Indian Indigenous Fruits as Radioprotective Agents: Past, Present and Future

Ionising radiation has been an important modality in cancer treatment and its value is immense when surgical intervention is risky or might debilitate/adversely affect the patient. However, the beneficial effect of radiation modality is negated by the damage to the adjacent healthy tissue in the field of radiation. Under these situations, the use of radioprotective compounds that can selectively protect normal tissues against radiation injury is considered very useful. However, research spanning over half a century has shown that there are no ideal radioprotectors available. The United States Food and Drug Administration (FDA or USFDA) approved amifostine, or WR-2721 (Walter Reed-2721) [chemically S-2-(3-aminopropyl-amino) ethyl phosphorothioic acid] is toxic at their optimal concentrations. This has necessitated the need for agents that are safe and easily acceptable to humans.

Dietary agents with beneficial effects like free radical scavenging, antioxidant and immunomodulatory effects are being recognized as useful and have been investigated for their radioprotective properties. Studies in these lines have shown that the fruits of Aegle marmelos (stone apple or bael), Emblica officinalis or Phyllanthus emblica (Indian gooseberry/amla), Eugenia jambolana or Syzygium jambolana (black plum/jamun), Mangifera indica (mango) and Grewia asiatica (phalsa or falsa) that are originally reported to be indigenous to India have been investigated for their usefulness as radioprotective agents.

The objective of this review is to summarize the beneficial effects of the Indian indigenous fruits, stone apple, mango, Indian gooseberry, black plum, and phalsa, in mitigating radiation-induced side effects, emphasize the underlying mechanism of action for the beneficial effects and address aspects that merit detail investigations for these fruits to move towards clinical application in the near future.

The authors data-mined Google Scholar, PubMed, Embase, and the Cochrane Library for publications in the field from 1981 up to July 2020. The focus was on the radioprotection and the mechanism responsible for the beneficial effects, and accordingly, the articles were collated and analyzed.

This article emphasizes the usefulness of stone apple, mango, Indian gooseberry, black plum, and phalsa as radioprotective agents. From a mechanistic view, reports are suggestive that the beneficial effects are mediated by triggering free radical scavenging, antioxidant, anti-mutagenic and anti-inflammatory effects.

For the first time, this review addresses the beneficial effects of mango, Indian gooseberry, black plum, stone apple and phalsa as radioprotective agents. The authors suggest that future studies should be directed at understanding the selective radioprotective effects with tumor-bearing laboratory animals to understand their usefulness as radioprotective drug/s during radiotherapy and as a food supplement to protect people from getting exposed to low doses of radiation in occupational settings. Phase I clinical trial studies are also required to ascertain the optimal dose and the schedule to be followed with the standardized extract of these fruits. The most important aspect is that these fruits, being a part of the diet, have been consumed since the beginning of mankind, are non-toxic, possess diverse medicinal properties, have easy acceptability, all of which will help take research forward and be of benefit to patients, occupational workers, agro-based sectors and pharma industries.