Fig. 1

Study flow diagram. Out of a total of 390 records identified through a search of seven electronic databases, 299 records after removing 91 duplicates were screened by titles and abstract, which identified 77 ineligible records (9 conference proceedings, 51 review articles, 10 case reports and 7 editorials or letters) and 198 irrelevant reports. Out of the remaining 24 records, 7 records were excluded, which were composed of 3 records that were retrieved through Google Scholar but unable to be identified due to unavailable links and unclear source information, 1 registered trial that was on-going without any result available and 3 non-English articles (1 German and 2 Bulgarian) that were unable to be interpreted due to lack of resources. The remaining 17 articles were retrieved as full-texts and 9 of them were excluded due to no description of a specific treatment in 6 articles and a different target disease in 3 articles. Finally, eight reports/studies were deemed eligible for the review