Pomegranate allergy and pathogenesis-related protein 4

Reporting of adverse effects of pomegranate in clinical studies: a systematic review

OBJECTIVES

Numerous studies have shown the pharmacological effects of pomegranate, such as: anti-cancer, cholesterol-lowering, anti-diabetic, and antihypertensive features. Pomegranate consumption has also revealed some adverse effects. This systematic review aimed to explore the adverse effects of pomegranate reported in clinical studies.

CONTENT

The keywords "pomegranate", "Punica granatum", "side effect", "clinical trial", and "case report or case series" were searched for in valid databases. Reports about adverse effects of pomegranate were also collected from several international registries.

SUMMARY

This systematic review included a total of 66 clinical articles. Eleven articles have reported side effects of pomegranate. Twenty-one articles have recorded no side effects in the pomegranate group while 34 articles have not mentioned any side effects for this plant. The study also included 7 case report studies. The most common side effects included gastrointestinal problems, flu-like symptoms, and urinary problems. In case report studies, the most significant reported side effect was allergic reaction.

OUTLOOK

In summary, pomegranate and its extract seem to be safe according to the reported adverse effects. Meanwhile, conducting more robust controlled trials with pomegranate products and documentation of any probable side effect is warranted.

Efficacy and safety of pomegranate medicinal products for cancer

Preclinical in vitro and in vivo studies demonstrate potent effects of pomegranate preparations in cancer cell lines and animal models with chemically induced cancers. We have carried out one systematic review of the effectiveness of pomegranate products in the treatment of cancer and another on their safety. The PubMed search provided 162 references for pomegranate and cancer and 122 references for pomegranate and safety/toxicity. We identified 4 clinical studies investigating 3 pomegranate products, of which one was inappropriate because of the low polyphenol content. The evidence of clinical effectiveness was poor because the quality of the studies was poor. Although there is no concern over safety with the doses used in the clinical studies, pomegranate preparations may be harmful by inducing synthetic drug metabolism through activation of liver enzymes. We have analysed various pomegranate products for their content of anthocyanins, punicalagin, and ellagic acid in order to compare them with the benchmark doses from published data. If the amount of coactive constituents is not declared, patients risk not benefiting from the putative pomegranate effects. Moreover, pomegranate end products are affected by many determinants. Their declaration should be incorporated into the regulatory guidance and controlled before pomegranate products enter the market.