Antiviral Therapeutic Potential of Curcumin: An Update

Advances in Nanocarrier Systems for Overcoming Formulation Challenges of Curcumin: Current Insights

Curcumin, an organic phenolic molecule that is extracted from the rhizomes of Curcuma longa Linn, has undergone extensive evaluation for its diverse biological activities in both animals and humans. Despite its favorable characteristics, curcumin encounters various formulation challenges and stability issues that can be effectively addressed through the application of nanotechnology. Nano-based techniques specifically focused on enhancing solubility, bioavailability, and therapeutic efficacy while mitigating toxicity, have been explored for curcumin. This review systematically presents information on the improvement of curcumin's beneficial properties when incorporated, either individually or in conjunction with other drugs, into diverse nanosystems such as liposomes, nanoemulsions, polymeric micelles, dendrimers, polymeric nanoparticles, solid-lipid nanoparticles, and nanostructured lipid carriers. Additionally, the review examines ongoing clinical trials and recently granted patents, offering a thorough overview of the dynamic landscape in curcumin delivery. Researchers are currently exploring nanocarriers with crucial features such as surface modification, substantial loading capacity, biodegradability, compatibility, and autonomous targeting specificity and selectivity. Nevertheless, the utilization of nanocarriers for curcumin delivery is still in its initial phases, with regulatory approval pending and persistent safety concerns surrounding their use.

Entry inhibitors as arenavirus antivirals

Arenaviruses belonging to the Arenaviridae family, genus mammarenavirus, are enveloped, single-stranded RNA viruses primarily found in rodent species, that cause severe hemorrhagic fever in humans. With high mortality rates and limited treatment options, the search for effective antivirals is imperative. Current treatments, notably ribavirin and other nucleoside inhibitors, are only partially effective and have significant side effects. The high lethality and lack of treatment, coupled with the absence of vaccines for all but Junín virus, has led to the classification of these viruses as Category A pathogens by the Centers for Disease Control (CDC). This review focuses on entry inhibitors as potential therapeutics against mammarenaviruses, which include both New World and Old World arenaviruses. Various entry inhibition strategies, including small molecule inhibitors and neutralizing antibodies, have been explored through high throughput screening, genome-wide studies, and drug repurposing. Notable progress has been made in identifying molecules that target receptor binding, internalization, or fusion steps. Despite promising preclinical results, the translation of entry inhibitors to approved human therapeutics has faced challenges. Many have only been tested in in vitro or animal models, and a number of candidates showed efficacy only against specific arenaviruses, limiting their broader applicability. The widespread existence of arenaviruses in various rodent species and their potential for their zoonotic transmission also underscores the need for rapid development and deployment of successful pan-arenavirus therapeutics. The diverse pool of candidate molecules in the pipeline provides hope for the eventual discovery of a broadly effective arenavirus antiviral.

Phytochemical profiling of the essential oils from three Curcuma species and their in vitro and in silico dengue protease inhibition activity

The chemical compositions, in vitro and in silico anti-dengue activity of the essential oils of the rhizomes of Curcuma longa Linn., C. aeruginosa Roxb., and C. xanthorrhiza Roxb. had been investigated. The C. longa oil was mainly composed of ar-turmerone (54.0%) and curlone (17.7%), while the C. aeruginosa oil was rich in curzerenone (23.4%), 1,8-cineole (21.2%), and camphor (7.1%). Xanthorrhizol (21.6%), β-curcumene (19.5%), ar-curcumene (14.2%), and camphor (9.2%) were the major compounds in the C. xanthorrhiza oil. Among the oils, the C. longa oil was found to be the most active NSB-NS3 protease inhibitor (IC50 1.98 μg/mL). PLS biplot disclosed that the essential oils were classified into three separated clusters based on their characteristic chemical compositions, with C. longa positioned closest to the in vitro anti-dengue activity. Four compounds from the C. longa oil have both hydrogen and hydrophobic bonds that could be responsible for the DENV-2 NS2B-NS3 inhibitory effect.

Curcumin as an antiviral agent and immune-inflammatory modulator in COVID-19: A scientometric analysis

Background

Reports regarding the antiviral activity of curcumin have surfaced. However, to date there has been no scientometric analysis of the relationship between curcumin and Coronavirus Disease 2019 (COVID-19). To comprehensively understand the studies involving curcumin in the context of COVID-19, we conducted a scientometric analysis to provide an exhaustive review of these studies.

Methods

We systematically searched the Web of Science core collection database for bibliographic data indexed from January 1, 2020, to December 31, 2022, using keywords such as 'curcumin', 'COVID-19', and their synonyms. To clarify the research content and trends related to curcumin in COVID-19, we utilized VOSviewer, Origin 2023, and Charticulator for analysis, supplemented by external data.

Results

The final count of publications included in this study was 252. These publications originated from 63 countries or territories, with India contributing the highest number of publications. They were published across 170 journals. Notably, the Egyptian Knowledge Bank (EKB) emerged as the most important institution that carried out this study. The most cited publication had been referenced 166 times. The main elements involved in the keyword analysis were reflected in the antiviral activity of curcumin and the immuno-inflammatory modulation of the inflammatory cytokine storm. Furthermore, the pharmacological mechanisms of curcumin for treating COVID-19 emerged as a prominent area of research. Simultaneously, there exists direct evidence of clinical usage of curcumin to enhance COVID-19 outcomes.

Conclusions

The scientometric analysis underscores the burgeoning professional domain of curcumin-based treatment for COVID-19. Ongoing studies have focused on the antiviral activity of curcumin and its immunomodulatory effects on inflammatory cytokine storms. On the other hand, the pharmacological mechanism of curcumin in the treatment of COVID-19 is a hot spot in the research field at present, which may become the main research trend in this field in the future. While maintaining a focus on foundational research, the clinical application of curcumin in COVID-19 infection is developing in parallel, highlighting its obvious guiding value in clinical practice. These insights offer researchers a snapshot of the present state of curcumin treatment for COVID-19 and guide further mechanistic validation efforts in the future.

Natural photosensitizers potentiate the targeted antimicrobial photodynamic therapy as the Monkeypox virus entry inhibitors: An in silico approach

BACKGROUND

Monkeypox is a viral zoonotic disease that has emerged as a threat to public health. Currently, there is no treatment approved specifically targeting Monkeypox disease. Hence, it is essential to identify and develop therapeutic approaches to the Monkeypox virus. In the current in silico paper, we comprehensively involve using computer simulations and modeling to insights and predict hypotheses on the potential of natural photosensitizers-mediated targeted antimicrobial photodynamic therapy (aPDT) against D8L as a Monkeypox virus protein involved in viral cell entry.

MATERIALS AND METHODS

In the current study, computational techniques such as molecular docking were combined with in silico ADMET predictions to examine how Curcumin (Cur), Quercetin (Qct), and Riboflavin (Rib) as the natural photosensitizers bind to the D8L protein in Monkeypox virus, as well as to determine pharmacokinetic properties of these photosensitizers.

RESULTS

The three-dimensional structure of the D8L protein in the Monkeypox virus was constructed using homology modeling (PDB ID: 4E9O). According to the physicochemical properties and functional characterization, 4E9O was a stable protein with the nature of a hydrophilic structure. The docking studies employing a three-dimensional model of 4E9O with natural photosensitizers exhibited good binding affinity. D8L protein illustrated the best docking score (-7.6 kcal/mol) in relation to the Rib and displayed good docking scores in relation to the Cur (-7.0 kcal/mol) and Qct (-7.5 kcal/mol).

CONCLUSIONS

The findings revealed that all three photosensitizers were found to obey the criteria of Lipinski's rule of five and displayed drug-likeness. Moreover, all the tested photosensitizers were found to be non-hepatotoxic and non-cytotoxic. In summary, our investigation identified Cur, Qct, and Rib could efficiently interact with D8L protein with a strong binding affinity. It can be concluded that aPDT using these natural photosensitizers may be considered an adjuvant treatment against Monkeypox disease.

Curcuma Longa Induces the Transcription Factor FOXP3 to Downregulate Human Chemokine CCR5 Expression and Inhibit HIV-1 Infection

HIV mutations occur frequently despite the substantial success of combination antiretroviral therapy, which significantly impairs HIV progression. Failure to develop specific vaccines, the occurrence of drug-resistant strains, and the high incidence of adverse effects due to combination antiviral therapy regimens call for novel and safer antivirals. Natural products are an important source of new anti-infective agents. For instance, curcumin inhibits HIV and inflammation in cell culture assays. Curcumin, the principal constituent of the dried rhizomes of Curcuma longa L. (turmeric), is known as a strong anti-oxidant and anti-inflammatory agent with different pharmacological effects. This work aims to assess curcumin's inhibitory effects on HIV in vitro and to explore the underpinning mechanism, focusing on CCR5 and the transcription factor forkhead box protein P3 (FOXP3). First, curcumin and the RT inhibitor zidovudine (AZT) were evaluated for their inhibitory properties. HIV-1 pseudovirus infectivity was determined by green fluorescence and luciferase activity measurements in HEK293T cells. AZT was used as a positive control that inhibited HIV-1 pseudoviruses dose-dependently, with IC50 values in the nanomolar range. Then, a molecular docking analysis was carried out to assess the binding affinities of curcumin for CCR5 and HIV-1 RNase H/RT. The anti-HIV activity assay showed that curcumin inhibited HIV-1 infection, and the molecular docking analysis revealed equilibrium dissociation constants of [Formula: see text]9.8[Formula: see text]kcal/mol and [Formula: see text]9.3[Formula: see text]kcal/mol between curcumin and CCR5 and HIV-1 RNase H/RT, respectively. To examine curcumin's anti-HIV effect and its mechanism in vitro, cell cytotoxicity, transcriptome sequencing, and CCR5 and FOXP3 amounts were assessed at different concentrations of curcumin. In addition, human CCR5 promoter deletion constructs and the FOXP3 expression plasmid pRP-FOXP3 (with an EGFP tag) were generated. Whether FOXP3 DNA binding to the CCR5 promoter was blunted by curcumin was examined using transfection assays employing truncated CCR5 gene promoter constructs, a luciferase reporter assay, and a chromatin immunoprecipitation (ChIP) assay. Furthermore, micromolar concentrations of curcumin inactivated the nuclear transcription factor FOXP3, which resulted in decreased expression of CCR5 in Jurkat cells. Moreover, curcumin inhibited PI3K-AKT activation and its downstream target FOXP3. These findings provide mechanistic evidence encouraging further assessment of curcumin as a dietary agent used to reduce the virulence of CCR5-tropic HIV-1. Curcumin-mediated FOXP3 degradation was also reflected in its functions, namely, CCR5 promoter transactivation and HIV-1 virion production. Furthermore, curcumin inhibition of CCR5 and HIV-1 might constitute a potential therapeutic strategy for reducing HIV progression.

Greener Stability-Indicating HPLC Approach for the Determination of Curcumin in In-House Developed Nanoemulsion and Curcuma longa L. Extract

Despite the fact that several analytical methodologies have been reported for the determination of curcumin (CCM) in a wide range of sample matrices, the greener liquid chromatographic approaches to determine CCM are scarce in the literature. Therefore, this research is designed to develop and validate a greener stability-indicating “high-performance liquid chromatography (HPLC)” methodology to determine CCM in an in-house developed nanoemulsion, Curcuma longa L. extract, and commercial tablets. CCM was measured on a Nucleodur (150 mm × 4.6 mm) RP C18 column with 5 µm-sized particles. Ethanol and ethyl acetate (83:17 v/v) made up the greener eluent system, which was pumped at a flow speed of 1.0 mL/min. At a wavelength of 425 nm, CCM was detected. The greener HPLC methodology was linear in the 1–100 µg/mL range, with a determination coefficient of 0.9983. The greener HPLC methodology for CCM estimation was also rapid (Rt = 3.57 min), accurate (%recoveries = 98.90–101.85), precise (%CV = 0.90–1.11), and sensitive (LOD = 0.39 µg/mL and LOQ = 1.17 µg/mL). The AGREE approach predicted the AGREE score of 0.81 for the established HPLC technique, indicating an outstanding greenness profile. The utility of the greener HPLC methodology was demonstrated by determining CCM in the in-house developed nanoemulsion, Curcuma longa extract, and commercial tablets. The % amount of CCM in the in-house developed nanoemulsion, Curcuma longa extract, and commercial tablets was found to be 101.24%, 81.15%, and 78.41%, respectively. The greener HPLC methodology was able to detect its degradation product under various stress conditions, suggesting its stability-indication characteristics. These results suggested that CCM in developed nanoemulsion, plant extract samples, and commercial tablets may be routinely determined using the greener HPLC methodology.

Anti-viral drug discovery against monkeypox and smallpox infection by natural curcumin derivatives: A Computational drug design approach

Background

In the last couple of years, viral infections have been leading the globe, considered one of the most widespread and extremely damaging health problems and one of the leading causes of mortality in the modern period. Although several viral infections are discovered, such as SARS CoV-2, Langya Henipavirus, there have only been a limited number of discoveries of possible antiviral drug, and vaccine that have even received authorization for the protection of human health. Recently, another virial infection is infecting worldwide (Monkeypox, and Smallpox), which concerns pharmacists, biochemists, doctors, and healthcare providers about another epidemic. Also, currently no specific treatment is available against Monkeypox. This research gap encouraged us to develop a new molecule to fight against monkeypox and smallpox disease. So, firstly, fifty different curcumin derivatives were collected from natural sources, which are available in the PubChem database, to determine antiviral capabilities against Monkeypox and Smallpox.

Material and method

Preliminarily, the molecular docking experiment of fifty different curcumin derivatives were conducted, and the majority of the substances produced the expected binding affinities. Then, twelve curcumin derivatives were picked up for further analysis based on the maximum docking score. After that, the density functional theory (DFT) was used to determine chemical characterizations such as the highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), softness, and hardness, etc.

Results

The mentioned derivatives demonstrated docking scores greater than 6.80 kcal/mol, and the most significant binding affinity was at -8.90 kcal/mol, even though 12 molecules had higher binding scores (-8.00 kcal/mol to -8.9 kcal/mol), and better than the standard medications. The molecular dynamic simulation is described by root mean square deviation (RMSD) and root-mean-square fluctuation (RMSF), demonstrating that all the compounds might be stable in the physiological system.

Conclusion

In conclusion, each derivative of curcumin has outstanding absorption, distribution, metabolism, excretion, and toxicity (ADMET) characteristics. Hence, we recommended the aforementioned curcumin derivatives as potential antiviral agents for the treatment of Monkeypox and Smallpox virus, and more in vivo investigations are warranted to substantiate our findings.

Phytochemicals in the Prevention and Treatment of SARS-CoV-2-Clinical Evidence

The first case of SARS-CoV-2 infection was reported in December 2019. Due to the rapid spread of the disease and the lack of adequate therapy, the use of plants that have a long history in the treatment of viral infections has often been considered. The aim of this paper is to provide a brief review of the literature on the use of phytochemicals during the new pandemic. An extensive search of published works was performed through platforms Google Scholar, PubMed, Science Direct, Web of Science and Clinicaltrials.gov. Numerous preclinical studies on the use of phytochemicals (quercetin, curcumin, baicalin, kaempferol, resveratrol, glycyrrhizin, lycorine, colchicine) against SARS-CoV-2 have shown that these components can be effective in the prevention and treatment of this infection. Clinical research has proven that the use of black cumin and green propolis as well as quercetin has positive effects. As for other phytochemicals, in addition to preclinical testing which has already been carried out, it would be necessary to conduct clinical tests in order to assert their effectiveness. For those phytochemicals whose clinical efficacy has been proven, it would be necessary to conduct research on a larger number of patients, so that the conclusions are more representative.