A nutrient mixture reduced tumor growth of SK-UT-1 human leiomyosarcoma cells in vivo and in vitro by inhibiting MMPs and inducing apoptosis

BACKGROUND

Uterine leiomyosarcoma is a rare malignant smooth muscle tumor originating in the uterine wall that generally responds poorly to chemotherapy and radiation.

AIM

We investigated the in vitro effects of a novel nutrient mixture containing lysine, proline, ascorbic acid, and green tea extract on the human leiomyosarcoma cell line SK-UT-1 by measuring cell proliferation, invasiveness, apoptosis, and expression of matrix metalloproteinases (MMP). We also tested the effects of nutrient mixture in vivo using nude mice.

MATERIALS AND METHODS

Human leiomyosarcoma SK-UT-1 cells were treated with different concentrations of nutrient mixture. Cell proliferation was determined by MTT assay; MMP expression by gelatinase zymography; invasion by Matrigel assay; migration by scratch test; apoptosis using Live Green caspase kit. In vivo studies were conducted on 5-6 weeks old female nude mice inoculated subcutaneously with 3 • 10⁶ SK-UT-1 cells. The mice were fed a regular diet or a diet supplemented with 0.5% nutrient mixture. After four weeks, the mice were sacrificed and the tumors were weighed and processed for histology.

RESULTS

In vitro, nutrient mixture treatment was not toxic to SK-UT-1 cells at 250 µg/ml but exhibited 20% and 40% cytotoxicity at 500 and 1000 µg/ml respectively. Zymography did not show bands for either MMP-2 or MMP-9 in SK-UT-1 cells. However, treatment with phorbol myristate acetate stimulated the expression of MMP-9, both active and inactive forms in equal proportion. Nutrient mixture inhibited the secretion of both active and inactive forms in a dose dependent manner. Invasion through Matrigel and migration by scratch test were inhibited in a dose dependent fashion, with both invasion and migration inhibited at 250 µg/ml. Live Green Caspase apoptosis assay demonstrated slight apoptosis at 100 µg/ml and significant apoptosis at 250 to 1000 µg/ml. The results of in vitro studies were further confirmed in vivo by showing 50% decrease in tumor weight, 40% reduction in tumor burden compared to the tumors from mice fed regular diet.

CONCLUSION

The results suggest a therapeutic potential for nutrient mixture in uterine leiomyosarcoma treatment.

Fat-Soluble Vitamins Affect Composition of Extracellular Matrix Deposited by Human Aortic Smooth Muscle and Endothelial Cells In Vitro

Atherosclerotic cardiovascular disease is accompanied by changes in arterial connective tissue. We evaluated the effects of fat-soluble vitamins A, D, and E individually and in combinations on the composition of extracellular matrix produced and deposited by arterial wall cells, human aortic smooth muscle cells, and endothelial cells. Individually, vitamins D and E stimulated collagen type I extracellular matrix deposition in human aortic smooth muscle cell cultures. However, vitamins A, D, and E reduced collagen type IV deposition by human aortic smooth muscle cell, counteracting the stimulatory effects of vitamin C. The extracellular matrix deposition of heparan sulfate by human aortic smooth muscle cells increased by vitamin C and its combination (C+D+E). β-carotene + D + C induced the extracellular matrix deposition of collagen I by endothelial cells. Vitamin E with other vitamins resulted in either induction (E+C+A) or inhibition (E+D). The extracellular matrix deposition of type IV collagen and elastin by human aortic endothelial cells was not affected by test vitamins, except the extracellular matrix type IV collagen decrease by combinations (A+E), (A+D+E), and (C+D+E). The extracellular matrix deposition of all tested glycosaminoglycans was reduced by vitamin A and its combination (A+C+D+E). Therefore, the fat-soluble vitamins applied individually or in combination—both with each other or with ascorbic acid—can affect extracellular matrix deposition of type I and IV collagens, and key glycosaminoglycans by cultured human aortic arterial wall cells.

Down regulation of u-PA by a nutrient mixture in hemangioma (EOMA) cells by inducing caspase-dependent apoptosis

Hemangiomas are the most common congenital vascular and benign tumor in infants and children. Most hemangiomas do not cause major symptoms to require intervention, however, the larger hemangiomas have tendency to bleed and may require surgical removal. Experimental studies have demonstrated the role of urokinase plasminogen activator (u-PA), especially cell surface u-PA, as an initiator of extra-cellular matrix proteolysis and associated tumor cell invasion.

AIM

To examine, whether the antitumor effects of a specific nutrient mixture are due to induction of apoptosis by inhibition of u-PA.

MATERIALS AND METHODS

A nutrient mixture containing lysine, proline, ascorbic acid, and green tea extract which has showed anticancer activity against a number of cancer cell lines was used as an experimental composition. EOMA cells were grown in appropriate media with antibiotics in 24-well tissue culture plates. At near confluence, the cells were treated with nutrition mixture at 10, 100, 1000 µg/ml in triplicate. Analysis of u-PA activity was carried out by fibrin zymography. Morphological changes and caspase activation associated with apoptosis induction was checked by H&E staining and Live Green caspase assay, respectively. Apoptosis inducing anticancer drug camptothecin (10 µM) was used as positive control.

RESULTS

The nutrition mixture exhibited dose response toxicity with maximum toxicity 55% (p < 0.001) at 1000 µg/ml. EOMA cells expressed u-PA, which was inhibited by nutrition mixture in a dose-dependent manner. The caspase analysis revealed a dose dependent increase in apoptosis of EOMA hemangioma cells, with an increasing apoptosis observed at 100 μg/ml, and maximum at 1000 μg/ml. Cells treated with nutrition mixture showed significantly more apoptotic changes than the control or camptothecin-treated cells.

CONCLUSION

These results suggest that NM may induce apoptosis of hemangioma cells in vitro thus warranting further investigation.

Reciprocal cooperation of phytochemicals and micronutrients against typical and atypical forms of Borrelia sp

AIMS

Borrelia sp., a causative pathogenic factor of Lyme disease (LD), has become a major public health threat. Current treatments based on antibiotics often lead to relapse after their withdrawal. Naturally derived substances that could work synergistically to display higher efficacy compared with the individual components may serve as a resource for the development of novel approaches to combat both active and latent forms of Borrelia sp.

METHODS AND RESULTS

Using checkerboard assay, we investigated the anti-borreliae reciprocal cooperation of phytochemicals and micronutrients against two species of Borrelia selected as prevalent causes of LD in the United States and Europe. We tested 28 combinations of phytochemicals such as polyphenols (baicalein, luteolin, rosmarinic acids), fatty acids (monolaurin, cis-2-decenoic acid) and micronutrients (ascorbic acid, cholecalciferol and iodine). The results showed that the combinations of baicalein with luteolin as well as monolaurin with cis-2-decenoic acid expressed synergistic anti-spirochetal effects. Moreover, baicalein and luteolin, when combined with rosmarinic acid or iodine, produced additive bacteriostatic and bactericidal effects against typical corkscrew motile spirochaetes and persistent knob/round-shaped forms, respectively. An additive anti-biofilm effect was noticed between baicalein with luteolin and monolaurin with cis-2-decenoic acid. Finally, application of the combination of baicalein with luteolin increased cytoplasmic permeability of Borrelia sp. but did not cause DNA damage.

CONCLUSIONS

These results show that a specific combination of flavones might play a supporting role in combating Borrelia sp. through either synergistic or additive anti-borreliae effects.

SIGNIFICANCE AND IMPACT OF THE STUDY

Presented here in vitro results might help advancing our knowledge and improving the approach to target Borrelia sp.

In vitro evaluation of antibacterial activity of phytochemicals and micronutrients against Borrelia burgdorferi and Borrelia garinii

Aims

Little is known about the effects of phytochemicals against Borrelia sp. causing Lyme disease. Current therapeutic approach to this disease is limited to antibiotics. This study examined the anti‐borreliae efficacy of several plant‐derived compounds and micronutrients.

Methods and Results

We tested the efficacy of 15 phytochemicals and micronutrients against three morphological forms of Borrelia burgdoferi and Borrelia garinii: spirochetes, latent rounded forms and biofilm. The results showed that the most potent substances against the spirochete and rounded forms of B. burgdorferi and B. garinii were cis‐2‐decenoic acid, baicalein, monolaurin and kelp (iodine); whereas, only baicalein and monolaurin revealed significant activity against the biofilm. Moreover, cis‐2‐decenoic acid, baicalein and monolaurin did not cause statistically significant cytotoxicity to human HepG2 cells up to 125 μg ml⁻¹ and kelp up to 20 μg ml⁻¹.

Conclusions

The most effective antimicrobial compounds against all morphological forms of the two tested Borrelia sp. were baicalein and monolaurin. This might indicate that the presence of fatty acid and phenyl groups is important for comprehensive antibacterial activity.

Significance and Impact of the Study

This study reveals the potential of phytochemicals as an important tool in the fight against the species of Borrelia causing Lyme disease.

A nutrient mixture inhibits glioblastoma xenograft U-87 MG growth in male nude mice

BACKGROUND

Brain tumors are highly aggressive tumors characterized by secretions of high levels of matrix metalloproteinase-2 and -9, leading to tumor growth, invasion and metastasis by digesting the basement membrane and extracellular matrix components. We previously demonstrated the effectiveness of a nutrient mixture (NM) containing ascorbic acid, lysine, proline, and green tea extract in vitro: on activity of urokinase plasminogen activator, matrix metalloproteinases and TIMPs in various human glioblastoma (LN-18, T-98G and A-172) cell lines and on glioblastoma A-172 cell proliferation and Matrigel invasion.

AIM

Our main objective in this study was to investigate the effect of the NM in vivo on human glioblastoma U-87 MG cell line.

MATERIALS AND METHODS

Athymic male nude mice inoculated with 3·10(6) U-87 MG cells subcutaneously and were fed a regular diet or a regular diet supplemented with 0.5% NM. Four weeks later, the mice were sacrificed, the tumors were weighed and measured. The samples were studied histologically.

RESULTS

NM inhibited tumor weight and tumor burden by 53% (p = 0.015) and 48% (p = 0.010), respectively.

CONCLUSIONS

These results suggest the therapeutic potential of NM as an adjuvant in the treatment of glioblastoma.

In vitro and in vivo inhibition of human Fanconi anemia head and neck squamous carcinoma by a phytonutrient combination

Head and neck squamous cell carcinoma (HNSCC) and acute myeloid leukemia are the major causes of mortality and morbidity in Fanconi anemia (FA) patients. The objective of this study was to investigate the antineoplastic activity of PB, an antineoplastic nutrient mixture (containing quercetin, curcumin, green tea, cruciferex and resveratrol) on human FA HNSCC in vitro and in vivo. Human FA HNSCC cell line OHSU-974 (Fanconi Anemia Research Fund) was cultured in RPMI medium supplemented with 20% FBS and anti-biotics. At near confluence, cells were treated in triplicate with different concentrations of PB: 0, 10, 25, 50, 75 and 100 µg/ml. Cells were also treated with PMA to induce MMP-9 activity. Cell proliferation was detected by MTT assay, secretion of MMPs by gelatinase zymography, invasion through Matrigel, migration by scratch test and morphology by hematoxylin and eosin (H&E) staining. In vivo, athymic male nude mice (n=12) were inoculated with 3x106 OHSU-974 cells subcutaneously and randomly divided into two groups: group A was fed a regular diet and group B a regular diet supplemented with 1% PB. Four weeks later, the mice were sacrificed and their tumors were excised, weighed and processed for histology. NM inhibited the growth of OHSU-974 tumor by 67.6% (p<0.0001) and tumor burden by 63.6% (p<0.0001). PB demonstrated dose-dependent inhibition of cell proliferation, with 27% (p=0.0003) and 48% (p=0.0004) toxicity at 75 and 100 µg/ml, respectively. Zymography revealed MMP-2 and PMA-induced MMP-9 secretion. PB suppressed secretion of both MMPs in a dose-dependent manner, with total block of both at 50 µg/ml. PB inhibited cell migration (by scratch test) and OHSU-974 invasion through Matrigel in a dose-dependent fashion with total block at 50 µg/ml. H&E staining showed no morphological changes below 50 µg/ml. The results suggest that PB has potential therapeutic use in the treatment of human FA HNSCC.

Effects of a nutrient mixture on immunohistochemical localization of cancer markers in human cervical cancer HeLa cell tumor xenografts in female nude mice

Although fully treatable in the early stages, once cervical cancer has metastasized, patient outcome is poor. The main objective of this study was to examine the effect of dietary supplementation with a nutrient mixture (NM) containing lysine, ascorbic acid, proline, green tea extract and other micronutrients on HeLa cell xenografts in nude female mice. Tumor growth was measured and immunohistochemical staining was evaluated for the following cancer markers: Ki67 (proliferation); matrix metalloproteinase (MMP)-2 and -9 (invasion/metastasis); vascular endothelial growth factor (VEGF) (angiogenesis); terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and B-cell lymphoma 2 (Bcl-2) (apoptosis); cyclooxygenase 2 (COX-2) and inducible nitric oxide synthase (iNOS) (inflammation); and glutathione S-transferase π (GSTπ) (a general cancer marker). Following housing for a week, 5/6-week-old female athymic nude mice (n=12) were inoculated subcutaneously with 3×10⁶ HeLa cells in 0.2 ml phosphate-buffered saline and 0.1 ml Matrigel™ and randomly divided into two groups; control group mice were fed regular mouse chow and NM group mice the regular diet supplemented with 0.5% NM (w/w). After four weeks, the mice were sacrificed and their tumors were excised and processed for histology. The NM strongly inhibited the growth of HeLa xenografts in nude mice. The mean tumor weight was reduced to 59% (P=0.001) in the mice fed the NM compared with the tumor weight in the controlled diet mice. Ki67, MMP-2 and -9, VEGF, TUNEL, Bcl-2, COX-2, iNOS and GSTπ all showed a lower intensity and frequency of staining in the NM group compared with that in the control group. In conclusion, NM supplementation strongly inhibited tumor growth and cancer markers in female nude mice injected with HeLa xenografts.

In vitro inhibition of matrix metalloproteinases, invasion and growth of Fanconi anemia human FANCA and FANCC lymphoblasts by nutrient mixture

AIM

Fanconi anemia is a rare genetic disorder with high propensity for development of cancers, such as aplastic anemia, leukemia and head and neck cancers. Collagen digesting matrix metalloproteinase (MMP) enzymes have been implicated in for their role in various malignancies and to promote metastasis. Biological agents that prevent extracellular matrix digestion by the MMPs have been shown to be promising therapeutic approaches to cancer. In this study, we investigated effects of a nutrient mixture (NM) containing, ascorbic acid, lysine, proline and green tea extract, on human FANCA and FANCC lymphoblasts for viability, MMP secretion and invasion.

METHODS

Human FANCA lymphoblasts GM13022 and HCS536 were challenged with NM at concentration range within 10-1000 µg/ml. Cell toxicity was assessed by Trypan blue dye exclusion test. Invasion was evaluated through Matrigel and gelatinase zymography for MMP activity.

RESULTS

NM was toxic in dose dependent mode to HCS536 cells but not to GM13022 cells. GM13022 cells but not HCS536 cells exhibited MMP-9 secretion, which was inhibited by NM. Matrigel invasion was inhibited in HCS536 cells at 100 and 500 µg/ml by 27% and 93%, respectively. In GM13022 cells, the NM showed completely blocked Matrigel invasion at 500 µg/ml.

CONCLUSION

NM inhibited MMP secretion and Matrigel invasion in FANCA and inhibited invasion and induced toxicity in FANCC lymphoblasts. These results suggest that the NM may have therapeutic potential in Fanconi anemia associated neoplasia.

In vitro and in vivo effects of a nutrient mixture on breast cancer progression

Long-term survival of patients with breast cancer remains poor, due to metastasis and recurrence. We investigated the effects of a novel nutrient mixture (NM) containing ascorbic acid, lysine, proline and green tea extract in vitro and in vivo on 4T1 murine breast cancer, a representative model for metastatic breast cancer. After one week of isolation, 5-6-week-old female Balb/C mice were inoculated with 5x10⁵ 4T1 cells into the mammary pad and randomly divided into two groups; the control group was fed a regular diet and the NM group a regular diet supplemented with 0.5% NM. After four weeks, the mice were sacrificed and their tumors, lungs, livers, kidneys, hearts and spleens were excised and processed for histology. Dimensions (length and width) of tumors were measured using a digital caliper, and the tumor burden was calculated using the following formula: 0.5 x length x width. We also tested the effect of NM in vitro on 4T1 cells, measuring cell proliferation by MTT assay, MMP secretion by zymography, invasion through Matrigel, migration by scratch test and morphology by H&E staining. NM inhibited tumor weight and burden of 4T1 tumors by 50% (p=0.02) and 53.4% (p≤0.0001), respectively. Lung metastasis was profoundly inhibited by NM supplementation: mean number of colonies was reduced by 87% (p<0.0001) and mean weight of lungs by 60% (p=0.0001) compared to control mice. Metastasis to liver, spleen, kidney and heart was significantly reduced with NM supplementation. In vitro, NM exhibited 50% toxicity over the control at 250 and 500 µg/ml concentrations. Zymography demonstrated MMP-2 and MMP-9 secretion which was inhibited by NM in a dose-dependent manner, with virtual total inhibition of both at 1,000 µg/ml. Migration by scratch test and invasion through Matrigel were inhibited in a dose-dependent manner with total block of invasion at 250 and of migration at 1,000 µg/ml. These results suggest that NM has therapeutic potential in the treatment of breast cancer.

Effect of a nutrient mixture on matrix metalloproteinase-9 dimers in various human cancer cell lines

Strong clinical and experimental evidence demonstrates association of elevated levels of matrix metalloproteinase MMP-9 with cancer progression, metastasis and shortened patient survival, as it plays a key role in tumor cell invasion and metastasis by digesting the basement membrane and ECM components. MMP-9 is secreted in both the monomeric and dimeric form. Although there is little research on MMP-9 dimers, some studies have shown the dimer to be associated with more aggressive tumor progression. Our objective was to study the relative secretion patterns of MMP-9 monomer and dimer in a variety of cancer cell lines and the effect of a nutrient mixture (NM) containing lysine, proline, ascorbic acid and green tea extract on MMP-9 secretion. The cancer cell lines were grown in their respective media, supplemented with 10% FBS, penicillin (100 U/ml) and streptomycin (100 µg/ml) in 24-well tissue culture plates. At near confluence, the cells were treated with NM at 0,10, 50, 100, 500 and 1000 µg/ml. Parallel sets of cultures were treated with PMA (100 ng/ml) for induction of MMP-9. Cell MMP-9 secretion was assayed by gelatinase zymography. MMP-9 dimer secretion patterns of cancer cells fell into different categories. We observed no MMP-9 dimer in prostate DU-145 and PC-3, pancreatic MIA-Pa-Ca2, colon HCT-116, bladder T-24, head and neck FaDu, glioblastoma A-172, T-98 and LN-18 and leukemia HL-60, Jurkat, and Raji cell lines. MMP-dimer secretion only with PMA induction was seen in breast MCF-7 and MDA-MB-231, uterine SK-UT-1, lung A-549, tongue SC-25, melanoma A2058, osteosarcoma U-2OS, rhabdomyosarcoma, fibrosarcoma HT-1080, chondrosarcoma SW-1350 and liposarcoma SW-872. Cervical HeLa and DoTc 2 4510, renal 786-0 and HCC SK-Hep-1 cells exhibited MMP-9 dimer without PMA treatment and increased secretion with PMA treatment. Sarcomas had the highest levels of MMP-9 monomer and dimer with and without PMA among these cancer cell lines. Cervical, uterine and male breast cancer cell lines showed the next highest levels of MMP-9, followed by breast cancer cell lines. Melanoma, renal, lung, head and neck and HCC showed lower levels and prostate, glioblastoma, bladder and leukemia cell lines the lowest. NM showed dose-dependent inhibition of MMP-9 monomer and dimer in all cell lines tested. In conclusion, high MMP-9 and dimer secretion levels correlated with the most aggressive cancer cell lines. NM was effective in inhibiting MMP-9 and dimer secretion in all cell lines tested, suggesting its therapeutic potential as an antimetastatic agent.

In vitro modulation of MMP-2 and MMP-9 in pediatric human sarcoma cell lines by cytokines, inducers and inhibitors

The highly aggressive pediatric sarcomas are characterized by high levels of matrix metalloproteinase (MMP)-2 and MMP-9, which play crucial roles in tumor invasion and metastasis by degradation of the extracellular membrane leading to cancer cell spread to distal organs. We examined the effects of cytokines, mitogens, inducers and inhibitors on MMP-2 and -9 expression in osteosarcoma (U2OS) and rhabdomyosarcoma (RD). The selected compounds included natural cytokines and growth factors, as well as chemical compounds applied in therapy of sarcoma and natural compounds that have demonstrated anticancer therapeutic potential. These cell lines were cultured in their respective media to near confluence and the cells were washed with PBS and incubated in serum-free medium with various concentrations of several cytokines, mitogens and inhibitors. After 24 h the media were removed and analyzed for MMP-2 and -9 by gelatinase zymography and quantitated by densitometry. Osteosarcoma and rhabdomyosarcoma showed bands corresponding to MMP-2 and -9 with dose-dependent enhancement of MMP-9 with phorbol 12-myristate 13-acetate (PMA) treatment. Tumor necrosis factor-α, interleukin-1β and LPS enhanced osteosarcoma U2OS MMP-9 secretion but had no effect on MMP-2 secretion. Tumor necrosis factor-α stimulated rhabdomyosarcoma MMP-2 expression, but had no effect on MMP-9 secretion. Doxycycline, epigallocatechin gallate, nutrient mixture (NM), actinomycin-D, cyclohex-amide, retinoic acid and dexamethasone inhibited MMP-2 and -9 in U2OS osteosarcoma cells. PMA-treated RD cells showed dose-response inhibition of MMP-9 by doxycycline and epigallocatechin gallate and both MMPs by NM. Dexamethasone and actinomycin-D showed inhibition of MMP-2 secretion of RD cells. Our results show that cytokines, mitogens and inducers show variable upregulation of U2OS osteosarcoma and RD rhabdomyosarcoma MMP-2 and -9 secretion, and inhibitors demonstrate downregulation under stimulatory conditions, suggesting the application of these agents for the development of effective therapies in pediatric sarcomas.

In vitro modulation of MMP-2 and MMP-9 in adult human sarcoma cell lines by cytokines, inducers and inhibitors

The highly aggressive adult sarcomas are characterized by high levels of matrix metalloproteinase (MMP)-2 and -9, which play crucial roles in tumor invasion and metastasis by degradation of the extracellular membrane leading to cancer cell spread to distal organs. We examined the effect of cytokines, mitogens, inducers and inhibitors on MMP-2 and MMP-9 secretion in chondrosarcoma (SW-1353), fibrosarcoma (HT-1080), liposarcoma (SW-872) and synovial sarcoma (SW-982) cell lines. The selected compounds included natural cytokines and growth factors, as well as chemical compounds applied in therapy of sarcoma and natural compounds that have demonstrated anticancer therapeutic potential. MMP-2 and MMP-9 secretions were analyzed by gelatinase zymography following 24-h exposure to the tested agents and quantitated by densitometry. Fibrosarcoma, chondrosarcoma, liposarcoma and synovial sarcoma showed bands corresponding to MMP-2 and MMP-9 with dose-dependent enhancement of MMP-9 with phorbol 12-myristate 13-acetate (PMA) treatment. In chondrosarcoma cells, tumor necrosis factor (TNF)-α had a stimulatory effect on MMP-9 and insignificant effect on MMP-2 and interleukin (IL)-1β stimulated MMP-9 and MMP-2. In fibrosarcoma and liposarcoma cells, TNF-α had a profound stimulatory effect on MMP-9, but no effect on MMP-2 and in synovial sarcoma an inhibitory effect on MMP-2 and no effect on MMP-9. IL-1β had a slight inhibitory effect on fibrosarcoma, liposarcoma and synovial sarcoma MMP-2 and MMP-9 except for MMP-9 in synovial sarcoma which showed slight stimulation. Lipopolysaccharide (LPS) stimulated expression of MMP-2 in fibrosarcoma and chondrosarcoma while inhibited it in liposarcoma. Doxycycline, epigallocatechin gallate and the nutrient mixture inhibited MMP-2 and MMP-9 in all cell lines. Actinomycin-D, cyclohexamide, retinoic acid, and dexamethasone inhibited MMP-2 and -9 in chondrosarcoma and fibrosarcoma cells. Our results show that cytokines, mitogens, inducers and inhibitors have an up or down regulatory effect on MMP-2 and MMP-9 expression in adult sarcoma cell lines, suggesting these agents may be effective strategies to treat these cancers.

Inhibition of growth and expression of inflammation mediators in human leukemic cell line U-937 by a nutrient mixture

AIM

A nutrient mixture (NM) containing ascorbic acid, lysine, proline and green tea extract has exhibited anticancer activity in vitro and in vivo in a number of cancer cell lines. We investigated the effect of NM on human leukemic myeloid U-937 cells in vitro by measuring: cell proliferation, MMP expression, invasion, apoptosis, and COX-2 and COX-1 protein expression.

METHODS

Human leukemic cell line U-937 (ATCC) was cultured in RPMI medium supplemented with fetal bovine serum and antibiotics. After 24 h, the cells were treated with NM at 0, 50, 100, 250, 500 and 1000 Ојg/ml, in triplicate at each dose. Phorbol 12-myristate 13-acetate (PMA), 100 ng/ml was added to cells to induce MMP-9 secretion. Cell proliferation was evaluated by MTT assay, MMP expression by gelatinase zymography, invasion through Matrigel, apoptosis by using live green caspase detection kit (Molecular Probe), and COX-2 and COX-1 expression by Western blot.

RESULTS

NM had no effect on U-937 cell growth at a concentration of 250 Ојg/ml and exhibited an antiproliferative effect at 500 Ојg/ml concentration. Zymography did not demonstrate MMP-2 or MMP-9 secretion in normal cells; however, PMA strongly induced MMP-9, which was inhibited by NM in a dose-dependent manner. Cell penetration through Matrigel was significantly reduced (by 95%) at 250 Ојg/ml NM and completely blocked at 500 Ојg/ml NM. NM induced slight apoptosis at 100 Ојg/ml and moderate at 500 and 1000 Ојg/ml concentration. NM inhibited COX-2 expression in a dose-dependent fashion and had no effect on COX-1 expression.

CONCLUSIONS

Our results suggest that NM has potent inhibitory effects on U-937 cell growth and expression of inflammatory mediators, significant parameters in AML progression.

Repression of matrix metalloproteinases and inhibition of cell invasion by a nutrient mixture, containing ascorbic acid, lysine, proline, and green tea extract on human Fanconi anemia fibroblast cell lines

AIM

Fanconi Anemia, an autosomal recessive disorder, is characterized by chromosomal abnormality leading to birth defects, progressive bone marrow failure, and a high probability of developing malignancy at an early age. Head and neck squamous cell carcinoma and myeloid leukemia are the major causes of cancer related morbidity and mortality in Fanconi anemia patients.

METHODS

We investigated the effect of a nutrient mixture on Fanconi Anemia human fibroblast cell lines FA-A:PD20 and FA-A:PD220 on matrix metalloproteinase expression, invasion, cell proliferation, morphology and apoptosis. The cell lines were grown in a modified Dulbecco's Eagle medium and at near confluence were treated with the nutrient mixture at increasing doses: 0; 10; 50; 100; 500; 1000 µg/ml. The cells were also treated with PMA to induce MMP-9 expression.

RESULTS

Zymography demonstrated MMP-2 and PMA-induced MMP-9 activity. The nutrient mixture inhibited expression of both, MMP-2 and MMP-9, in a dose dependent manner with virtually total inhibition observed at 500 µg/ml. Matrigel invasion was inhibited in both cells lines; with 100% inhibition for FA-A:PD20 at 500 µg/ml and 100% inhibition of FA-A:P220 cells at 100 µg/ml. H&E staining did not indicate any change in cell morphology and causes apoptosis at higher doses.

CONCLUSION

Our data demonstrated that the nutrient mixture inhibited matrix metalloproteinase expression, invasion and induced apoptosis, the important parameters for cancer prevention. The results suggest that the nutrient mixture may have therapeutic potential in Fanconi Anemia associated neoplasia.

In vitro and in vivo inhibition of human Fanconi anemia-associated head and neck squamous cell carcinoma by a novel nutrient mixture

Head and neck squamous cell carcinoma (HNSCC) and acute myeloid leukemia are the major causes of mortality and morbidity in Fanconi anemia (FA) patients. The objective of this study was to investigate the antineoplastic activity of a novel antineoplastic nutrient mixture (NM) (containing lysine, proline, ascorbic acid and green tea extract) in human FA-associated HNSCC (FA HNSCC) in vitro and in vivo. The human FA HNSCC cell line, OHSU-974 (Fanconi Anemia Research Fund), was cultured in RPMI medium supplemented with 20% FBS and antibiotics. At near confluence, cells were treated in triplicate with various concentrations of NM: 0, 50, 100, 250, 500 and 1,000 μg/ml. Cells were also treated with phorbol 12-myristate 13-acetate (PMA) to induce matrix metalloproteinase (MMP)-9 activity. Cell proliferation was detected by MTT assay, the secretion of MMPs by gelatinase zymo graphy, cell invasion through Matrigel, cell migration by a scratch test and morphology by hematoxylin and eosin (H&E) staining. In vivo, athymic male nude mice (n=12) were inoculated with 3×10⁶ OHSU-974 cells subcutaneously and randomly divided into 2 groups: group A was fed a regular diet and group B a regular diet supplemented with 1% NM. Four weeks later, the mice were sacrificed and their tumors were excised, weighed and processed for histological analysis. NM inhibited the growth of OHSU-974 tumors by 47% and tumor burden by 50%. At lower concentrations, NM demonstrated no effect on proliferation, but at 1,000 μg/ml a 40% toxicity was observed. Zymography revealed the MMP-2 and PMA-induced MMP-9 secretion. NM suppressed the secretion of both MMPs in a dose-dependent manner, with a virtual inhibition at 500 μg/ml. NM inhibited OHSU-974 cell invasion through Matrigel in a dose-dependent manner with a complete block at 1,000 μg/ml. H&E staining showed no morphological changes below 500 μg/ml. These results suggest that NM has potential therapeutic use in the treatment of human FA HNSCC.

Ascorbate depletion increases growth and metastasis of melanoma cells in vitamin C deficient mice

AIM

Our main objective was to determine the effect of ascorbate supplementation in mice unable to synthesize ascorbic acid (gulo KO) when challenged with murine B16FO cancer cells.

METHODS

Gulo KO female mice 36-40 weeks of age were deprived of or maintained on ascorbate in food and water for 4 weeks prior to subcutaneous injection of 2.5×10(6) B16FO murine melanoma cells in the right flank of mice. A control group of wild type mice were also injected with the melanoma cells and maintained on a regular murine diet. Mice were continued on their respective diets for another 2 weeks after injection. The mice were then sacrificed, blood was drawn and their tumors were measured, excised and processed for histology.

RESULTS

Mean weight of animals decreased significantly (30%, p < 0.0001) in the ascorbate-restricted group but increased slightly, but insignificantly, in the ascorbate-supplemented group. The mean tumor weight in ascorbate supplemented mice was significantly reduced (by 64%, p = 0.004) compared to tumor weight in ascorbate-deprived gulo mice. The mean tumor weight of wild type mice did not differ significantly from the ascorbate-supplemented mice. Gulo KO mice supplemented with ascorbate developed smaller tumors with more collagen encapsulation and fibrous capsule interdigitation, while gulo KO mice deprived of ascorbate hosted large tumors with poorly defined borders, showing more necrosis and mitosis. Ascorbate supplementation of gulo KO mice resulted in profoundly decreased serum inflammatory cytokine IL-6 (90% decrease, p = 0.04) and IL-1β (62% decrease) compared to the levels in gulo KO mice deprived of ascorbate.

CONCLUSION

Ascorbate supplementation modulated tumor growth and inflammatory cytokine secretion as well as enhanced encapsulation of tumors in scorbutic mice.

Nutrient mixture inhibits in vitro and in vivo growth of human acute promyelocytic leukemia HL-60 cells

AIM

Untreated acute promyelocytic leukemia is the most malignant form of acute leukemias, with median survival of less than one month. We investigated in vitro and in vivo synergistic effects of a nutrient mixture (NM) containing ascorbic acid, lysine, proline, and green tea extract, on acute promyelocytic leukemia HL-60 cells.

METHODS

In vitro, the HL-60 cells were cultured and exposed to NM at doses 0-1000 μg/ml. Cell viability was assessed by Trypan blue dye exclusion test, matrix metalloproteinases (MMP) expression by gelatinase zymography, invasion through Matrigel and apoptosis by live green Poly Caspase Detection Kit. In vivo studies were carried out in athymic nude mice subcutaneously inoculated with HL-60 cells.

RESULTS

In vitro, NM exhibited a dose dependent reduction in cells viability. Zymography revealed matrix MMP-2 and phorbol 12-myristate 13-acetate induced MMP-9 expression. NM inhibited expression of both MMP in a dose dependent manner. Similar step-wise reduction in the Matrigel invasion by HL-60 cells was also observed by this combination with incremental doses. Gradually increasing doses of NM induced significant apoptosis in HL-60 cells. In vivo, NM inhibited tumor growth by 50%.

CONCLUSION

The results indicate that NM significantly suppresses tumor growth, decreases cell viability, inhibits MMP expression, Matrigel invasion and induces apoptosis in HL-60 cells.

Anticancer effects of a specific mixture of nutrients in the multidrug-resistant human uterine sarcoma MES-SA/Dx5 and the drug-sensitive MES-SA cell lines

A specific nutrient mixture (NM) containing lysine, proline, ascorbic acid and green tea extract has demonstrated a broad spectrum of antitumor activity against a number of cancer cell lines. In this study, our main objective was to investigate the comparative effects of NM on anticancer parameters, such as cytotoxicity, matrix metalloproteinase (MMP) secretion and Matrigel invasion in the human uterine sarcoma drug-resistant MES-SA/Dx5 and the drug-sensitive MES-SA cell lines. In addition we studied the effects of NM on P-glycoprotein (Pgp) on these cell lines. Cell proliferation was evaluated by MTT assay, MMPs by gelatinase zymography, invasion through Matrigel, morphology by H&E and Pgp expression by Western blot analysis and immunodetection using FITC-conjugated antibody and rhodamine 123 (Rh123) accumulation and efflux assays. NM exhibited antiproliferative effects on MES-SA/Dx5, by 20% at 50 and 100 µg/ml and by 36, 40 and 48% at 250, 500 and 1,000 µg/ml, respectively. By contrast, NM treatment of MES-SA cells resulted in significantly increased cytotoxicity: 40, 46, 65 and 72% at 50, 100, 500 and 1,000 µg/ml, respectively. In both cell lines, zymography demonstrated a band corresponding to MMP-2 in normal cells and MMP-9 with phorbol 12-myristate 13-acetate treatment. The two MMPs showed dose-response inhibition by NM. As shown by Western blot analysis and immunodetection, NM treatment resulted in a dose-dependent decrease in Pgp expression in the MES-SA/Dx5 cell line. The MES-SA cell line does not exhibit Pgp. NM enhanced the accumulation and efflux of the Pgp substrate, Rh123, in the MES-SA/Dx5 uterine sarcoma cell line but not in the drug-sensitive cell line, MES-SA. Therefore, it can be concluded that NM demonstrates potent anticancer effects in both the drug-resistant and sensitive cell lines and modulates Pgp, suggesting its potential therapeutic effects in drug-resistant as well as sensitive cancers.

Nutritional improvement of metabolic syndrome parameters in immature fructose-fed wild-type mice

The incidence of type 2 diabetes mellitus is on the increase worldwide, with both environmental and genetic factors implicated in its development. Diabetes is often preceded by metabolic syndrome (MS) and may develop in normal adults ingesting a high fructose diet. The effect of high fructose intake on the development of MS in children and adolescents is less clear. Our objective was to study the effects of a nutrient mixture and metformin (MET), a widely used oral diabetic medication, in modulating the physiological and biochemical parameters of a high fructose diet in immature mice. C57BL/6J wild‑type mice aged 7 weeks were administered 12% fructose in their water and MET in distilled water or a diabetic nutrient mix (DNM) over 7 weeks. DNM-fed mice showed a decrease in systolic blood pressure, total cholesterol and fructosamine compared to the fructose-fed only group (p<0.05). A discordant result was observed in the MET group, with a decrease in blood pressure but increases in total cholesterol and fructosamine (p<0.05). Serum glucose did not change significantly among the groups. Thus, symptoms of fructose-induced MS in young mice could be countered nutritionally. Additionally, MET may improve certain biochemical markers while worsening others.

In vivo and in vitro antitumor effects of nutrient mixture in murine leukemia cell line P-388

AIM

Leukemia is characterized by uncontrolled marrow cell proliferation and metastatic foci. We investigated the antitumor potential of a nutrient mixture on malignant leukemia P-388 cells.

METHODS

The nutrient mixture containing lysine, proline, ascorbic acid, green tea extract and other nutrients is formulated to target key pathways in cancer progression. The cells were treated with the mixture, and tested at doses 0, 10, 50, 100, 500 and 1000 μg/ml in triplicates. The effects were evaluated by cell proliferation, Matrigel invasion, cell morphology and apoptosis. The in vivo effect was measured in male nude mice (n = 12) inoculated with P-388 cells. After randomly dividing in two groups, each group was fed regular and the nutrient mixture supplemented diet and the mice were sacrificed after four weeks.

RESULTS

The nutrient mixture decreased P-388 cell proliferation at 500 and 1000 μg/ml. Only 10% cells were viable at 1000 μg/ml. Matrigel invasion was significantly inhibited in a dose dependent manner with virtually total inhibition at 1000 μg/ml. Cell morphological features notably changed with dose increase to 1000 μg/ml. Analysis of apoptotic cells on live green caspase kit exhibited gradual increase with the increasing dose of the nutrient mixture, and at 1000 μg/ ml 92% of P-388 cells were in late apoptosis. Tumors in the group of mice supplemented with the nutrient mixture had 50% lower weight compared to the tumors in control group (p = 0.0105). Histopathologically, both the groups of tumors were similar, yet size of tumors in the group treated with the nutrient mixture was considerably smaller.

CONCLUSION

These results indicate that the nutrient mixture exhibited significant action against multiple targets in P-388 leukemia and may have potential in human leukemia.

Micronutrient synergy--a new tool in effective control of metastasis and other key mechanisms of cancer

Consumption of a plant-based diet has been associated with prevention of the development and progression of cancer. We have developed strategies to inhibit cancer development and its spread by targeting common mechanisms used by all types of cancer cells that decrease stability and integrity of connective tissue. Strengthening of collagen and connective tissue can be achieved naturally through the synergistic effects of selected nutrients, such as lysine, proline, ascorbic acid and green tea extract (NM). This micronutrient mixture has exhibited a potent anticancer activity in vivo and in vitro in a few dozen cancer cell lines. Its anti-cancer effects include inhibition of metastasis, tumor growth, matrix metalloproteinase (MMP) secretion, invasion, angiogenesis, and cell growth as well as induction of apoptosis. Many cancers are often diagnosed at later stages, when metastasis has occurred, which standard treatment has been unable to control. Our studies on NM effects on hepatic and pulmonary metastasis demonstrated profound, significant suppression of metastasis in a murine model. Evaluation of effects of NM on xenografts in murine models demonstrated significant reduction in tumor size and tumor burden in all human cancer cell lines tested. In vitro studies demonstrated that NM was very effective in inhibition of cell proliferation (by MTT assay), MMP secretion (by gelatinase zymography), cell invasion (through Matrigel), cell migration (by scratch test), induction of apoptosis (by live green caspase) and induction of pro-apoptotic genes in many diverse cancer cell lines. Furthermore, in vivo and in vitro studies of effects of individual micronutrients compared to their specific combination demonstrated synergistic effects resulting in improved anticancer potency.

Inhibition of invasion and MMPs by a nutrient mixture in human cancer cell lines: a correlation study

Matrix metalloproteinase (MMP)-2 and -9 secretion is elevated in various human cancers and their elevated expression has been associated with poor prognosis due to associated increased cancer cell invasion and metastasis.

AIM

To examine the correlation between in vitro MMP-2 and MMP-9 secretion and Matrigel invasion in 42 different human cancer cell lines (selected on the basis of organ malignancies) treated with a nutrient mixture (NM).

MATERIALS AND METHODS

The cells were cultured in their recommended media supplemented with 10% FBS and antibiotics in 24-well tissue culture plates. At near confluence, the cells were treated with NM dissolved in media at 0, 10, 50, 100, 500 and 1000 μg/mL in triplicate. Parallel sets of cultures were also treated with phorbol 12-myristate 13-acetate (PMA) 100 ng/mL for induction of enzymes. After 24 h the media were collected and MMP-2 and MMP-9 levels were assayed by gelatinase zymography. Invasion studies were conducted using Matrigel in 24-well plates.

RESULTS

Correlation of pooled data from different cancer cell line groups demonstrated dose-dependent inhibition of MMP-2 and -9 and Matrigel invasion with NM treatment and significant negative correlation between MMP-2 and MMP-9 levels and Matrigel invasion. Pooled data of cell lines expressing only MMP-2 and resistance to PMA induction of MMP-9 showed significant negative correlation (r = -0.77, p = 0.003) between MMP-2 secretion and inhibition of invasion through Matrigel. Cell lines expressing only MMP-9, showed significant negative correlation (r = -0.726, p = 0.003) between MMP-9 secretion and Matrigel invasion. Pooled data of cell lines expressing MMP-2 and MMP-9 demonstrated significant negative correlation (r = -0.821, p < 0.0001) between MMP-9 secretion and inhibition of invasion through Matrigel. Pooled data of cancer cell lines expressing no basal MMP- 9 secretion demonstrated significant negative correlation (r = -0.686, p < 0.0001) between PMA-induced MMP-9 secretion and inhibition of invasion through Matrigel.

CONCLUSIONS

In conclusion, regardless of MMP-2 and MMP-9 patterns of expression, MMP modulation by NM was found to be significantly correlated with NM modulation of Matrigel invasion of these cell lines.

Comparative effects of EGCG, green tea and a nutrient mixture on the patterns of MMP-2 and MMP-9 expression in cancer cell lines

Type IV collagenase matrix metalloproteinases (MMPs), especially MMP-2 and MMP-9, have been found to promote invasion and metastasis of malignant tumors. Extracellular matrix (ECM) degradation by MMPs and increased expression of MMPs in cancer cells and tumor microvascular endothelial cells make MMPs an attractive target for cancer. Focused on a common pathomechanism of cancer growth and invasion, the disintegration of connective tissue, we used natural approaches to increase the integrity and strength of connective tissues. Utilizing the principle of nutrition synergy, we developed a novel micronutrient mixture (NM) containing lysine, proline, ascorbic acid and green tea extract. This study evaluates the potency of the components EGCG and green tea extract independently compared to that of NM on modulation of patterns of MMP-2 and MMP-9 expression in four cancer cell lines expressing MMP-2, MMP-9 or both. Human fibrosarcoma (HT-1080), hepatocellular carcinoma (SK-Hep-1), glioblastoma (T-98G), uterine leiomyosarcoma (SK-UT-1) cell lines were obtained from ATCC and grown in minimum essential medium (MEM) supplemented with 10% FBS, penicillin (100 U/ml) and streptomycin (100 mg/ml) in 24-well tissue culture plates. At near confluence, the cells were treated with agents dissolved in media and tested at concentrations indicated in triplicate at each dose. Cells were also treated with PMA 100 ng/ml to study enhanced expression of MMP-9. MMP expression was assessed by gelatinase zymography. Fibrosarcoma and hepatocellular carcinoma cells expressed both MMP-2 and MMP-9. Glioblastoma cells expressed MMP-2 and PMA treatment induced MMP-9 expression. Uterine leimyosarcoma cells expressed no MMPs but PMA induced MMP-9. NM was the most potent dose-dependent inhibitor of MMPs, followed by green tea extract and EGCG. In conclusion, these results suggest the enhanced efficacy of nutrients working in synergy to modulate complex pathways such as MMP expression.

In vivo and In vitro effect of a nutrient mixture on human hepatocarcinoma cell line SK-HEP-1

Long-term survival of patients with hepatocellular carcinoma (HCC), a common cancer worldwide, remains poor, due to metastasis and recurrence.

AIM

To investigate the effect of a novel nutrient mixture (NM) containing ascorbic acid, lysine, proline, and green tea extract on human HCC cell line Sk-Hep-1 In vivo and In vitro.

METHODS

After one week of isolation, 5-6 week old male athymic nude mice were inoculated with 3 x 10(6) SK-Hep-1 cells subcutaneously and randomly divided into two groups; group A was fed a regular diet and group B a regular diet supplemented with 0.5% NM. Four weeks later, the mice were sacrificed and their tumors were excised, weighed and processed for histology. We also tested the effect of NM In vitro on SK-Hep-1 cells, measuring cell proliferation by MTT assay, invasion through Matrigel, apoptosis by green caspase detection kit, MMP secretion by zymography, and morphology by H&E staining.

RESULTS

NM inhibited tumor weight and burden of SK-Hep-1 xenografts by 42% and 33% respectively. In vitro , NM exhibited 33% toxicity over the control at 500 and 1,000 microg/ml concentration. Zymography demonstrated MMP-2 and MMP-9 secretion which was inhibited by NM in a dose dependent fashion, with virtual total inhibition at 1000 microg/ml. Invasion through Matrigel was inhibited at 100, 500 and 1,000 microg/ml by 53%, 83% and 100% respectively. NM induced slight apoptosis at 100 microg/ml, and profound apoptosis at 500 microg/ml and 1000 microg/ml concentration.

CONCLUSIONS

These results suggest that NM has therapeutic potential in treatment of HCC.

Antiangiogenic properties of a nutrient mixture in a model of hemangioma

The pathogenesis of hemangiomas is still largely unknown and the current therapy, such as systemic corticosteroid, vincristine, and interferon-alpha, is toxic and remains unsatisfactory. A nutrient mixture (NM) containing lysine, proline, ascorbic acid and green tea extract has shown significant anti-angiogenic and anti-tumor effect against a number of cancer cell lines.

AIM

Using a mouse hemangioendothelioma model, we investigated the efficacy of NM. We also tested the effect of NM in vitro, evaluating cell viability, MMP secretion, invasion, morphology and apoptosis.

METHODS

Athymic nude mice, 5-6 weeks old, were inoculated with 3 x10(6) EOMA cells subcutaneously and randomly divided into two groups; group A was fed a regular diet and group B - a regular diet supplemented with 0.5% NM. Four weeks later, the mice were sacrificed and their tumors were excised, weighed and processed for histology. We also tested the effect of NM in vitro.

RESULTS

NM inhibited the growth of tumors by 50%. In vitro, NM exhibited dose response cytotoxicity with 10%, 30% and 55% at 10, 100 and 1000 microg/ml. Invasion through Matrigel was inhibited at 50, 100 and 500 microg/ml by 25%, 30% and 100% respectively. NM induced dose-dependent apoptosis of EOMA cells.

CONCLUSIONS

These results suggest that NM may have therapeutic potential in treating infantile hemangioendotheliomas and, perhaps, other cutaneous vascular tumors.

Antineoplastic effects of nutrient mixture on raji and jurkat t cells: the two highly aggressive non Hodgkin's lymphoma cell lines

Non-Hodgkin lymphomas incidence has increased more than 70% in last 25 years. Aggressiveness, higher relapse rate, and treatment complications pose significant barriers. Decreased food intake and side effects of treatments make cancer patients vulnerable to deficiency of essential nutrients such as vitamin C, lysine, and proline leading to the formation of weak extra cellular matrix susceptible to easy breakdown by matrix metalloproteinase enzymes. Inhibition of these enzymes has shown promise in stopping metastasis.

AIM

In this study, we investigated the effects of a specific nutrient mixture, containing ascorbic acid, lysine, proline, green tea extract among others, in most aggressive forms of non-Hodgkin's lymphoma - Burkitt's lymphoma, and T-cell lymphoma - using Raji and Jurkat cells respectively.

METHODS

Nutrient mixture (NM) doses of 0, 10, 50, 100, 500, 1000 microg/ml, were used to study effects on cell proliferation, expression of matrix metalloproteinase, Matrigel invasion and apoptosis.

RESULTS

The results demonstrated that the dose response toxicity of the nutrient mixture on Raji cells gradually increased with increasing concentration. The nutrient mixture was non-toxic to Jurkat cells, however exhibited anti-proliferative properties at higher concentrations. Zymography demonstrated, NM had a significant inhibitory effect on matrix metalloproteinase-9 expression with total inhibition at 1000 microg/ml for Raji cells and at 500 microg/ml for Jurkat cells. The NM at 100 microg/ml completely inhibited Matrigel invasion for Raji cells, and at 1000 microg/ml for Jurkat cells. After the NM challenge virtually all Raji and Jurkat cells exposed to 1000 microg/ml were in late apoptosis.

CONCLUSION

Considering the lack of treatment options and continually increasing incidence, NM could be further explored for its therapeutic potential in Burkitt's lymphoma and T-cell lymphoma.

Marked Inhibition of Growth and Invasive Parameters of Head and Neck Squamous Carcinoma FaDu by a Nutrient Mixture

Head and neck squamous cell carcinomas (HNSCCs) are known for their aggressive growth and propensity to metastasize. The authors investigated the effect of a novel nutrient mixture (NM) containing ascorbic acid, lysine, proline, and green tea extract on human HNSCC cell line FaDu in vivo and in vitro. Athymic male nude mice (n = 12) were inoculated with 3 × 106 FaDu cells subcutaneously and randomly divided into 2 groups: group A was fed a regular diet and group B a regular diet supplemented with 0.5% NM. Four weeks later, the mice were sacrificed and their tumors were excised, weighted, and processed for histology. In vitro, FaDu cells were cultured in Dulbecco's modified Eagle's medium and exposed to NM at 0 to 1000 µg/mL in triplicate. Cell proliferation was assessed by MTT assay, matrix metalloproteinase (MMP) secretion by gelatinase zymography, invasion through Matrigel, apoptosis by live-green caspases, and cell morphology by hematoxylin—eosin staining. NM inhibited the growth of tumors by 55% ( P = .0002) and exhibited dose-dependent toxicity on FaDu cells in vitro, with 53% ( P = .0003) at 1000 µg/mL NM. Zymography revealed MMP-2 and phorbol 12-myristate 13-acetate—induced MMP-9 secretion. NM inhibited secretion of both MMPs in a dose-dependent manner, with virtual total inhibition at 1000 µg/mL. NM significantly inhibited FaDu invasion through Matrigel with total block at 1000 µg/mL. NM induced dose-dependent apoptosis. In conclusion, NM has therapeutic potential in the treatment of HNSCC by significantly suppressing tumor growth and significantly inhibiting MMP secretion and invasion of HNSCC cells in vitro.

Patterns of MMP-2 and MMP-9 expression in human cancer cell lines

MMP-2 and MMP-9 secretion is elevated in several types of human cancers and their elevated expression has been associated with poor prognosis. Expression of MMPs is highly regulated by cytokines and signal transducation pathways, including those activated by phorbol 12-myristate 13-acetate (PMA). The aim of this study was to examine the effect of PMA on MMP-2 and MMP-9 secretion in 42 different human cancer cell lines, selected on the basis of their organ malignancies. They were cultured in the recommended media supplemented with 10% FBS and antibiotics in 24-well tissue culture plates. At near confluence, the cells were washed with PBS, 0.5 ml of medium was added, and the cultures were incubated. Parallel sets of cultures were also treated with PMA for induction of enzymes. After 24 h the media were collected and MMP-2 and MMP-9 levels were assayed by gelatinase zymography. Based on MMP-2 and MMP-9 secretion without and with PMA treatment, the various human cancer cell lines fell into one of two major groups. The first group characterized by low basal MMP-9 secretion fell into three different categories of susceptibility to PMA induction of MMP-9 expression: resistant, moderately susceptible and highly susceptible. High basal MMP-9 levels responsive to PMA induction characterized the second group. Most cancer cell lines examined exhibited basal levels of MMP-2, MMP-9 or both. MMP-2 secretion was not induced by PMA in any of the cancer cells examined.

Distinct patterns of matrix metalloproteinase-2 and -9 expression in normal human cell lines

Invasion of surrounding tissues by malignant cells is a complex process mediated by the matrix degrading enzymes. In many solid tumors, the expression of MMPs, especially MMP-2 and MMP-9, is higher in stromal cells than in the tumor cells, suggesting stromal cells as the major source of these enzymes. Cytokines and signal transduction pathways, including those activated by phorbol 12-myristate 13-acetate (PMA), regulate the expression of MMPs. The aim of this study was to examine the pattern of MMP-2 and MMP-9 expression in human normal cells and in PMA-treated cells to determine if specific patterns of expression were associated with tissues of different origin. Epithelial, connective, and muscle tissues were selected since carcinomas, sarcomas, and adenosarcomas are derived from these tissue types, respectively. The cell lines were cultured in their recommended media and supplemented with 10% FBS and antibiotics in 24-well tissue culture plates. At near confluence, the cells were washed and fresh medium added. A parallel set of cultures was treated with PMA. After 24 h of incubation, media were collected and analyzed for MMP-2 and MMP-9 by gelatinase zymography. The results indicate that the normal cell expression of MMP-2 and MMP-9 depends on their primary tissue subtype. All cell lines, regardless of tissue origin, expressed MMP-2. PMA induced MMP-9 expression in glandular epithelia, supportive connective tissue, and muscle tissue cell lines. However, cell lines of endothelial origin and proper connective tissue were insensitive to PMA. These results suggest that MMP-2 and MMP-9 are differentially regulated and an understanding of this may open up avenues to use these enzymes as targets for therapy.

Essential nutrients suppress inflammation by modulating key inflammatory gene expression

We investigated the effects of a nutrient mixture (NM) consisting of ascorbic acid, quercetin, naringenin, hesperetin, tea catechins, lysine, proline, arginine and N-acetylcysteine on experimental in vivo and in vitro inflammation triggered by bacterial lipopolysaccharide (LPS). BALB/c mice (n=36) were administered NM (200 mg/kg BW) or ibuprofen (20 mg/kg BW) for two weeks. Blood plasma, collected three hours after a single intraperitoneal injection with LPS (1 mg/kg BW), was analyzed with 14 cytokine microarray. LPS inflammatory effects were analyzed in human U937 macrophages by cytokine release, cyclooxygenase (COX) enzymatic activity, COX protein expression (Western blot analysis), specific mRNA levels (RT-PCR), and nuclear factor kappabeta (NFkappabeta) activation (phosphorylated p65 immunoassay). Nutrient supplementation in mice altered the LPS-induced cytokine response in a manner similar to ibuprofen (r=0.4157, p=0.139). Cytokine response to LPS in cultured macrophages was similar to the in vivo study (r=0.718, p=0.023). NM inhibited COX-2 enzymatic activity, and COX-2 and pro-inflammatory cytokine protein expression levels were downregulated by NM at the transcription level complementing a blockade in NFkappabeta activation. NM demonstrated strong beneficial effects on the experimental inflammation by targeting multiple responsible mechanisms in the complex process involved in the inflammatory reaction to pathogens.

A nutrient mixture suppresses carbon tetrachloride–induced acute hepatic toxicity in ICR mice

We examined the effect of a nutrient mixture (NM) that contains lysine, proline, ascorbic acid, and green tea extract in mice treated with carbon tetrachloride (CCl4), a model of liver injury in which free radical, oxidative stress, and cytokine production are closely linked. Seven-week-old male Imprinting Control Region (ICR) mice were divided into four groups (A–D) of five animals each. Groups A and C mice were fed a regular diet for 2 weeks, whereas groups B and D mice were supplemented with 0.5% NM (w/w) during that period. Groups A and B received corn oil i.p., whereas groups C and D received CCl4 (25 μL/kg, in corn oil, i.p.). All animals were killed 24 h after CCl4 administration, serum was collected to assess liver and kidney functions, and livers and kidneys were excised for histology. Mean serum aspartate aminotransferase and alanine aminotransferase were comparable in groups A and B, increased markedly in group C, and significantly lowered in group D compared with group C. CCl4 had no significant effect on renal markers (blood urea nitrogen [BUN], creatinine, and BUN/creatinine ratio). CCl4 administration caused an intense degree of liver necrosis that was less severe in the NM fed group D. These results indicate that NM could be a useful supplement in preventing acute chemical-induced liver toxicity.

A nutrient mixture prevents acetaminophen hepatic and renal toxicity in ICR mice

Acetaminophen (APAP) overdose is often fatal, leading to fulminant hepatic and renal tubular necrosis in humans and animals. We studied the effect of a nutrient mixture (NM) containing, among other nutrients, lysine, proline, ascorbic acid, N-acetyl cysteine, and green tea extract, which has previously been demonstrated to exhibit a broad spectrum of therapeutic properties on APAP-induced hepatic and renal damage in ICR (Imprinting Control Region) mice. Seven-week-old male ICR mice were divided into four groups (A–D) of five animals each. Groups A and C mice were fed a regular diet for 2 weeks, while groups B and D mice were supplemented with 0.5% NM (w/w) during that period. Groups A and B received saline i.p., while groups C and D received APAP (600 mg/kg) i.p. All animals were killed 24 h after APAP administration, serum was collected to assess the liver and kidney functions, and the livers and kidneys were excised for histology. Mean serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, BUN (Blood Urea Nitrogen), creatinine, and BUN/creatinine ratios were comparable in groups A and B, increased markedly in group C and significantly lower in group D compared with group C. APAP caused significant centrilobular necrosis and glomerular damage in unsupplemented animals, while NM prevented these alterations. The results indicate that NM has potential to protect against APAP-induced liver and kidney damage.

Inhibition of 7,12-dimethylbenzanthracene-induced skin tumors by a nutrient mixture

The annual incidence of all forms of skin cancer, the most common of all human cancers, is increasing yearly. A unique nutrient mixture (NM) was shown to exhibit anticancer activity in vivo and in vitro. We examined the effect of NM on the development of skin cancer induced by 7,12-dimethylbezanthracene (DMBA) in female SENCAR mice by a complete carcinogenesis protocol. Mice (n=55) were divided into four groups and carefully shaved on dorsum. After 2 days, the mice in Groups 1 (n=10), 3 (n=20), and 4 (n=20) were treated topically with 100 nM DMBA in 0.2 ml of acetone twice a week for 4 weeks; Group 2 (n=5), the control group, was treated with acetone 0.2 ml. Groups 1 and 2 were fed the regular diet. Group 3A (n=10) was fed a diet containing 0.5% NM from the day of DMBA treatment and 3B (n=10) the regular diet and received NM (75 mg in 0.4 ml of 1:1 acetone/water) topically to the shaved area 15 min before DMBA application twice a week for 4 weeks. Group 4 mice were fed a diet containing 0.5% NM for 2 weeks prior to the application of DMBA and then divided into two groups: 4A (n=10) was fed the 0.5% NM diet as in 3A, and 4B (n=10) the regular diet as described for 3B. Body weight and diet consumption of the mice were monitored and the skin tumors (papillomas) were counted and recorded. Ten weeks thereafter the mice were euthanized, skinned, and tumors were processed for histology. NM significantly (P<0.0001) inhibited DMBA-induced skin tumor multiplicity by 59, 62, 69, and 86% in NM-treated Groups 3A, 3B, 4A, and 4B, respectively. These results suggest that NM has strong potential as a useful therapeutic regimen for skin cancer by significantly inhibiting the incidence and tumor multiplicity of DMBA-induced skin tumors.

A nutrient mixture suppresses hepatic metastasis in athymic nude mice injected with murine B16FO melanoma cells

Highly metastatic melanoma is resistant to existing therapies. A unique micronutrient mixture (NM) containing ascorbic acid, amino acids, green tea extract has been shown to exhibit anticancer activity in vivo and in vitro in a number of cancer cell lines including human and murine melanoma cells lines. In this study we examined the effect of dietary NM supplementation on hepatic metastasis of intrasplenic injection of B16FO melanoma cells in athymic nude mice. Athymic nude mice (n = 10), 10-12 weeks of age, received 10(6) B16FO melanoma cells by injection into the spleen and divided into two groups. The Control group of mice received Purina mouse chow and the NM group received the regular diet supplemented with NM 0.5%. After two weeks, animals were sacrificed and spleens, livers, kidneys and lungs were excised from all animals, examined, weighed and processed for histology. The Control mice developed large black spleens and livers indicating growth in the spleen and metastasis to the liver. However, the mice supplemented with NM not only showed less tumor growth in the spleen as the Control mice, but also drastically reduced metastasis to the liver. In all groups, no metastasis to the kidneys and lungs was evident. In conclusion, these results suggest that NM has potential in suppression of tumor metastasis.

Inhibition of cellular invasive parameters in influenza A virus-infected MDCK and Vero cells by a nutrient mixture

Influenza, a long-standing common infection, poses a serious health problem causing significant morbidity and mortality, and imposing substantial economic costs. To date there are no effective antiviral therapies. A unique nutrient mixture (NM), containing lysine, proline, ascorbic acid, green tea extract, N-acetyl cysteine and selenium among other micro nutrients, has been shown to exert a wide range of biochemical and pharmacological effects, among them anti-carcinogenic and anti-atherogenic activity both in vitro and in vivo. In a previous study, NM was found to significantly inhibit influenza virus A associated neuraminidase enzyme as well as production of NP antigen in a dose-dependent manner. Influenza virus A not only infects pulmonary areas, but also manifests in extrapulmonary areas, which require basement membrane disruption by matrix metalloproteinases capable of degrading collagen type IV. This prompted us to study the effect of NM on cellular invasive parameters of virus-infected and non-infected MDCK and Vero cells. NM inhibited extracellular invasive parameters such as MMP-2 and MMP-9 secretion and Matrigel invasion. Results indicated that the relatively non-toxic nutrient mixture tested in this investigation has potential in influenza treatment by not only decreasing viral multiplication in infected cells but also by blocking the enzymatic degradation of the extracellular matrix.

Epigallocatechin-3-gallate induces apoptosis and cell cycle arrest in HTLV-1-positive and -negative leukemia cells

The objective of this study is to evaluate the efficacy of epigallocatechin gallate against ATL cells. The anti-proliferative and pro-apoptotic effects of EGCG were evaluated in HTLV-1-positive and -negative cells. EGCG exhibited a marked decrease in proliferation of ATL cells at 96 h of treatment. The results indicated that TGF-alpha was down-regulated whereas levels of TGF-beta2 increased. Cell cycle distribution analysis revealed an increase in cells in the pre-G(1) phase which was confirmed by ELISA. The results on proteins showed an up-regulation of p53, Bax and p21 protein levels while the levels of Bcl-2alpha were down-regulated.

Naturally produced extracellular matrix inhibits growth rate and invasiveness of human osteosarcoma cancer cells

Enhanced supplementation with certain naturally occurring nutrients and vitamins has been associated with a reduction in occurrence and progression of human cancer. The exact mechanisms of this action are still under investigation. Extracellular matrix (ECM) plays a key role in the development of cancer. Therefore, we studied whether nutrients could exert anticancer effects through alteration of ECM biological properties. Confluent cultures of normal human dermal fibroblasts were allowed to produce and deposit ECM during a 7 d incubation period in the presence of tested compounds. Subsequently, fibroblasts were removed and the growth rates of freshly placed cultures of human osteosarcoma cells (lines U2-OS, MMNG, or SK.ES1) on pre-formed ECM were assayed in plain cell growth medium. In addition, ECM was deposited by fibroblasts on the upper surface of a porous plastic membrane and the subsequent migration of osteosarcoma cells to the other side was assayed in non-supplemented medium. The results demonstrated that the ECM produced by normal fibroblasts treated with a mixture of ascorbic acid, lysine, proline, arginine, cysteine, and green tea polyphenols significantly reduced the growth rate and invasive activity of osteosarcoma cells in contrast to the non-supplemented control. The changes in ECM properties were accompanied by significant changes in ECM protein and glycosaminoglycan composition as assayed immunochemically. We conclude that anticancer effects of nutrients involve beneficial changes in ECM biological properties. The role of ECM components in ECM-dependent regulation of tumor cell activities is discussed.

Suppression of influenza A virus nuclear antigen production and neuraminidase activity by a nutrient mixture containing ascorbic acid, green tea extract and amino acids

Influenza, one of the oldest and most common infections, poses a serious health problem causing significant morbidity and mortality, and imposing substantial economic costs. The efficacy of current drugs is limited and improved therapies are needed. A unique nutrient mixture (NM), containing ascorbic acid, green tea extract, lysine, proline, N-acetyl cysteine, selenium among other micronutrients, has been shown to exert anti-carcinogenic and anti-atherogenic activity both in vitro and in vivo. Many of the constituents of NM have been shown to have an inhibitory effect on replication of influenza virus and HIV. This prompted us to study the effect of NM on influenza A virus multiplication in infected cells and neuraminidase activity (NA) in virus particles. Addition of NM to Vero or MDCK cells post infection resulted in dose-dependent inhibition of viral nucleoprotein (NP) production in infected cells. NM-mediated inhibition of viral NP was selective and not due to cytotoxicity towards host cells. This antiviral effect was enhanced by pretreatment of virus with the nutrient mixture. Individual components of NM, namely ascorbic acid and green tea extract, also blocked viral NP production, conferring enhanced inhibition when tested in combination. Incubation of cell-free virus with NM resulted in dose-dependent inhibition of associated NA enzyme activity. In conclusion, the nutrient mixture exerts an antiviral effect against influenza A virus by lowering viral protein production in infected cells and diminishing viral enzymatic activity in cell-free particles.

Mechanistic aspects of apoptosis induction by l-lysine in both HTLV-1-positive and -negative cell lines

The retrovirus human T-cell lymphotrophic virus type-1 (HTLV-1) causes adult T-cell leukemia (ATL), which remains with no cure. This study evaluates the effects of l-lysine on proliferation and induction of apoptosis using non-cytotoxic concentrations of the test compound against HTLV-1 positive and negative malignant cell lines. The anti-proliferative effect of lysine was established and confirmed by studying the effects of the test compound on the expression of TGF mRNA expression by RT-PCR. To investigate the effect of l-lysine on the induction of apoptosis, DNA flow cytometry analyses was done and the results verified by cell death ELISA. The results indicated that a significant increase in the preG(1) phase and a decrease in the S phase of the cell cycle in all of the ATL cells tested. l-Lysine up-regulated p53, p21, and Bax protein levels and a down-regulation of Bcl-2alpha in all the cell lines tested. l-Lysine was found to exert its effect through the NF-kappaB pathway by inhibiting the p65 subunit specifically. Also l-lysine caused a decrease in the levels MMP-2 and MMP-9 as well as their enzymatic activity.

Suppression of human cervical cancer cell lines Hela and DoTc2 4510 by a mixture of lysine, proline, ascorbic acid, and green tea extract

Cervical cancer, the second most common cancer in women, once metastasized, leads to poor prognosis. We investigated the antitumor effect of a nutrient mixture (NM) containing lysine, proline, arginine, ascorbic acid, and green tea extract on human cervical cancer cells Hela (CCL-2) and DoTc2 4510 by measuring cell proliferation (MTT assay), modulation of matrix metalloproteinases (MMP)-2 and MMP-9) expression (gelatinase zymography), and cancer cell invasive potential (Matrigel). NM showed significant antiproliferative effect on CCL-2 and DoTc2 4510 cancer cells. The NM inhibited CCL-2 expression of MMP-2 and MMP-9 in a dose-dependent fashion, with virtual total inhibition of MMP-2 at 1000 microg/mL and MMP-9 at 500 microg/mL NM. Untreated DoTc2 4510 cells showed MMP-9 expression, which was enhanced with phorbol 12-myristate 13-acetate treatment. NM inhibited MMP-9 expression in a dose-dependent fashion, with virtual inhibition at 500 microg/mL. Invasion of human cervical cancer cells CCL-2 and DoTc2 4510 through Matrigel decreased in a dose-dependent fashion, with 100% inhibition at 500 microg/mL NM (P < 0.0001) and 1000 microg/mL NM (P < 0.0001), respectively. Our results suggest that the mixture of lysine, proline, arginine, ascorbic acid, and green tea extract has potential in the treatment of cervical cancer by inhibiting critical steps in cancer development and spread.

Bioflavonoids effectively inhibit smooth muscle cell-mediated contraction of collagen matrix induced by angiotensin II

Plant-derived bioflavonoids have been recognized to support arterial wall structural integrity and interfere with a variety of proatherosclerotic stimuli. In this study we tested the effects of bioflavonoids on the contractile activity of cultured human aortic smooth muscle cells (SMC) embedded in a 3-dimensional type I collagen matrix. Collagen I solution mixed with human aortic SMC in 24-well plates were allowed to form gels. Tested compounds were added to the wells, and the gels were set afloat by gentle tapping. Digital photographs of the gels were taken after 24 hours of incubation at 37 degrees C. The area of contracted gel was measured and expressed as a percentage of the control gel area from 3 or more replicates. Expression of matrix metalloproteinase (MMP-2) in conditioned media was assessed by gel zymography. Different classes of bioflavanoids showed variable efficiency in inhibiting angiotensin II (ATII)-dependent collagen gel contraction by SMCs. An increase in the number of gallate groups per catechin molecule was associated with increased inhibition of angiotensin II-dependent collagen gel contraction by SMC. Antioxidants (N-acetyl cysteine and ascorbic acid) did not inhibit collagen gel contraction. Bioflavonoid inhibition of collagen gel contraction by SMC correlated with inhibition of matrix metalloproteinase-2 expression. Bioflavonoids participate in the regulation of SMC-mediated contraction and have a strong potential in counteracting pathophysiological effects of ATII. Bioflavonoid activity depends on structural characteristics and can be related to extracellular matrix integrity.

Apoptosis induction by Epican Forte in HTLV-1 positive and negative malignant T-cells

The effects of a novel nutrient formulation Epican Forte (EF) were evaluated on proliferation and induction of apoptosis using non-cytotoxic concentrations against HTLV-1 positive (HuT-102 & C91-PL) and negative (CEM & Jurkat) cells. EF showed anti-proliferative effect as determined by MTT assay and TGF mRNA protein expression using RT-PCR. EF resulted in the down-regulation of TGF-alpha and an up-regulation in TGF-beta2. EF caused a significant increase in apoptotic cells in the preG1 phase. These results were confirmed using Cell Death ELISA and Annexin V-FITC. Induction of apoptosis was caused by an up-regulation of p53, p21 and Bax protein levels and a down-regulation of Bcl-2alpha protein expression level.

Suppression of human cervical cancer cell lines Hela and DoTc2 4510 by a mixture of lysine, proline, ascorbic acid, and green tea extract

Cervical cancer, the second most common cancer in women, once metastasized, leads to poor prognosis. We investigated the antitumor effect of a nutrient mixture (NM) containing lysine, proline, arginine, ascorbic acid, and green tea extract on human cervical cancer cells Hela (CCL-2) and DoTc2 4510 by measuring cell proliferation (MTT assay), modulation of matrix metalloproteinases (MMP)–2 and MMP-9) expression (gelatinase zymography), and cancer cell invasive potential (Matrigel). NM showed significant antiproliferative effect on CCL-2 and DoTc2 4510 cancer cells. The NM inhibited CCL-2 expression of MMP-2 and MMP-9 in a dose-dependent fashion, with virtual total inhibition of MMP-2 at 1000 μg/mL and MMP-9 at 500 μg/mL NM. Untreated DoTc2 4510 cells showed MMP-9 expression, which was enhanced with phorbol 12-myristate 13-acetate treatment. NM inhibited MMP-9 expression in a dose-dependent fashion, with virtual inhibition at 500 μg/mL. Invasion of human cervical cancer cells CCL-2 and DoTc2 4510 through Matrigel decreased in a dose-dependent fashion, with 100% inhibition at 500 μg/mL NM (P < 0.0001) and 1000 μg/mL NM (P < 0.0001), respectively. Our results suggest that the mixture of lysine, proline, arginine, ascorbic acid, and green tea extract has potential in the treatment of cervical cancer by inhibiting critical steps in cancer development and spread.

Transforming growth factor-beta 1 and ascorbate regulate proliferation of cultured smooth muscle cells by independent mechanisms

We previously reported that ascorbate (vitamin C) can regulate the growth of cultured vascular smooth muscle cells (VSMC) directly as well as by altering the properties of extracellular matrix (ECM) [Mol Cell Cardiol 1997;29:3293-303]. In the present study we compared the effects of ascorbate and transforming growth factor-beta 1 (TGF-beta1) on VSMC growth in order to determine whether their actions were mediated by similar mechanisms. When VSMC proliferation was stimulated by fetal bovine serum, the addition of TGF-beta1 (20 ng/ml) or ascorbate (1 mM) to the cell culture medium inhibited the cellular incorporation of [3H]thymidine by 19 and 59%, respectively, and by 85% when added together. The cell growth inhibitory effects of TGF-beta1 and ascorbate were partially mediated by changing the growth-regulatory properties of the ECM produced by the cells. Thus, VSMC grew more slowly on ECM deposited by VSMC under treatment with 20 ng/ml TGF-beta1 or 1 mM ascorbate (52 and 46% inhibition, respectively) than on control ECM, and their combination had an additional inhibitory effect (84%). Anti-TGF-beta1 neutralizing antibodies prevented the direct and ECM-mediated effects of TGF-beta1 on VSMC growth, but did not alter the effects of ascorbate. When ECM was pre-incubated with increasing concentrations of TGF-beta1, the growth rate of freshly plated VSMC gradually decreased, indicating that ECM-bound TGF-beta1 retained its biological activity. Comparison of the patterns of TGF-betal binding to ECM produced by VSMC in the presence or absence of ascorbate revealed no significant differences. Extraction of ECM-bound TGF-beta1 by incubation of exposed ECM with plasmin did not affect the ECM-mediated inhibitory effect of ascorbate, as the rate of proliferation of secondary VSMC cultures grown on ascorbate-dependent and independent matrices treated with plasmin were equally increased. These results suggest that the amount of ECM-bound TGF-beta1 was not altered by ascorbate. The secretion of TGF-beta1 into the cell culture medium by VSMC also did not depend on the ascorbate supply. Finally, addition of heparin to the VSMC culture medium during ECM production abolished the ECM-mediated growth inhibitory effects of ascorbate, but did not affect the action of TGF-beta1. Our data demonstrate that the growth inhibitory effects of ascorbate on cultured VSMC are independent of the action of TGF-beta1, and the effects of these two compounds on VSMC growth are additive.

Ascorbate affects proliferation of guinea-pig vascular smooth muscle cells by direct and extracellular matrix-mediated effects

Proliferation of smooth muscle cells and deposition of extracellular matrix proteins are important events in the formation of atherosclerotic plaques. We have investigated the direct and matrix-mediated effects of ascorbate on the proliferation rate of vascular smooth muscle cells (VSMC) isolated from the guinea-pig aorta. In the presence of ascorbate, cells showed a bi-phasic growth pattern. At 125 microM ascorbate, -3H--thymidine incorporation was stimulated 25%. However, higher concentrations of ascorbate gradually decreased cell-incorporated radioactivity up to 50% at 2 mM ascorbate. These effects of ascorbate on DNA synthesis in VSMC were paralleled by the changes in cell number and were not due to ascorbate cytotoxicity. Alpha-tocopherol (0.1 mM), individually and in combinations with 1 mm ascorbate, also inhibited DNA synthesis in VSMC. Ascorbate also influenced proliferation of smooth muscle cells through matrix-mediated effect. New VSMC culture plated on extracellular matrices deposited by smooth muscle cells in the presence of 0.1-1 mM ascorbate had up to 50% lower proliferation rate than on matrices from ascorbate-deficient cells, as assessed by [3H]-thymidine incorporation. This effect was independent from alpha-tocopherol and specific inhibitors of collagen synthesis: L-azetidine-2-carboxylic acid and pyridine-2,4-dicarboxylic acid. An ascorbate-dependent matrix effect was specific for smooth muscle cells grown on VSMC and human skin fibroblast-originated matrices, but not for human vascular endothelial cells. The possible involvement of ascorbate in the regulation of smooth muscle cells proliferation by its antioxidant/pro-oxidant effects and regulation of extracellular matrix composition are discussed.