In recent years, one of the most important issues in public health is the rapid growth of antibiotic resistance among pathogens. Multidrug-resistant (MDR) strains (mainly Enterobacteriaceae and non-fermenting bacilli) cause severe infections, against which commonly used pharmaceuticals are ineffective. Therefore, there is an urgent need for new treatment options and drugs with innovative mechanisms of action. Natural compounds, especially alkaloids, are showing promising potential in this area. This review focuses on the ability of the isoquinoline alkaloid berberine (BRB) to overcome various resistance mechanisms against conventional antimicrobial agents. BRB has demonstrated significant activity in inhibiting efflux pumps of the RND (Resistance-Nodulation-Cell Division) family, such as MexAB-OprM (P. aeruginosa) and AdeABC (A. baumannii). Moreover, BRB was able to decrease quorum sensing activity in both Gram-positive and Gram-negative pathogens, resulting in reduced biofilm formation and lower bacterial virulence. Additionally, BRB has been identified as a potential inhibitor of FtsZ, a key protein responsible for bacterial cell division. Particularly noteworthy, though requiring further investigation, are reports suggesting that BRB might inhibit β-lactamase enzymes, including NDM, AmpC, and ESβL types. The pleiotropic antibacterial actions of BRB, distinct from the mechanisms of traditional antibiotics, offer hope for breaking bacterial resistance. However, more extensive studies, especially in vivo, are necessary to fully evaluate the clinical potential of BRB and determine its practical applicability in combating antibiotic-resistant infections.

Pertussis is an infectious disease that contributes to hundreds of thousands of deaths worldwide each year. Despite the prevalence of preventive vaccination programs, there has been an increasing number of new cases of the disease over the past few decades. This poses a particular problem for the pediatric population among whom the highest mortality from the disease is recorded. Several reasons for this phenomenon can be mentioned, but what is particularly important from the microbiological point of view is the correlation of the increased number of pertussis cases with the introduction of a new form of vaccine—the acellular vaccine in place of the whole-cell vaccine. In this review, we summarized the current state of knowledge on potential factors that may contribute to the decline in immunization efficacy against the pathogen. The post-vaccination response profile, symptomatic of vaccination with vaccination-acellular, is characterized by recruitment of Th₂ and Th₁₇ lymphocytes; it has been reported that in the long term, this results in insufficient activation of B cells and low titers of antibodies to key bacterial antigens (hemagglutinin, pertactin). Moreover, the immune response proceeds by bypassing the recruitment of tissue-resident memory T cells, resulting in a lack of protection against colonization of the nasal cavity by the bacterium despite vaccination. The decline in vaccination efficacy should also be attributed to the phenotypic variability of Bordetella. The popularization of the PtxP3 strain, characterized by its ability to incompletely activate immune mechanisms, poses a real threat to public health. The growing resistance of B. pertussis to standardly used antibiotics including macrolides also remains a problem. This makes it difficult to eradicate pathogens from the nasal cavity area and increases the pool of bacterial carriers in the population area. The increasing prevalence of the disease prompts reflection on more effective methods of prevention. Particularly promising in this field seem to be new vaccines, especially mucosally implemented, e.g., intranasal, or developed on the basis of B. pertussis antigens other than those used so far.

Skin cancers are associated with a significant psychological burden across all age groups, particularly as their global incidence continues to rise. Ultraviolet (UV) radiation—primarily UVA and UVB—remains the leading etiological factor, inducing DNA mutations in key genes such as TP53 and BRAF. Among skin cancers, basal cell carcinoma (BCC) is the most prevalent and typically indolent. In contrast, squamous cell carcinoma (SCC) tends to be more invasive, while melanoma is the most aggressive and prone to metastasis. Melanoma is especially concerning due to its rapid dissemination and its occurrence not only on the skin but also in ocular, mucosal, and nail tissues. These challenges, along with rising treatment resistance and mortality, underscore the urgent need for novel anticancer agents. Berberine—a plant-derived isoquinoline alkaloid—has attracted increasing attention for its broad-spectrum anticancer potential, including against skin cancers. In this review, we summarize current evidence regarding berberine’s mechanisms of action in melanoma and SCC, emphasizing both its preventive and therapeutic effects. We further explore its potential as an adjuvant agent in combination with conventional treatments, offering a promising avenue for enhancing the clinical outcomes of skin cancer therapy.

Biofilm-associated infections pose a significant clinical challenge due to their increased antibiotic tolerance and strong association with multidrug-resistant pathogens. The biofilm protects bacteria against antimicrobial agents and host immune response through a complex matrix, altered cell metabolism, activation of quorum sensing, and overexpression of efflux pumps. Despite the availability of numerous therapeutic strategies, the effectiveness of treatment of these infections remains limited, justifying the search for new pharmaceutics, e.g., compounds of natural origin. Berberine, an isoquinoline alkaloid from the plants of the Berberidaceae family, is of growing interest due to its broad spectrum of antimicrobial and antibiofilm activities. This review summarizes the current state of knowledge regarding the molecular mechanisms of action of berberine against the biofilm forming Gram-(+) and Gram-(−) bacteria. Its effect on bacterial cell adhesion, modulation of quorum sensing, inhibition of extracellular matrix synthesis, disruption of biofilm maturation, and the dispersion process are discussed. The role of berberine as an adjuvant to antibiotic therapy was also analyzed, in particular, its ability to restore bacterial sensitivity to different classes of antibiotics. The pharmacokinetic limitations of berberine and the prospects for the use of modern delivery systems are also considered. The collected data indicate that berberine is a promising factor supporting the treatment of biofilm-related infections.

Chronic inflammation and the associated dysbiosis of the gut microbiota are increasingly recognized as key factors contributing to the development of inflammatory bowel disease (IBD) and colorectal cancer (CRC). The diet–gut microbiota–immune system–cancer axis is considered a key regulator of these processes. Among the bioactive compounds found in the diet, ellagitannins have garnered significant scientific interest due to their conversion by the gut microbiota into biologically active metabolites known as urolithins. Urolithin A (UroA), one of the best characterized compounds, exhibits broad anti-inflammatory, antioxidant, immunomodulatory, and anticancer properties. It modulates signaling pathways associated with inflammation, oxidative stress, mitochondrial dysfunction, and cell proliferation. Furthermore, UroA has been shown to improve intestinal barrier integrity, regulate immune cell activity, and induce mitophagy, thereby contributing to the restoration of mitochondrial and cellular homeostasis. A growing body of evidence also suggests that UroA may inhibit cancer cell proliferation, induce apoptosis, and disrupt the molecular pathways involved in colorectal carcinogenesis. This review summarizes the current state of knowledge regarding the biosynthesis and bioavailability of UroA, its molecular mechanisms of action in IBD, and its potential role in the prevention and treatment of CRC. Furthermore, the limitations of UroA-based therapies and future research directions are discussed. Although further, well-designed clinical trials are necessary, current findings suggest that UroA may represent a promising microflora-targeted therapeutic strategy in chronic inflammatory and CRC diseases.

Gastroesophageal reflux disease is one of the most frequently diagnosed conditions in the modern world. It is characterised by repeated movement of stomach acid into the oesophagus, causing irritation and symptoms such as heartburn and regurgitation. Due to their short residence time on the mucous membrane surface, the emulsions used so far do not fulfil their role. This research aimed to examine the effect of calcium alginate on the properties of gels containing chitosan. For this purpose, hydrophilic gels were prepared and tested for pH, dynamic viscosity, and their ability to move in a model simulating conditions in the oesophagus. Alginates have been shown to affect the increase of pH and give the ability to neutralise acidic stomach content. As pH exceeded the upper physiological limit, chitosan offered the potential to restore pH to the physiological range. Its addition had an additional important feature - an increase in the dynamic viscosity of gel and adhesion, which would lead to better gel adhesion to the oesophagus. In summary, the addition of chitosan to methylcellulose gels containing calcium alginate positively influenced the pH, making it more suitable for the oesophagus, and enhanced the dynamic viscosity, allowing the gel to adhere to the mucous membrane surface for protective purposes against reflux.