Kinetic Steering of Amyloid Formation and Polymorphism by Canagliflozin, a Type-2 Diabetes Drug 2025

Amyloid formation is involved in widespread health conditions such as Alzheimer’s disease, Parkinson’s disease, and type-2 diabetes. Amyloid fibrils have a similar cross-β architecture, but fibrils formed by a single protein sequence can have diverse structures, varying with time, self-assembly conditions, and sequence modifications. Fibril structure has been proposed to be diagnostic of disease, but why different structures result under different conditions, especially in vitro, remains elusive. We previously identified a small molecule, YX-I-1, which inhibits in vitro amyloid formation by islet amyloid polypeptide (IAPP), a peptide hormone whose amyloid formation is involved in type-2 diabetes. Here, using YX-I-1 as a lead, we identified regulator-approved drugs with similar structures by chemical similarity analysis and substructure searches, and monitored the effect of 24 of these potential ligands on IAPP amyloid assembly in vitro. We show that one such compound, canagliflozin (Invokana), a type-2 diabetes drug already in clinical use, can strongly delay the kinetics of IAPP amyloid formation, an activity independent of its intended mode of action (sodium-glucose linked transporter 2 (SGLT2) inhibitor) that may have important therapeutic implications. Combining analysis of amyloid self-assembly kinetics, biophysical characterization of monomer and fibril binding, and cryo-EM of the assembly products, we show that YX-I-1 and canagliflozin target IAPP early in aggregation, remodeling the energy landscape of primary nucleation and profoundly altering the resulting fibril structures. Early binding events thus imprint long-lasting effects on the amyloid structures that form.

However, two of the small molecules – doxazosin, an alpha-1 blocker used to treat hypertension and benign prostatic hyperplasia, and canagliflozin, one of the three most widely used flozins for treatment of type-2 diabetes via its action as an SGLT2 inhibitor – caused a pronounced and statistically significant inhibition (fold-change in half-time of 1.61 ± 0.29, p < 0.0001 and 1.55 ± 0.22, p < 0.0001, respectively), comparable to the inhibition observed for YX-I-1 (fold-change in halftime of 1.49 ± 0.18, p < 0.0001) (Table S7, Fig. S6). Canagliflozin and doxazosin are structurally distinct, but both possess a high degree of structural similarity to YX-I-1 enantiomer 1 as assessed by ROCS, with ComboScores of 0.759 (Table S1) and 0.864 (Table S2), respectively. The presence of shared tetrahydropyran and phenyl substructures makes this similarity particularly obvious for canagliflozin (Fig. 1c, Fig. 2c), but comparison of the ComboScores indicates that doxazosin nonetheless has a higher overall degree of shape and pharmacophoric similarity to YX-I-1, despite the aligned substructures being different (Fig. 2c).
Dapagliflozin (Fig. 5d), one of the closest analogs of canagliflozin in the screening set, showed a pattern of binding similar to canagliflozin, with greater attenuation of the aromatic protons compared to the aliphatic protons, but binding was weaker overall and inversion of the aromatic peaks did not occur.
Here, we have investigated whether regulator-approved small molecule drugs can be repurposed as inhibitors of IAPP amyloid formation, building upon our previous work that identified YX-I-1 as a lead26. Virtual screening, ThT assays and biophysical characterization successfully identified two widely used FDA-approved drugs, canagliflozin and doxazosin, as inhibitors of IAPP amyloid formation. Canagliflozin, currently used as a third-line type-2 diabetes medication with an intended mode of action (SGLT2 inhibitor) unrelated to islet amyloid, had the strongest inhibitory effect of all molecules tested. Whether treatment with canagliflozin provides additional clinically relevant benefits through an effect on IAPP fibrillization is unknown, although canagliflozin has been shown to improve pancreatic β-cell function via an uncharacterized SGLT2-independent mechanism. On the other hand, canagliflozin may currently be given too late in disease progression to take advantage of any therapeutic benefits by inhibiting IAPP amyloid formation. In addition, ex vivo structure determination of IAPP fibril deposits and clinical/animal studies will be required to determine whether canagliflozin treatment results in a change in IAPP fibril polymorphism in patients, and whether this affects disease outcomes. Doxazosin, on the other hand, is not currently used as a type-2 diabetes medication, but is widely used for conditions such as benign prostatic hyperplasia, and may also affect IAPP aggregation if administered to diabetic people with these conditions. As canagliflozin and doxazosin are both widely used drugs, and could be rapidly repurposed as amyloid-targeting type-2 diabetes treatments, the clinical effects of any current interactions with islet amyloid and the effects of early treatment in preor early-stage diabetic individuals should be investigated as a matter of urgency.

@DrFraser: I don’t understand the whole paper, but it’s one more datapoint in favor of SGLT2i (and specifically canagliflozin?) and alpha-blockers (and specifically doxazosin?). TBC…

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@RapAdmin I’m using an Indian sourced brand name. Having said that, aside from my water to down my two handful of pills at aprox 6pm (which can be an issue!), I do mostly drink earlier in the day, same with food… I start off strong and then taper off. What adssx said makes sense for me because I don’t notice it during the day either.

@dicarlo2 Thank you!! That makes sense! Whew! (I’m in dire need of muscle!)

@Bicep I do notice this helps with my glucose spikes much more than metformin ever did. I take this and a low dose glp1 (might be too low to do much) and according to my cgm, my glucose only breaks through 140 once most days, vs several times. Some days it’s zero

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I think hydration is one of the most underestimated and most important pillars of health, and it might be pretty neglected:

(1) Dehydration is highly tolerable (like apoB), so people can get used and live with it, up to 15% loss of body weight in water, where 2% loss have an impact.
(2) Dehydration decreases cognition, mood, decreases athletic performance, worse kidneys, etc, in humans.
(3) Dehydration increase aging rate and decrease lifespan in mice.
(4) Dehydration increase with aging.
(5) Thirst and similar differ among people and subject to distraction.

Max upper limit of water excretion is 0.7 L/h with normal kidney function.

The continuous hydration monitors in development and use seems very important especially (5) and similar.

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I’ve had the opposite experience - For at least ten years (I’m 43) I’ve had to get up and pee nearly every night but since starting SGLT2’s I don’t get up even once most nights now. Definitely preferred to metformin which made me feel weak in the mornings. I used to get a cramp nearly every morning since starting them but that’s now gone and I’m up to the full dose.

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Interesting article. I’ve seen others favoring canagliflozin over the dapagliflozin or empagliflozin. There is the new one sotagliflozin which may be even better than canagliflozin for heart failure/diabetes as has solid SGLT2/1 inhibition - however Canagliflozin is weaker on the SGLT-1 inhibition than this new agent.

It sounds as though, based on this paper that it may be a segment of this drug that interacts with amyloid formation, not based on the mechanism of the drug as an SGLT2/1-i, but due to part of it’s structure, that has some similarities to doxazosin.

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Flozins might help those with higher Lp(a) avoid aortic stenosis? @Davin8r et al any thoughts?


https://www.jacc.org/doi/abs/10.1016/j.jcin.2024.11.036

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That’s exciting!! Thanks so much for posting this, Neo.

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“The discovery that the pathogenetic mechanism of aortic stenosis is similar to the atherosclerosis process…”

Hopefully this means by extension that SGLT2i meds can inhibit Lp(a)-induced atherosclerosis in the coronary arteries in addition to the aortic valve.

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You’re misreading this. They’re saying there are limited studies on the effects of (a) insulin analogs, (b) empa, and (c) cana on EF. If they had meant what you misunderstood here, they would ahve said “studies examining the effect of the insulin analogues empagliflozin and canagliflozin on EF are limited” or “studies examining the effect of insulin analogues such as empagliflozin and canagliflozin on EF are limited”. At minimum, they would have omitted the comma.

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Correct. It was clarified not long after I made that post. My bad. I should’ve re-read it more carefully, since the claim would’ve been so bizarre otherwise.

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I took 50 mg of cana, half the usual starting dose. In anticipation of some initial dehydration, I upped my water intake to four quarts per day. After a week I had a blood test. It showed that my BUN (blood urea nitrogen), a sign of dehydration, had doubled from baseline.

I think that those of us with kidney problems, which in my case includes an episode of hypovolemia, should be careful with these inhibitors. In my opinion, a case of severe dehydration leaves behind at least a trace of damage, which makes the kidneys more susceptible to future dehydration. The body remembers.

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Interesting paper in how perhaps canagliflozin could target amyloid formation in patients with type-2 DM to prevent/slow dementia. While it might suggest another reason to take canagliflozin, a study from 2023 might suggest not getting too excited yet: Diabetes Care. 2023 Feb 1;46(2):297-304. “Association of Sodium-Glucose Cotransporter 2 Inhibitors With Time to Dementia: A Population-Based Cohort Study”. The Reader’s Digest version is among 106K diabetic patients followed, the hazard ratio for a subsequent dementia diagnosis was 0.53 for dapagliflozin, 0.78 for empagliflozin, and 0.96 for canagliflozin over a mean follow-up of 2.80 years from cohort entry (and cohort entry was delayed by 1 yr after starting the SGLT2i for better investigative integrity). So dapagliflozin dropped the risk by 47% but canagliflozin by only 4%.

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Concomitant use of statins and sodium-glucose co-transporter 2 inhibitors and the risk of myotoxicity reporting: A disproportionality analysis

https://bpspubs.onlinelibrary.wiley.com/doi/10.1111/bcp.15711

"Conclusion

There was no increased risk of myotoxicity reporting associated with concomitant use of SGLT2 inhibitors and statins or for specific drug pairs."

“SGLT2 inhibitors included canagliflozin, dapagliflozin, empagliflozin and ertugliflozin, while statins included atorvastatin, fluvastatin, lovastatin, pitavastatin, pravastatin, rosuvastatin and simvastatin.”

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Another win for poly pharmacy

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Chinese paper (not from the best university) with some weird findings: Effects of Sodium-Glucose Cotransporter 2 Inhibitors on Nervous System Disorders: A Systematic Review and Meta-Analysis 2025

We included 52 publications/trials covering 111 376 participants (SGLT2 inhibitors 62 192; Placebo 49 184). Sodium-glucose cotransporter 2 inhibitors had no significant effect on ischaemic stroke (RR = 0.97; 95% CI = 0.87-1.09; P = 0.64), cerebrovascular accident (RR = 1.05; 95% CI = 0.91-1.22; P = 0.50), dementia (RR = 1.29; 95% CI = 0.78-2.12; P = 0.32), carotid artery occlusion/carotid artery stenosis (RR = 1.18; 95% CI: 0.92-1.53; P = 0.20), haemorrhagic stroke (RR = 0.84; 95% CI = 0.62-1.12; P = 0.23), and transient ischaemic attack (RR = 0.97; 95% CI = 0.82-1.15; P = 0.73) compared to placebo. No significant heterogeneity was observed. However, SGLT2 inhibitors showed slight effects to reduce the risk of Parkinson’s disease (major heart failure subgroup). Empagliflozin and dapagliflozin significantly increased the risk of syncope (RR = 1.65; 95% CI = 1.15-2.38; P < 0.01) and carotid artery occlusion/carotid artery stenosis (RR = 1.65; 95% CI = 1.04-2.61; P = 0.03), respectively.

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From diuresis/dehydration?

If we start with the hypothesis that Parkinsons is accelerated aging of brain cells (because of too little melatonin in the CSF) then higher glucose levels will cause more ROS from Complexes 1 and 3 in the Electron Transport Train and further accelerate the aging process.

Hence if an SLGT2 helps control glucose peaks that should be useful.

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I don’t have access to the full paper, but following the link, I’m trying to understand the claims. The claim of carotid occlusion or stenosis is specific to empagliflozin and dapagliflozin, but not other SGLT2i?

That’s how I’m reading it, unless I’m misunderstanding something.

That’s rather odd. Empagliflozin and dapagliflozin, together with canagliflozin are some of the most studied SGLT2i. If these two cause carotid stenosis (at least in t2 diabetics), then it’s possible that all SGLT2i do, but we haven’t studied these other ones sufficiently to turn the non significant effect of 12% higher risk into a significant effect upon more data.

However, carotid stenosis is caused by atherosclerotic plaque at those locations. There are several risk factors for plaque deposition. The general effect of SGLT2i, including empa and dapa is some slight lowering of BP, or at least not raising BP, so that particular risk factor falls away. Lipid levels are effected very slightly if at all, so it’s unlikely that elevated lipids are the mechanism here. Inflammation is lowered rather than raised, and endothelial function seems to benefit and not be impaired by either of those SGLT2i. The question is: by what mechanism do these two increase carotid stenosis?

The Role of SGLT2 Inhibitors in Atherosclerosis: A Narrative Mini-Review

“We first review the underlying mechanisms of SGLT2-is on the development and progression of atherosclerosis, including favorable effects on lipid metabolism, reduction of systemic inflammation, and improvement of endothelial function. We then discuss the putative impact of SGLT2-is on the formation, composition, and stability of atherosclerotic plaque. Furthermore, we evaluate the effects of SGLT2-is in subclinical atherosclerosis assessed by carotid intima media thickness and pulse wave velocity. Subsequently, we summarize the effects of SGLT2-is in ASCVD events, including ischemic stroke, angina pectoris, myocardial infarction, revascularization, and peripheral artery disease, as well as major adverse cardiovascular events, cardiovascular mortality, heart failure, and chronic kidney disease. Moreover, we examine factors that could modify the role of SGLT2-is in atherosclerosis, including sex, age, diabetes, glycemic control, ASCVD, and SGLT2-i compounds.”

“PubMed and Google Scholar were searched to identify relevant publications on SGLT2-is and atherosclerosis. Key words included the following: “SGLT2 inhibitor, canagliflozin, dapagliflozin, empagliflozin, ertugliflozin, ipragliflozin, luseogliflozin, remogliflozin, sotagliflozin, tofogliflozin, atherosclerosis, carotid intima media thickness, plaque, ankle-brachial index, coronary artery calcification score, pulse wave velocity, transient ischemic attack, ischemic stroke, coronary heart disease, angina pectoris, acute coronary syndrome, myocardial infarction, coronary revascularization, renal artery stenosis, and peripheral artery disease.” All types of articles were considered, including clinical trials, animal studies, in vitro observations, reviews, and meta-analyses. Since this is a narrative mini-review, we prioritized the most clinically relevant and up-to-date articles in the current literature.”

I don’t want to quote the whole paper here, but the bottom line is that examining all commonly accepted risk factors for atherosclerosis, they find that SGLT2i, and empa and dapa too, either lower the risk factors or are neutral across multiple studies, including studies focused specifically on empa or dapa. When it came to plaque burden and size, canagliflozin was least effective at amelioration of plaque, so if we are to blame empa and dapa, you’d expect cana to be even worse, and yet, that’s not what the Chinese paper claims (and to be clear cana is at least as extensively studied).

Carotid stenosis or occlusion results in the clinical outcome of stroke. So how do empa/dapa/SGLT2i do with stroke? If they significantly increase carotid occlusion, you would expect to see increased incidence of strokes:

“Stroke and TIA. Several meta-analyses and reviews reported that SGLT2-is, including canagliflozin, dapagliflozin, and empagliflozin, do not affect the risk of stroke (Milonas and Tziomalos, 2018; Zheng et al., 2018; Sinha and Ghosal, 2019b; Sinha and Ghosal, 2019a; Zhu et al., 2020). In line, the empagliflozin and placebo arms in the EMPA-REG OUTCOME trial did not differ in the risk of TIA (Zinman et al., 2015). Further investigations evaluating the role of SGLT2-is in ischemic stroke are needed.”

Without reading the full Chinese paper, I am not going to attempt to evaluate it, but given my reading of the literature in the past few months, I find their claims rather puzzling and contrary to generally accepted clinical experience.

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I asked R1 + DeepSearch, and it suggested that the increase in carotid artery stenosis was simply the criteria among the trials differing in what that was, whether they measured at baseline, and simply a statistically significant result due to chance. It hallucinated a trial that didn’t exist though and I haven’t seen that in a long time.

I would think it is unlikely this result is case because carotid artery stenosis has also to do with atherosclerosis, why would empa and dapagliflozin increase this (the small increase in LDL can’t be it)? I haven’t looked at the full paper. It looks weird. I don’t know if they tested for everything if so the multiple comparison problem.

I’m waiting for agelessrx to have it as well. In the meantime, you can still get cana at https://gethealthspan.com for $100 a month.