Anticancer potential of rosmarinic acid and its improved production through biotechnological interventions and functional genomics

Toxicological Evaluation and Hepatoprotective Efficacy of Rosmarinic Acid-Rich Extract from Ocimum basilicum L

Exposure to carbon tetrachloride (CCl4) induces acute and chronic liver injuries as well as oxidative stress in rats. The present study was designed to evaluate the in vivo toxicity of rosmarinic acid-rich extract from Ocimum basilicum (RAE). The acute and subchronic oral toxicity of RAE was evaluated in Albinos mice. Hepatotoxicity was induced by the administration of CCl4-induced hepatic injury in rats. The hepatoprotective effect of RAE on aspartate aminotransferase, alanine transaminase, alkaline phosphatase, lactate dehydrogenase, bilirubin, total protein, albumin, triglycerides, total cholesterol, low-density lipoprotein, high-density lipoprotein, plasmatic glucose, urea, creatinine, and malondialdehyde was determined in CCl4-intoxicated rat. The extract did not produce treatment-related signs of toxicity or mortality in any of the animals tested during acute as well as subchronic toxicity studies. The administration of CCl4 resulted in marked increase in plasma hepatic enzymes (p < 0.001) and significant decrease of total protein (p < 0.001) and albumin (p < 0.001) when compared to normal. The RAE at 200 mg/kg body weight lowered significantly (p < 0.001) plasma enzyme activities of liver, which is designation of hepatoprotective action of extract. The phenolic extract exerts a significant increase in total protein (p < 0.001), and albumin (p < 0.001), accompanied with a marked reduction in the levels of malondialdehyde (p < 0.001), as compared to CCl4-treated group. Our study suggests that RAE may be used as a hepatoprotective agent against toxic effects caused by CCl4 and other chemical agents in the liver.

The influence of yeast extract and jasmonic acid on phenolic acids content of in vitro hairy root cultures of Orthosiphon aristatus

Phenolic acids represent a big group of plant secondary metabolites that can be used as food additives, nutraceuticals, and pharmaceuticals. Obtaining phenolic acids from the plant in vitro cultures provide an attractive alternative to produce high-value plant-derived products. The impact of yeast extract and jasmonic acid on the induction of defense responses and consequently the production of phenolic acids in vitro hairy root cultures of  O. aristatus have been investigated.  Treatment of O. aristatus cultures with jasmonic acid caused accumulation of 12.98 mg.g-1 DW of phenolic acids, elicitation with yeast extract resulted in the highest amount of phenolic acids, particularly in 17.99 mg.g-1 DW as compared to 4.03 mg.g-1 DW for the non-treated cultures. Individual phenolic acids showed a different response to elicitation. Particularly rosmarinic acid content on the control plot reached 2.89 mg.g-1 DW, while after the treatment with jasmonic acid is increased to 10.84 mg.g-1 DW and after yeast application, it was 14.31 mg.g-1 DW. Also, caffeic acid content increased until 0.75 and 2.01 mg.g-1 DW after application of jasmonic acid and yeast extract, while at the control plot its concentration was 0.58 mg.g-1 DW. Application of yeast extract influenced synthesis of phenolic acids in vitro cultures of O. aristatus stronger as jasmonic acid treatment.

Anti-Inflammatory Effects of Rosmarinic Acid-Loaded Nanovesicles in Acute Colitis through Modulation of NLRP3 Inflammasome

Ulcerative colitis (UC), one of the two main types of inflammatory bowel disease, has no effective treatment. Rosmarinic acid (RA) is a polyphenol that, when administered orally, is metabolised in the small intestine, compromising its beneficial effects. We used chitosan/nutriose-coated niosomes loaded with RA to protect RA from gastric degradation and target the colon and evaluated their effect on acute colitis induced by 4% dextran sodium sulphate (DSS) for seven days in mice. RA-loaded nanovesicles (5, 10 and 20 mg/kg) or free RA (20 mg/kg) were orally administered from three days prior to colitis induction and during days 1, 3, 5 and 7 of DSS administration. RA-loaded nanovesicles improved body weight loss and disease activity index as well as increased mucus production and decreased myeloperoxidase activity and TNF-α production. Moreover, RA-loaded nanovesicles downregulated protein expression of inflammasome components such as NLR family pyrin domain-containing 3 (NLRP3), adaptor protein (ASC) and caspase-1, and the consequent reduction of IL-1β levels. Furthermore, nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) protein expression increased after the RA-loaded nanovesicles treatment However, these mechanistic changes were not detected with the RA-free treatment. Our findings suggest that the use of chitosan/nutriose-coated niosomes to increase RA local bioavailability could be a promising nutraceutical strategy for oral colon-targeted UC therapy.

Effect of Rosmarinic Acid and Ionizing Radiation on Glutathione in Melanoma B16F10 Cells: A Translational Opportunity

To explain a paradoxical radiosensitizing effect of rosmarinic acid (RA) on the melanoma B16F10 cells, we analyzed the glutathione (GSH) intracellular production on this cell (traditionally considered radioresistant) in comparison with human prostate epithelial cells (PNT2) (considered to be radiosensitive). In PNT2 cells, the administration of RA increased the total GSH content during the first 3 h (p < 0.01) as well as increased the GSH/oxidized glutathione (GSSG) ratio in all irradiated cultures during all periods studied (1h and 3h) (p < 0.001), portraying an increase in the radioprotective capacity. However, in B16F10 cells, administration of RA had no effect on the total intracellular GSH levels, decreasing the GSH/GSSG ratio (p < 0.01); in addition, it caused a significant reduction in the GSH/GSSG ratio in irradiated cells (p < 0.001), an expression of radioinduced cell damage. In B16F10 cells, the administration of RA possibly activates the metabolic pathway of eumelanin synthesis that would consume intracellular GSH, thereby reducing its possible use as a protector against oxidative stress. The administration of this type of substance during radiotherapy could potentially protect healthy cells for which RA is a powerful radioprotector, and at the same time, cause significant damage to melanoma cells for which it could act as a radiosensitive agent.

Melissa officinalis Extract Induces Apoptosis and Inhibits Migration in Human Colorectal Cancer Cells

Colorectal cancer (CRC) is one of the most frequently diagnosed cancers worldwide. Lifestyle-related factors, such as diet, are associated with the development of CRC. Cumulating evidence indicates noticeable chemopreventive effects of phytochemicals on CRC, suggesting that drinking herbal tea potentially reduces the risk of distal colon cancer via its antiproliferative and anti-angiogenic activities. We examine the antitumor effects of nine components frequently found in herbal tea and uncover the underlying molecular mechanism. Among them, the hot water extract of Melissa officinalis (MO) exhibited the highest anticancer activity on CRC cells. We revealed that MO reduced cell proliferation, induced cell cycle arrest at the G₂/M phase, triggered caspase-dependent apoptotic cell death, and inhibited cell migration ability by modulating the epithelial-mesenchymal transition in HCT116 CRC cells. To examine the metabolite composition in the MO hot water extract, we applied mass spectrometry-based analysis and identified 67 compounds. Among them, the phenolic compounds, including lignans, phenylpropanoids, and polyketides, are widely found in natural products and possess various bioactivities such as anti-inflammatory, antioxidation, and anticancer effects. The results indicate that herbal tea consumption benefits CRC prevention and management.

The influence of in vitro gastrointestinal digestion on the Perilla frutescens leaf extract: Changes in the active compounds and bioactivities

In this study, the influence of in vitro gastrointestinal digestion on the Perilla frutescens leaf extract (PFLE) were measured. Results revealed that total phenolic content (TPC) and total flavonoid content (TFC) were significantly decreased after simulated digestion (ca. 53% of phenolics and 40% of flavonoids). The IC₅₀ value of DPPH· scavenging activity and ABTS⁺ scavenging ability increased by 23% and 56%, respectively, while ferric reducing antioxidant power reduced by 53%. For the inhibition ability on α-glucosidase, acetylcholinesterase, and MCF-7 cell proliferation, their IC₅₀ values increased by 360%, 197%, and 25%, respectively. Three phenolic acids and one flavonoid in PFLE were quantified by high-performance liquid chromatography. Overall, although significant losses of the active components and biological activities occurred during in vitro gastrointestinal digestion, it still showed the potential as an oral agent for treatment and prevention of oxidative stress, cancer, diabetes, and Alzheimer's disease. PRACTICAL APPLICATIONS: As an important annual herbaceous plant with rich biochemical compounds and many biological functions, Perilla frutescens leave is widely used in the food and traditional Chinese medicine. However, the dynamic changes of its active compounds and activities during the digestion process are unclear. In this study, the digestion results in significant loss of the active ingredients and biological activities of P. frutescens leaf extract (PFLE), particularly in the gastric digestion. In addition, PFLE remains to show certain antioxidant activity, α-glucosidase inhibitory ability, acetylcholinesterase inhibitory ability, and MCF-7 cell proliferation inhibitory ability after digestion. Therefore, this research might facilitate further research and development of P. frutescens.

Melatonin and calcium modulate the production of rosmarinic acid, luteolin, and apigenin in Dracocephalum kotschyi under salinity stress

Melatonin (Mel) and calcium (Ca2+) have a regulatory role in the induction of specialized metabolites production and defensive responses against stresses. Therefore, in this study, the effects of Mel and Ca2+ and the possible relationship between them in the increase of the production of phenolic compounds in Dracocephalum kotschyi Boiss. under both control and salinity stress conditions were investigated. The results showed that 75 mM NaCl reduced shoot dry biomass but elevated H2O2 content, electrolyte leakage (EL) level, total phenolic and flavonoid contents (TPC and TFC), and DPPH scavenging capacity. Salinity stress also upregulated gene expression of phenylalanine ammonia-lyase (PAL) and rosmarinic acid synthase (RAS), as well as the activities of PAL and tyrosine ammonia-lyase (TAL) enzymes. Pre-treatment of the plants with CaCl2 and Mel affected these attributes in a dose-dependent manner. Application of 5 mM Ca2+ and 100 μM Mel improved shoot dry biomass and reduced the level of EL and H2O2 content but enhanced TPC and TFC, DPPH scavenging capacity, PAL and TAL activities, PAL and RAS transcripts, and content of rosmarinic acid (RA), luteolin flavone (LF) and apigenin flavone (AF) under salinity stress. Pre-treatment of D. kotschyi with lanthanum chloride (LaCl3) as a plasma membrane channel blocker, ethylene glycol tetra-acetic acid (EGTA) as a Ca2+ chelator and trifluoperazine (TFP) as a calmodulin (CaM) antagonist, impaired Mel effects on the above attributes under salinity stress. In contrast, pre-treatment with p-chlorophenylalanine (p-CPA), as an inhibitor of Mel biosynthesis, did not impair the impacts of Ca2+ on the production of phenolic compounds in salt-exposed plants. These results suggested that the effect of Mel on the induction of phenolic compounds production requires the influx of extracellular Ca2+ into the cells and is dependent on Ca2+/CaM signaling.

Novel Perspective on Alzheimer's Disease Treatment: Rosmarinic Acid Molecular Interplay with Copper(II) and Amyloid β

Alzheimer's disease is a severe disorder that affects millions of people worldwide. It is a very debilitating disease with no cure at the moment. The necessity of finding an effective treatment is very demanding, and the entire scientific community is putting in a lot of effort to address this issue. The major hallmark of Alzheimer's disease is the presence of toxic aggregated species in the brain, impaired metal homeostasis, and high levels of oxidative stress. Rosmarinic acid is a well-known potent antioxidant molecule, the efficacy of which has been proved both in vitro and in vivo. In this study, we investigated the possible role played by rosmarinic acid as a mediator of the copper(II)-induced neurotoxicity. Several spectroscopic techniques and biological assays were applied to characterize the metal complexes and to evaluate the cytotoxicity and the mutagenicity of rosmarinic acid and its Cu(II) complex. Our data indicate that rosmarinic acid is able to interfere with the interaction between amyloid β and Cu(II) by forming an original ternary association.

Nanoparticles Derived from the Natural Antioxidant Rosmarinic Acid Ameliorate Acute Inflammatory Bowel Disease

Rosmarinic acid (RA), one of the most important polyphenol-based antioxidants, has received growing interest because of its bioactive properties, including anti-inflammatory, anticancer, and antibacterial activities. Despite the high therapeutic potential of RA, its intrinsic properties of poor water solubility and low bioavailability have limited its translation into the clinic. Here, we report on the synthesis and preparation of PEGylated RA-derived nanoparticles (RANPs) and their use as a therapeutic nanomedicine for treatment of inflammatory bowel disease (IBD) in a dextran sulfate sodium (DSS)-induced acute colitis mouse model. PEGylated RA, synthesized via a one-step process from RA and a PEG-containing amine, self-assembled in buffer to form nanoparticles (RANPs) with a diameter of 63.5 ± 4.0 nm. The resulting RANPs showed high colloidal stability in physiological medium up to 2 weeks. RANPs were capable of efficiently scavenging H2O2, thereby protecting cells from H2O2-induced damage. Furthermore, the corticosteroid drug, dexamethasone (DEX), could be loaded into RANPs and released in response to a reactive oxygen species stimulus. Intravenously administered RANPs exhibited significantly improved pharmacokinetic parameters compared with those of the parent RA and were preferentially localized to the inflamed colon. Intravenous administration of RANPs in DSS-induced colitis mice substantially mitigated colonic inflammation in a dose-dependent manner compared with the parent RA, as evidenced by significantly reduced disease activity index scores, body weight loss, and colonic inflammatory damage. In addition, RANPs suppressed expression and production of typical pro-inflammatory cytokines in the inflamed colon. Furthermore, DEX-loaded RANPs showed enhanced therapeutic efficacy in the colitis model compared with bare RANPs at the equivalent dose, indicating synergy with a conventional medication. These findings suggest that RANPs deserve further consideration as a potential therapeutic nanomedicine for the treatment of various inflammatory diseases, including IBD.

Anticancer Activity of Rosmarinus officinalis L.: Mechanisms of Action and Therapeutic Potentials

Alternative treatments for neoplastic diseases with new drugs are necessary because the clinical effectiveness of chemotherapy is often reduced by collateral effects. Several natural substances of plant origin have been demonstrated to be successful in the prevention and treatment of numerous tumors. Rosmarinus officinalis L. is a herb that is cultivated in diverse areas of the world. There is increasing attention being directed towards the pharmaceutical capacities of rosemary, utilized for its anti-inflammatory, anti-infective or anticancer action. The antitumor effect of rosemary has been related to diverse mechanisms, such as the antioxidant effect, antiangiogenic properties, epigenetic actions, regulation of the immune response and anti-inflammatory response, modification of specific metabolic pathways, and increased expression of onco-suppressor genes. In this review, we aim to report the results of preclinical studies dealing with the anticancer effects of rosemary, the molecular mechanisms related to these actions, and the interactions between rosemary and anticancer drugs. The prospect of utilizing rosemary as an agent in the treatment of different neoplastic diseases is discussed. However, although the use of rosemary in the therapy of neoplasms constitutes a fascinating field of study, large and controlled studies must be conducted to definitively clarify the real impact of this substance in clinical practice.

In vitro bioaccessibility and activity of Greek oregano (Origanum vulgare L. ssp. hirtum (link) Ietswaart) compounds as affected by nitrogen fertilization

BACKGROUND

Greek oregano is a culinary and medicinal herb native to the Mediterranean region; however nowadays it is cultivated in many regions all over the world. It is commonly used as a spice for flavoring food products and in various traditional medicine applications. This study investigated the effect of nitrogen fertilization at 0-150 kg N ha-1 on the potential bioaccessibility and activity of Greek oregano compounds. For this purpose the total phenolic content, rosmarinic acid content, and antioxidant activities of the raw material, as well as digested fractions, were determined.

RESULTS

Nitrogen fertilization had a negative influence on the phenolic content and antioxidant activity of raw material; however, its effect on the potential bioaccessibility varied depending on the dose. The highest potential bioaccessibility and activity was determined for plants fertilized with 30 kg N ha-1 . For the gastric and intestinal phases of digestion, the potential bioaccessibility percentages were 39.5% and 29.6% for total phenolics, 53.1% and 11.2% for rosmarinic acid content, 45.2% and 44.4% for antiradical activity against 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS), 39.2% and 27.2% for antiradical activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 50.2% and 23.4% for reducing power, respectively.

CONCLUSION

The results showed that nitrogen fertilization is an important factor determining the in vitro bioaccessibility of Greek oregano compounds. Furthermore, the nutraceutical potential of herbs, in term of the bioaccessibility of bioactive compounds, may be optimized during plant cultivation by applying an accurate nitrogen level. © 2020 Society of Chemical Industry.

Rosmarinic acid exerts an anticancer effect on osteosarcoma cells by inhibiting DJ-1 via regulation of the PTEN-PI3K-Akt signaling pathway

BACKGROUND

Osteosarcoma is the most common type of primary malignant bone tumor. This disease has exhibited a progressively lower survival rate over the past several decades, which has resulted in it becoming a main cause of death in humans. Rosmarinic acid (RA), a water-soluble polyphenolic phytochemical, exerts powerful anticancer effects against multiple types of cancer; however, its potential effects on osteosarcoma remain unknown. Hence, the present study investigated the efficacy of RA against osteosarcoma and aimed to clarify the mechanisms underlying this process.

METHODS

The effects of RA on cell viability, apoptosis, cell cycle distribution, migration, invasion, and signaling molecules were analyzed by CCK-8 assay, flowcytometric analysis, wound healing assay, Transwell assay, proteomic analysis, and use of shRNAs.

RESULTS

RA exerted anti-proliferation and pro-apoptotic effects on U2OS and MG63 osteosarcoma cells. Apoptosis was induced via extrinsic and intrinsic pathways by increasing the Bax/Bcl-2 ratio, triggering the intracellular production of reactive oxygen species (ROS), reducing the mitochondrial membrane potential (MMP), and upregulating the cleavage rates of caspase-8, caspase-9, and caspase-3. Additionally, RA suppressed the migration and invasion of osteosarcoma cells by inhibiting the expression levels of matrix metalloproteinase-2 and -9 (MMP-2 and -9), which are associated with a weakening of the epithelial-mesenchymal transition (EMT). Moreover, proteomic analyses identified DJ-1 as a potential target for RA. Several studies have indicated an oncogenic role for DJ-1 using knockdowns via the lentiviral-mediated transfection of shRNA, which caused the conspicuous suppression of cell proliferation, migration, and invasion as well as the arrest of cell cycle progression. At the molecular level, the expression levels of DJ-1, p-PI3K, and p-Akt were reduced, whereas the protein levels of phosphatase and tensin homologue (PTEN) were increased.

CONCLUSION

In conjunction with the high levels of DJ-1 expression in osteosarcoma tissues and cell lines, the present results suggested that RA exhibited anticancer effects in osteosarcoma cells by inhibiting DJ-1 via regulation of the PTEN-PI3K-Akt signaling pathway. Therefore, DJ-1 might be a biological target for RA in osteosarcoma cells.

Methanol Extract of Coleus amboinicus (Lour) Exhibited Antiproliferative Activity and Induced Programmed Cell Death in Colon Cancer Cell WiDr

Coleus amboinicus(Lour) (CA) has been reported to possess many pharmacological activities. In this study, evaluation of cytotoxicity using brine shrimp lethality bioassay and MTT assay using WiDr cell lines was carried out. The expression of several genes responsible for programmed cell death of the methanol extract of CA was also investigated. The morphology of the cells undergoing apoptosis was detected using Hoechst staining assay. The gene expression of BAX, BCL2, P53, Caspase 1, 7, 8, and 9 of treated samples with different concentrations (10, 15, 25 & 50 µg/ml) were measured with RT PCR. The phytochemical profiles were investigated using LC MS. The results showed that the lethality concentration (LC50) of methanol extract using brine shrimp was 34.545 µg/ml and the extract exhibited good antiproliferative activity against cancer cells WiDr with IC50 value (8.598 ± 2.68 µg/ml) as compared to standard drug 5-fluorouracil (IC50 value 1.839 ± 0.03 µg/ml). There was apoptotic evidences from the morphology of treated cells. The expressions of BAX,P53, and Caspase 9 were upregulated in lower concentration of the extract (10 and 15 µg/ml) but downregulated in higher concentration (25 and 50 µg/ml). BCL2 as anti-apoptotic gene was downregulated in all concentrations. Caspase 1 and Caspase 7 were upregulated in high concentration (25 and 50 µg/ml), but downregulated in lower concentrations. These data provide a mode of cell death for the methanol extract of CA in low concentrations corresponding to apoptosis with intrinsic pathway. Many valuable compounds identified including caffeic acid, rosmarinic acid, malic acid, eicosapentanoic acid, benserazide, alpha-linolenic acid, betaine, Salvanolic B, 4-hydroxibenzoic acid and firulic acid have been previously reported as being active agents against many cancer cells. This study suggested that CA might become an effective ingredient for health-beneficial foods to prevent colon cancer.

Rosmarinic Acid as a Potent Influenza Neuraminidase Inhibitor: In Vitro and In Silico Study

BACKGROUND

Neuraminidase (NA), a major glycoprotein found on the surface of the influenza virus, is an important target for the prophylaxis and treatment of influenza virus infections. Recently, several plant-derived polyphenols, especially caffeic acid analogs, have been reported to exert the inhibitory activity against NA.

OBJECTIVE

Herein, we aimed to investigate the anti-influenza NA activity of caffeic acid and its hydroxycinnamate analogues, rosmarinic acid and salvianolic acid A, in comparison to a known NA inhibitor, oseltamivir.

METHODS

In vitro MUNANA-based NA inhibitory assay was used to evaluate the inhibitory activity of the three interested hydroxycinnamic compounds towards the influenza NA enzyme. Subsequently, allatom molecular dynamics (MD) simulations and binding free energy calculations were employed to elucidate the structural insights into the protein-ligand complexations.

RESULTS

Rosmarinic acid showed the highest inhibitory activity against NA with the IC50 of 0.40 μM compared to caffeic acid (IC50 of 0.81 μM) and salvianolic acid A (IC50 of >1 μM). From 100-ns MD simulations, the binding affinity, hot-spot residues, and H-bond formations of rosmarinic acid/NA complex were higher than those of caffeic acid/NA model, in which their molecular complexations was driven mainly by electrostatic attractions and H-bond formations from several charged residues (R118, E119, D151, R152, E227, E277, and R371). Notably, the two hydroxyl groups on both phenyl and phenylacetic rings of rosmarinic acid play a crucial role in stabilizing NA through a strongly formed Hbond( s).

CONCLUSION

Our findings shed light on the potentiality of rosmarinic acid as a lead compound for further development of a potential influenza NA inhibitor.

In vitro anti-pancreatic cancer activity of HPLC-derived fractions from Helicteres hirsuta Lour. stem

Pancreatic cancer (PC) is one of the leading causes of cancer death in Western societies. The absence of specific symptoms, late diagnosis and the resistance towards chemotherapy result in significant treatment difficulties. As such, it is important to find more effective therapeutic agents for the treatment of PC. Helicteres hirsuta Lour. (H. hirsuta) has been traditionally used in many countries for the treatment of various ailments, indicating that it contains potential therapeutic agents. This study aimed to derive different fractions from the saponin-enriched extract of H. hirsuta stem using RP-HPLC and examine the in vitro anti-pancreatic cancer activity of the derived fractions (F0-F5). With the exception of F0, the five fractions (F1-F5) possessed strong inhibitory activity against PC cells at IC₅₀ values of 3.11-17.12 μg/mL. The flow cytometry assays revealed the active fractions caused cell cycle arrest at S phase and promoted apoptosis in MIAPaCa-2 PC cells. The LC/MS analysis revealed that the isolated fractions contained bioactive compounds, such as caffeic acid, rosmarinic acid, sagerinic acid, usnic acid, cucurbitacins and absinthin. It can be concluded that the fractions isolated from H. hirsuta stem exhibit potent in vitro anti-pancreatic cancer activity and thus warrant further in vivo studies to assess their activity against PC followed by isolation of individual bioactive compounds and the evaluation of their anti-pancreatic cancer activity.

Correlation between cytotoxicity in cancer cells and free radical-scavenging activity: In vitro evaluation of 57 medicinal and edible plant extracts

Cancer is a complex interaction among multiple signaling pathways involving a variety of target molecules. Cancer causes morbidity and mortality in millions of people worldwide, and due to its prevalence, the discovery of novel anticancer drugs is urgently required. Nature is considered an important source of the discovery of anticancer treatments, and many of the cytotoxic medicines in clinics today are derived from plants and other natural sources. Reactive oxygen species (ROS) induce a variety of human cancers, and antioxidants or scavengers are used to counteract them. The current study reports on the screening of extracts from 57 plants that are used in the galilee district as a food and/or for traditional medicine. Investigating the free radical scavenging capacity and these plants, and their cytotoxicity, may prove helpful to high-throughput screening projects that use antioxidants and cytotoxic natural products. The current study assessed the correlation between free radical scavenging and cytotoxicity. Correlational analysis is important for increasing the efficiency of the screening process. In the present study, free radical scavenging was assessed using a DPPH assay, while cytotoxicity was measured using a XTT assay. A total of 9 extracts were indicated to exhibit EC₅₀ values <250 µg/ml, and 4 others exhibited a high antioxidant content, with EC₅₀ values, for free radical scavenging, of <0.5 µg/ml. An in-depth analysis of the results revealed that the extracts of plants that exhibit an EC₅₀ of free radical scavenging ≤10 µg/ml show a degree of enrichment toward increased cytotoxicity. It is recommended that future studies test the validity of the conclusions of the current study on other cancer cell-lines, and isolate and identify the bioactive agents that are found in the most cytotoxic extracts of plants.

Spica Prunellae Extract Enhances Fluorouracil Sensitivity of 5-Fluorouracil-Resistant Human Colon Carcinoma HCT-8/5-FU Cells via TOP2α and miR-494

The use of 5-fluorouracil (5-FU) has been proven benefits, but it also has adverse events in colorectal cancer (CRC) chemotherapy. In this study, we explored the mechanism of 5-FU resistance by bioinformatics analysis of the NCBI public dataset series GSE81005. Fifteen hub genes were screened out of 582 different expressed genes. Modules of the hub genes in protein-protein interaction networks gathered to TOP2α showed a decrease in HCT-8 cells but an increase in 5-FU-resistant HCT-8/5-FU cells with 5-FU exposure. Downregulation of TOP2α with siRNA or miR-494 transfection resulted in an increase of cytotoxicity and decrease of cell colonies to 5-FU for HCT-8/5-FU cells. Moreover, we found that an ethanol extract of Spica Prunellae (EESP), which is a traditional Chinese medicine with clinically beneficial effects in various cancers, was able to enhance the sensitivity of 5-FU in HCT-8/5-FU cells and partly reverse the 5-FU resistance effect. It significantly helped suppress cell growth and induced cell apoptosis in HCT-8/5-FU cells with the expression of TOP2α being significantly suppressed, which increased by 5-FU. Consistently, miR-494, which reportedly regulates TOP2α, exhibited reverse trends in EESP/5-FU combination treatment. These results suggested that Spica Prunellae may be beneficial in the treatment of 5-FU-resistant CRC patients.

Rosmarinic inhibits cell proliferation, invasion and migration via up-regulating miR-506 and suppressing MMP2/16 expression in pancreatic cancer

Pancreatic cancer is the fourth leading cause of cancer-related deaths worldwide. However, therapeutic strategies for the treatment of pancreatic cancer are still limited. Therefore, it is urgent for us to develop novel effective therapies for pancreatic cancer. In this study, we explored the effects of rosmarinic acid on pancreatic progression and explored the underlying molecular mechanisms. Rosmarinic acid significantly suppressed cell viability, cell growth, cell invasion and migration as well as epithelial mesenchymal transition (EMT) of pancreatic cancer cells, and induced cell apoptosis in pancreatic cells. In addition, rosmarinic acid significantly up-regulated the expression of miR-506 in pancreatic cancer cells, and knockdown of miR-506 attenuated the suppressive effects of rosmarinic acid on cell growth, cell invasion and migration and EMT, and prevented the enhanced effects of rosmarinic acid on cell apoptosis in pancreatic cancer cells. Mechanistically, the luciferase reporter assay showed that miR-506 targeted the 3' untranslated region of matrix metalloproteinase (MMP)-2/16, and miR-506 overexpression and rosmarinic acid treatment suppressed the expression of MMP2/16 in pancreatic cancer cells. Overexpression of MMP2/16 attenuated the inhibitory effects of rosmarinic acid on pancreatic cell invasion and migration. In vivo studies showed that rosmarinic acid dose-dependently suppressed tumor growth of pancreatic cancer cells, and increased the expression of miR-506, while suppressed the expression of MMP2/16 and Ki-67 in dissected tumor tissues from xenograft nude mice. Collectively, our results for the first time revealed the anti-tumor effects of rosmarinic acid in pancreatic cancer, and the anti-tumor effects of rosmarinic acid were via regulating the miR-506/MMP2/16 axis in pancreatic cancer.

Neuroprotection Comparison of Rosmarinic Acid and Carnosic Acid in Primary Cultures of Cerebellar Granule Neurons

Neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS), Alzheimer's disease, and Parkinson's disease, are characterized by the progressive loss of neurons in specific regions of the brain and/or spinal cord. Neuronal cell loss typically occurs by either apoptotic or necrotic mechanisms. Oxidative stress and nitrosative stress, along with excitotoxicity and caspase activation, have all been implicated as major underlying causes of neuronal cell death. Diverse nutraceuticals (bioactive compounds found in common foods) have been shown to have neuroprotective effects in a variety of in vitro and in vivo disease models. In the current study, we compared the neuroprotective effects of two polyphenolic compounds, rosmarinic acid and carnosic acid, which are both found at substantial concentrations in the herb rosemary. The capacity of these compounds to rescue primary cultures of rat cerebellar granule neurons (CGNs) from a variety of stressors was investigated. Both polyphenols significantly reduced CGN death induced by the nitric oxide donor, sodium nitroprusside (nitrosative stress). Rosmarinic acid uniquely protected CGNs from glutamate-induced excitotoxicity, while only carnosic acid rescued CGNs from caspase-dependent apoptosis induced by removal of depolarizing extracellular potassium (5K apoptotic condition). Finally, we found that carnosic acid protects CGNs from 5K-induced apoptosis by activating a phosphatidylinositol 3-kinase (PI3K) pro-survival pathway. The shared and unique neuroprotective effects of these two compounds against diverse modes of neuronal cell death suggest that future preclinical studies should explore the potential complementary effects of these rosemary polyphenols on neurodegenerative disease progression.