Identification of Estrogen Receptor Modulators as Inhibitors of Flavivirus Infection

CRISPR activation as a platform to identify interferon stimulated genes with anti-viral function

Interferon Stimulated Gene (ISG) expression plays a key role in the control of viral replication and development of a robust adaptive response. Understanding this dynamic relationship between the pathogen and host is critical to our understanding of viral life-cycles and development of potential novel anti-viral strategies. Traditionally, plasmid based exogenous prompter driven expression of ISGs has been used to investigate anti-viral ISG function, however there are deficiencies in this approach. To overcome this, we investigated the utility of CRISPR activation (CRISPRa), which allows for targeted transcriptional activation of a gene from its endogenous promoter. Using the CRISPRa-SAM system to induce targeted expression of a panel of anti-viral ISGs we showed robust induction of mRNA and protein expression. We then employed our CRISPRa-SAM ISG panel in several antiviral screen formats to test for the ability of ISGs to prevent viral induced cytopathic cell death (CPE) and replication of Dengue Virus (DENV), Zika Virus (ZIKV), West Nile Virus Kunjin (WNVKUN), Hepatitis A Virus (HAV) and Human Coronavirus 229E (HCoV-229E). Our CRISPRa approach confirmed the anti-viral activity of ISGs like IFI6, IFNβ and IFNλ2 that prevented viral induced CPE, which was supported by high-content immunofluorescence imaging analysis. This work highlights CRISPRa as a rapid, agile, and powerful methodology to identify and characterise ISGs and viral restriction factors.

Aminopyrimidine Derivatives as Multiflavivirus Antiviral Compounds Identified from a Consensus Virtual Screening Approach

Around three billion people are at risk of infection by the dengue virus (DENV) and potentially other flaviviruses. Worldwide outbreaks of DENV, Zika virus (ZIKV), and yellow fever virus (YFV), the lack of antiviral drugs, and limitations on vaccine usage emphasize the need for novel antiviral research. Here, we propose a consensus virtual screening approach to discover potential protease inhibitors (NS3pro) against different flavivirus. We employed an in silico combination of a hologram quantitative structure-activity relationship (HQSAR) model and molecular docking on characterized binding sites followed by molecular dynamics (MD) simulations, which filtered a data set of 7.6 million compounds to 2,775 hits. Lastly, docking and MD simulations selected six final potential NS3pro inhibitors with stable interactions along the simulations. Five compounds had their antiviral activity confirmed against ZIKV, YFV, DENV-2, and DENV-3 (ranging from 4.21 ± 0.14 to 37.51 ± 0.8 μM), displaying aggregator characteristics for enzymatic inhibition against ZIKV NS3pro (ranging from 28 ± 7 to 70 ± 7 μM). Taken together, the compounds identified in this approach may contribute to the design of promising candidates to treat different flavivirus infections.

Increasing expression of STING by ERα antagonizes LCN2 downregulation during chronic endometritis

Chronic endometritis has a high incidence in infertile women, which is caused by endometrial microbiome infection. In response to microbial infection, the role of defensins during chronic endometritis need explored. Besides, the expression of estrogen and its receptors vary in different menstrual cycles, but their roles in chronic endometritis are still unclear. In this study, we used the human endometrial tissues to examine the expression of antimicrobial peptides (AMPs) α-defensin hNP-1 and β-defensins hBD-1, hBD-2, hBD-3, hBD-4 and LCN2. We found the expression of hBD-1 and LCN2 were downregulated in endometritis tissues, while the expressions of hBD-2, hBD-3, hBD-4, hNP-1, and estrogen and ERα were upregulated in chronic endometritis tissues compared to normal tissues. The expression and phosphorylation of STING, which is a crucial mediator of mammalian innate immunity in response to pathogens, was regulated with the treatment of ERα inhibitor raloxifene (Rx). Furthermore, using with the estrogen receptor inhibitor Rx and STING inhibitor H-151 significantly decreases the LCN2 expression. Taken together, these results suggested ERα was upregulated to modulate STING expression inducing LCN2 antimicrobial peptide expression to modulate the mucosal immunity during chronic endometritis.

Pros and Cons of Skeletal Medications in the COVID-19 Era

Purpose of Review

This review provides an overview regarding osteoporosis therapies during the COVID-19 pandemic.

Recent Findings

The COVID-19 pandemic has disrupted treatments for osteoporosis and resulted in decreased adherence particularly for parenteral regimens. Osteoporosis medications are safe and effective during the pandemic and should be continued whenever possible. Bisphosphonates have long-lasting effects on bone turnover such that delays in their administration are unlikely to be harmful to skeletal health. In contrast, interruption of denosumab treatment is strongly discouraged because of rapid loss of bone mass and an associated increased risk for rebound vertebral fractures. When osteoanabolic treatments cannot be continued during the pandemic, change to an oral bisphosphonate is advised. Preclinical data suggest possible beneficial effects of some therapies against COVID-19, but require validation in clinical studies. Vitamin D deficiency is associated with a more severe COVID-19 clinical course but data supporting improvements in outcomes with vitamin D supplementation are lacking.

Summary

The impact of the COVID-19 pandemic on long-term bone health remains unknown but focused interventions to ensure osteoporosis treatment initiation/maintenance should be implemented. Future studies are needed to determine whether osteoporosis medications have an impact on SARS-CoV-2 pathophysiology and COVID-19 clinical outcomes.

Mosquito-Borne Flaviviruses and Current Therapeutic Advances

Mosquito-borne flavivirus infections affect approximately 400 million people worldwide each year and are global threats to public health. The common diseases caused by such flaviviruses include West Nile, yellow fever, dengue, Zika infection and Japanese encephalitis, which may result in severe symptoms and disorders of multiple organs or even fatal outcomes. Till now, no specific antiviral agents are commercially available for the treatment of the diseases. Numerous strategies have been adopted to develop novel and promising inhibitors against mosquito-borne flaviviruses, including drugs targeting the critical viral components or essential host factors during infection. Research advances in antiflaviviral therapy might optimize and widen the treatment options for flavivirus infection. This review summarizes the current developmental progresses and involved molecular mechanisms of antiviral agents against mosquito-borne flaviviruses.

A phase 2 randomized, double-blinded, placebo-controlled, multicenter trial evaluating the efficacy and safety of raloxifene for patients with mild to moderate COVID-19

BACKGROUND

Current available therapeutic options for Coronavirus Disease-2019 (COVID-19) are primarily focused on treating hospitalized patients, and there is a lack of oral therapeutic options to treat mild to moderate outpatient COVID-19 and prevent clinical progression. Raloxifene was found as a promising molecule to treat COVID-19 due to its activity to modulate the replication of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and act as an immunomodulator to decrease proinflammatory cytokines.

METHODS

This was a phase 2 multicenter, randomized, placebo-controlled trial to evaluate the efficacy and safety of raloxifene in adult patients with mild to moderate COVID-19 between October 2020 to June 2021 in five centers located in Italy. This was a planned 2/3 adaptive study, but due to operational difficulties, the study was discontinued during the phase 2 study segment. Participants were randomized 1:1:1 to receive oral placebo, raloxifene 60 mg, or raloxifene 120 mg by self-administration for a maximum of two weeks. The primary outcomes were the proportion of patients with undetectable SARS-CoV-2 via nasopharyngeal swabs at day 7 and the proportion of patients who did not require supplemental oxygen therapy or mechanical ventilation on day 14. Safety was assessed. The trial is registered (EudraCT 2021-002,476-39, and ClinicalTrials.gov: NCT05172050).

FINDINGS

A total of 68 participants were enrolled and randomized to placebo (n = 21), raloxifene 60 mg (n = 24), and raloxifene 120 mg (n = 23). The proportion of participants with undetectable SARS-CoV-2 after seven days of treatment with raloxifene 60 mg [36.8%, 7/19 vs. 0.0%, 0/14] and 120 mg [22.2%, 4/18 vs. 0.0%, 0/14] was better compared to placebo, [risk difference (RD) = 0·37 (95% C.I.:0·09-0·59)] and [RD = 0·22 (95% C.I.: -0·03-0·45)], respectively. There was no evidence of effect for requirement of supplemental oxygen and/or mechanical ventilation with effects for raloxifene 60 mg and raloxifene 120 mg over placebo, [RD = 0·09 (95% C.I.: -0·22-0·37)], and [RD = 0·03 (95% C.I.: -0·28-0·33)], respectively. Raloxifene was well tolerated at both doses, and there was no evidence of any difference in the occurrence of serious adverse events.

INTERPRETATION

Raloxifene showed evidence of effect in the primary virologic endpoint in the treatment of early mild to moderate COVID-19 patients shortening the time of viral shedding. The safety profile was consistent with that reported for other indications. Raloxifene may represent a promising pharmacological option to prevent or mitigate COVID-19 disease progression.

FUNDING

The study was funded by Dompé Farmaceutici SpA and supported by the funds from the European Commission - Health and Consumers Directorate General, for the Action under the Emergency Support Instrument- Grant to support clinical testing of repurposed medicines to treat SARS-COV-2 patients (PPPA-ESI-CTRM-2020-SI2.837140), and by the COVID-2020-12,371,675 Ricerca finalizzata and line 1 Ricerca Corrente COVID both funded by Italian Ministry of Health.

Characterization of raloxifene as a potential pharmacological agent against SARS-CoV-2 and its variants

The new coronavirus SARS-CoV-2 is the causative agent of the COVID-19 pandemic, which so far has caused over 6 million deaths in 2 years, despite new vaccines and antiviral medications. Drug repurposing, an approach for the potential application of existing pharmaceutical products to new therapeutic indications, could be an effective strategy to obtain quick answers to medical emergencies. Following a virtual screening campaign on the most relevant viral proteins, we identified the drug raloxifene, a known Selective Estrogen Receptor Modulator (SERM), as a new potential agent to treat mild-to-moderate COVID-19 patients. In this paper we report a comprehensive pharmacological characterization of raloxifene in relevant in vitro models of COVID-19, specifically in Vero E6 and Calu-3 cell lines infected with SARS-CoV-2. A large panel of the most common SARS-CoV-2 variants isolated in Europe, United Kingdom, Brazil, South Africa and India was tested to demonstrate the drug's ability in contrasting the viral cytopathic effect (CPE). Literature data support a beneficial effect by raloxifene against the viral infection due to its ability to interact with viral proteins and activate protective estrogen receptor-mediated mechanisms in the host cells. Mechanistic studies here reported confirm the significant affinity of raloxifene for the Spike protein, as predicted by in silico studies, and show that the drug treatment does not directly affect Spike/ACE2 interaction or viral internalization in infected cell lines. Interestingly, raloxifene can counteract Spike-mediated ADAM17 activation in human pulmonary cells, thus providing new insights on its mechanism of action. A clinical study in mild to moderate COVID-19 patients (NCT05172050) has been recently completed. Our contribution to evaluate raloxifene results on SARS-CoV-2 variants, and the interpretation of the mechanisms of action will be key elements to better understand the trial results, and to design new clinical studies aiming to evaluate the potential development of raloxifene in this indication.

Urolithins: The Colon Microbiota Metabolites as Endocrine Modulators: Prospects and Perspectives

Selective estrogen receptor modulators (SERMs) have been used in hormone related disorders, and their role in clinical medicine is evolving. Tamoxifen and raloxifen are the most commonly used synthetic SERMs, and their long-term use are known to create side effects. Hence, efforts have been directed to identify molecules which could retain the beneficial effects of estrogen, at the same time produce minimal side effects. Urolithins, the products of colon microbiota from ellagitannin rich foodstuff, have immense health benefits and have been demonstrated to bind to estrogen receptors. This class of compounds holds promise as therapeutic and nutritional supplement in cardiovascular disorders, osteoporosis, muscle health, neurological disorders, and cancers of breast, endometrium, and prostate, or, in essence, most of the hormone/endocrine-dependent diseases. One of our findings from the past decade of research on SERMs and estrogen modulators, showed that pomegranate, one of the indirect but major sources of urolithins, can act as SERM. The prospect of urolithins to act as agonist, antagonist, or SERM will depend on its structure; the estrogen receptor conformational change, availability and abundance of co-activators/co-repressors in the target tissues, and also the presence of other estrogen receptor ligands. Given that, urolithins need to be carefully studied for its SERM activity considering the pleotropic action of estrogen receptors and its numerous roles in physiological systems. In this review, we unveil the possibility of urolithins as a potent SERM, which we are currently investigating, in the hormone dependent tissues.

Selective estrogen receptor modulators limit alphavirus infection by targeting the viral capping enzyme nsP1

Alphaviruses cause animal or human diseases that are characterized by febrile illness, debilitating arthralgia, or encephalitis. Selective estrogen receptor modulators (SERMs), a class of FDA-approved drugs, have been shown to possess antiviral activities against multiple viruses, including Hepatitis C virus, Ebola virus, dengue virus, and vesicular stomatitis virus. Here, we evaluated three SERM compounds, namely 4-hydroxytamoxifen, tamoxifen, and clomifene, for plausible antiviral properties against two medically important alphaviruses, chikungunya virus (CHIKV) and Sindbis virus (SINV). In cell culture settings, these SERMs displayed potent activity against CHIKV and SINV at non-toxic concentrations with EC₅₀ values ranging between 400 nM and 3.9 μM. Further studies indicated that these compounds inhibit a post-entry step of the alphavirus life cycle, while enzymatic assays involving purified recombinant proteins confirmed that these SERMs target the enzymatic activity of non-structural protein 1 (nsP1), the capping enzyme of alphaviruses. Finally, tamoxifen treatment restrained CHIKV growth in the infected mice and diminished musculoskeletal pathologies. Combining biochemical, cell culture-based studies, and in vivo analyses, we strongly argue that SERM compounds, or their derivatives, may provide for attractive therapeutic options against alphaviruses.

Alkyne-Tagged Apigenin, a Chemical Tool to Navigate Potential Targets of Flavonoid Anti-Dengue Leads

A flavonoid is a versatile core structure with various cellular, immunological, and pharmacological effects. Recently, flavones have shown anti-dengue activities by interfering with viral translation and replication. However, the molecular target is still elusive. Here we chemically modified apigenin by adding an alkyne moiety into the B-ring hydroxyl group. The alkyne serves as a chemical tag for the alkyne-azide cycloaddition reaction for subcellular visualization. The compound located at the perinuclear region at 1 and 6 h after infection. Interestingly, the compound signal started shifting to vesicle-like structures at 6 h and accumulated at 24 and 48 h after infection. Moreover, the compound treatment in dengue-infected cells showed that the compound restricted the viral protein inside the vesicles, especially at 48 h. As a result, the dengue envelope proteins spread throughout the cells. The alkyne-tagged apigenin showed a more potent efficacy at the EC₅₀ of 2.36 ± 0.22, and 10.55 ± 3.37 µM, respectively, while the cytotoxicities were similar to the original apigenin at the CC₅₀ of 70.34 ± 11.79, and 82.82 ± 11.68 µM, respectively. Molecular docking confirmed the apigenin binding to the previously reported target, ribosomal protein S9, at two binding sites. The network analysis, homopharma, and molecular docking revealed that the estrogen receptor 1 and viral NS1 were potential targets at the late infection stage. The interactions could attenuate dengue productivity by interfering with viral translation and suppressing the viral proteins from trafficking to the cell surface.

Repurposing the estrogen receptor modulator raloxifene to treat SARS-CoV-2 infection

The ongoing coronavirus disease 2019 (COVID-19) pandemic caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) necessitates strategies to identify prophylactic and therapeutic drug candidates to enter rapid clinical development. This is particularly true, given the uncertainty about the endurance of the immune memory induced by both previous infections or vaccines, and given the fact that the eradication of SARS-CoV-2 might be challenging to reach, given the attack rate of the virus, which would require unusually high protection by a vaccine. Here, we show how raloxifene, a selective estrogen receptor modulator with anti-inflammatory and antiviral properties, emerges as an attractive candidate entering clinical trials to test its efficacy in early-stage treatment COVID-19 patients.

Amaryllidaceae Alkaloid Cherylline Inhibits the Replication of Dengue and Zika Viruses

Dengue fever, caused by dengue virus (DENV), is the most prevalent arthropod-borne viral disease and is endemic in many tropical and subtropical parts of the world, with an increasing incidence in temperate regions. The closely related flavivirus Zika virus (ZIKV) can be transmitted vertically in utero and causes congenital Zika syndrome and other birth defects. In adults, ZIKV is associated with Guillain-Barré syndrome. There are no approved antiviral therapies against either virus. Effective antiviral compounds are urgently needed. Amaryllidaceae alkaloids (AAs) are a specific class of nitrogen-containing compounds produced by plants of the Amaryllidaceae family with numerous biological activities. Recently, the AA lycorine was shown to present strong antiflaviviral properties. Previously, we demonstrated that Crinum jagus contained lycorine and several alkaloids of the cherylline, crinine, and galanthamine types with unknown antiviral potential. In this study, we explored their biological activities. We show that C. jagus crude alkaloid extract inhibited DENV infection. Among the purified AAs, cherylline efficiently inhibited both DENV (50% effective concentration [EC₅₀], 8.8 μM) and ZIKV replication (EC₅₀, 20.3 μM) but had no effect on HIV-1 infection. Time-of-drug-addition and -removal experiments identified a postentry step as the one targeted by cherylline. Consistently, using subgenomic replicons and replication-defective genomes, we demonstrate that cherylline specifically hinders the viral RNA synthesis step but not viral translation. In conclusion, AAs are an underestimated source of antiflavivirus compounds, including the effective inhibitor cherylline, which could be optimized for new therapeutic approaches.

Selective estrogen receptor modulator, tamoxifen, inhibits Zika virus infection

Zika virus (ZIKV) is an arbovirus belonging to the flaviviridae family with a risk assessment that has been increasing in recent years and was labeled a global health emergency by the World Health Organization in 2016. There are currently no Food and Drug Administration-approved treatment options available for ZIKV, so expeditious development of treatment options is urgent. To expedite this process, an on-market drug, tamoxifen (TAM), was selected as a promising candidate for repurposing due to its wide range of biological activities and because it has already been shown to possess activity against hepatitis C virus, a flavivirus in a separate genus. Anti-ZIKV activity of TAM was assessed by compound screens using an infectious virus and mechanistic details were gleaned from time of addition and virucidal studies. TAM and an active metabolite, 4-hydroxytamoxifen (TAM-OH), both showed promising antiviral activity (EC50 ≈9 and 5 µM, respectively) in initial compound screening and up to 8-h postinfection, though the virucidal assay indicated that they do not possess any direct virucidal activity. Additionally, TAM was assessed for its activity against ZIKV in the human male germ cell line, SEM-1, due to the sexually transmitted nature of ZIKV owing to its extended survival times in germ cells. Virus titers show diminished replication of ZIKV over 7 days compared to controls. These data indicate that TAM has the potential to be repurposed as an anti-ZIKV therapeutic and warrants further investigation.

The importance of viral and cellular factors on flavivirus entry

The flavivirus are emerging and re-emerging arthropod-borne pathogens responsible for significant mortality and morbidity worldwide. The genus comprises more than 70 viruses, and despite genomic and structural similarities, infections by different flaviviruses result in different clinical presentations. In the absence of a safe and effective vaccine against these infections, the search for new strategies to inhibit viral infection is necessary. The life cycle of arboviruses begins with the entry process composed of multiple steps: attachment, internalization, endosomal escape and capsid uncoating. This mini-review describes factors and mechanisms involved in the viral entry as events required to take over the cellular machinery and host factors and cellular pathways commonly used by flaviviruses as possible approaches for developing broad-spectrum antiviral drugs.

Estrogen Receptor Modulators in Viral Infections Such as SARS-CoV-2: Therapeutic Consequences

COVID-19 is a pandemic respiratory disease caused by the SARS-CoV-2 coronavirus. The worldwide epidemiologic data showed higher mortality in males compared to females, suggesting a hypothesis about the protective effect of estrogens against severe disease progression with the ultimate end being patient's death. This article summarizes the current knowledge regarding the potential effect of estrogens and other modulators of estrogen receptors on COVID-19. While estrogen receptor activation shows complex effects on the patient's organism, such as an influence on the cardiovascular/pulmonary/immune system which includes lower production of cytokines responsible for the cytokine storm, the receptor-independent effects directly inhibits viral replication. Furthermore, it inhibits the interaction of IL-6 with its receptor complex. Interestingly, in addition to natural hormones, phytestrogens and even synthetic molecules are able to interact with the estrogen receptor and exhibit some anti-COVID-19 activity. From this point of view, estrogen receptor modulators have the potential to be included in the anti-COVID-19 therapeutic arsenal.

iPSC screening for drug repurposing identifies anti-RNA virus agents modulating host cell susceptibility

Human pathogenic RNA viruses are threats to public health because they are prone to escaping the human immune system through mutations of genomic RNA, thereby causing local outbreaks and global pandemics of emerging or re-emerging viral diseases. While specific therapeutics and vaccines are being developed, a broad-spectrum therapeutic agent for RNA viruses would be beneficial for targeting newly emerging and mutated RNA viruses. In this study, we conducted a screen of repurposed drugs using Sendai virus (an RNA virus of the family Paramyxoviridae), with human-induced pluripotent stem cells (iPSCs) to explore existing drugs that may present anti-RNA viral activity. Selected hit compounds were evaluated for their efficacy against two important human pathogens: Ebola virus (EBOV) using Huh7 cells and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using Vero E6 cells. Selective estrogen receptor modulators (SERMs), including raloxifene, exhibited antiviral activities against EBOV and SARS-CoV-2. Pioglitazone, a PPARγ agonist, also exhibited antiviral activities against SARS-CoV-2, and both raloxifene and pioglitazone presented a synergistic antiviral effect. Finally, we demonstrated that SERMs blocked entry steps of SARS-CoV-2 into host cells. These findings suggest that the identified FDA-approved drugs can modulate host cell susceptibility against RNA viruses.

Antiviral Compounds for Blocking Arboviral Transmission in Mosquitoes

Mosquito-borne arthropod-borne viruses (arboviruses) such as the dengue virus (DENV), Zika virus (ZIKV), and chikungunya virus (CHIKV) are important human pathogens that are responsible for significant global morbidity and mortality. The recent emergence and re-emergence of mosquito-borne viral diseases (MBVDs) highlight the urgent need for safe and effective vaccines, therapeutics, and vector-control approaches to prevent MBVD outbreaks. In nature, arboviruses circulate between vertebrate hosts and arthropod vectors; therefore, disrupting the virus lifecycle in mosquitoes is a major approach for combating MBVDs. Several strategies were proposed to render mosquitoes that are refractory to arboviral infection, for example, those involving the generation of genetically modified mosquitoes or infection with the symbiotic bacterium Wolbachia. Due to the recent development of high-throughput screening methods, an increasing number of drugs with inhibitory effects on mosquito-borne arboviruses in mammalian cells were identified. These antivirals are useful resources that can impede the circulation of arboviruses between arthropods and humans by either rendering viruses more vulnerable in humans or suppressing viral infection by reducing the expression of host factors in mosquitoes. In this review, we summarize recent advances in small-molecule antiarboviral drugs in mammalian and mosquito cells, and discuss how to use these antivirals to block the transmission of MBVDs.

Raloxifene as Treatment for Various Types of Brain Injuries and Neurodegenerative Diseases: A Good Start

Recent studies have shown that the selective estrogen receptor modulator (SERM) raloxifene had pronounced protective effects against progressing brain damage after traumatic brain injury (TBI) in mice. These studies, indicating beneficial effects of raloxifene for brain health, prompted the study of the history and present state of knowledge of this topic. It appears that, apart from raloxifene, to date, four nonrelated compounds have shown comparable beneficial effects—fucoidan, pifithrin, SMM-189 (5-dihydroxy-phenyl]-phenyl-methanone), and translocator protein (TSPO) ligands. Raloxifene, however, is ahead of the field, as for more than two decades it has been used in medical practice for various chronic ailments in humans. Thus, apart from different types of animal and cell culture studies, it has also been assessed in various human clinical trials, including assaying its effects on mild cognitive impairments. Regarding cell types, raloxifene protects neurons from cell death, prevents glial activation, ameliorates myelin damage, and maintains health of endothelial cells. At whole central nervous system (CNS) levels, raloxifene ameliorated mild cognitive impairments, as seen in clinical trials, and showed beneficial effects in animal models of Parkinson’s disease. Moreover, with stroke and TBI in animal models, raloxifene showed curative effects. Furthermore, raloxifene showed healing effects regarding multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS) in cell culture. The adverse biological signals typical of these conditions relate to neuronal activity, neurotransmitters and their receptors, plasticity, inflammation, oxidative stress, nitric oxide, calcium homeostasis, cell death, behavioral impairments, etc. Raloxifene favorably modulates these signals toward cell health—on the one hand, by modulating gene expression of the relevant proteins, for example by way of its binding to the cell nuclear estrogen receptors ERα and ERβ (genomic effects) and, on the other hand (nongenomic effects) by modulation of mitochondrial activity, reduction of oxidative stress and programmed cell death, maintaining metabolic balance, degradation of Abeta, and modulation of intracellular cholesterol levels. More specifically regarding Alzheimer’s disease, raloxifene may not cure diagnosed Alzheimer’s disease. However, the onset of Alzheimer’s disease may be delayed or arrested by raloxifene’s capability to attenuate mild cognitive impairment. Mild cognitive impairment is a condition that may precede diagnosis of Alzheimer’s disease. In this review, relatively new insights are addressed regarding the notion that Alzheimer’s disease can be caused by bacterial (as well as viral) infections, together with the most recent findings that raloxifene can counteract infections of at least some bacterial and viral strains. Thus, here, an overview of potential treatments of neurodegenerative disease by raloxifene is presented, and attention is paid to subcellular molecular biological pathways that may be involved.