Impact of the Combined Treatment of Curcumin and Resveratrol Liposomed Polyphenols With G04CB02 on the Clinical Improvement of ALS Patients

Amyotrophic lateral sclerosis (ALS) is the most common neurodegenerative disease of an inflammatory nature among those affecting motor neurons, with a life expectancy of 3 to 5 years. It is characterised by the loss of motor neurons, and can be of the bulbar type when the pathology begins to affect the motor neurons located in the spinal bulb, or of the medullary type when it begins with a loss of strength and weakness in the extremities. Both types eventually lead to an affectation of both motor neurons that results in progressive paralysis of the voluntary muscles until the patient dies. In addition, the pathology presents cognitive and behavioural alterations. Specifically, deficits have been described in verbal fluency, memory, emotional processing or social cognition, which appear to be mainly associated with hypoperfusion of the prefrontal area or hypometabolism.

Pathogenically, ALS is characterised by an alteration in mitochondrial energy use at a neuronal level, mainly linked to a lower activity of the enzymes of the electron transport chain in the spinal cord. This alteration is a consequence of loss of oxidative control, excessive generation of oxidative free radicals, accumulation of neurofilaments, and excitotoxicity linked to an increase in the neurotransmitter glutamate.

In this respect, it has been suggested that bacterial dysbiosis, related to cognitive and behavioural worsening, could also contribute to this adverse neuroinflammatory state, having been associated with a greater risk of suffering from neurodegenerative diseases. Specifically in ALS, a variation in intestinal microbial composition has recently been observed, with an increased abundance of E. coli and enterobacteria, and a low abundance of total yeast, in patients suffering from ALS; and lower levels of non-butyrate producing bacteria needed to maintain the integrity of the intestinal barrier, immune competition and energy metabolism. In contrast, increased Akkermansia muciniphila has been associated with higher levels of nicotinamide and improved disease symptoms in the animal model of the disease.

This evidence, associated with the lack of medical treatment to cure the disease, makes it necessary to look for new therapeutic alternatives of a non-pharmacological nature. These include the administration of effective antioxidants, which reverse the high oxidative stress and inflammation characteristic of the disease. This type of treatment (specifically the association of the antioxidants Pterostilbene and Nicotinamide riboside) has already been applied by our research group to patients with ALS, achieving significant clinical improvements such as: greater functional capacity, greater respiratory capacity, increased muscle strength and electrical activity in the upper and lower limbs, as well as an increase in the percentage of skeletal muscle associated with fat loss. In this sense, several polyphenols have also been tested in animal models, among which the activity shown by Resveratrol stands out, with a high antioxidant power and great neuroprotective capacity, which is associated with an increase in the expression and activation of SIRT1 and AMPK in the ventral part of the spinal cord after its administration. Both mediators promoted the normalization of autophage flow and, more importantly, increased mitochondrial biogenesis in SOD1-G93A mice. However, their beneficial effects are strongly limited by their low availability. This limitation can be overcome by administering Resveratrol and its natural analogues, incorporated in liposomes or nanoparticles, as this is the best option for guaranteeing stability and bioavailability, after administration and absorption of the antioxidant.

Moreover, the effects of the polyphenol Curcumin have already been studied in ALS. In a paper by Chico et al, its effects were studied in ALS patients at doses of 600mg/day for 6 months. In this study they found that Curcumin generated a slight slowdown in the progression of the disease, improving aerobic metabolism and oxidative damage. Furthermore, the use of nanobiotechnology with Curcumin (80mg/day) in the treatment of ALS patients obtained positive results showing that nanocurcumin is safe and could improve the probability of survival as an additional treatment in these patients, especially those with existing bulbar symptoms. In short, the use of both antioxidants in liposome form improves the bioavailability and effects of both, and their liposome combination has already been successfully tested in vivo in prostate cancer patients.

These anti-ALS effects of the two molecules could be complemented by their action in improving the microbiota. To obtain the bioactive products of Curcumin, biotransformation by the human intestinal microflora is necessary; in a bidirectional manner, it has been demonstrated that Curcumin has beneficial effects on the intestinal microbiota by increasing the number of bacterial families such as: Prevotellaceae, Bifidobacterium, Lactobacilli, Bacteroidaceae and Rikenellaceae, and reducing the number of pro-inflammatory bacterial families such as: Enterobacteria and Enterococci. With regard to Resveratrol, as occurs with Curcumin, the intestinal microflora contributes to its metabolism; and also stands out in the increased production of anti-inflammatory bacteria of the Lactobacillus or Bifidobacterium genera. In addition, it has been found to increase levels of the bacterium Akkermansia Muciniphila, which is associated with an improvement in the prognosis of the disease.

Finally, the use of these two antioxidants in ALS would be combined synergistically by repositioning G04CB02, a drug selected after a molecular topology scan of more than 30,000 drugs from two databases: CMC and Drugbank. It is currently marketed for the treatment of different pathologies, such as benign prostatic hyperplasia and androgenic alopecia. According to the in silico studies based on Molecular Topology carried out by Dr. Gálvez's team, a very promising anti-ALS effect has been identified for G04CB02, linked to the TDP-43 RNA mediator, among others. Drug design using molecular topology consists of applying topological descriptors to identify and describe, using a specific mathematical pattern, molecules and/or drugs related to a specific disease, in this case ALS. Using molecules with proven anti-ALS activity (Edaravone and Riluzole) and the TDP-43 RNA mediator, this mathematical pattern was identified and the databases mentioned above were traced with the aim of identifying drugs that share the same pattern and therefore have potential anti-ALS activity. In addition, considering the current shortage of effective treatments for ALS, other mathematical patterns related to anti-inflammatory, antioxidant, neuroprotective and analgesic activity were taken into account when selecting the G04CB02 candidate. To date, molecular topology has enabled the identification of new treatments for CNS diseases such as Alzheimer's, cancer and very recently SARS-Cov-2, among others.