Antithrombotic/anticoagulant and anticancer activities of selected medicinal plants from South Africa

Nine plants available in the Eastern Cape Province of South Africa were tested for antithrombotic and/or anticoagulant activity. Organic (methanol) and aqueous (distilled water) extractions were performed on the various plant parts. The thrombin assay and clotting time assays (thrombin-induced and CaCl 2 -induced) were utilised. Several extracts displayed activity, but in most cases this was due to the presence of tannins. Only the aqueous extracts displayed activity after tannin removal. The Sutherlandia frutescens leaf extract displayed antithrombotic activity, with an IC 50 value of 2.17 mg/ml. Gloriosa superba and Zantedeschia aethiopica leaf extracts displayed anticoagulant properties by inhibiting thrombin-induced clotting, with IC 50 values of 2.97 and 3.05 mg/ml, respectively. The Leonotis leonurus root extract was found to decrease the CaCl 2 -induced clotting time by 50% at 8.88 mg/ml. A decrease in this value accompanied by a decrease in fibrin formation was preferable for the CaCl 2 -induced assay, since decreased fibrin formation may have a role in the prevention of cancer metastasis. As tannins were found to contribute minimally to the anticoagulant effect of L. leonurus, the cytotoxicity potential of the extracts of this species against five cell lines was determined. Only the organic extract yielded significant cytotoxity

Antithrombotic/anticoagulant and anticancer activities of selected medicinal plants from South Africa

Nine plants available in the Eastern Cape Province of South Africa were tested for antithrombotic and/or anticoagulant activity. Organic (methanol) and aqueous (distilled water) extractions were performed on the various plant parts. The thrombin assay and clotting time assays (thrombin-induced and CaCl 2 -induced) were utilised. Several extracts displayed activity, but in most cases this was due to the presence of tannins. Only the aqueous extracts displayed activity after tannin removal. The Sutherlandia frutescens leaf extract displayed antithrombotic activity, with an IC 50 value of 2.17 mg/ml. Gloriosa superba and Zantedeschia aethiopica leaf extracts displayed anticoagulant properties by inhibiting thrombin-induced clotting, with IC 50 values of 2.97 and 3.05 mg/ml, respectively. The Leonotis leonurus root extract was found to decrease the CaCl 2 -induced clotting time by 50% at 8.88 mg/ml. A decrease in this value accompanied by a decrease in fibrin formation was preferable for the CaCl 2 -induced assay, since decreased fibrin formation may have a role in the prevention of cancer metastasis. As tannins were found to contribute minimally to the anticoagulant effect of L. leonurus, the cytotoxicity potential of the extracts of this species against five cell lines was determined. Only the organic extract yielded significant cytotoxity

Purification and biochemical characterisation of a putative sodium channel agonist secreted from the South African Knobbly sea anemone Bunodosoma capense

Voltage gated ion channels have become a subject of investigation as possible pharmaceutical targets. Research has linked the activity of ion channels directly to anti-inflammatory pathways, energy homeostasis, cancer proliferation and painful diabetic neuropathy. Sea anemones secrete a diverse array of bioactive compounds including potassium and sodium channel toxins. A putative novel sodium channel agonist (molecular mass of 4619.7 Da) with a predicted sequence: CLCNSDGPSV RGNTLSGILW LAGCPSGWHN CKKHKPTIGW CCK was isolated from Bunodosoma capense using a modified stimulation technique to induce the secretion of the neurotoxin rich mucus confirmed by an Artemia nauplii bio-assay. The peptide purification combined size-exclusion and reverse-phase high performance liquid chromatography. A thallium-based ion flux assay confirmed the presence of a sodium channel agonist/inhibitor and purity was determined using a modified tricine SDS-PAGE system. The peptide isolated indicated the presence of multiple disulfide bonds in a tight β-defensin cystine conformation. An IC50 value of 26 nM was determined for total channel inhibition on MCF-7 cells. The unique putative sodium channel agonist initiating with a cystine bond indicates a divergent evolution to those previously isolated from Bunodosoma species

Synthesis, characterization and biological activity of some Dithiourea Derivatives:

Novel dithiourea derivatives have been designed as HIV-1 protease inhibitors using Autodock 4.2, synthesized and characterized by spectroscopic methods and microanalysis

Biochemical characterization of Acacia schweinfurthii serine proteinase inhibitor

One of the many control mechanisms of serine proteinases is their specific inhibition by protein proteinase inhibitors. An extract of Acacia schweinfurthii was screened for potential serine proteinase inhibition. It was successfully purified to homogeneity by precipitating with 80% (v/v) acetone and sequential chromatographic steps, including ion-exchange, affinity purifica- Q2 tion and RP-HPLC. Reducing SDS-PAGE conditions revealed an inhibitor (ASTI) consisting of two polypeptide chains A and B of approximate molecular weights of 16 and 10 kDa, respectively, and under non-reducing conditions, 26 kDa was observed. The inhibitor was shown to inhibit bovine trypsin (Ki of 3.45 nM) at an approximate molar ratio of inhibitor: trypsin (1:1). The A- and B-chains revealed complete sequences of 140 and 40 amino acid residues, respectively. Sequence similarity (70%) was reported between ASTI A-chain and ACTI A-chain (Acacia confusa) using the ClustalW. The B-chain produced a 76% sequence similarity between ASTI and Leucaena leucocephala trypsin inhibitor

Cannabinoid Combination Induces Cytoplasmic Vacuolation in MCF-7 Breast Cancer Cells

This study evaluated the synergistic anti-cancer potential of cannabinoid combinations across the MDA-MB-231 and MCF-7 human breast cancer cell lines. Cannabinoids were combined and their synergistic interactions were evaluated using median effect analysis. The most promising cannabinoid combination (C6) consisted of tetrahydrocannabinol, cannabigerol (CBG), cannabinol (CBN), and cannabidiol (CBD), and displayed favorable dose reduction indices and limited cytotoxicity against the non-cancerous breast cell line, MCF-10A. C6 exerted its effects in the MCF-7 cell line by inducing cell cycle arrest in the G2 phase, followed by the induction of apoptosis. Morphological observations indicated the induction of cytoplasmic vacuolation, with further investigation suggesting that the vacuole membrane was derived from the endoplasmic reticulum. In addition, lipid accumulation, increased lysosome size, and significant increases in the endoplasmic reticulum chaperone protein glucose-regulated protein 78 (GRP78) expression were also observed. The selectivity and ability of cannabinoids to halt cancer cell proliferation via pathways resembling apoptosis, autophagy, and paraptosis shows promise for cannabinoid use in standardized breast cancer treatment

Preliminary insight into the relationship between environmental factors and the nutritional condition and growth of Gilchristella aestuaria larvae in the upper reaches of South African estuaries

Estuarine systems play a critical role as nursery areas for some fish species. Nursery function, nevertheless, is likely to vary among estuaries, mostly due to differences in habitat quality. High quality nursery habitats are those in which growth and survival of early stages of fish are enhanced. The nutritional condition of larval fishes has vital implications for their mortality and growth, and thereby their recruitment. This study aimed to compare the nutritional condition of Gichristella aestuaria larvae, using individual RNA-DNA ratios and growth rates in the upper reaches of six estuaries in South Africa to find the environmental factors that better determine the nutritional condition of fish larvae. Physico-chemical factors as well as calorific value of zooplankton were used to correlate to fish body condition. Results showed that the larvae of G. aestuaria from the freshwater rich Gamtoos and the Sundays estuaries were in better nutritional condition than the larvae from other estuaries, while larvae from the Swartkops Estuary, a highly eutrophic system, presented the worst nutritional condition of all studied larvae. Salinity and the abundance of zooplankton were the major factors determining the nutritional condition of G. aestuaria larvae in these warm temperate estuaries. In addition, our results suggest that the match-mismatch hypothesis might also be important in estuarine systems. This study represents one of the few studies worldwide that applied a multispecies growth model for fish larvae in warm temperate estuarie

The effect of cancer procoagulant on expression of metastatic and angiogenic markers in breast cancer and embryonic stem cell lines

Cancer procoagulant is present only in malignant tumours and the undifferentiated tissues of human placenta. Its possible role in angiogenesis and metastasis was investigated. Cancer procoagulant increased the steady-state mRNA level of L1 cell adhesion molecule (L1CAM) in MCF-7 breast cancer cells and E14 mouse embryonic stem cells (MESCs), while an increase in angiogenin mRNA was observed in MDA-MB-231 breast cancer cells. Furthermore, production of vascular endothelial growth factor (VEGF) protein in MCF-7 breast cancer cells and E14 MESCs, but decreased in MDA-MB-231 breast cancer cells. We conclude that cancer procoagulant could potentially play a part in angiogenesis in cancer and vascular development during embryonic development

Real-time monitoring of 3T3-L1 preadipocyte differentiation using a commercially available electric cell-substrate impedance sensor system:

Real-time analysis offers multiple benefits over traditional end point assays. Here, we present a method of monitoring the optimisation of the growth and differentiation of murine 3T3-L1 preadipocytes to adipocytes using the commercially available ACEA xCELLigence Real-Time Cell Analyser Single Plate (RTCA SP) system. Our findings indicate that the ACEA xCELLigence RTCA SP can reproducibly monitor the primary morphological changes in pre- and post-confluent 3T3-L1 fibroblasts induced to differentiate using insulin, dexamethasone, 3-isobutyl-1-methylxanthine and rosiglitazone; and may be a viable primary method of screening compounds for adipogenic factors