Another anti-myeloma compound: pristimerin

Remember my post/page on celastrol (from the thunder of god vine)? Well, for a memory refresher, you can scroll down my Pages to the one titled: Other anti-myeloma/cancer substances.


At any rate, a few weeks ago, looking through the table of contents for the April 23 edition of “Blood,” I came across a study discussing a related compound (Sherlock, grazieee!, sent me the full study): pristimerin, a naturally-occuring substance that has strong anti-myeloma activity. See abstract:


Since one of the proliferation factors involved in myeloma is cyclin D, a group of researchers from different cancer institutions conducted high-throughput chemical library screens for compounds that induce suppression of cyclin D2 promoter transcription. The top-ranked compound was a natural triterpenoid, pristimerin.


A natural triter…huh? No worries, I looked it up. Triterpenoids (hehe, try saying “triterpenoid” ten times FAST!) are biologically active, anti-inflammatory, anticancer and antioxidant compounds extracted from many plants, e.g. from the Celastrus and Maytenus species. Remember my posts/pages on glycyrrhizin, ursolic acid, betulinic acid, celastrol and oleanolic acid? Well, these substances are triterthingies, too. Okay, with that matter cleared up, let’s give this thing a go.


From the abstract we learn that pristimerin strongly inhibits proteasomes. (Ah, just like bortezomib and, ta-da!, curcumin.) In fact, I found a 2008 study on that very topic: The abstract tells us that pristimerin has been used for ages in folk medicine as an anti-inflammatory remedy. Now, where have I heard THAT before…? Anyway, in addition to killing breast cancer cells, pristimerin also targets proteasomes in prostate cancer cells. Well, well…


Okay, back to the April 2009 “Blood” study. Interesting titbit: pristimerin’s anti-proteasome activity occurs even at low concentrations. Furthermore, this substance inhibits our old enemy, hyperactive NF-kappaB, as well as cyclin D expression. In fact, it does such a good inhibiting job that the researchers make the following statement: As a consequence, pristimerin induces selective myeloma cell apoptosis in vitro and in vivo with greater potency than that described for other antineoplastic triterpenoids such as celastrol or CDDO, which are currently in clinical trials. Not bad, eh…


Okay, let’s get to the good stuff. In lab tests, pristimerin caused substantial suppression of all the cyclin D proteins. Even myeloma-friendly cytokines such as IL-6 could not protect myeloma cells from certain death. Hah!


Pristimerin was tested in vivo, too…specifically, on…gee, one guess!…nude mice with implanted plasmacytomas. The first experiment showed that high doses of pristimerin were too toxic…the mice had to be put out of their misery. So the researchers developed a liposomal formulation, which turned out to be less toxic and better tolerated in a second mice-based experiment. Result: Statistically significant tumor growth inhibition occurred at pristimerin doses of 2 to 3 mg/kg intravenously twice weekly, compared with vehicle-treated mice.


Pristimerin also worked in synergy with bortezomib. The two substances alone were less effective than when combined.


In the study’s Discussion, the researchers declare that pristimerin possesses substantial antimyeloma cytotoxic activity […] with a potency more than 10-fold that of CDDO or betulinic acid for solid organ malignancies, and more than 2- to 3-fold that of CDDO for multiple myeloma,39 and that pristimerin is synergistically cytotoxic with bortezomib, perhaps the most active antimyeloma agent in the clinic today.


Further on, they add that Uniquely, we find that pristimerin induces significant proteasome inhibition, which likely contributes to both its inhibition of NF-kB pathway signaling and specific cytotoxicity in myeloma. To our knowledge, no other triterpenoid has been demonstrated to inhibit proteosome function, although such activity could perhaps account for some of the activities of cytotoxic triterpenoids. Using in vitro and in vivo studies, we demonstrate that pristimerin causes selective antimyeloma cytotoxicity, within a therapeutic window, identifying it as a lead compound for the development of enhanced triterpenoid-derived anticancer pharmaceuticals.


They also raise the possibility that pristimerin might be able to overcome myeloma’s well-known ability to become resistant to conventional treatments.


Well, this is simply an introductory report on yet another promising anti-myeloma substance extracted from plants. Clearly, more research and testing are needed…and no, I am not ready to fly to China, hunt down and munch on the roots of Celastrus hypoleucus, a pristimerin-containing plant…nope, not yet!


A few links to pristimerin studies


1. “Antiproliferative activity of pristimerin isolated from Maytenus ilicifolia (Celastraceae) in human HL-60 cells,” 2008:

2. Triterpenoids and doxorubicin, 2006:

3. Anti-cytomegalovirus activity of pristimerin, 2007:

4. Antifungal properties of pristimerin and celastrol, 2005:

5. More information on triterpenoids, 1986:

You’ve got a friend

My cousin (thanks a bunch!) sent me the links to a some extraordinary “sand art” videos. I was so mesmerized that, even though I am in the middle of a serious bit of research right now, I paused to watch four of these magical performances, including “Ocean.” Wow. 

Start with these two: and

Oh, by the way, I finally went to Careggi Hospital at the break of dawn this morning to hand in my 24-hour urine samples and have my blood tests done. Yay! Even though by the time I arrived there were already 50 people in front of me (!), the whole shebang took less than two hours…not bad at all. I should have my results in early June (I am having them mailed to my house, so it is impossible to know when exactly they will arrive). Good or bad, I will post the most significant ones, as is my wont. Today I am going to stop taking feverfew (I am down to my last five feverfew pills, anyway!). Until I decide what my next experiment will be, I will continue to take curcumin capsules (8 grams/day), quercetin (1 gram/day) and fish oil (4 grams a day).

Curcumin and cachexia

Today, while doing research on something different, I came across an abstract (see: that may be of interest to some of you.


Cachexia is a syndrome that unfortunately affects about 50% of cancer patients and, in general, people with chronic diseases such as AIDS or COPD. Symptoms are: progressive weight loss, muscle atrophy, fatigue, anemia, weakness and loss of appetite. The body basically stops absorbing nutrients. No matter how much you eat. From the little I read just now, this condition cannot be easily reversed…


Well, things may soon change. According to this recent study, in fact, curcumin didn’t just prevent weight loss in mice with colon tumours but also—in higher doses— resulted in approximately 25 % (P < 0.05) weight gain as compared with the placebo-treated animals. Holy cats!


In other words, curcumin prevented AND was even able to reverse cachexia. Another feather in curcumin’s impressive (and, by now, very large!) cap…

Oasi Stagni di Focognano

Yesterday my computer decided it needed a rest and refused even to boot…unfortunately Stefano couldn’t fix it until today…which reminds me how lucky I am to be married to a computer genius…oh, and speaking of being married to a genius (not just in the field of computers, by the way) and whatnot, yesterday was our 10th wedding anniversary. WOW! 10 years…already…

I have to say, though, that we were so tired last night that we didn’t do anything much out of the ordinary…but since cimg_0108heesecake is one of Stefano’s favourite sweets, day before yesterday I prepared a scrumptious New York style cheesecake, and last night we brought pizzas home for dinner (I usually make my own pizza with herbs…but not on my anniversary!).

Then, this morning, while my computer was mulling things over (Stefano launched a “get-your-act-together-or-else!” program that needed to run for hours), we went to a WWF oasis right outside of Florence, in the municipality of Campi Bisenzio: Oasi Stagni di Focognano. It’s a swampy area that hosts quite a variety of migrating bird species at different times of the year. Who would have thought…so close to Florence…! See: (in Italian)img_0059

We were quite lucky this morning. We saw and took photos of white herons, black-winged stilts (in Italian, they have a nobler name: cavalieri d’Italia, or Italian knights), grey herons (aironi cenerino), common coots (folaghe) and great crested grebes (svassi). We actually spotted more birds, but these are the main ones.

Apparently, though, the best time of year to visit the oasis is in the autumn and the early spring. When bimg_0140irds are migrating, of course. Last fall we were told that a few storks landed in the main lake, and as late as last week a kingfisher (martin pescatore) was spotted. Too bad we missed it! So this morning Stefano and I registered at the oasis as “photographers,” which means that next time we won’t need to be accompanied by a guide but can go off on our own and stay as long as we want. Excellent.

These are some of the photos I took. Stefano’s photos are much better (he has a BIG camera with a super-long lens), but he is still looking through them, and I didn’t want to wait…oops, it’s late, time for dinner…and, uhm, for some more cheesecake! Ciao!

Ciao, G.

Yesterday morning I was just about to leave the house to go to work when I received the news that Stefano’s cousin’s husband, G., had passed away the previous night. His death did not come as a surprise. When he was admitted to the hospital last week, in fact, the doctors told him that there was nothing more that could be done…that he was dying. We all knew it was a matter of days, perhaps hours.

You see, G. found out in late January that he had pancreatic cancer. By that time, the blasted cancer had metastasized and spread to other organs.

Well, Stefano and I have just returned to Florence, after attending G.’s funeral in southern Italy late yesterday afternoon.

Eh, I cannot write about this right now. Too many emotions…sorrow, anger (=of the “life is so bloody unfair” type), shock, exhaustion, distress…

G. was only 42 years old…father of a three-year-old boy…

That time of year again…

Ah yes, it’s that time of year: the dreaded SPRING CLEANING! spring_cleaning1For the past few days (it was a long holiday weekend in Italy), Stefano and I have been cleaning the house and rearranging things. From early morning until dinnertime. We have also begun the yearly chore of weeding and cleaning up our organic garden. Every muscle in my body aches, even muscles that I didn’t know existed…but we are pleased with the results (so far…we aren’t done yet!), and that’s what counts. Anyway, I have had almost no time to check my e-mail and even less time to do any research…oh well.

A friend (thanks!) sent me a link to an interesting BBC Science article (mainly) on the dancing cockatoo that I posted about not too long ago. Watching this bird bob up and down cracks me up every time:

Okay, I’d better get back to my cleaning (sigh), then I have my classes to prepare for tomorrow. Ciao!