There have been several interesting reports from around the world over the past six weeks, although none meets the same “gold standard” for clinical research as the randomized, placebo-controlled clinical trial on neem toothpaste that we reported on in January.
Inflammatory Bowel Disease*: First, a report on nimbolide and experimental colitis recently appeared in 
Phytotherapy Research. Nimbolide—a compound extracted from neem leaves that displays a variety of biological activities —was first brought into the laboratory in the mid-1980s. There was just a handful of studies over the next 20 years, then suddenly in 2005, interest in nimbolide came to life. There have been about 50 studies in this past decade. This most recent study focused on nimbolide’s anti-inflammatory properties in the context of mice bred to develop colitis. Some of these mice developed acute disease, and some of them developed chronic colitis. Nimbolide treatment quieted the inflammatory pathways involved in developing and maintaining colitis, and suppressed the body’s production of the inflammatory biochemicals that lead to symptoms. It reduced weight loss, colon shortening, and disease activity index scores in these mice. “These results suggest nimbolide could be a potentially new treatment for inflammatory bowel disease,” the investigators said.
Dengue Fever* — Using new technology, another report is an “in silico” study published in the Journal of Vector Borne Diseases. This term—a word play on the silicon used to manufacture computers—refers to research conducted or produced using computer simulation or modeling. Making the computer such a central element is hoped eventually to speed the rate of discovery while reducing the need for expensive lab work and clinical trials.
This study—which focuses on dengue fever, a difficult-to-treat viral infection and health problem in tropical parts of the world—looks at how five chemical compounds found in neem react at the molecular level with a critical enzyme in the virus that causes it. Taking this particular enzyme out of action could disable the virus and eliminate the infection. Using a technique called molecular docking, researchers discovered that three of the five tested compounds (nimbin, desacetylnimbin and desacetylsalannin) bind with this viral enzyme (a protease) and inhibit its function, and thus can be considered potential inhibitors of dengue fever for further development. Ironically, two of neem’s most recognized compounds—azadirachtin and salinnin—did not show any interaction with the target protease.
Oral Bacteria* — A study published in the peer-reviewed Open Dentistry Journal compares the effect of neem extracts to the herbs myrrh and licorice and to the antibiotic chlorhexidine against a bacteria often found in teeth after root canal procedures. Although neem didn’t perform as well as chlorhexidine, while the myrrh actually outperformed the standard antibacterial agent by a tiny amount, neem was much more effective than the control-group treatment. This indicates that it may be a useful alternative in cases where chlorhexidine is contraindicated.
Liver Cancer* — We are always particularly happy when researchers look at neem’s efficacy compared to standard treatments that often have highly adverse side effects. One such study, published in Zeitschrift für Naturforschung C (A Journal of Biosciences) by a team of researchers from the U.S. and China, evaluates the effect of neem tree extract on liver cancer in mice. They injected susceptible mice with human liver cancer cells, then divided them into 3 groups for the next 27 days. One got the experimental treatment, neem tree extract (NTE), daily. These mice were assigned to one of 3 different dose levels. Then there were two control groups. One of them was a “blank” control. They received an inert substance normally used to lubricate dry eyes. The active control group was given cyclophosphamide, a common (and harsh) chemotherapy drug. Liver tumors were evaluated after the 27 days of treatment. The mice in both active treatment groups—the three NTE doses and standard chemotherapy—had significantly fewer and smaller tumors than the mice in the blank control group. Even more encouraging was that the NTE mice on the highest dose had a much better survival rate than either of the control groups. Looking more closely, the researchers found that—in contrast to chemotherapy drugs—neem was highly targeted. It was not only much more destructive to the cancerous liver cancer cells than the cyclophosphamide, but it left healthy liver cells alone. And there was yet another benefit to the high-dose NTE. The thymus and spleen—important parts of the immune system—were in better health. This “indicated that NTE could facilitate the growth of immune organs,” the researchers said, adding that the combination of results “indicates that NTE is a promising candidate for antitumor treatment with high efficacy and safety.”
As always, journal links in this report connect to either abstracts from the publication or to the full report if it’s not protected by copyright. Please contact vicki@neemtreefarms.com with questions or comments.
* IMPORTANT NOTE: These statements have not been evaluated by the U.S. Food and Drug Administration. All material included in this document is provided for educational purposes only. Consult a physician or health care professional before using any herbal medications. Neem Tree Farms does not sell products which are intended to diagnose, treat, cure or prevent any disease, or to kill or repel any insect on humans or animals. The research presented on this site is not intended to diagnose, treat, cure or prevent any disease. Results of user testimonials may not be typical. We accept no liability for information provided regarding the uses of neem as described here.