Investigation of the Therapeutic Potential of Annona Muricata Tea on Oxidative Stress Markers, Testosterone, and Prostate Tumor Biomarkers in Patients with Prostate Cancer in Awka

Prostate cancer remains a leading cause of cancer-related morbidity and mortality among men worldwide. Oxidative stress and hormonal imbalance play significant roles in its pathogenesis and progression. Annona muricata (soursop) has been reported to possess antioxidant and anticancer properties; however, clinical evidence using readily consumable forms such as tea is limited. 

Objective: This study aimed to evaluate the therapeutic effects of Annona muricata tea on oxidative stress biomarkers, serum testosterone, and total prostate-specific antigen (TPSA) in patients with prostate cancer. 

Methods: This randomized controlled interventional study was conducted at the Chukwuemeka Odumegwu Ojukwu University Teaching Hospital, Awka, Nigeria. Forty (40) male participants with histologically confirmed prostate cancer were randomly assigned into two groups: treatment (n = 20) and control (n = 20). Participants in the treatment group consumed Annona muricata tea (200 mL, twice daily) for 8 weeks, while the control group received a placebo beverage. Blood samples were collected at baseline and after the intervention. Oxidative stress biomarkers—malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH)—were analyzed using standard spectrophotometric methods. Serum testosterone was measured using ELISA, while TPSA was determined using chemiluminescent immunoassay (CLIA). Data were analyzed using SPSS version 25.0. Statistical significance was set at p < 0.05. 

Results: The treatment group showed a significant reduction in MDA levels and a significant increase in antioxidant enzymes (SOD, CAT, and GSH) compared to baseline (p < 0.05). Serum testosterone levels increased significantly, while TPSA levels decreased markedly following Annona muricata tea consumption (p < 0.05). In contrast, no significant changes were observed in the control group. The intervention was well tolerated, with only mild adverse effects reported. 

Conclusion: Annona muricata tea significantly improves oxidative stress status, enhances antioxidant defenses, modulates testosterone levels, and reduces TPSA in prostate cancer patients. These findings suggest that it may serve as a safe and effective adjunct therapy in prostate cancer management.

Prostate cancer is one of the most frequently diagnosed malignancies among men globally and remains a major contributor to cancer-related morbidity and mortality. Its prevalence continues to rise with increasing life expectancy, particularly in aging male populations [1]. Epidemiological data indicate that prostate cancer is especially common in men above 50 years of age, with higher incidence rates reported in developed regions, although mortality is disproportionately higher in developing countries due to late presentation and limited access to screening and treatment [2].

The development of prostate cancer is multifactorial, involving genetic predisposition, hormonal imbalance, environmental exposure, dietary habits, and lifestyle factors. Androgenic stimulation, particularly through testosterone and its more active form dihydrotestosterone (DHT), plays a central role in prostate cell proliferation and tumor progression. In addition, dietary patterns high in saturated fats and red meat, obesity, physical inactivity, alcohol consumption, and exposure to environmental toxins have all been implicated in increasing risk [3-,5]. Conversely, lifestyle interventions such as regular physical activity and diets rich in fruits, vegetables, and natural antioxidants have been associated with a reduced risk of prostate cancer development and progression.

Clinically, prostate cancer diagnosis and monitoring rely heavily on the measurement of total prostate-specific antigen (TPSA), digital rectal examination, imaging techniques, and histological confirmation through biopsy. Elevated TPSA levels are commonly used as a biomarker for early detection and disease monitoring, although they are not entirely specific. Hormonal profiling, particularly serum testosterone levels, also provides insight into disease progression and treatment response, as hormonal shifts significantly influence tumor growth dynamics [6-8].

Oxidative stress has been increasingly recognized as a key mechanism in prostate carcinogenesis. It results from an imbalance between reactive oxygen species (ROS) production and the body’s antioxidant defense systems, leading to cellular damage, lipid peroxidation, DNA mutations, and chronic inflammation. [8-10]. This oxidative imbalance is strongly associated with tumor initiation and progression. Biomarkers such as malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH) are widely used to assess oxidative stress status and antioxidant capacity in cancer studies [8-10].

In addition to oxidative stress, hormonal dysregulation is a critical feature of prostate cancer pathophysiology. Alterations in testosterone levels and androgen receptor signaling contribute significantly to tumor growth and progression. These hormonal shifts, combined with oxidative damage, create a biological environment that promotes malignancy and resistance to therapy [11,12].

Conventional treatment modalities, including surgery, radiotherapy, and chemotherapy, remain the mainstay of prostate cancer management. However, these approaches are often associated with significant adverse effects, high cost, and variable efficacy, particularly in advanced disease stages. As a result, there is growing interest in complementary and alternative therapeutic strategies, especially those derived from natural products with antioxidant, anti-inflammatory, and hormone-modulating properties [13,14].

Annona muricata, commonly known as soursop or graviola, is widely used in traditional medicine across Africa, South America, and the Caribbean. It has been reported to possess diverse pharmacological activities, including antioxidant, anti-inflammatory, and anticancer effects. These biological activities are attributed to its rich phytochemical composition, which includes annonaceous acetogenins, flavonoids, alkaloids, phenolic compounds, and vitamin C. These compounds have demonstrated potential in modulating oxidative stress, inducing cancer cell apoptosis, and regulating hormonal activity [15-17].

Despite extensive preclinical evidence from in vitro and animal studies, there remains limited clinical research evaluating the effects of Annona muricata in human cancer populations, particularly prostate cancer patients. Furthermore, although soursop tea is widely consumed as a traditional remedy, its use in a standardized, commercially prepared tea bag form has not been adequately explored in clinical settings.

This study therefore addresses this research gap by evaluating the effects of Annona muricata tea consumption on oxidative stress biomarkers (MDA, SOD, CAT, and GSH), serum testosterone levels, and total prostate-specific antigen (TPSA) in patients with prostate cancer. The findings aim to provide clinical evidence on its potential role as a complementary therapeutic agent, particularly through its antioxidant and hormonal modulatory effects in prostate cancer management.

Study Design

This study was a randomized, controlled, interventional clinical trial designed to assess the effects of Annona muricata tea on oxidative stress markers, serum testosterone, and TPSA levels in male patients with prostate cancer.

Study Area and Population

The study was conducted at Chukwuemeka Odumegwu Ojukwu Teaching Hospital Awka, Anambra State, Nigeria. Participants were recruited from urology and oncology outpatient clinics. Diagnosis of prostate cancer was confirmed through histological findings and elevated TPSA levels.

Inclusion Criteria

Participants eligible for inclusion in this study were males aged between 40 and 80 years with histologically confirmed prostate cancer. In addition, individuals were required not to be currently using antioxidant supplements or herbal therapies, in order to avoid potential confounding effects on study outcomes. All participants were also required to demonstrate willingness to provide informed consent prior to enrollment.

Exclusion Criteria

Individuals were excluded from the study if they were undergoing chemotherapy, radiotherapy, or hormone therapy at the time of recruitment. Patients with a history of other malignancies were also excluded to ensure the specificity of findings. Furthermore, those with severe comorbid conditions, including hepatic, renal, or cardiovascular diseases, were not considered eligible. Participants with a history of substance abuse were similarly excluded to minimize potential interference with compliance and study results.

Sample Size and Randomization

A total of 40 participants were recruited for the study and were randomly assigned to two groups. The treatment group, consisting of 20 participants, received Annona muricata tea, while the control group, also comprising 20 participants, received a placebo beverage. This random allocation was implemented to reduce selection bias and ensure comparability between groups.

Ethical Approval: Ethical clearance was obtained from the Research Ethics Committee of Chukwuemeka Odumegwu Ojukwu University Awka with reference number of COOUTH/HREC/VOL.11/412.   Written informed consent was obtained from all participants.

Preparation and Administration of Annona muricata Tea

The Commercially available Annona muricata (soursop) tea was obtained from Lipton Company (Unilever Nigeria Ltd) and was of the same brand and batch number 16255. NAFDAC Reg. NO: B1-8966. Commercially available Annona muricata (soursop) tea bags were utilized in this study to ensure a high level of standardization and reproducibility. Each tea bag, containing approximately 2–3 g of dried soursop leaf material, was prepared by infusing it in 200 mL of hot water at a temperature range of 90–100°C and allowing it to steep for 5–10 minutes. Participants assigned to the treatment group consumed one cup (200 mL) of the freshly prepared tea twice daily, in the morning and evening, over a period of eight weeks. In contrast, participants in the control group were administered a placebo beverage that was carefully matched in color and taste but lacked the active phytochemical constituents of Annona muricata. This was done according to the manufacturer’s guidelines.

Sample Collection and Processing

Venous blood samples, approximately 10 mL in volume, were collected from participants using lithium heparin tubes at two time points: baseline (Day 0) and post-intervention (Day 56). Following collection, the samples were centrifuged at 3000 rpm for 10 minutes to separate the serum. The obtained serum was then carefully aliquoted and stored at −20°C until further biochemical analysis was conducted.

Compliance Monitoring

Participant adherence to the Annona muricata tea regimen was monitored through a combination of subjective and objective methods to enhance reliability and minimize bias. Each participant was provided with a structured daily intake log to record morning and evening tea consumption. In addition, weekly follow-ups were conducted via phone calls and/or clinic visits to reinforce compliance and document adherence. The tea bag count method was also employed during follow-up visits; whereby unused tea bags were counted and compared against expected usage to estimate compliance levels. Furthermore, direct interviews were conducted to assess participants’ consistency, timing of intake, and any missed doses. Participants whose adherence fell below 80% were identified and considered during data analysis. The integration of self-reported records and objective measures such as tea bag counts strengthened the overall assessment of compliance.

Biomarker Assessment Methods

The assessment of biomarkers in this study was carried out using established and validated analytical techniques to ensure accuracy and reproducibility. Oxidative stress biomarkers were evaluated using spectrophotometric methods. Malondialdehyde (MDA) levels were measured using the Thiobarbituric Acid Reactive Substances (TBARS) assay, with absorbance read at 532 nm. Superoxide dismutase (SOD) activity was determined using the Misra and Fridovich method, which is based on the inhibition of epinephrine auto-oxidation and measured at 480 nm. Catalase (CAT) activity was assessed using the Aebi method by monitoring the decomposition of hydrogen peroxide at 240 nm. Reduced glutathione (GSH) levels were estimated using Ellman’s reagent (DTNB), with absorbance measured at 412 nm [8,9,18,19].

In addition to oxidative stress parameters, hormonal and tumor biomarkers were also analyzed. Serum testosterone levels were quantified using the enzyme-linked immunosorbent assay (ELISA), with absorbance read at 450 nm. Total prostate-specific antigen (TPSA) was measured using a chemiluminescent immunoassay (CLIA), which is based on antigen–antibody interactions detected through luminescence. These methods collectively provided a comprehensive evaluation of the biochemical and clinical effects of the intervention [16,17,18,19].

Outcome Measures

The outcome measures for this study were categorized into primary and secondary endpoints. The primary outcomes focused on evaluating the biochemical and clinical effects of the intervention. These included changes in oxidative stress biomarkers—specifically malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH)—as well as alterations in serum testosterone levels and total prostate-specific antigen (TPSA) levels. The secondary outcomes assessed the safety and practicality of the intervention. These involved monitoring the occurrence of any adverse effects and evaluating the overall tolerance and acceptability of Annona muricata tea consumption among participants.

Phytochemical Analysis of Annona muricata Tea Using High-Performance Liquid Chromatography (HPLC) Analysis

Phytochemical profiling of Annona muricata tea infusion was carried out using High-Performance Liquid Chromatography (HPLC) to identify and quantify major bioactive constituents.

Sample Preparation

The tea infusion was prepared by steeping one tea bag (2–3 g) in 200 mL of hot distilled water (90–100°C) for 10 minutes. The extract was filtered using Whatman No. 1 filter paper and further purified through a 0.45 µm membrane filter prior to HPLC analysis.

HPLC Conditions

The high-performance liquid chromatography (HPLC) analysis was carried out using a system equipped with a UV–Visible detector. Separation of compounds was achieved on a C18 reverse-phase column measuring 250 mm × 4.6 mm with a particle size of 5 µm. The mobile phase consisted of a gradient mixture of acetonitrile and water containing 0.1% formic acid, which facilitated optimal resolution of the analytes. The flow rate was maintained at 1.0 mL/min, while a sample injection volume of 20 µL was used for each run. Detection of eluted compounds was performed at wavelengths of 254 nm and 280 nm, and the total run time for each analysis was 30 minutes. Identification of the compounds was accomplished by comparing their retention times and UV spectra with those of standard reference compounds [19-21].

Table 1: HPLC-Quantified Phytochemicals in Annona muricata Tea

High-performance liquid chromatography (HPLC) analysis demonstrated that Annona muricata tea contains a diverse range of bioactive compounds, with a predominance of flavonoids, phenolic acids, and annonaceous acetogenins. The identified phenolic compounds, such as gallic acid and chlorogenic acid, contribute substantially to the tea’s antioxidant activity. In addition, flavonoids including quercetin, kaempferol, and rutin are well recognized for their anti-inflammatory and anticancer properties. The presence of annonaceous acetogenins, particularly annonacin and annomuricin E, is noteworthy, as these compounds are associated with cytotoxic effects against cancer cells, primarily through the inhibition of mitochondrial function. Collectively, these bioactive constituents are likely to act synergistically, thereby contributing to the observed reduction in oxidative stress and tumor biomarkers [19,20,22,23,24].

Data Analysis

Data obtained from the study were analyzed using the Statistical Package for the Social Sciences (SPSS) version 25.0. The results were presented as mean ± standard deviation (SD) to summarize central tendency and variability. Paired t-tests were employed to compare baseline and post-treatment values within the same group, while independent t-tests were used to evaluate differences between the treatment and control groups. Statistical significance was determined at a p-value of less than 0.05.

Baseline Characteristics of Participants

A total of 40 participants completed the study, with 20 in the treatment group and 20 in the control group. There were no statistically significant differences (p > 0.05) in baseline characteristics, including serum testosterone, TPSA, and oxidative stress markers between both groups.

Table 2: Effect of Annona muricata Tea on Oxidative Stress Markers

There was a significant decrease in MDA levels and significant increases in SOD, CAT, and GSH in the treatment group (p < 0>

Table 3: Effect on Serum Testosterone Levels

A significant increase in serum testosterone levels was observed in the treatment group compared to the control group, suggesting a possible hormone-modulating effect of Annona muricata tea.

Table 4: Effect on Total Prostate-Specific Antigen (TPSA)

There was a statistically significant reduction in TPSA levels in the treatment group (p < 0.05), indicating a potential inhibitory effect on prostate tumor activity. The control group showed no significant change.

Adverse Effects and Tolerability

No severe adverse effects were observed during the study period. However, a small proportion of participants reported mild symptoms, including nausea (10%) and a bitter taste (15%). These effects were transient and did not result in discontinuation of the intervention. Overall, Annona muricata tea was well tolerated among the study participants.

The findings of this study demonstrate that Annona muricata tea exerts significant therapeutic effects on oxidative stress, hormonal regulation, and prostate tumor biomarkers in patients with prostate cancer. These outcomes are consistent with previous studies that have reported the pharmacological benefits of Annona muricata, particularly its antioxidant and anticancer properties [25-27].

The observed reduction in malondialdehyde (MDA) levels indicates a decrease in lipid peroxidation, a key marker of oxidative damage. Concurrently, the significant increases in superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH) levels reflect an enhancement of the endogenous antioxidant defense system. These results corroborate earlier experimental findings attributing the antioxidant capacity of Annona muricata to its high content of flavonoids and phenolic compounds, which are known to neutralize reactive oxygen species and protect cellular integrity [25,26,27].

Furthermore, the significant elevation in serum testosterone levels observed in this study suggests a modulatory influence on endocrine function. While prostate cancer is traditionally considered androgen-dependent, the normalization of testosterone levels observed here may indicate restoration of physiological homeostasis rather than stimulation of tumor growth. This finding aligns with emerging evidence that balanced androgen levels may play a complex role in prostate cancer progression and patient well-being [28].

Notably, the significant reduction in total prostate-specific antigen (TPSA) levels observed in this study suggests a potential inhibitory effect of Annona muricata on prostate tumor activity. This effect may be attributed to the presence of annonaceous acetogenins, bioactive compounds reported to exert cytotoxic effects on cancer cells by inducing apoptosis and disrupting mitochondrial function [29,30,31,32,33]. These mechanisms may contribute to the suppression of tumor growth and progression observed in the present study.

Overall, the combined antioxidant, hormonal, and antiproliferative effects of Annona muricata tea highlight its potential as a complementary therapeutic agent in the management of prostate cancer. However, further large-scale clinical trials and mechanistic studies are recommended to validate these findings and establish optimal dosage, safety, and long-term efficacy.

The use of tea bags in this study enhances its clinical relevance, as it reflects a practical and accessible mode of administration. Unlike concentrated extracts, tea preparations are more likely to be adopted by patients in real-world settings, thereby improving compliance.However, this study has limitations. The sample size was relatively small, and the duration of intervention was limited to 8 weeks. Additionally, the phytochemical composition of the tea may vary depending on the manufacturer, which could affect reproducibility.

Future studies should focus on larger populations, longer intervention periods, and detailed phytochemical standardization to validate these findings. Annona muricata tea demonstrates significant therapeutic potential in the management of prostate cancer through multiple biological effects. It contributes to the reduction of oxidative stress while simultaneously enhancing the body’s antioxidant defense systems. In addition, it plays a role in modulating serum testosterone levels and lowering total prostate-specific antigen (TPSA) levels. Collectively, these findings suggest that Annona muricata tea may serve as a promising adjunct therapy in the management of prostate cancer.

This study demonstrates several important strengths that enhance both its scientific robustness and clinical relevance. Foremost among these is the adoption of a randomized controlled trial design, which significantly reduces selection bias and strengthens the internal validity of the findings. By ensuring that participants are randomly assigned, the study provides a more reliable basis for attributing observed effects directly to the intervention.

Another key strength lies in the use of a clinically relevant intervention. The administration of Annona muricata in tea bag form closely mirrors real-world consumption patterns, thereby improving the translational value of the findings. This approach not only enhances patient acceptability and compliance but also bridges the gap between experimental research and everyday clinical practice, unlike studies that rely solely on laboratory-prepared extracts.

The study is further strengthened by its comprehensive assessment of biochemical markers. By evaluating oxidative stress indices such as malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH), alongside hormonal status (testosterone) and tumor biomarker (total prostate-specific antigen, TPSA), the research provides a holistic understanding of the intervention’s physiological and pathological effects.

Reliability and reproducibility are also reinforced through the use of standardized and validated laboratory methods for biomarker analysis. These established procedures ensure consistency in data generation and enhance confidence in the results obtained.

Ethical and clinical rigor constitute another notable strength. The study was conducted in a tertiary healthcare setting with appropriate ethical approval and informed consent from participants, reflecting adherence to internationally accepted research standards and reinforcing the credibility of the findings.

Participant compliance was carefully monitored using multiple strategies, including intake logs, follow-up assessments, and tea bag counts. This multi-faceted approach minimizes compliance bias and improves the accuracy of the collected data.

In addition, the incorporation of both qualitative and quantitative phytochemical analyses provides a strong biochemical foundation for the observed therapeutic effects. This aspect strengthens the mechanistic interpretation of the findings and links clinical outcomes to underlying bioactive compounds. Finally, the study addresses an under-researched area by contributing to the limited body of human clinical research on Annona muricata in prostate cancer management, particularly using a standardized tea formulation. This focus enhances its relevance and positions it as a valuable contribution to emerging therapeutic research. Despite its strengths, this study has several limitations that should be considered when interpreting the findings. One of the primary limitations is the relatively small sample size of 40 participants, which may restrict the generalizability of the results to a wider population.

The short duration of the intervention, spanning only eight weeks, also limits the ability to assess long-term effects of Annona muricata tea on prostate cancer progression and overall patient outcomes. Longer follow-up periods would be necessary to establish sustained efficacy and safety.

Another limitation relates to potential variability in the composition of the tea. The phytochemical content of commercially available tea bags can differ depending on factors such as manufacturing processes, plant sourcing, and storage conditions, which may introduce inconsistencies in the intervention.

Closely related to this is the lack of standardization of bioactive compounds. Unlike purified extracts, the precise concentration of active constituents such as annonaceous acetogenins—was not quantified or standardized, which may affect reproducibility and dose–response interpretation.

Although participant adherence was monitored using multiple methods, reliance on self-reported compliance introduces the possibility of reporting bias, which could influence the accuracy of adherence data.

Furthermore, the study did not incorporate molecular or histopathological analyses to elucidate the underlying mechanisms of action. The absence of such detailed investigations limits the depth of mechanistic understanding and the ability to link biochemical changes to cellular or tissue-level effects.

These limitations underscore the need for larger-scale studies with extended durations, standardized formulations, and in-depth mechanistic evaluations to further validate the therapeutic potential of Annona muricata tea in prostate cancer management.

In conclusion, this study provides promising evidence supporting the potential therapeutic benefits of Annona muricata tea in the management of prostate cancer, particularly through its antioxidant, hormonal, and tumor biomarker-modulating effects. The findings highlight its potential as a complementary, accessible, and patient-friendly intervention. However, given the identified limitations, further large-scale, long-term, and mechanistic studies are required to confirm these results and establish its role in clinical practice.