell migration observed 24 h after treatment compared to control values. Controls indicate untreated cells. Values are expressed as mean ± standard deviation, and statistical significance is indicated by ***p < 0.01. The scale bar indicates 10× magnification.
Figure 10.
(A) The cell-free area of the scratched region was measured with ImageJ soft-ware. (B) The extent of cell migration is presented as the percentage of scratch cell migration observed 24 h after treatment compared to control values. Controls indicate untreated cells. Values are expressed as mean ± standard deviation, and statistical significance is indicated by ***p < 0.01. The scale bar indicates 10× magnification.
Figure 11.
Hoechst and PI staining of CA-ZnO-NPs and detection of cellular apoptosis via cell disruption and breakage of the cell wall, as indicated with arrowheads. (A) Hoechst staining (light-blue live cells and dark-blue apoptotic cells), (B) PI staining (dark-red dead cells), and (C)merged images. Original scale bar 20×.
Figure 11.
Hoechst and PI staining of CA-ZnO-NPs and detection of cellular apoptosis via cell disruption and breakage of the cell wall, as indicated with arrowheads. (A) Hoechst staining (light-blue live cells and dark-blue apoptotic cells), (B) PI staining (dark-red dead cells), and (C)merged images. Original scale bar 20×.
Figure 12.
Effects of Cisplatin, CA-Extract and CA-ZnO-NPs on the apoptosis-related genes' levels of mRNA expression in A549 cells. Cisplatin, CA-Extract and CA-ZnO-NPs were applied to A549 cells at a concentration of 15 and 20 μg/mL for 24 h. Following the extraction of total RNA, qPCR was used to analyze the transcript ex-pression levels using primers that targeted (A) p53 (B) BAX (C) Bcl-2 (D) Caspase 9 and (E) Caspase 3 (F) Cyto C. Each bar displays the mean ± SE of duplicate samples from 3 independent experiments (*** p < 0.01 using Student’s t-test compared to the non-treated control).
Figure 12.
Effects of Cisplatin, CA-Extract and CA-ZnO-NPs on the apoptosis-related genes' levels of mRNA expression in A549 cells. Cisplatin, CA-Extract and CA-ZnO-NPs were applied to A549 cells at a concentration of 15 and 20 μg/mL for 24 h. Following the extraction of total RNA, qPCR was used to analyze the transcript ex-pression levels using primers that targeted (A) p53 (B) BAX (C) Bcl-2 (D) Caspase 9 and (E) Caspase 3 (F) Cyto C. Each bar displays the mean ± SE of duplicate samples from 3 independent experiments (*** p < 0.01 using Student’s t-test compared to the non-treated control).
Figure 13.
The effects of Zinc Salt, CA-Extract, CA-ZnO-NPs on (A) NO production were assessed by 1 μg/mL LPS induced RAW 264.7 cells (B) generation of intercellular reactive oxygen species (ROS) was compared to a control. Data presented as ±SEM, *** p < 0.01 vs. control cell. All treatment was performed three times.
Figure 13.
The effects of Zinc Salt, CA-Extract, CA-ZnO-NPs on (A) NO production were assessed by 1 μg/mL LPS induced RAW 264.7 cells (B) generation of intercellular reactive oxygen species (ROS) was compared to a control. Data presented as ±SEM, *** p < 0.01 vs. control cell. All treatment was performed three times.
Table 1.
Sequences of primers used for mRNA gene expression analysis by qRT-PCR.
Table 1.
Sequences of primers used for mRNA gene expression analysis by qRT-PCR.
Gene |
Primer Sequences (5′-3′) |
p53 |
F: TCT TGGGCC TGT GTT ATC TCC R: CGC CCA TGC AGG AAC TGT TA |
Bcl2 |
F: GAA GGG CAG CCG TTA GGAAA R: GCG CCC AAT ACG ACC AAA TC |
BAX |
F: GGT TGC CCT CTT CTA CTT T R: AGC CAC CCT GGT CTT G |
CASPASE 3 |
F: GAA GGA ACA CGC CAG GAA AC R: GCA AAG TGA AAT GTA GCA CCA A |
CASPASE 9 |
F: GCC CGA GTT TGA GAG GAA AA R: CAC AGC CAG ACC AGG AC |
COX-2 |
F: CCT GAG CAT CTA CGG TTT GC R: ACT GCT CAT CAC CCC ATT CA |
TNF-α |
F: GCCAGAATGCTGCAGGACTT R: GGCCTAAGGTCCACTTGTGTCA |
iNOS |
F: CCT GAG CAT CTA CGG TTT GC R: ACT GCT CAT CAC CCC ATT CA |
IL-6 |
F: AGGGTTGCCAGATGCAATAC R: AAACCAAGGCACAGTGGAAC |
IL-8 |
F: CCGGAGAGGAGACTTCACAG R: GGAAATTGGGGTAGGAAGGA |
GAPDH |
F: CAA GGT CAT CCA TGA CAA CTT TG R: GTC CAC CAC CCT GTT GCT GTA G |