NEWS AND VIEWS

NEWS AND VIEWS

Fumagillin fights intestinal microsporidiosis

esearchers have reported that fumagillin – a drug first used more than 40 years ago to combat intestinal amoebiasis – is very effective against Enterocytozoon bieneusi, the causal agent of intestinal microsporidiosis in immunocompromised patients.
        Jean Michel Molina and co-workers, gave either a placebo or 60 mg fumagillin per day orally for 2 weeks to two groups of six immunocompromised patients with intestinal microsporidiosis. The effect of the drug on the parasite was measured by checking patients with stools for microsporidia, which disappeared from all of those treated. When the original placebo patients, in whom infection continued, were eventually given open label fumagillin, their stools too became microspodia-free. Two HIV patients from the originally treated group relapsed, although one was cured by a further course of fumagillin.
       Despite being around for a long time, no one knows how the drug works; studies suggests it irreversibly inhibits methionine aminopeptidase 2.
       Although this type of infection in HIV patients due to the success of HAART, this is still good news since antiviral therapy takes time to work.

September 2002,The lancet Vol. 2

*******

Snake venom can prevent heart attacks

he scientists at the Indian Institute of Chemical Biology, Kolkata have isolated organ specific haemorrhagic chemicals from Snake Venom that target lung, eye, brain and intestine. In their latest study, they purified a haemorrhagic that specifically causes bleeding of skin and muscle. The toxin, which the researchers called VRR-73 has a relative molecular mall of 73000. In laboratory tests VRR-73 has been found to be even better at breaking down fibrin than urokinase, a standard drug currently used to dissolved the blood clots that lead to heart attacks.

When the blood of experimental mice was injected with 2 mg of VRR-73, it did not clot even after 180 seconds, whereas clotting occurred in less than 90 seconds in control animals that did not receive the drug. The mechanism of the fibrin by activating a chemical called plasminogen. Production of this clot buster is being planned through genetic engineering.

May-June 2002, Natural Product
Radiance

*******

Genetic diversity challenges malaria control

wo new studies suggest that plasmodium falciparum is both ancient and generally diverse, a finding that looks set to be important in the development of antimalarial drugs and vaccines.
            Xin-Zhuan Su and colleagues have found a relatively high level of diversity in single nucleotide polymorphisms (SNPs) at “silent” (non-coding) sites, which, Su says, “is consistent with a common ancestry [of P falciparum] about 100000- 180000 years ago-” about the time that the human population began to spread around the world.
            Chloroquine esistance was first reported 45 years ago in two foci in Southeast Asia and South America. Since then, says Su “resistance has spread very fast through the population”. The researchers saw remarkably little diversity in the pfcrt chloroquine-resistance gene among chloroquine-resistance strains, a finding that might seem to support the bottleneck hypothesis, had not the authors found substantial variability in pfcrt in chloroquine-sensitive isolates and in more than 300 polymorphic microsatellite markers elsewhere in the parasite’s genome.They confidently attribute the spread of resistance to “strong directional selective sweeps [in response to the use of chlorine] occurring over only about 20-80 generations”- equivalent to about 6-30 years in endemic areas. This observation, the authors say, “emphasis the profound influence of chloroquine on recent P falciparum evolution”.
            Just as importantly, findings evidence of natural selection on particular parts of the genome can help identify potential new targets for chemotherapy or vaccination”.

September 2002,The lancet Vol. 2

*******

Yoga for pain relief

or those whose chronic pain can’t be quelled with medication, physical therapy, or other traditional methods, research now suggests there may be another way: yoga. Scientists from the Cleveland Clinic Foundation in Ohio recently looked at yoga’s effect on 18 people suffering from such problems as low back pain, carpal tunnel syndrome, and arthritis, putting them through three 90 – minute sessions a week for 4 weeks. By the end of the treatment, which involved a combination of yoga body moves called asanas and controlled, meditative breathing exercises called pranayamas, the investigators found that yoga not only alleviated the volunteers’ pain but also improved their moods and decreased their requirement for various pain medications. Over time, improvements in pain are seen.

Jan-Mar 2002, Probe Vol. XLI

*******

Scientists join smallpox vaccine controversy

cientists on both sides of the Atlantic have attacked a US report claiming that the New York City Board of Health (NYCBH) smallpox vaccine (vaccinia virus) should be the strain of choice for stockpiling against a possible bioterrorist attack.
The report concludes that any vaccine against a smallpox attack should use derivatives of the vaccine strains that were successful during the eradication campaign – ie, NYCBH, not Lister strains, which were “mainly viewed as maintenance vaccines”.
“The report looked rather biased, as though it had been written on behalf of a pharmaceutical company”, adds John Oxford. “Differences in the efficiency of vaccines used at different times in the eradication campaign are not explicable by the strain of vaccines used. Many factors were involved”. Of the potential bioterrorism threat from Soviet-derived smallpox material, Oxford says, “I don’t buy that ……..We simply don’t know where a new threat might come from”.

September 2002,The lancet Vol. 2

*******

Mystery Anti-HIV factor unmasked

ixteen years ago, in the relatively early days of the AIDS epidemic, virologist Jay Levy of the University of California (UC), San Francisco, proposed an answer to one puzzle about the AIDS virus and created another. He had tantalizing evidence that immune system cells secrete a chemical that can stop HIV, and he suggested that HIV-infected people who have high levels of this factor could live for decades without damage to their immune systems.
              In the study, the Aaron Diamond researchers teamed up with scientists from Ciphegen Biosystems Inc. in Fremont, California, to compare secretions of CD8 cells from three HIV-infected “long term non-progressors,” four HIV-infected “progressors,” and 15 uninfected people. Ciphergen makes tiny arrays of proteins that, with the help of mass spectrometry, allowed them to analyze the components in each sample. Company scientists found that only the long term nonprogressors and uninfected people produced three small, related proteins that a database search revealed as defensins.
            At first reported by Lehrer, human defensins are secreted primarily by neutrophils and break down bacterial walls, acting like natural antibiotics. A group in Japan 9 years ago showed that defensins from guinea pigs, rabbits, and rats could inhibit HIV, but the work received little notice. Some AIDS researchers also have incorporated defensins into their vaccines because the molecules can act like an adjuvant, boosting the immune response to the HIV components of the preparation.
            When Ho and his colleagues depleted the defensins in the secretions from the long-term nonprogressors, they found that the secretions had markedly less anti-HIV activity. And when they depleted both defensins and immune messengers known as b-chemokines – which Gallo’s lab in 1995 showed powerfully prevent HIV entry into cells – the secretions had almost no antiviral activity. In what’s sure to be the paper’s most controversial assertion, the researchers state that the a-defensins “collectively account for the anti-HIV-1 activity of CAF that is not attributable to b-chemokines.” As for the mechanism, Ho and Zhang say the shortage of clean defensin material makes it difficult to conduct experiments that might tease out how it combats HIV. But they have now begun those experiments.

September 27, 2002, Science Vol. 297

*******

Mint has male antifertility activity

int, Mentha arvensis Linn. Is known to be used as an abortifacient by tribal women. It is also known to be effective in the prevention and interruption of pregnancy in the experimental mammals. The effect of mint on male fertility was also studied and it is reported that the aqueous extract of the leaves possesses antispermatogenic property. Recently investigation on the effect of petroleum ether extract of Mint leaves on fertility and toxicity in male albino mice has been done by Sharma and Jacob at University of Rajasthan. It is reported that at the doses of 10 and 20 mg/mouse per day for 20, 40 and 60 days, when administered orally, showed a dose and duration dependent reduction in the number of offspring of the treated male mated with normal females. Negative fertility was observed in both regimens after 60 days of treatment. The body weight and libido of the treated animals remained unaffected. However, a significant decrease in the weight of testis, epididymis, cauda epididymal sperm count, motility, viability and normal morphology of the spermatozoa was observed. The levels of serum protein, bilirubin, GOT, GPT, and acid phosphatase, blood urea and haematological indices were unaltered throughout the course of investigation. All the altered parameters were reversible following withdrawal of treatment. Thus crude petroleum ether exacts of Mint leaves possibly exerts a reversible antifertility.

May-June 2002, Natural Product Radiance

*******

Pure cocoa powder contains cancer prevention polyphenols

he seeds of Cocoa (Theobroma cacoa Linn.) are used as ingredients for various ice-cream, puddings, beverages and many bakery products. They are reported to be rich in polyphenols. Now-a-days polyphenols have gained considerable attention because of their antioxidant, antimutagenic and cancer preventive activities; some polyphenols may reduce the risk of coronary heart disease. Reportedly one of the mechanism responsible for these effects involves their inhibition of the oxidation of low-density lipoprotein (LDL). The studies conducted on analysis of polyphenols in cacoa and chocolate revealed that pure cocoa powder contains more polyphenols. However, further experiments are required to conclude the role of cocoa products in controlling certain diseases.

Jan-Feb 2002, Natural Product Radiance

*******

Bacteria Shared Photosynthesis Genes

istorically, sun-loving microbes that converts solar energy to biomass, it seems, were quite promiscuous: They readily swapped DNA. Since then, they have been basking in the light for hundreds of million of years, adding life-supporting energy and oxygen to the environment and making possible the variety of organisms on Earth today. Early on, these species were remarkably free, as researchers explain on page 1616, in sharing the photosynthesis genes that enable them to draw energy from sunlight – so free that it’s hard to use these genes to trace the microbes ancestry. “There’s been massive horizontal gene transfer” among these organisms, says co-author Robert Blankenship, a biochemist at Arizona State University in Tempe.
            Until about 5 years ago, researchers considered the transfer of genetic material from one species to another an oddity. Since then, have moved around quite a bit. Even so, microbiologists assumed this would not be true for genes involved in translating DNA to RNA, for example, or sunlight to biomass; they couldn’t see how genes of such mixed ancestry could possibly coordinate these complex processes.
            In the summer 2001, graduate student Jason Raymond and his colleagues began to analyse the genome sequences of one organism from each of the five photosynthetic groups: a cyanobacterium, a filamentous green bacterium, a purple bacterium a green sulfur bacterium, and a helio bacterium. Comparing the five genomes using several computer programs, including one called BLAST, they found 200 genes that were common to all.
            Among those 200 shared genes, Raymond and his colleagues found about 50 photosynthesis genes.
            The photosynthesis genes the researchers identified provided other clues to the microbes’ photosynthetic past.

November 22, 2002, SCIENCE Vol 298.

*******

Green tea may prevent and cure Alzheimer’s disease

rolyl endopeptidase (PEP) which is a serine protease has been found to be more active in Alzheimer’s patients than that in a normal person. As a result, scientists postulated that PEP inhibitors have already been isolated from microbes but not from plant sources. Kim and his colleagues at Department of Agricultural Chemistry, College of Agriculture, Kyungpook National University, South Korea while searching PEP inhibitors from edible plants, found that ethyl alcohol soluble fraction of green tea leaves showed significant activity.
The isolated compounds are expected to be useful for preventing and curing of Alzheimer’s disease.

July-August 2002, Natural Product Radiance

*******

Watered Down

ater shortage might be threatening agriculture, but it is proving beneficial for the environment in some ways. A study by researchers from Durham-based University of New Hampshire indicates that using less water for paddy cultivation worldwide has reduced methane emissions by around 12 percent.
As a result of water shortage, farmers in many parts of the world drain rice fields several times during a crop season, instead of leaving them flooded. The researchers calculated the impact of this practice, along with other agricultural management changes, on methane emissions. They found that, in China alone, the amount of tonnes between 1980 and 2000. Since china produces about a third of the world’s rice, this makes a significant difference globally.
According to the researchers, the findings are noteworthy. “Improving water use efficiency of agricultural practices can reduce methane emission,” says Changsheng Li, the lead author of the study.

December 13, 2023 Down To Earth

*******

Germinated seeds to reduce wrinkles in the skin

he main products that have been used to prevent skin ageing and as hair tonics are hydrolysed placenta and other animal derivatives. Now animal products are being replaced by plant products, which act in the same way as placenta extract. In this context, Benaiges and others from Spain evaluated the activity of germinated seeds extract (GSE) on cell metabolism in order to study the suitability of this extract as a cosmetically active product.

The synthesis of new molecules takes place more and more slowly as the number of fibroblasts falls with age, protein synthesis loses momentum and the compounds necessary for such synthesis are not so readily available. In the same way, the structure of the fibres that already exists is altered, causing the appearance of cutaneous flaccidity and wrinkles in the skin. Focussing on that idea, these scientists developed a new plant extract obtained from germinated seeds of Alfalfa, Radish, Wheat and Soybean. GSE comprises a set of bioactive molecules which could be capable of penetrating the innermost layers of the skin and providing the necessary energy to increase synthesis of collagen, elastin and glycosaminoglycans, thus having a beneficial effect on the skin by preventing the delaying the appearance of the clear signs of ageing (wrinkles). This bioactive complex could also be used in hair products due to a revitalizing action and an enhancement of protein synthesis. Thus the germinated seeds present a source for new potential active ingredients for cosmetics.

July-August 2002, Natural Product Radiance

*******

Dendritic cells show self-control

endritic cells (DCs) are increasingly being recognized for their ability to shut down some types of immune response and for contributing to the state of immune tolerance. Elucidation of putative tolerogenic DC subsets is under way, although the mechanisms by which these cells might modulate immunity have yet to be established. Munn et. al. (p. 1867) now describe a subset of human DCs that can inhibit T cell responses, at least in vitro, to alloantigens through the catabolism of tryptophan by the enzyme indoleamine 2,3 – dioxygenase (IDO). It is known that IDO can prevent antigen – specific responses of T cells in vivo, as well as in vitro. The present demonstration that a subset of human DCs can inhibit T cell responses via IDO in vitro makes it plausible that these cells might use the same mechanism in vivo. Whether DCs actually regulate immune responses to self – antigens, transplants, and tumors by this mechanism remains to be established.

September 13,2023 SCIENCE Vol. 297

*******

Clitoria improves memory

litoria ternatea Linn. Is widely used in the traditional system of medicine as a brain tonic and is believed to promote memory and intelligence. Scientists at KLES College of Pharmacy, Belgaon Karnataka examined the effectiveness of alcoholic extract of this plant at 300 and 500 mg/kg doses orally in rats attenuating electroshock-induced amnesia. Extracts at 300mg/kg dose produced significant memory retention and the root parts were found to be more effective.
Root parts are found to be more effective in attenuating memory deficits as compared to aerial parts. The mechanism by which this plant produced memory retention appears to be similar to the standard drug pyritinol, since aerial parts, root parts and pyritinol have similar influence on cholinergic activity of the brain.

Mar-Apr 2002, Natural Product Radiance

*******

Gene therapy a suspect in leukemia-like disease

French gene-therapy team that was hailed in 2000 for its breakthrough in curing children of a lethal immune deficiency reported a serious adverse event this week. One of 10 children they treated has developed a blood disorder resembling leukemia. Concerned that the therapy might have caused the problem, researchers Alain Fischer and Marina Cavazzana-Calvo of the Necker Hospital in Paris have halted the trial and urged others who use similar methods to hold off until the risks are assessed. At press time, French regulatory officials were preparing a public advisory.
            This French trial was designed to identify children with a type of severe combined immunodeficiency (SCID) caused by a mutation on the X chromosome and to treat them early. So far, the team has treated nine infants and one teenager. All faced the prospect of lethal infections or harsh therapy such as bone marrow transplantation, which itself often has fatal consequences. Gene therapy offered a way out; in most cases it restored the immune system without toxicity.
            During a routine check of their fourth patient last spring, however, the French researchers noted that the child had a high number of gd T cells in his blood. The import didn’t hit home until late August, Fischer says, when the T cell count climbed “very high” – to 200,000 cells per microliter. Other symptoms also appeared, including mild anemia and the child was hospitalized.
            Although gene therapy probably contributed to the patient’s T cell response, Fischer says, other factors probably played a role, too. For example, the child might have been predisposed to disease, as other members of his family have had childhood cancers. And an infection might have been important as well; the child got chickenpox shortly before his T cell count spun out of control. But at the moment, Fischer acknowledges, it’s not clear whether this was a “very unlucky” random event or a sign that the risk of using retrovirus vectors has been “underestimated” in the past.
            Few gene therapy researchers were available to comment on the case at press time. But Jennifer Puck, leader of the planned SCID therapy trial at NIH, knows of four other groups that are using or were planning to use similar gene-therapy techniques. At the moment, she says, “we don’t know whether the risks [of insertional mutagenesis] are one in 80 or one in 100 million.”
            US regulatory officials declined to comment on the case. But NIH’s Recombinant DNA Advisory Committee is reported to be preparing a broad review of the case at its next meeting scheduled tentatively for 4 to 6 December.

October 4, 2002, Science Vol. 298

*******

Hard facts about soft drinks

oft drinks are junk food-sugary drinks that are high in calories but supply no nutrients. They now account for at least 27% of refined sugar consumption. Soft drinks are available everywhere, and the standard 6-ounce Coke bottle of the 1950s has been replaced by jumbo sizes-upto 64 ounces. Obviously a soda now and then won’t hurt anybody. But what about habitual consumption? Here are answers to some of your questions:
Will soft drinks make me fat? As soft drink consumption has increased in this country, so have obesity rates, but soft drinks are not necessarily the culprit, or the only culprit. A 12-ounce cola contains the equivalent of 10 teaspoons of sugar and 150 calories. If you are consuming – and burning – 2,000 calories a day and you add one soft drink to your daily diet with no other changes in intake or physical activity, you’ll gain weight.
Do sugary soft drinks cause tooth decay? Dental caries (cavities) actually have decreased in this country as soft drinks consumption has risen. But the decrease is due to many things – notably widespread fluoridation of water, fluoridated toothpastes, and better dental care.
Does soda increase the risk of bone fracture? If so, it’s probably because those who consume a lot of soft drinks are likely to consume less milk, leafy greens, and other calcium sources. Everyone under age 25, especially teenage girls, need a high calcium intake to build strong bones for later years; those over 50 also need high levels of calcium (at least 1,200 milligrams a day).

Jan-Mar 2002, Probe Vol. XLI

*******

Spirulina is good for reducing blood glucose level

he increased rate of diabetes mellitus throughout the world has made it impressive for dieticians to find out suitable diet, which can help in reducing blood glucose level in patients. Spirulina-a microalga has been found to be a good food supplement which reduces the blood sugar level. A study was carried out on non-insulin dependent diabetic patients in the age group of 40-60 years. Four grams of Spirulina per day was given to them for a period of 60 days was to them for a period of 60 days. This study confirmed that Spirulina has a hypoglycaemic effect on non-insulin dependent diabetics.

Jan-Feb 2002, Natural Product Radiance

*******

Soy protein isolate and its hydrolysate are good for reducing genetical obesity

t is well known that soy protein has a better hypocholesterolemic effect when compared with animal proteins such as casein. Also the studies have shown that milk whey protein, in contrast to milk casein, decreased serum cholesterol in the same as soy protein. A seeding trial on obese animals conducted by Japanese scientists revealed that soy protein and its peptide are more effective than milk casein in reducing the body fat while maintaining the body protein. In order to confirm the anti-obesity action of soy protein isolate (SPI) and its hydrolyzate (SPI-H) Aoyama and his team studied and compared action of SPI and SPI-H with the corresponding milk whey protein and SPI-H in genetically obese (yellow KK) mice. The results of their study indicated that soy protein and its peptide are appropriate protein sources for weight reduction and it is a good dietary mean to treat diabetes mellitus.

Jan - Feb 2002, Natural Product
Radiance

*******

Some facts about coffee drinking and pregnancy

· Its perfectly safe for pregnant woman to consume coffee/caffeine. Daily consumption of up to 200-400 mg/day has shown no adverse effect.

· Caffeine consumption during pregnancy does not cause any birth defects.

· Caffeine consumption has no effect on intrauterine growth of the foetus.

· Caffeine is not among the risk factors associated with delayed or decreased fertility.

· Consumption of coffee and other caffeinated beverages by mothers before, during or after delivery did not increase the risk of Sudden Infant Death Syndrome (SIDS).

· There is no association between caffeine intake and breast cancer.

Jul-Aug 2002, Natural Product Radiance

*******

Genetic diversity challenges malaria control

*******

Yoga for pain relief

Mystery Anti-HIV factor unmasked

Green tea may prevent and cure Alzheimer’s disease

*******

BACK