Could Carica papaya leaf extract impact chemotherapy-induced thrombocytopenia? A systematic review and meta-analysis

Background: Chemotherapy-induced thrombocytopenia (CIT) impacts a significant number of patients undergoing oncological treatment. Aim: This study explored the usefulness of Carica papaya leaf extract (CPLE) in the context of CIT, including side effect and optimal treatment dosage and duration. Methods: Systematic literature reviews were conducted on (a) studies of patients with solid tumors and CIT who received CPLE, and (b) animal studies focused on CPLE for CIT. Risk of bias was assessed and meta-analyses were conducted. Results: In the meta-analysis of studies on oncological patients with CIT (total N = 410, intervention N = 205), the overall effect size for CPLE administration was 2.20, 95% confidence interval (CI): 0.96–3.44, P < 0.001. In the meta-analysis on animal models (total N = 84, intervention N = 42), two effect sizes were computed for two platelet measurements at different time intervals: 5.74, 95% CI: 0.32 = 11.16, P < 0.001 and 7.13, 95% CI: 4.23–10.02, P < 0.001, respectively. CPLE dosage varied between 580 and 3300 mg, with a mean of 1500 mg per day. No studies reported major side effects of CPLE administration. Conclusion: Despite heterogeneity and risk of bias concerns, the research literature available so far of both animal models and human participants suggests that CPLE might be an effective strategy for dealing with CIT. However, more rigorous research is still needed.