Peppers may increase energy expenditure in people tying to lose weight....

We know that, Capsinoids, which include capsiate, dihydrocapsiate,  and nordihydrocapsiate, are substances naturally present in chili peppers. Although they are structurally similar to capsaicin, the substance that causes pungency in hot peppers, they largely lack that characteristic. Capsinoids have an estimated “hot taste threshold” which is about 1000 times lower than of that of capsaicin. Many health effects have been ascribed to capsaicin and capsinoids, both anecdotally and through scientific study, including anticancer, anti-inflammatory, analgesic activity, and weight management.

Now researchers form UCLA's Center for Human Nutrition in Los Angeles, CA, lead by Dr. David Heber have come up with more interesting findings, i.e., "peppers may increase energy expenditure in people tying to lose weight". 


In a study designed to test the weight-loss potential of this DCT containing, non-spicy cousin of hot peppers, researchers at the UCLA Center for Human Nutrition set out to document its ability to increase heat production in human subjects consuming a weight-loss diet.

Under the direction of Dr. David Heber (Professor of Medicine and Public Health), they recruited 34 men and women who were willing to consume a very low-calorie liquid meal replacement product for 28 days. The researchers then randomized the subjects to take either placebo pills or supplements containing the non-burning DCT pepper analog. Two dosage levels of dihydrocapsiate DCT (see above structure ) were tested. At the beginning and end of the study, body weight and body fat were assessed, and the researchers determined energy expenditure (heat production) in each subject after he or she consumed one serving of the test meal.

The data provided convincing evidence that, at least for several hours after the test meal was consumed, energy expenditure was significantly increased in the group consuming the highest amount of DCT. In fact, it was almost double that of the placebo group. This suggests that eating this pepper-derived substance that doesn't burn can have the same potential benefit as hot peppers at least in part by increasing food-induced heat production. They were also able to show that DCT significantly increased fat oxidation, pushing the body to use more fat as fuel. This may help people lose weight when they consume a low-calorie diet by increasing metabolism. 


However, that a limitation to this study was that, the researchers only tested the effect of DCT on the thermic response to a single meal. Heber and colleagues also point out that that there might be a different effect in lean vs. obese subjects. But to their credit, this was the first study ever conducted to examine the potential health benefits of DCT consumed together with a very low calorie diet....

Ref : Dr. David Heber et. al., FASEB Journal 

New study confirms 98.9% specificity of the T-SPOTspan TB assay

The study highlights the very high specificity of the T-SPOT.TB assay and confirms its utility in the identification of latent TB infection....

New study confirms 98.9% specificity of the T-SPOTspan style="vertical-align:super; font-size:80%;"®/span.iTB/i assay

Rib-X Pharmaceuticals to demonstrate three presentations at Antibacterial Drug Development Conference

Rib-X Pharmaceuticals, Inc, is presenting three separate presentations at the Cambridge Healthtech Institute's 4^th Annual Antibacterial Drug Development Conference, Resistance is Futile: The Challenge of Antibacterial Drug Development, April 27 - 28, in San Diego,

The presentations include overviews on radezolid (see below structure)  

delafloxacin  (see  right  structure) and the Company's proprietary platform for unlocking the bacterial ribosome, which has allowed for the design and generation of three novel classes of antibiotics that have been tuned for both multi-drug resistant Gram-negative and Gram-positive activity and have shown efficacy in multiple animal models of infection. 

Hope these results will  lead to relief from multi-drug–resistant infections (e.g., MRSA, uSSSI  and community acquired pneumonia,CAP).


Ref : http://www.rib-x.com/news_and_events/release_2010_04_12

Chokeberry extract reduces weight gain in insulin-resistant animals.....

Chokeberries (Aronia) are a great example of those fruits that both  taste good and show a number of health benefits for the body. Chokeberries' rich antioxidant content may be beneficial as a dietary preventative for reducing the risk of diseases caused by oxidative stress. Among the models under evaluation where preliminary results show benefits of chokeberry anthocyanins are colorectal cancer, chronic inflammation, gastric mucosal disorders (peptic ulcer),eye inflammation (uveitis) and liver failure cardiovascular disease.

Now Drs. Bolin Qin and Richard Anderson from the US Department of Agriculture in Beltsville, MD, have come up with some more interesting info about chokeberries, i.e., "chokeberry extract reduces weight gain in insulin-resistant animals". 

Qin and Anderson found that at the end of the study,  the rats consuming the chokeberry-spiked water weighed less than the controls; both levels of chokeberry had the same effect in this regard. Similar beneficial effects of chokeberry consumption were found for body fat (specifically, that of the lower abdominal region). They also discovered that animals that had been drinking chokeberry extract had lower blood glucose and reduced levels of plasma triglycerides, cholesterol, and low-density lipoprotein (LDL) cholesterol when compared to the control animals. These alterations would theoretically lead to lower risk for diabetes and cardiovascular disease in humans.

To add even more evidence for a healthful impact of this super-berry, the researchers documented numerous alterations in expression of genes that would likely lead to reduced chronic inflammation and perhaps even lower cancer risk. For instance, drinking chokeberry extract lowered expression of the gene coding for interleukin-6 (IL-6), a protein that normally triggers inflammation following trauma or infection. Chronic overproduction of IL-6 has been documented in many diseases such as diabetes, arthritis, and atherosclerosis and is thought to be a partial cause of these conditions.

Researchers conclude that though human trials are essential to further substantiate their claim,  they believe their study "provides evidence that the chokeberry extract inhibits weight gain in insulin-resistant animals and that it modulates multiple genes associated with adipose tissue growth, blood glucose regulation, and inflammatory pathways."....

Ref : Bolin Qin and Richard A Anderson, :  Abstract in FASEB, 

(those interested can read other benefits and other details at the link)

MIF (Macrophage migration Inhibitory Factor) - a new molecular target for the treatment of depressant and anxiety...

Clinical depression affects 121 million people around the world,  according to the World Health Organization, but only 60% to 80% of cases are effectively treated with current medication and psychotherapy.  Now researchers from Ecole Polytechnique Fédérale de Lausann, (EPFL), have come up with an interesting target, i.e., macrophage migration inhibitory factor, MIF. 

MIF(see strucutre : wikipedia : a pro-inflammatory cytokine that is expressed in the CNS) is normally thought to play a role in tissue swelling (inflammatory mediator possibly associated with rheumatoid arthritis,  RA-severity) and even cancer development (metastatic potential in speculative models of cancer), but its precise location and function in the brain remained a mystery before Carmen Sandi's (lead researcher) study. 

 The research team, first detected a concentration of MIF protein in stem cells in the hippocampus, (a key area for memory formation and neuron generation during adulthood). New neurons are thought to be linked to the creation of new memories but they may also play an important role in curbing anxiety  (previous studies have shown that prolonged periods of stress reduce neurogenesis, and many anti-depressants actually boost the production of new neurons).

By genetically and pharmaceutically manipulating the level of MIF in the hippocampus of rats, the researchers discovered that the absence of MIF significantly reduced the production of neurons and increased anxiety They also found that the lack of MIF decreases the ability of anti-depressants to stimulate neurogenesis. 

Researchers, identified  MIF expression in neurogenic cells  (in stem cells, cells undergoing proliferation, and in newly proliferated cells undergoing maturation) in the subgranular zone of the rodent dentate gyrus. A causal function for MIF in cell proliferation was shown using genetic (MIF gene deletion) and pharmacological (treatment with the MIF antagonist Iso-1 - see (right side) chemical structure : (S,R)-3-(4-Hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid, methyl ester) approaches. 

As per the claim by the researchers,  genetic deletion of MIF resulted in increased anxiety and depression-like behaviors, as well as of impaired hippocampus-dependent memory. Researchers conclude that,   MIF as a potentially relevant molecular target for the development of treatments linked to deficits in neurogenesis, as well as to problems related to anxiety, depression, and cognition....

Ref : Carmen Sandi et. al., Molecular Psychiatry, 23 February 2010

 

HAMLET (found in breast milk) may target molecules in specific membrane regions.....

We know that HAMLET (human α-lactalbumin made lethal to tumor cells) is a molecular complex of α-lactalbumin and oleic acid (see structure courtesy : Lunds Univ). It induces apoptosis in tumor cells, but normal differentiated cells are resistant to its effect . The activity of HAMLET was discovered by serendipity, while using human milk fractions to investigate bacteria adherence to lung carcinoma cell lines. In addition to blocking adherence, one milk fraction actually killed the cells by inducing apoptosis. Cell death was accompanied by changes in morphology, nuclear condensation, cytoplasmic blebbing, and formation of apoptotic bodies, similar to cells that undergo classical apoptosis.

Further studies showed that HAMLET comprises a protein and a fatty acid that are both found naturally in breast milk. So far, however, it has not been proven that the HAMLET complex is spontaneously formed in the milk. It is speculated, however, that HAMLET can form in the acidic environment of the babies´ stomachs. Laboratory experiments have shown that HAMLET kills 40 different types of cancer, and the researchers are studying  its effect on skin cancer, tumours in the mucous membranes and brain tumours. Importantly, HAMLET kills only cancer cells and does not affect healthy cells.

Although the substance was found several years ago, it is only now that it has been possible to test it on humans. Patients with cancer of the bladder who were treated with the substance excreted dead cancer cells in their urine after each treatment, which has given rise to hopes that it can be developed into medication for cancer care in the future.

Researchers at the University of Gothenburg are focussed on how HAMLET can be taken up into tumour cells. Researchers  lead by,  Roger Karlsson attempting to gain an in-depth understanding of how the substance interacts with cell membranes. 

In their study, researchers examined the interactions of HAMLET with in vitro generated membranes of known composition, and compared HAMLET to the native or partially unfolded, fatty acid free proteins. They also examined the effect of HAMLET on plasma membrane vesicles (PMVs) obtained from tumor cells. Researchers could show that HAMLET interacts with membranes and disturbs their integrity under physiological conditions. Binding to intact tumor cell membranes showed a patchy distribution, indicating that HAMLET may target molecules in specific membrane regions.

Researchers conclude that, HAMLET engages membranes by a mechanism requiring both the protein and the fatty acid. HAMLET binding alters the morphology of the membrane and compromises its integrity, suggesting that membrane perturbation could be an initial step in inducing cell death...

Ref : Roger Karlsson et.al.,  PLoS One., February 23, 2010

PA-824 - Aerosol: New Tool Against Tuberculosis?

We know the epidemic rates of HIV/TB coinfection as well as emerging multidrug-resistant  (MDR) and extensively drug-resistant (XDR) TB strains those are contributing to increased TB-associated deaths worldwide. 

Now PA-824 (see structure), a compound capable of being formulated into a dry powder, has not only shown promising activity against MDR (multidrug-resistant tuberculosis) and XDR (extensively drug-resistant tuberculosis, or latent TB) but has also proven safe and effective in patients coinfected with HIV and TB. Previous studies showed that PA-824 was well-tolerated in tablet form, however, side effects such as headache and stomach discomfort were reported. Aerosol delivery of PA-824 directly to the primary site of infection would limit systemic exposure and ultimately eliminate potentially bothersome side effects.

About  PA-824 :

Nitroimidazoles are widely used drugs in humans for a variety of primarily anaerobic microbial infections. Metronidazole, a 5-nitroimidazole, is an important bactericidal agent for the treatment of anaerobic infections  and shows excellent selective toxicity toward anaerobic bacterial and protozoal pathogens. This class of compounds has only recently begun to be explored for Mtb, because only anaerobic activity of metronidazole against Mtb has been reported. Bicyclic 4-nitroimidazoles such as PA-824 (a nitroimidazo-oxazine) and CGI-17341 (a nitroimidazo-oxazole) have inhibitory activity against aerobically growing and nonreplicating anaerobic Mtb. Although anaerobic conditions have not been demonstrated during TB disease in humans, various authors have suggested that an anaerobic microenvironment may contribute to a nonreplicating state that may be linked with latent disease in humans. Thus, PA-824 has been developed, in part, because it may be a promising lead for therapy against latent disease that may be linked to anaerobically persisting bacilli. The Global Alliance for TB Drug Development has recently initiated phase-I clinical trials with PA-824 

Researchers from the University of North Carolina School of Pharmacy, Chapel Hill, North Carolina; and Harvard School of Engineering and Applied Sciences, Cambridge, Massachusetts, lead by  Dr. Anthony J Hickey  have achieved this interesting finding, i.e., potential use of PA-824 dry powder aerosols in the treatment of TB.

In the study guinea pigs were used to evaluate the effects of PA-824 aerosols on TB infection. One month following infection with TB some guinea pigs received high daily aerosol treatments while others received low daily treatments for 4 weeks. Lung and spleen analysis of guinea pigs receiving the high dose of aerosol PA-284 showed less inflammation, bacterial burden and tissue damage.

"The present studies indicate the potential use of PA-824 dry powder aerosols in the treatment of TB,” say the researchers".

Ref : http://aac.asm.org/cgi/content/abstract/54/4/1436.

Chitosan could repair spinal damage - first evidence....

Polyethylene glycol (PEG) was reported to seal and repair damaged spinal cord nerve cells,  by repairing the damaged membranes of nerve cells. Researchers lead by  Richard Borgens and his team claimed that, PEG can restore the spinal cord's ability to transmit signals to the brain. However, there is one possible clinical drawback: PEG's breakdown products are potentially toxic. 

So, is there a biodegradable non-toxic compound that is equally effective at targeting and repairing damaged nerve membranes? Borgens teamed up with physiologist Riyi Shi and chemist Youngnam Cho, who pointed out that some sugars are capable of targeting damaged membranes. Borgens and his team  has  now come up with an interesting finding i.e.,  chitosan (see structure; source  : Wikipedia) can repair damaged nerve cell membranes. 

Having initially tested mannose and found that it did not repair spinal cord nerve membranes, Cho decided to test a modified form of chitin, one of the most common sugars that is found in crustacean shells. Converting chitin into chitosan, Cho isolated a segment of guinea pig spinal cord, compressed a section, applied the modified chitin and then added a fluorescent dye that could only enter the cells through damaged membranes.  Viewing a section of the spinal cord under the microscope, Cho was amazed to see that the spinal cord was completely dark and none of the dye had entered the nerve cells and Cho concluded that Chitosan had repaired the damaged cell membranes.

Borgens is extremely excited by this discovery that chitosan is able to locate and repair damaged spinal cord tissue and is even more enthusiastic by the prospect that nanoparticles of chitosan could also target delivery of neuroprotective drugs directly to the site of injury.

'giving us a dual bang for our buck,' says Borgens....

 Ref :  http://jeb.biologists.org/cgi/content/full/213/9/i-a

Positive results from second phase 3 Study of Fidaxomicin for the treatment of Clostridium difficile Infection..

Fidaxomicin  is the first in a new class of narrow spectrum macrocyclic  antibiotic drugs.  It is non-systemic (minimally absorbed into the bloodstream)  bactericidal, and  has demonstrated selective eradication of pathogenic Clostridium difficile with minimal disruption to the multiple species of bacteria that make up the normal, healthy intestinal flora. The maintenance of normal physiological conditions in the colon can reduce the probability of clostridium difficile infection recurrence.

Now Optimer Pharmaceuticals, Inc.,  announced the top-line results from its second fidaxomicin Phase 3 clinical study in patients with Clostridium difficile infection (CDI) at the 20th Annual European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) in Vienna, Austria. 

As per the claim by the company, in the trial, fidaxomicin met the primary endpoint of non-inferiority in clinical cure compared to Vancocin®.  Importantly, fidaxomicin also had significantly lower recurrence rates compared to Vancocin (p = 0.002), and significantly higher global cure rates (defined as cure with no recurrence within four weeks of completing therapy) compared to Vancocin (p < 0.001).  Interestingly  the se robust results from this second fidaxomicin Phase 3 trial confirm the results from the first fidaxomicin Phase 3 trial.  Together these trials enrolled more than 1,100 subjects thus making them the two largest comparative studies ever conducted against Vancocin in CDI.

"Fidaxomicin offers potential advantages over existing therapies as a single agent that can provide a high cure rate and fewer recurrences for Clostridium difficile infection," said Dr. Crook, M.D., Consultant Microbiologist/Infectious Diseases and Professor of Infectious Diseases and Microbiology, Experimental Medicine Division, Nuffield Department of Clinical Medicine (NDM), University of Oxford"...  

Ref :  http://www.optimerpharma.com/news.asp?news_story=113&page_num=

Anti-cancer agent stops metastasis in its tracks....

Like microscopic inchworms, cancer cells slink away from tumors to travel and settle elsewhere in the body. Now, researchers at Weill Cornell Medical College, have found  that new anti-cancer agent, i.e., macroketone (see structure) break down the loping gait these cells use to migrate, stopping them in their tracks.

As per the claim by the lead researcher, Dr. Xin-Yun Huang, a professor in the Department of Physiology and Biophysics at Weill Cornell Medical College, mice implanted with cancer cells and treated with the small molecule macroketone lived a full life without any cancer spread, compared with control animals, which all died of metastasis. When macroketone was given a week after cancer cells were introduced, it still blocked greater than 80 percent of cancer metastasis in mice. He further adds that, these findings provide a very encouraging direction for development of a new class of anti-cancer agents, the first to specifically stop cancer metastasis. 

Dr. Huang and his research team have been working on macroketone since 2003. Their work started after researchers in Japan isolated a natural substance, dubbed migrastatin, secreted by Streptomyces bacteria, that is the basis of many antibiotic drugs. The Japanese researchers noted that migrastatin had a weak inhibitory effect on tumor cell migration. After a lot of modifications, researchers made several versions that were a thousand-fold more potent than the original. In 2005, they published a study showing that several of the new versions, including macroketone, stopped cancer cell metastasis in laboratory animals, but they didn't know how the agent worked. 

Interestingly, in the current study, the researchers revealed the mechanism. As per the claim  macroketone targets an actin cytoskeletal protein known as fascin that is critical to cell movement. In order for a cancer cell to leave a primary tumor, fascin bundles actin filaments together like a thick finger. The front edge of this finger creeps forward and pulls along the rear of the cell. Cells crawl away in the same way that an inchworm moves. Macroketone latches on to individual fascin, preventing the actin fibers from adhering to each other and forming the pushing leading edge Because individual actin fibers are too soft when they are not bundled together, the cell cannot move.

Researchers conclude that, the new animal experiments detailed in the study confirmed the power of macroketone. The agent did not stop the cancer cells implanted into the animals from forming tumors or from growing.

"This suggests to us that an agent like macroketone could be used to both prevent cancer spread and to treat it as well," Dr. Huang says. "Of course, because it has no effect on the growth of a primary tumor, such a drug would have to be combined with other anti-cancer therapies acting on tumor cell growth."

 Ref : http://weill.cornell.edu/news/releases/wcmc/wcmc_2010/04_14_10.shtml