ß-Caryophyllene Induces Apoptosis and Inhibits Angiogenesis in Colorectal Cancer Models.

Beta-Caryophyllene (BCP), a naturally occurring sesquiterpene abundantly found in cloves, hops, and cannabis, is the active candidate of a relatively new group of vascular-inhibiting compounds that aim to block existing tumor blood vessels. Previously, we have reported the anti-cancer properties of BCP by utilizing a series of in-vitro anti-tumor-related assays using human colorectal carcinoma cells. The present study aimed to investigate the effects of BCP on in-vitro, ex-vivo, and in-vivo models of anti-angiogenic assays and evaluate its anti-cancer activity in xenograft tumor (both ectopic and orthotopic) mice models of human colorectal cancer. Computational structural analysis and an apoptosis antibody array were also performed to understand the molecular players underlying this effect. BCP exhibited strong anti-angiogenic activity by blocking the migration of endothelial cells, tube-like network formation, suppression of vascular endothelial growth factor (VEGF) secretion from human umbilical vein endothelial cells and sprouting of rat aorta microvessels. BCP has a probable binding at Site#0 on the surface of VEGFR2. Moreover, BCP significantly deformed the vascularization architecture compared to the negative control in a chick embryo chorioallantoic membrane assay. BCP showed a remarkable reduction in tumor size and fluorescence molecular tomography signal intensity in all the mice treated with BCP, in a dose-dependent relationship, in ectopic and orthotopic tumor xenograft models, respectively. The histological analysis of the tumor from BCP-treated mice revealed a clear reduction of the density of vascularization. In addition, BCP induced apoptosis through downregulation of HSP60, HTRA, survivin, and XIAP, along with the upregulation of p21 expressions. These results suggest that BCP acts at multiple stages of angiogenesis and could be used as a promising therapeutic candidate to halt the growth of colorectal tumor cells.

Mesua ferrea stem bark extract induces apoptosis and inhibits metastasis in human colorectal carcinoma HCT 116 cells, through modulation of multiple cell signalling pathways.

Considering the great potential of natural products as anticancer agents, the present study was designed to explore the molecular mechanisms responsible for anticancer activities of Mesua ferrea stem bark extract against human colorectal carcinoma. Based on MTT assay results, bioactive sub-fraction (SF-3) was selected for further studies using HCT 116 cells. Repeated column chromatography resulted in isolation of less active α-amyrin from SF-3, which was identified and characterized by GC-MS and HPLC methods. α-amyrin and betulinic acid contents of SF-3 were measured by HPLC methods. Fluorescent assays revealed characteristic apoptotic features, including cell shrinkage, nuclear condensation, and marked decrease in mitochondrial membrane potential in SF-3 treated cells. In addition, increased levels of caspases-9 and -3/7 levels were also observed in SF-3 treated cells. SF-3 showed promising antimetastatic properties in multiple in vitro assays. Multi-pathway analysis revealed significant down-regulation of WNT, HIF-1α, and EGFR with simultaneous up-regulation of p53, Myc/Max, and TGF-ß signalling pathways in SF-3 treated cells. In addition, promising growth inhibitory effects were observed in SF-3 treated HCT 116 tumour spheroids, which give a hint about in vivo antitumor efficacy of SF-3 phytoconstituents. In conclusion, these results demonstrated that anticancer effects of SF-3 towards colon cancer are through modulation of multiple molecular pathways.

Colorectal, Prostate and Pancreas Human Cancers Targeted Bioassay-guided Isolations and Characterization of Chemical Constituents from Tephrosia apollinea.

BACKGROUND: Cancer is characterized by uncontrolled cell division caused by dysregulation of cell proliferation. Therefore, agents that impair cancer cell proliferation could have potential therapeutic value. Higher plants are considered to be a good source of anticancer agents, and several clinically tested chemotherapeutic agents have been isolated from plants or derived from constituents of plant origin. METHODS: In the present study, a prenylated flavone (isoglabratephrin) was isolated from aerial parts of Tephrosia apollinea using a bioassay-guided technique. Chemical structure of the isolated compound was elucidated using spectroscopic techniques (NMR, IR, and LC-MC), elemental analysis and confirmed by using single crystal X-ray analysis. The antiproliferative effect of isoglabratephrin was tested using three human cancer cell lines (prostate (PC3), pancreatic (PANC-1), and colon (HCT-116) and one normal cell line (human fibroblast). RESULTS: Isoglabratephrin displayed selective inhibitory activity against proliferation of PC3 and PANC-1 cells with median inhibitory concentration values of 20.4 and 26.6 µg/ml, respectively. Isoglabratephrin demonstrated proapoptotic features, as it induced chromatin dissolution, nuclear condensation, and fragmentation. It also disrupted the mitochondrial membrane potential in the treated cancer cells. CONCLUSION: Isoglabratephrin could be a new lead to treat human prostate (PC3) and pancreatic (PANC-1) malignancies.

Cat's whiskers (Orthosiphon stamineus) tea modulates arthritis pathogenesis via the angiogenesis and inflammatory cascade.

BACKGROUND: Orthosiphon stamineus is used traditionally to treat gout, arthritis, and inflammatory related conditions. The in vitro anti-inflammatory effects of the plant have been scientifically investigated. The goal of the present study was to evaluate the potential of the 50% ethanol extract of O. stamineus (EOS) to treat rheumatoid arthritis. METHODS: Anti-arthritic activity was assessed using the in vitro heat denaturation test and the (FCA)-induced arthritis model. Efficacy was assessed by measurements of paw edema and granulation, X-ray radiography, fluorescence molecular tomography (FMT), and histological evaluation. Levels of (TNF-α), interleukin-1 (IL-1), and (COX-1 and COX-2) were analyzed in vitro in lipopolysaccharide (LPS)-stimulated human macrophage (U937). TNF-α and IL-1 levels in the serum samples of arthritic rats were also measured using an ELISA kit. RESULTS: Treatment with EOS resulted in dose-dependent inhibition of paw edema in acute and chronic models of inflammation. It also inhibited significantly the production of TNF-α, IL-1 COX-1, and COX-2 in the LPS-stimulated U937 macrophages. EOS significantly suppressed FCA-induced paw edema as well as the serum levels of TNF-α and IL-1. X-rays of the synovial joint of the hind leg showed considerable improvement in joint integrity and recovery of tibia-talus bones from degeneration and osteoporotic lesions. Histology of proximal interphalangeal joints of EOS-treated animals showed obvious protection of cartilage and soft tissue. Finally, FMT analysis strongly supported the anti-arthritic effect of EOS. EOS had high phenolic and total flavonoid content as well as strong antioxidant activity. CONCLUSIONS: Results illustrated that the anti-arthritic properties of O. stamineus could be beneficial for prevention and management of rheumatoid arthritis and other chronic inflammatory disorders. Illustration of the Anti- arthritis efficacy of Orthosiphon Stamineus standardized extract.

Chemotherapeutic potentials of the stem bark of Balanite aegyptiaca (L.) Delile: an antiangiogenic, antitumor and antioxidant agent.

BACKGROUND: Balanite aegyptiaca (L.) Delile, is a plant with extensive medicinal properties. Its stem bark is traditionally known for its spasmolytic and antiepileptic properties and used to treat yellow fever, jaundice and syphilis. Angiogenesis (sprouting of new blood vessels) is crucial for tumor growth and metastasis. The goal of this study is investigate the antiangiogenic, cytotoxicity and antioxidant activity as well as antitumor in vivo properties of B. aegyptiaca stem bark extracts. METHOD: The dried powder of stem bark was extracted sequentially with n-hexane, chloroform, methanol and water. Rat aorta ring assay (RARA) was used as a platform to screen for antiangiogenic affect. The most active extract was subjected to further confirmatory antiangiogenic tests i.e. cell migration, tube formation and VEGF inhibition and finally evaluated for its in vivo antitumor efficacy in nude mice. The cytotoxicity of extracts on four cancer cell lines (HCT-116, K562, U937 and MCF-7) and one normal cells line (HUVEC) was evaluated. To assess the antioxidant activity screening, four methods were used, (DPPH•) and ABTS radical scavenging activity, as well as total flavonoids and phenolic contents. RESULTS: Methanol extract of B. aegyptiaca stem bark (MBA) showed the highest antiangiogenic, antioxidant and anticancer properties. It was found selectively cytotoxic to leukemia cell lines as well as breast cancer cell line MCF-7. (MBA) thus exhibited antiangiogenic in ex-vivo rat aorta ring model; it was found to excel its antiangiogenic effect via inhibition of the key growth factor (VEGF) as well as to halt HUVEC cell migration and tube formation, furthermore animals bearing colon cancer treated with (MBA) showed significant reduction in tumor growth. CONCLUSION: Different extracts of B. aegyptiaca stem bark showed various anticancer and antiangiogenic properties. MBA demonstrated potent antiangiogenic, antioxidant and antitumor in vivo. The outcome of this study suggests the potential of stem bark of the B. aegyptiaca for developing chemotherapeutic agent against solid tumor as well as leukemia.

Evaluation of in vitro and in vivo anti-inflammatory effects of (-)-pseudosemiglabrin, a major phytoconstituent isolated from Tephrosia apollinea (Delile) DC.

ETHNOPHARMACOLOGICAL RELEVANCE: Tephrosia apollinea (Delile) DC (Leguminosae) has been used in folk medicine in Arabian countries to treat inflammatory disorders. The plant has been described to treat swelling, bone fracture, bronchitis, cough, earache and wounds. AIM OF THE STUDY: the current study aims to evaluate the anti-inflammatory properties of the major active phytoconstituent of T. apollinea and elucidate the mechanisms by which it inhibits inflammation in vitro and in vivo. MATERIAL AND METHODS: The compound, (-)-pseudosemiglabrin (SSG) was isolated as a major component from the aerial parts of T. apollinea using column chromatography techniques. Sub-chronic in vivo anti-inflammatory effect of SSG was assessed using cotton pellet granuloma assay in SD rats and serum levels of tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1) and nitric oxide (NO) were measured, whereas, tail flick assay was performed to assess the analgesic effect of SSG. Furthermore, the anti-inflammatory effects of SSG were confirmed by measuring the levels of IL-1, TNF-α, and NO in vitro using human macrophage cell lines (U937). In addition COX inhibition assay was also conducted in cells-free system. In silico study was performed to dock SSG in cyclooxygenase enzymes and opioid receptor to predict its structure-activity and molecular mechanism. RESULTS: SSG displayed potential inhibition of granuloma tissue in rats and significantly (P<0.05) lowered the production of cytokines (TNF- α and IL-1) in vivo as well as human macrophages. Further investigation revealed that, SSG selectively inhibited COX-2 by 60% with negligible effect on COX-1. The selectivity of SSG towards COX-2 was confirmed in silico wherein, SSG demonstrated significant binding affinity with binding energy (-9.42kcal/mol). The binding found to be through covalent energy with Ser-530 amino acid residue of the active pocket of COX-2. SSG was found to prolong the flick tail time in mice by two folds. Further computational studies reveal that SSG binds to opioid receptor (µ-OR) through Ile-144 and Thr-218 with affinity two folds compared to the reference compounds, codeine and aspirin. CONCLUSION: In the present study the major phytoconstituent (-)-pseudosemiglabrin (SSG) from the aerial parts of T. apollinea demonstrated potent anti-inflammatory effect by inhibiting of granuloma tissue in rats and prolonging the tail flick time in mice. Investigation of levels of pro-inflammatory cytokines in SSG-treated rats and human macrophages demonstrated that SSG significantly inhibited TNF-α and IL-1. Also SSG showed selective inhibitory effect towards COX-2. In silico study exhibited pronounced binding affinity between SSG and µ-opioid receptor better than that of codeine and aspirin. The obtained results justify the use of aerial parts of T. apollinea to treat various inflammatory diseases and indicate that (-)-pseudosemiglabrin has a great potential to be further developed as a promising anti-inflammatory drug.

Scopoletin, an active principle of tree tobacco (Nicotiana glauca) inhibits human tumor vascularization in xenograft models and modulates ERK1, VEGF-A, and FGF-2 in computer model.

We recently reported the antineovascularization effect of scopoletin on rat aorta and identified its potential anti-angiogenic activity. Scopoletin could be useful as a systemic chemotherapeutic agent against angiogenesis-dependent malignancies if its antitumorigenic activity is investigated and scientifically proven using a suitable human tumor xenograft model. In the present study, bioassay-guided (anti-angiogenesis) phytochemical investigation was conducted on Nicotiana glauca extract which led to the isolation of scopoletin. Further, anti-angiogenic activity of scopoletin was characterized using ex vivo, in vivo and in silico angiogenesis models. Finally, the antitumorigenic efficacy of scopoletin was studied in human colorectal tumor xenograft model using athymic nude mice. For the first time, an in vivo anticancer activity of scopoletin was reported and characterized using xenograft models. Scopoletin caused significant suppression of sprouting of microvessels in rat aortic explants with IC50 (median inhibitory concentration) 0.06µM. Scopoletin (100 and 200mg/kg) strongly inhibited (59.72 and 89.4%, respectively) vascularization in matrigel plugs implanted in nude mice. In the tumor xenograft model, scopoletin showed remarkable inhibition on tumor growth (34.2 and 94.7% at 100 and 200mg/kg, respectively). Tumor histology revealed drastic reduction of the extent of vascularization. Further, immunostaining of CD31 and NG2 receptors in the histological sections confirmed the antivascular effect of scopoletin in tumor vasculature. In computer modeling, scopoletin showed strong ligand affinity and binding energies toward the following angiogenic factors: protein kinase (ERK1), vascular endothelial growth factor A (VEGF-A), and fibroblast growth factor 2 (FGF-2). These results suggest that the antitumor activity of scopoletin may be due to its strong anti-angiogenic effect, which may be mediated by its effective inhibition of ERK1, VEGF-A, and FGF-2.

The Anticancer, Antioxidant and Antimicrobial Properties of the Sesquiterpene ß-Caryophyllene from the Essential Oil of Aquilaria crassna.

The present study reports a bioassay-guided isolation of ß-caryophyllene from the essential oil of Aquilaria crassna. The structure of ß-caryophyllene was confirmed using FT-IR, NMR and MS. The antimicrobial effect of ß-caryophyllene was examined using human pathogenic bacterial and fungal strains. Its anti-oxidant properties were evaluated by DPPH and FRAP scavenging assays. The cytotoxicity of ß-caryophyllene was tested against seven human cancer cell lines. The corresponding selectivity index was determined by testing its cytotoxicity on normal cells. The effects of ß-caryophyllene were studied on a series of in vitro antitumor-promoting assays using colon cancer cells. Results showed that ß-caryophyllene demonstrated selective antibacterial activity against S. aureus (MIC 3 ± 1.0 µM) and more pronounced anti-fungal activity than kanamycin. ß-Caryophyllene also displayed strong antioxidant effects. Additionally, ß-caryophyllene exhibited selective anti-proliferative effects against colorectal cancer cells (IC50 19 µM). The results also showed that ß-caryophyllene induces apoptosis via nuclear condensation and fragmentation pathways including disruption of mitochondrial membrane potential. Further, ß-caryophyllene demonstrated potent inhibition against clonogenicity, migration, invasion and spheroid formation in colon cancer cells. These results prompt us to state that ß-caryophyllene is the active principle responsible for the selective anticancer and antimicrobial activities of A. crassnia. ß-Caryophyllene has great potential to be further developed as a promising chemotherapeutic agent against colorectal malignancies.