A defined anthocyanin mixture sourced from bilberry and black currant inhibits Measles virus and various herpesviruses

Structural and functional properties of common natural organic cations

BACKGROUND

Natural products have emerged as a critical focus in modern scientific research due to their structural diversity and therapeutic potential. Among these are natural organic cations-a distinct class of nitrogen- and oxygen-containing compounds. Despite their pharmacological relevance, the literature lacks a systematic synthesis of structure-activity relationships for natural organic cations (NOC). This gap hinders the rational development of NOC-based therapies as sustainable alternatives to synthetic compounds.

METHODS

Literature was searched and collected using databases, including PubMed, Science Direct, and Web of Science. The search terms used included "natural organic cation", "alkaloid", "anthocyanin", "structure-activity relationship", "charge interaction", "π-cation interaction", "biological activity", "antimicrobial", "antioxidant", "anticancer", "neuroprotection", "anti-inflammatory", "berberine", "coptisine", "palmatine", "cyanidin", "delphinidin", "pelargonidin", "free radical scavenging", "gut microbiota metabolism", "NF-κB pathway", "G-quadruplex DNA", "isoquinoline alkaloid", "protoberberine", "benzophenanthridine", "planar conjugated system", "charge delocalization", "methylenedioxy group", and several combinations of these words.

RESULTS

The bioactivity of NOC is underestimated. This review uncovers the structure-activity relationships of NOC. Firstly, planar conjugated systems and substituents control target binding: N⁺ in alkaloids enhances DNA/protein affinity, while O⁺ in anthocyanins enables free radical scavenging and enzyme inhibition. Secondly, cationic species outperform neutral analogs in antimicrobial potency, antioxidant capacity, and target selectivity. NOC bind to biomolecules via π-cation/π-π stacking and electrostatic binding. Charge localization in conjugated systems enhances stability and bioactivity.

CONCLUSION

This review consolidates evidence that NOC represent promising candidates for replacing synthetic compounds in therapies for cancer, neurodegeneration, metabolic disorders, etc. Key findings highlight the superiority of cationic species in target engagement and bioactivity, driven by planar conjugated systems and substituent effects. However, clinical translation requires addressing gaps in bioavailability and long-term safety. Future research must prioritize structural optimization and mechanistic validation. By bridging these gaps, NOC could advance as sustainable, low-toxicity agents in precision medicine and functional nutrition.

Improved quality, sensory properties and nutraceutical potential of the fermented beverages fortified with freeze-dried berries and acacia honey

This study evaluates the impact of acacia honey (AH) and freeze-dried berries (raspberry (R) and blackcurrant (B) on yogurt (Y), kefir (K), and buttermilk (BM). The additives (RAH and BAH) were tested for their utility and effects on product formulation, stability, bioactive properties, and immunoreactivity. 0.5-4 % (w/v) freeze-dried fruits and 5 % (w/v) honey enhanced the functional properties of beverages by increasing antioxidant activity (10-20 times) without negatively affecting physicochemical properties. K-BAH exhibited an 80 % higher increase in total polyphenol content compared to K-RAH and other products. Additives also boosted by 1.5 log CFU/mL the growth of specific bacterial and yeast cultures in yogurt and kefir. The products met ISO microbiological standards after 28 days of storage. Safety tests indicated increased cow's alpha-amylase 2B isoform immunoreactivity starting from 1.5 % BAH-containing products. Overall, Y-RAH and Y-BAH demonstrated the highest stability, bioactivity, and sensory appeal (p < 0.05) what was confirmed through QDA and consumer trials.

A systematic analysis of anthocyanins inhibiting human, murine, and equine herpesviruses

BACKGROUND

Herpesviruses are common animal and human pathogens that cause severe health problems in children, immunocompromised patients, and infected animals with a host range from fish to mammals. Anthocyanin-containing plant extracts have been described as potent antivirals, which might cause fewer harmful side effects than direct-acting antivirals. Here, we report that an extract of Aristotelia chilensis (Molina) Stuntz (Elaeocarpaceae) (MBE) with a high content of the anthocyanin delphinidin suppresses lytic replication of equine, murine and human herpesviruses of replication in vitro.

METHODS

We treated cultured cells with MBE and purified individual anthocyanins present in the extract to determine the most active compound at different concentrations. We subsequently infected the cultures with human herpesviruses 1 (HSV-1) or 8 (HHV-8), murine cytomegalovirus (CMV), or equine herpesviruses 1 (EHV-1) and determined the number of infected cells and viral infectivity.

RESULTS

MBE inhibited the HSV-1, murine CMV, and EHV-1 by up to 2 orders of magnitude. In the presence of the stabilizing randomly methylated-beta-cyclodextrin, the inhibitory concentration could be lowered significantly. We identified delphinidin as an active antiviral compound and showed that the non-glycosylated delphinidin solved and stabilized with sulfobutylether-beta-cyclodextrin allowed usage of approximately 50 times lower concentrations.

CONCLUSION

Glycosylated delphinidin derivatives were identified as active antiviral compounds of MBE. This suggests that plant extracts rich in delphinidin-anthocyanins have potent antiviral properties that could be used in treatment and prevention.

Flavonoids with Anti-Herpes Simplex Virus Properties: Deciphering Their Mechanisms in Disrupting the Viral Life Cycle

The herpes simplex virus (HSV) is a double-stranded DNA human virus that causes persistent infections with recurrent outbreaks. HSV exists in two forms: HSV-1, responsible for oral herpes, and HSV-2, primarily causing genital herpes. Both types can lead to significant complications, including neurological issues. Conventional treatment, involving acyclovir and its derivatives, faces challenges due to drug resistance. This underscores the imperative for continual research and development of new drugs, with a particular emphasis on exploring the potential of natural antivirals. Flavonoids have demonstrated promise in combating various viruses, including those within the herpesvirus family. This review, delving into recent studies, reveals the intricate mechanisms by which flavonoids decode their antiviral capabilities against HSV. By disrupting key stages of the viral life cycle, such as attachment to host cells, entry, DNA replication, latency, and reactivation, flavonoids emerge as formidable contenders in the ongoing battle against HSV infections.

Modulation of the replication of positive-sense RNA viruses by the natural plant metabolite xanthohumol and its derivatives

The COVID-19 pandemic has highlighted the importance of identifying new potent antiviral agents. Nutrients as well as plant-derived substances are promising candidates because they are usually well tolerated by the human body and readily available in nature, and consequently mostly cheap to produce. A variety of antiviral effects have recently been described for the hop chalcone xanthohumol (XN), and to a lesser extent for its derivatives, making these hop compounds particularly attractive for further investigation. Noteworthy, mounting evidence indicated that XN can suppress a wide range of viruses belonging to several virus families, all of which share a common reproductive cycle. As a result, the purpose of this review is to summarize the most recent research on the antiviral properties of XN and its derivatives, with a particular emphasis on the positive-sense RNA viruses human hepatitis C virus (HCV), porcine reproductive and respiratory syndrome virus (PRRSV), and severe acute respiratory syndrome corona virus (SARS-CoV-2).

The Flavonoid Cyanidin Shows Immunomodulatory and Broad-Spectrum Antiviral Properties, Including SARS-CoV-2

New antiviral treatments are needed to deal with the unpredictable emergence of viruses. Furthermore, vaccines and antivirals are only available for just a few viral infections, and antiviral drug resistance is an increasing concern. Cyanidin (a natural product also called A18), a key flavonoid that is present in red berries and other fruits, attenuates the development of several diseases, through its anti-inflammatory effects. Regarding its mechanism of action, A18 was identified as an IL-17A inhibitor, resulting in the attenuation of IL-17A signaling and associated diseases in mice. Importantly, A18 also inhibits the NF-κB signaling pathway in different cell types and conditions in vitro and in vivo. In this study, we report that A18 restricts RSV, HSV-1, canine coronavirus, and SARS-CoV-2 multiplication, indicating a broad-spectrum antiviral activity. We also found that A18 can control cytokine and NF-κB induction in RSV-infected cells independently of its antiviral activity. Furthermore, in mice infected with RSV, A18 not only significantly reduces viral titers in the lungs, but also diminishes lung injury. Thus, these results provide evidence that A18 could be used as a broad-spectrum antiviral and may contribute to the development of novel therapeutic targets to control these viral infections and pathogenesis.

Molecular Mechanisms of Flavonoids against Tumor Gamma-Herpesviruses and Their Correlated Cancers-A Focus on EBV and KSHV Life Cycles and Carcinogenesis

Epstein-Barr virus (EBV) and Kaposi sarcoma-associated herpesvirus (KSHV) are cancer-causing viruses that belong to human gamma-herpesviruses. They are DNA viruses known to establish lifelong infections in humans, with the ability to develop various types of cancer. Drug resistance remains the main barrier to achieving effective therapies for viral infections and cancer. Thus, new medications with dual antiviral and anticancer actions are highly needed. Flavonoids are secondary metabolites biosynthesized by plants with diverse therapeutic effects on human health. In this review, we feature the potential role of flavonoids (flavones, protoflavones, isoflavones, flavanones, flavonols, dihydroflavonols, catechins, chalcones, anthocyanins, and other flavonoid-type compounds) in controlling gamma-herpesvirus-associated cancers by blocking EBV and KSHV infections and inhibiting the formation and growth of the correlated tumors, such as nasopharyngeal carcinoma, Burkitt's lymphoma, gastric cancer, extranodal NK/T-cell lymphoma, squamous cell carcinoma, Kaposi sarcoma, and primary effusion lymphoma. The underlying mechanisms via targeting EBV and KSHV life cycles and carcinogenesis are highlighted. Moreover, the effective concentrations or doses are emphasized.

Introduction to Traditional Medicine and Their Role in Prevention and Treatment of Emerging and Re-Emerging Diseases

Infectious diseases have been a threat to human health globally. The relentless efforts and research have enabled us to overcome most of the diseases through the use of antiviral and antibiotic agents discovered and employed. Unfortunately, the microorganisms have the capability to adapt and mutate over time and antibiotic and antiviral resistance ensues. There are many challenges in treating infections such as failure of the microorganisms to respond to the therapeutic agents, which has led to more chronic infections, complications, and preventable loss of life. Thus, a multidisciplinary approach and collaboration is warranted to create more potent, effective, and versatile therapies to prevent and eradicate the old and newly emerging diseases. In the recent past, natural medicine has proven its effectiveness against various illnesses. Most of the pharmaceutical agents currently used can trace their origin to the natural products in one way, shape, or form. The full potential of natural products is yet to be realized, as numerous natural resources have not been explored and analyzed. This merits continuous support in research and analysis of ancient treatment systems to explore their full potential and employ them as an alternative or principal therapy.