Synergistic Effects of Green Tea and Herbal Extracts Against Urinary Tract Infection (UTI) Pathogens

Abstract

If treatment is not received, Urinary Tract Infections (UTIs), which are frequent microbial illnesses affecting the urinary system, can lead to discomfort and problems. Because they have antibacterial qualities and can potentially reduce UTI symptoms, natural treatments have been used. Supplements or juice made from cranberries are one popular natural treatment. Proanthocyanidins, which are found in cranberries, have the potential to inhibit bacteria, especially E. coli, from adhering to the lining of the urinary tract, hence decreasing the risk of infection. Its efficacy is still up for discussion, though , and certain drinks’ high sugar content may make UTI symptoms worse. D-mannose, a kind of sugar included in fruits like peaches and cranberries, is another commonly utilised treatment. mannose inhibits germs from sticking to the walls of the urinary system, in a manner akin to that of cranberries. It’s believed to be effective against E. coli, a common UTI-causing bacterium, but it’s ideal dosage and long-term effects require further research. Probiotics are thought to be helpful for UTIs, particularly those that contain lactobacilli strains. They may lessen the chance of infection by assisting in the maintenance of a balanced population of bacteria in the urinary tract and gut. There is, however, little data to support their direct influence on UTI treatment. Herbal treatments with possible antibacterial effects, such as buchu, goldenseal, and bearberry (uva-ursi), have been used historically. These herbs have ingredients that may aid in the battle against germs in the urinary system, but further research is needed to determine how safe and effective they are. Increasing water consumption is a simple yet effective treatment. Drinking enough water dilutes urine, which lowers the quantity of bacteria that could lead to an illness, and aids in the removal of bacteria from the urinary system. Even while these natural treatments seem promising for treating UTIs, it is important to see a doctor before using them, particularly if you think the illness may be serious. Certain medical issues may prevent the use of natural therapies, or they may interact negatively with medicines. When used as the only treatment for acute UTIs, they are frequently less successful than when used as preventative measures or in conjunction with traditional medicines. The main line of treatment for severe or persistent UTIs is still medical intervention.

Keywords

Introduction

Urinary tract infections (UTIs) are among the most common bacterial infections worldwide, affecting millions of individuals each year and placing a significant burden on healthcare systems. They are primarily caused by uropathogenic bacteria such as Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Staphylococcus saprophyticus. The increasing prevalence of antibiotic-resistant strains has made the treatment of UTIs more challenging, leading to higher recurrence rates, prolonged illness, and increased medical costs. This growing antimicrobial resistance crisis underscores the urgent need for alternative and complementary therapeutic strategies. In recent years, there has been a renewed interest in plant-based therapies due to their wide availability, lower side effects, and diverse bioactive compounds. Among these, green tea (Camellia sinensis) has attracted considerable attention for its potent antimicrobial, antioxidant, and anti-inflammatory properties. The major active constituents of green tea, particularly catechins such as epigallocatechin gallate (EGCG), have demonstrated inhibitory effects against a broad spectrum of pathogenic microorganisms, including UTI-causing bacteria. Green tea has also been shown to interfere with bacterial adhesion, biofilm formation, and virulence factors, which are critical in the pathogenesis of UTIs. Similarly, various herbal extracts—derived from plants such as cranberry (Vaccinium macrocarpon), garlic (Allium sativum), turmeric (Curcuma longa), and others— have been traditionally used in the prevention and treatment of urinary infections. These herbs possess antimicrobial, anti-adhesive, and immunomodulatory properties that can help combat uropathogens. Importantly, many herbal compounds exhibit mechanisms distinct from conventional antibiotics, making them promising candidates in overcoming antibiotic resistance. The concept of synergism, where the combined effect of two or more agents exceeds the sum of their individual effects, has gained attention in phytotherapy research. Combining green tea with selected herbal extracts may enhance antimicrobial efficacy, reduce required dosages, and minimize the risk of resistance development. Such synergistic interactions could target multiple pathways simultaneously, including bacterial growth inhibition, disruption of biofilms, and modulation of host immune responses. This review aims to explore the synergistic effects of green tea and various herbal extracts against UTI pathogens. It will summarize current findings on their antimicrobial mechanisms, evaluate evidence from in vitro and in vivo studies, and discuss their potential as alternative or adjunct therapies in the management of urinary tract infections. Additionally, the review will highlight existing gaps in research and propose directions for future studies to better understand and utilize these natural combinations in clinical practice.

2. Pathophysiology of UTIs :

The hematogenous and ascending routes are the primary pathways through which Pathogens can enter and spread within the urinary system. In contrast, there is limited Evidence to suggest that infections commonly spread to the urinary system via the Lymphatic channels. Ascending Infections Urinary tract infections (UTIs) in women often follow an upward progression. These Infections typically originate from fecal flora uro pathogens that colonize the vaginal Introitus, displacing the normal microbial flora. A critical early stage in recurrent UTIs is the Colonization of the vaginal introitus by Escherichia coli (E. Coli). From there, the urethra Serves as the main pathway for the uro pathogen to reach the bladder.[9] KRONIKA JOURNAL (ISSN NO-0023:4923) VOLUME 26 ISSUE 2 2026 PAGE NO: 342 Hematogenous spread refers to the distribution of infection through the bloodstream. While urinary tract infections are more common in females due to the ascending route Hematogenous kidney infections occur less frequently.

These infections are typically Caused by Staphylococcus aureus, a Grampositive bacterium often responsible for Bacteraemia and endocarditis. It is the leading cause of renal parenchymal infections via the bloodstream, such as kidney abscesses. In contrast, hematogenous kidney infections Caused by Gram-negative bacteria are extremely rare [10,11] lymphatogenous Spread In men, infections can enter the bladder and prostate via lymphatic veins from the colon and rectum. In women, lymphatic spread occurs through the peri uterine lymphatic vessels, Facilitating infection of the urinary tract.

3. Herbs user for the management and treatment for UTI :

3.1 GREEN TEA (Camellia sinensis) :

Green tea is derived from the tea plant Camellia sinensis, which belongs to the family theaceae. Green tea is generally safe, non-toxic, and free from side effects when Consumed [28,29,30] Green tea is made from the non-fermented leaves of the Camellia sinensis plant, while Black teas are produced from its fermented leaves [31,32] .The primary active components in green tea responsible for its various Effects are polyphenols, specifically catechins. The main catechins found in green tea Include (−)-epicatechin (EC), (−)-epicatechin3-gallate (ECG), (−)- KRONIKA JOURNAL(ISSN NO-0023:4923) VOLUME 26 ISSUE 2 2026 PAGE NO: 345 epigallocatechin (EGC), And (−)-epigallocatechin-3-gallate (EGCG), which together account for roughly 30–40% of The water soluble content in brewed green tea [33,34]Among these, ECG, EGC, and EGCG have demonstrated antimicrobial activity against a Broad range of microorganisms. Camellia sinensis is known to contain a wide array of Phytoconstituents, including catechins, alkaloids, proteins, enzymes, vitamins, Carbohydrates, polyphenols, lipids, and minerals. [35,36,37,38,39,40] The analysis of its volatile components is typically Performed using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS), a hyphenated analytical technique. As the name suggests, GC-MS combines two Methods: gas chromatography, which separates the individual components of a mixture, and mass spectrometry, which identifies and characterizes each.

3.2 Plant Description :

Green tea derived from the leaves of the camellia sinensis plant. Originally cultivated in East Asia, this plant grow as large as a shrub or tree. Today, Camellia sinensis grows throughout Asia and parts of the Middle East and Africa. People in Asian countries more commonly consume green oolong tea while black tea is most popular the United States. Green tea is prepared from unfermented leaves, the leaves of oolong tea are partially fermented, and black tea is fully fermented.

3.3 Chemical Constituent :

The healthful properties of green tea are largely attributed to polyphenols, chemicals with potent antioxidant properties. In fact, the antioxidant effects of polyphenols appear to be greater than vitamin C. The polyphenols in green tea also give it a somewhat bitter flavour. Polyphenols contained in teas are classified as catechins. Green tea contains six primary catechin compounds: catechin, Gallaogatech in, epicatech in, epigallocatechin, epicatechin gallate, and apigallocatech in gallate (also known as EGCG) [6-9]. EG CG is the most studied polyphenol component in green tea and the most active [10]. Green tea also contains alkaloids including caffeine [11], Theobromine [12], and theophylline. These alkaloids provide green tea's stimulant effects. Tea leaves contain many compounds, such as polysaccharides, volatile oils, vitamins, minerals, purines, alkaloids e.g. caffeine and polyphenols e.g. catechins, flavonoids. Although all three tea types have antibacterial and free radical capturing (antioxidizing) activities, the efficacy decreases substantially the darker the variety of tea. This is due to lower contents of anti-oxidising polyphenols remaining in the leaves. The polyphenols found in tea are more commonly known as flavanols or catechins and comprise 30-40 percent of the extractable solids of dried.

4. Antimicrobial Sensitivity Test (In Vitro Testing) :

Antibiotic susceptibility test was determined using the Kirby-Bauer disc diffusion method according to the recommendations of the Clinical and Laboratory Standard Institute - CLSI (CLSI, 2015). The isolates were subcultured on nutrient agar and incubated at 37°C for 18-24 h. Thereafter, the colonies of each of the isolate were adjusted to 0.5 McFarland turbidity standards in sterile nutrient broth. The standardized broth culture was incubated for 10 min and using sterile swab stick, the standardized broth culture of the isolates was inoculated onto Mueller-Hinton agar plates. The surface of the medium was streaked in four directions while the plates were rotated approximately 60° to ensure even distribution. The inoculated Mueller Hinton agar plates were allowed to dry for few minutes. The following standard antibiotic discs (Oxoid, UK) were used against the isolates ciprofloxacin, aztreonam, nalidixic acid, ceftazidime, and cefotaxime. Sterilized forceps were used to place the antibiotic discs evenly on the inoculated Mueller-Hinton agar so that the disc should be about 15 mm from the edge of the plate and not closer than 25 mm from disc to disc. After 30 min, the plates were inverted and incubated for 24 h. A ruler was used to measure the diameter of each zone of inhibition in mm on the underside of the plate. The inhibitory zone diameter was interpreted as susceptible or resistant according to the criteria of CLSI (2015).

5. Synergistic effect :

Studies have shown that combining green tea with herbal extracts enhances antimicrobial efficacy.

Green tea + cranberry: Improved prevention of E. coli adhesion.

Green tea + garlic: Increased bacterial cell death.

Green tea + hibiscus: Enhanced inhibition of bacterial growth synergy occurs due to the combined action of different bioactive compounds targeting multiple pathways.

6. Discussion :

We are using several allopathic medicines for Urinary tract infection it produces major side effects. Now days plant extract also have major therapeutic action in Urinary tract infection to treat that it also proved in scientific research. we have referred several research articles as well as some popular journals to manage Urinary tract infection by using some plant herbs and their bioactive molecules. In this generation herbal plants are have main therapeutic effects as well as fewer side effects. Women are facing lot of problems the major problem are Urinary tract infection by treating with herbs 95% problems have been cured. We have discussed some plant herbs like Green tea, garlic, ginger, cranberry, tulsi, grapefruits, horse reddish, clove, moringa, uva-ursi, buchu, kantakari, echinacea purpurea, chamomilla flower, hybanthus etc… By using this plant herbs treat and manage the Urinary tract infection with lesser side effects and more therapeutic effect. The bio constituent also play a major role in the UTI problem. Some bio constituents have been discussed above the article are Epigallocatechin gallate, Resveratrol, Flavonoids, Type A procyanidins, sinigrin, eugenol, allicin, 6- gingerol, quercetin, arbutin, etc. We concluded by using this plant herbs and bio active constituents are Anti- microbial, Anti-inflammatory, Diuretics some other actions also produced like Anti- adhesive, Anti- biofilm activity, Immunomodulatory effect. By using plant herbs and bio active constituents we have conclude our discussion it produce potential action and fewer side effects.

CONCLUSION

In this review, antimicrobial and synergistic effects of green tea for treatment of UTIs have been evaluated. UTIs are the most common nosocomial infections, and result in billions of dollars in medical care costs.1, 3Green tea is a safe, nontoxic, cheap, and widely available drink in Asian countries. Green tea catechins have antimicrobial effects against different bacteria and synergistic effect with antibiotics like chloramphenicol, amoxicillin, sulfamethoxazole, azithromycin, levofloxacin, gentamycin, methicillin nalidixic acid, and, especially, ciprofloxacin. 7, 36, 40, 42, 43, 44, 45 Therefore, it may improve the treatment of UTI and decrease its costs. Different studies have reported the antimicrobial effect of green tea against E. coli, which is the most important cause of 80–90% of all UTIs. EGC and ECGg have been shown to have the greatest antimicrobial effects but only EGC has been shown to be excreted in urine. Several studies showed that a cup of Japanese green tea (approximately contains 7.5 g of dried green tea leaves) is equivalent to approximately 150 mg of EGC. Urinary excretion of EGC peaked 8 hours after a single ingested dose and ECG levels in the urine reached 3–5 mg, which is a high enough concentration to potentially be effective as an antimicrobial agent.3, 46Data from in vitro studies on the antimicrobial effects of green tea are promising, but human data are currently lacking. Therefore, it is essential to have in vivo studies on antibacterial effects of green tea and evaluated the efficacy of its catechins in the treatment of UTIs in the future. Human clinical trial also need to evaluate the synergistic effect between green tea and antibiotics used in UTIs.

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