Ethnopharmacology in overdrive: the remarkable anti-HIV activity of Artemisia annua

Ethnopharmacological relevance

Artemisia annua contains the well-known antimalarial compound artemisinin, which forms the backbone of the global malaria treatment regime. In African countries a tea infusion prepared from Artemisia annua has been used for the treatment of malaria only for the past 10–20 years. Several informal claims in Africa exist that the Artemisia annua tea infusions are also able to inhibit HIV. Since HIV is a relatively newly emerged disease, the claims, if substantiated, could provide a very good example of “ethnopharmacology in overdrive”.The objective of this study was to provide quantitative scientific evidence that the Artemisia annua tea infusion exhibits anti-HIV activity through in vitro studies. A second objective was to determine if artemisinin plays a direct or indirect (synergistic) role in any observed activity. This was done by the inclusion of a chemically closely related species, Artemisia afra, known not to contain any artemisinin in our studies.

Materials and methods

Validated cellular systems were used to test Artemisia annua tea samples for anti-HIV activity. Two independent tests with different formats (an infection format and a co-cultivation format) were used. Samples were also tested for cellular toxicity against the human cells used in the assays.

Results

The Artemisia annua tea infusion was found to be highly active with IC₅₀ values as low as 2.0 μg/mL. Moreover we found that artemisinin was inactive at 25 μg/mL and that a chemically related species Artemisia afra (not containing artemisinin) showed a similar level of activity. This indicates that the role of artemisinin, directly or indirectly (synergism), in the observed activity is rather limited. Additionally, no cellular toxicity was seen for the tea infusion at the highest concentrations tested.

Conclusion

This study provides the first in vitro evidence of anti-HIV activity of the Artemisia annua tea infusion. We also report for the first time on the anti-HIV activity of Artemisia afra although this was not an objective of this study. These results open the way to identify new active pharmaceutical ingredients in Artemisia annua and thereby potentially reduce the cost for the production of the important antimalarial compound artemisinin.     

Transient lymphocyte decrease due to adhesion and migration following catumaxomab (anti-EpCAM x anti-CD3) treatment <Emphasis Type="Italic">in vivo</Emphasis>

Introduction  

In patients, a transient decrease in peripheral blood lymphocyte counts was observed following intraperitoneal administration of the trifunctional monoclonal antibody catumaxomab (anti-human EpCAM x anti-human CD3). The aim of this study was to clarify the observed effect in a preclinical mouse model and to analyse the related mechanism of action in vitro.     

Role of ventral striatum in reward-based decision making

So far, the specific role of the ventral striatum in reward-based decision making remains elusive. Here, we examined the role of the ventral striatum in reward-based decision making using functional MRI and a probabilistic object reversal task. During decision making, activity in the ventral striatum increased monotonically as a function of association learning and was greatest when the individuals expected to be rewarded for the decision with high certainty. Conversely, during the reward phase, activity in the ventral striatum showed an inverted U-shaped modulation by learning and was greatest when uncertainty about the outcome was maximal. Our data indicate that, during reward-based decision making, the ventral striatal signal dynamically changes over time dependent on the phase of the reward process and on the learning status and thereby acts as a motivational engine for the continuation of behavior.     

Her-2/neu and EGFR tyrosine kinase activation predict the efficacy of trastuzumab-based therapy in patients with metastatic breast cancer

Her-2/neu overexpression in human breast cancer leads to an aggressive biological behavior and poor prognosis. Although the anti-Her-2/neu antibody trastuzumab (Herceptin(R)) has become a valuable therapeutic option for patients with Her-2/neu-overexpressing breast cancer, many patients do not benefit from this therapy. To evaluate the effect of receptor activation on tumor response, we have investigated the phosphorylation status of Her-2/neu and EGFR in 46 Her-2/neu-overexpressing tumor samples from trastuzumab-treated metastatic breast cancer patients by immunohistochemistry. Activated (p)tyr-1248 Her-2/neu was detected in 9 of 46 breast cancers (20%), and activated (p)tyr-845 and (p)tyr-1173 EGFR were both present in 6 tumors (13%) while EGFR was present in 16 cases (35%). ptyr-1248 Her-2/neu showed a trend to correlate with increased response to trastuzumab (p = 0.063), while ptyr-845, ptyr-1173 EGFR and EGFR did not. The presence of ptyr-1248 Her-2/neu and ptyr-845 or ptyr-1173 EGFR, however, was a strong predictor of both response to trastuzumab-based treatment (OR = 8.0, p = 0.021 and OR = 8.0, p = 0.021) and clinical benefit (OR = 5.47, p = 0.041 and OR = 6.22, p = 0.028 multivariate logistic regression analysis). Furthermore, ptyr-845 EGFR and ptyr-1248 Her-2/neu were both independent predictors of progression-free survival (RR = 0.21, p = 0.01 and RR = 0.45, p = 0.026, multivariate analysis). Patients with ptyr-845 EGFR positive tumors also tended toward increased overall survival (RR = 0.17, p = 0.082). Taken together, we have demonstrated that the determination of activated EGFR improves the utility of ptyr-1248 Her-2/neu staining in predicting the clinical outcome of patients undergoing trastuzumab treatment. We hypothesize that the activation state of both Her-2/neu and EGFR are key determinants for trastuzumab efficacy.     

A novel neoplastic primary tumor-derived human prostate epithelial cell line

Research into molecular and genetic mechanisms underlying prostate carcinogenesis would be greatly advanced by in vitro models of prostate tumors representing primary tumors. The generation of immortalized primary prostate cancer cells that will accurately reflect the in situ characteristics of malignant epithelium is greatly needed. We have successfully established a neoplastic immortalized human prostate epithelial (HPE) cell culture derived from a primary tumor. The RC-9 cells transduced through infection with a retrovirus vector expressing the E6 and E7 genes (E6E7) of human papilloma virus-16 (HPV-16) are currently growing well at passage 40, whereas RC-9 cells senesced at passage 7. RC-9/E6E7 cells exhibit epithelial morphology and high level of telomerase activity. More importantly, these immortalized cells produced tumors (SCID5038D) when inoculated into SCID mice. RC-9/E6E7 cells and SCID-5038D cells exhibit a high level of telomerase activity and androgen-responsiveness when treated with R1881. Expression of prostate specific antigen (PSA), androgen receptor (AR), prostate stem cell antigen (PSCA), an androgen-regulated prostate specific gene (NKX3.1), p16, cytokeratins 8, 15 and HPV-16 E6 gene was detected in both of these cells. RC-9/E6E7 and SCID5038D cells also showed growth inhibition when exposed to retinoic acid and transforming growth factor (TGF)-beta1, potent inhibitors of prostate epithelial cell growth. A number of chromosome alterations were observed including the loss of chromosomes 2p, 3p, 8p, 13, 14, 16, 17, 18, 21 and the gain of 7 and 20 in the tumor cell line (SCID5038D). These results demonstrate that this primary tumor-derived HPE cell line retained its neoplastic phenotypes and its prostate-specific markers and should allow studies to elucidate molecular and genetic alterations involved in prostate cancer. This is the first documented case of a malignant AR and PSA positive established human prostate cancer cell line from a primary tumor of a prostate cancer patient.     

Bleomycin hydrolase (Blh1p), a multi-sited thiol protease in search of a distinct physiological role

Bleomycin hydrolase, Blh1p, from yeast was co-purified with Gce1p, a cAMP-binding ectoprotein, anchored to the plasma membrane by a glycosyl-phosphatidylinositol (GPI) anchor. Blh1p is a hydrophilic thiol protease lacking transmembrane domains. We have used polyclonal antibodies to study the topology of the over-expressed protein in yeast and have found that it is amphitropic. Part of Blh1p is associated with plasma membranes, and most of the rest occurs in the cytosol. Both the growth conditions and calcium were found to have minor influences on the topology of Blh1p, in that glucose and the earth-alkali ion slightly enhanced recruitment to the membrane. We have examined the possibility that co-purification of Blh1p with Gce1p has a functional basis, and have observed that over-expression of BLH1 in yeast leads to an acceleration of the glucose-induced amphiphilic to hydrophilic conversion of Gce1p, wherein Blh1p could either directly catalyse the proteolytic removal of the polar headgroup of the GPI anchor subsequent to an initial lipolytic cleavage by a GPI-specific phospholipase C or indirectly modulate the reaction. The data show that a thiol protease is involved, but point to an indirect role of Blh1p in GPI processing. Proteases with similar or overlapping substrate specificity are likely to exist, since deletion of BLH1 neither entails a growth defect on any carbon source tested, nor the loss of proteolytic processing of the GPI anchor of Gce1p. Reduced proteolytic GPI processing is, however, observed in the blh1 mutant and the corresponding acceleration in the respective BLH1 multi-copy transformant. Received: 20 September 1996 / 23 April 1997     

Tranexamsäure: der Stellenwert des korrekten Einsatzes und einer individualisierten Risiko-Nutzen-Abwägung

Die Anaesthesiologie -     

Familial Liability to Epilepsy and Attention-Deficit/Hyperactivity Disorder: A Nationwide Cohort Study

Background

Epilepsy and attention-deficit/hyperactivity disorder (ADHD) are strongly associated; however, the underlying factors contributing to their co-occurrence remain unclear. A shared genetic liability has been proposed as one possible mechanism. Therefore, our goal in this study was to investigate the familial coaggregation of epilepsy and ADHD and to estimate the contribution of genetic and environmental risk factors to their co-occurrence.