Berberine is a natural isoquinoline alkaloid extracted from several plants, e.g. those of the Berberis genera. It has been used from centuries in the traditional chinese and ayurvedic medicine to treat enteric diarrheas and other intestinal infections, thanks to its strong antimicrobial activity.

The urogenital infections happen when bacteria cross the urethra and reach the urinary tract and here they proliferate and grow, leading to inflammation. This kind of pathologies are common, especially in women, but they can happen in both sexes and at all ages.

The urogenital infections are many: cystitis are inflammations of the bladder and are the most frequent; urethritis are inflammations of the urethra; ureteritis are inflammations of the ureter. The bacteria usually responsible for these infections are Escherichia coli, Staphylococcus saprophyticus, Klebsiella pneumoniae and Proteus mirabilis. There are also the vaginal infections, which can have bacterial, fungal (the Candida species) or viral origins.

Berberine is an interesting compound to treat urogenital infections, with many advantages compared to the more common and largely used antibiotics. First of all, not all the infections are bacterial infection, so the antibiotic treatment is not always suitable. Secondly, these pathologies are often recurrent, so the first antibiotic treatment improve the symptoms without eradicating the infection, if a second antibiotic treatment is required, it weaken the immune system and the beneficial microbiome, exposing to new infections. Moreover, the use of antibiotics contributes to the spread of antibiotic resistant bacteria. So, the use of antimicrobial compound as alternatives to antibiotics is the solution to many points.

Here some studies about the antimicrobial properties of berberine are reported.

Chu and colleagues (2014) evaluated the effect of berberine treatments against the enteritis caused by LPS, a bacterial endotoxin. As shown in the figure, berberine allows the decreasing of the lethality of the infected mice up to 90%.

The same research group evaluated the ability of berberine to treat Methicillin-resistant Staphylococcus aureus infections, which means caused by S. aureus strains resistant to β-lactam antibiotics: this resistance does not lead to a higher degree of virulence, but makes the infections stronger and more dangerous. One of the most interesting point of the article is the ability of berberine to inhibit the biofilm formation (Chu et al., 2016). Biofilm is a complex aggregation of microorganisms, characterized by the secretion of an adhesive and protective substance and in this form the bacterial infections are hard to defeat. The ability of berberine to weaken the biofilm makes it a strong ally in the treatment of bacterial infection, since biofilms can colonize also the tissues of the organs involved in the previous mentioned diseases.

One of the most common causes of cystitis is E. coli and many strains belonging to this species are resistant to many antibiotics. The research of Bandyopadhyay et al. (2013) shows that berberine is able to reduce E. coli multi-resistant strains vitality up to 90%, representing a strategy to treat these dangerous pathogens.

Interestingly, berberine is active also against several species of Candida, a fungus often associated to vaginal infections. Berberine is able to inhibit the fungal biofilm formation, which results in a poorer structure, in terms of cells number and organization, as shown in the figure (Xie et al., 2020). The antifungal activity of berberine is possible thanks to the ability to alter the cellular membranes; the consequences of this effect are lower levels of ATP, mitochondrial damage and, in the end, cellular death (da Silva et al., 2016).

We highlighted some researches about the antimicrobial properties of berberine, in particular related to urogenital infections, for which the traditional antibiotic treatments are often not suitable.

References

Bandyopadhyay, S., Patra, P. H., Mahanti, A., Mondal, D. K., Dandapat, P., Bandyopadhyay, S., … & Baruah, K. K. (2013). Potential antibacterial activity of berberine against multi drug resistant enterovirulent Escherichia coli isolated from yaks (Poephagus grunniens) with haemorrhagic diarrhoea. Asian Pacific journal of tropical medicine, 6(4), 315-319.

Chu, M., Ding, R., Chu, Z. Y., Zhang, M. B., Liu, X. Y., Xie, S. H., … & Wang, Y. D. (2014). Role of berberine in anti-bacterial as a high-affinity LPS antagonist binding to TLR4/MD-2 receptor. BMC complementary and alternative medicine, 14(1), 1-9.

Chu, M., Zhang, M. B., Liu, Y. C., Kang, J. R., Chu, Z. Y., Yin, K. L., … & Wang, Y. D. (2016). Role of berberine in the treatment of methicillin-resistant Staphylococcus aureus infections. Scientific reports, 6(1), 1-9.

da Silva, A. R., de Andrade Neto, J. B., da Silva, C. R., Campos, R. D. S., Costa Silva, R. A., Freitas, D. D., … & Nobre Júnior, H. V. (2016). Berberine antifungal activity in fluconazole-resistant pathogenic yeasts: action mechanism evaluated by flow cytometry and biofilm growth inhibition in Candida spp. Antimicrobial agents and chemotherapy, 60(6), 3551-3557.

Xie, Y., Liu, X., & Zhou, P. (2020). In vitro antifungal effects of berberine against Candida spp. In planktonic and biofilm conditions. Drug design, development and therapy, 14, 87.