The use of guarana (Paullinia cupana) as a dietary supplement for fatigue in cancer patients: a systematic review with a meta-analysis

Evidence for the efficacy of anti-inflammatory plants used in Brazilian traditional medicine with ethnopharmacological relevance

ETHNOPHARMACOLOGICAL RELEVANCE

When exacerbated, inflammatory processes can culminate in physical and emotional disorders and, if not stopped, can be lethal. The high prevalence of inflammation has become a public health problem, and the need for new drugs to treat this pathology is imminent. The use of medicinal plants has emerged as an alternative, and a survey of data that corroborates its application in inflammatory diseases is the starting point. Furthermore, Brazil harbors a megadiversity, and the traditional use of plants is relevant and needs to be preserved and carefully explored for the discovery of new medicines.

AIM OF THE STUDY

This review sought to survey the medicinal plants traditionally used in Brazil for the treatment of inflammatory processes and to perform, in an integrative way, a data survey of these species and analysis of their phytochemical, pharmacological, and molecular approaches.

MATERIALS AND METHODS

Brazilian plants that are traditionally used for inflammation (ophthalmia, throat inflammation, orchitis, urinary tract inflammation, ear inflammation, and inflammation in general) are listed in the DATAPLAMT database. This database contains information on approximately 3400 native plants used by Brazilians, which were registered in specific documents produced until 1950. These inflammatory disorders were searched in scientific databases (PubMed/Medline, Scopus, Web of Science, Lilacs, Scielo, Virtual Health Library), with standardization of DECS/MESH descriptors for inflammation in English, Spanish, French, and Portuguese, without chronological limitations. For the inclusion criteria, all articles had to be of the evaluated plant species, without association of synthesized substances, and full articles free available in any of the four languages searched. Duplicated articles and those that were not freely available were excluded.

RESULTS

A total of 126 species were identified, culminating in 6181 articles in the search. After evaluation of the inclusion criteria, 172 articles representing 40 different species and 38 families were included in the study. Comparison of reproducibility in intra-species results became difficult because of the large number of extraction solvents tested and the wide diversity of evaluation models used. Although the number of in vitro and in vivo evaluations was high, only one clinical study was found (Abrus precatorius). In the phytochemical analyses, more than 225 compounds, mostly phenolic compounds, were identified.

CONCLUSION

This review allowed the grouping of preclinical and clinical studies of several Brazilian species traditionally used for the treatment of many types of inflammation, corroborating new searches for their pharmacological properties as a way to aid public health. Furthermore, the large number of plants that have not yet been studied has encouraged new research to revive traditional knowledge.

Bisphenol-A induced cyto-genotoxicity on retinal pigment epithelial cells is differentially modulated by a multi-supplement containing guarana, selenium, and L-carnitine

Bisphenol A (BPA) may adversely affect human health by inducing oxidative stress and irreversible damage to cells. Bioactive compounds found in some functional foods, individually or in combination, can attenuate the negative effects of BPA exposure; an example is the multi-supplement containing guarana (Gua), selenium (Se), and L-carnitine (LC) -GSC- which has already demonstrated antioxidant, genoprotective, and immunomodulatory activities. This study aimed to determine the effect of GSC and its constituents on oxidative and genotoxic alterations triggered by BPA exposure in the retinal epithelial cell line. The cells exposed to BPA (0.001, 0.01, 0.1, 1, 3, and 10 µM) to determine the lowest concentration required to induce cyto-genotoxicity. ARPE-19 cells were then concomitantly exposed to the selected BPA concentration, GSC, and its components (Gua, 1.07 mg/mL; Se, 0.178 µg/mL; and LC, 1.43 mg/mL). Flow cytometry, biochemical assays, qRT-PCR, genotoxicity, apoptosis, and cellular proliferation. Based on our results, 10 µM of BPA could induce cyto-genotoxic and oxidative alterations. BPA did not alter the Bcl-2/BAX expression ratio but induced Casp3 and Casp8 overexpression, suggesting that apoptosis was induced mainly via the extrinsic pathway. GSC partially reversed the alterations triggered by BPA in ARPE-19 cells. However, Se had unexpected negative effects on ARPE-19 cells. The multi-supplement GSC may attenuate changes in oxidative and genotoxic markers related to exposure of ARPE-19 cells to BPA. our results revealed that the antioxidant, anti-apoptotic, and genoprotective properties of GSC were not universally shared by its individual, once Se did not exhibit any positive impact.

Efficacy and safety of traditional Chinese medicine for cancer-related fatigue: a systematic literature review of randomized controlled trials

BACKGROUND

Cancer-related fatigue (CRF) is an extremely common and long-term condition that affects the physical and mental health of oncology patients. While the treatment for CRF with western medicine and non-pharmacological therapy remains uncertain and challenging, traditional Chinese medicine (TCM) has become a trending option for the patients. Based on the findings from randomized controlled trials (RCTs), this study aims to identify and evaluate the evidence about the efficacy and safety of TCM for CRF.

METHODS

A systematic literature search was conducted according to the PRISMA literature research guidelines. Seven electronic databases including PubMed, the Cochrane Library, Embase, Web of Science, Scopus, China National Knowledge Infrastructure (CNKI) and Wanfang database were searched to identify RCTs which investigated TCM in the treatment of CRF published since inception to December 2022. RCTs comparing TCM with no treatment, placebo, or pharmacological interventions were considered eligible for this review. The Consolidated Standards of Reporting Trials Statement extensions for Chinese herbal medicine Formulas (CONSORT-CHM) and the Cochrane Collaboration's Risk of Bias tool were used in this review to evaluate the quality and the risk of bias of all included trials.

RESULTS

A total of 82 RCTs were included in this review, regardless of whether they were published in English or Chinese. After data extraction and results evaluation, 78 trials demonstrated overall efficacy in using TCM for CRF patients compared with the control group, in which 33 trials showed that the efficacy rate was statistically significant (p < 0.05 or p < 0.01). TCM was also shown to be beneficial in improving the scores of relevant scales (e.g., PFS, QoL, TCM syndrome score, other fatigue scales etc.) or physical tests indicators (e.g., cytokines, blood test etc.). The most common herbs found in Chinese medicine were Astragali Radix, Ginseng Radix and Codonopsis Radix. Some TCM products, such as Kangai Injection, Buzhong Yiqi Decoction and Shenqi Fuzheng Injection could provide a reference for medication in this review. A range of non-serious, reversible adverse effects associated with the use of TCM was also reported. However, the result of evaluation showed that none of the trials fully met all the CONSORT-CHM criteria, the quality of included trials was generally poor and the risk of bias was mostly uncertain.

CONCLUSION

There is some evidence supporting the efficacy and safety of TCM in managing CRF in this systematic review. However, no clear conclusion can be made due to the inadequate reporting of efficacy and adverse reactions. In view of some concerns about the existing evidence after the evaluation, it is essential to standardize the comprehensive identification and efficacy measurement standards, improve the quality of RCTs and conduct more multicomponent therapies to provide an updated reference for CRF patients medication in the future. The protocol of this systematic review has been registered on PROSPERO (CRD42023413625). [ https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023413625 ].

Management of Fatigue in Patients with Advanced Cancer

OPINION STATEMENT

Fatigue is a common and distressing symptom experienced by patients with cancer. It is most common in patients with locally advanced or metastatic incurable disease. It can have profound effects on quality-of-life and physical functioning. In addition to general supportive measures (directed at tackling contributory conditions and comorbidities), a variety of specific interventions have been developed which can be broadly categorised as physical therapies, psychological therapies or medication. There is some evidence that each of these approaches can have benefits in patients with earlier stage disease, those undergoing active treatment and in cancer survivors. The best evidence is for aerobic exercise, yoga, cognitive-behavioural therapy (CBT) and psycho-educational interventions. Less strong evidence supports the use of medications such as methylphenidate or ginseng. In patients with advanced disease, it is likely that the mechanisms of fatigue or the factors contributing to fatigue maintenance may be different. Relatively fewer studies have been undertaken in this group and the evidence is correspondingly weaker. The authors recommend the cautious use of aerobic exercise (e.g. walking) in those who are still mobile. The authors advise considering the use of psycho-educational approaches or CBT in those patients who are able to engage in such forms of therapy. In patients near the end-of-life, the authors advise use of dexamethasone (short-term use) and other pharmacological treatments only on the basis of a clinical trial.

Effect of Guarana (Paullinia cupana) on Cognitive Performance: A Systematic Review and Meta-Analysis

The plant extract guarana is known for its caffeine content and other bioactive ingredients, which purportedly may improve cognitive performance. Recent reviews have examined the effects of chronic supplementation of guarana in clinical populations; however, the acute effects of guarana on cognitive tasks, while of interest, have produced mixed results. Whether acute guarana ingestion improves human cognitive performance was assessed by performing a systematic review coupled with a meta-analysis. Eight placebo-controlled studies were identified and met the inclusion criteria providing data on 328 participants. The dose of guarana (37.5 to 500 mg) with reported caffeine content (4.3 to 100 mg) varied. Effect sizes (ESs) were calculated as the standardized mean difference and meta-analyses were completed using a random-effects model. The ESs for guarana averaged across a variety of cognitive measures and outcome variables were less than trivial (Hedge’s g = 0.076, p = 0.14). Using a subgroup meta-analysis (Q = 12.9, p < 0.001), ESs indicating a faster response time for guarana vs. a placebo (g = 0.202, p = 0.005) differed from the accuracy measures (g = −0.077, p = 0.4) which were non-significant. For response time, guarana ingested in a capsule (g = 0.111) tended to differ (Q = 2.96, p = 0.085) compared to guarana when dissolved in liquid (g = 0.281). Meta-regression of the study ESs of overall cognitive task performance was not related to the guarana dose (R2 < 0.001) or to the time allowed prior to cognitive testing (R2 < 0.001). Acute guarana ingestion had a small effect on the response time (faster performance) during a variety of cognitive tasks without affecting the accuracy. Whether the changes were linked to the caffeine content or other bioavailable substances in guarana is unknown. Additional studies that directly compare matched doses of caffeine versus guarana are needed to understand its effects on cognitive performance.

The Role of Complementary and Alternative Medicine on Cancer-Related Fatigue in Adults: An Overview of Systematic Reviews

BACKGROUND

Cancer-related fatigue (CRF) has an enormous adverse impact on quality of life and subsequent therapy of cancer patients. Complementary and alternative medicine (CAM) is reported to improve CRF in many systematic reviews (SRs), but the effects are controversial because of variations in the quality and outcomes.

METHODS

Thirteen databases were searched from inception to September 2022. Only SRs of randomized controlled trials (RCTs) were included. We assessed the quality of included SRs with the AMSTAR-2 tool, the strength of evidence with the GRADE system, the risk of bias with the ROBIS tool, and the integrity of SRs with the PRISMA checklist.

RESULTS

We included 30 eligible SRs (27 meta-analyses). Based on the AMSTAR-2 tool, 29 SRs were rated as "critically low" quality, and only one was rated as "low" quality. With the ROBIS tool, 19 SRs demonstrated a low risk of bias. According to the PRISMA checklist, no SRs reported all the items, and 10 SRs sufficiently reported over 70%. Based on the GRADE system, 7 outcomes were assessed as high-quality evidence.

CONCLUSION

This overview demonstrates promising evidence for the effectiveness of CAM interventions in the treatment of CRF in adults. The roles of qigong, music, auricular point therapy, and dietary supplements in CRF need further evaluation. Although findings are mixed, it is recommend to select appropriate CAM to manage cancer-related fatigue under the guidance of physicians. More studies with rigorous methodological designs and sufficient sample sizes are needed.

A Systematic Review of Systematic Reviews and a Pooled Meta-Analysis on Complementary and Integrative Medicine for Improving Cancer-Related Fatigue

PURPOSE

Evidence supporting complementary and integrative medicine (CIM) for improving cancer-related fatigue (CRF) is still fragmented. This study therefore critically appraised all the systematic reviews (SRs) regarding the effectiveness of CIM in mitigating CRF in adults.

METHODS

A systematic review of SRs and a meta-analysis were conducted in 4 databases. The effect sizes of the included SRs were quantitatively pooled (standardized mean difference [SMD]; 95% CI) using a random-effects model. Heterogeneity was tested by using χ² (Q) tests and I² statistics.

FINDINGS

Twenty-two SRs met the inclusion criteria, and results from 20 SRs underwent meta-analysis. The pooled significant estimate of fatigue reduction was as follows: SMD, -0.50; 95% CI, -0.67 to -0.32; P < 0.001. The subgroup analysis based on the type of CIM intervention revealed that the approach showing higher effects in reducing fatigue thus far is acupuncture: SMD, -0.99; 95% CI = -1.37 to -0.62, P < 0.001; I² = 84%. CIM therapies showed a significant reduction of fatigue in patients with breast cancer: SMD, -0.46; 95% CI, -0.69 to -0.23; P < 0.001; I² = 82%.

IMPLICATIONS

CIM interventions showed effectiveness in reducing CRF. Subgroup analysis suggested some potential influencing, such as tumor type and specific CIM therapy factors, that require in-depth assessment in future research. Study protocol registration: PROSPERO CRD42020194254.

Alterations in Bacterial Metabolism Contribute to the Lifespan Extension Exerted by Guarana in Caenorhabditis elegans

Guarana (Paullinia cupana) is a widely consumed nutraceutical with various health benefits supported by scientific evidence. However, its indirect health impacts through the gut microbiota have not been studied. Caenorhabditis elegans is a useful model to study both the direct and indirect effects of nutraceuticals, as the intimate association of the worm with the metabolites produced by Escherichia coli is a prototypic simplified model of our gut microbiota. We prepared an ethanoic extract of guarana seeds and assessed its antioxidant capacity in vitro, with a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, and in vivo, utilizing C. elegans. Additionally, we studied the impact of this extract on C. elegans lifespan, utilizing both viable and non-viable E. coli, and assessed the impact of guarana on E. coli folate production. The extract showed high antioxidant capacity, and it extended worm lifespan. However, the antioxidant and life-extending effects did not correlate in terms of the extract concentration. The extract-induced life extension was also less significant when utilizing dead E. coli, which may indicate that the effects of guarana on the worms work partly through modifications on E. coli metabolism. Following this observation, guarana was found to decrease E. coli folate production, revealing one possible route for its beneficial effects.