Antithrombocytopenic and immunomodulatory potential of metabolically characterized aqueous extract of Carica papaya leaves.

CONTEXT

Carica papaya Linn. (Caricaceae) leaf (CPL) juice has long been traditionally used in ethnomedicine for dengue fever.

OBJECTIVE

The study examines the effects of standardized CPL aqueous extract (SCPLE) on platelet count, extramedullary haematopoiesis (EMH), and immunomodulation in cyclophosphamide (CP)-induced animal model of thrombocytopenia.

MATERIALS AND METHODS

The extract was analyzed for myricetin, caffeic acid, trans-ferulic acid, and kaempferol using HPTLC for standardization followed by UPLC-qTOF/MS fingerprinting for metabolite signature. The effects of SCPLE (50 and 150 mg/kg p.o.) on proliferative response of platelet count and total leucocyte count (TLC) were observed up to 14 days in Wistar rat. However, delayed-type hypersensitivity (DTH), haemagglutination titre (HT), and in vivo carbon clearance were examined as immunomodulatory parameters in albino mice at 150 mg/kg p.o. against CP.

RESULTS

The quantitative HPTLC estimation of SCPLE showed the presence of myricetin, caffeic acid, trans-ferulic acid, and kaempferol up to 280.16 ± 5.99, 370.18 ± 6.27, 1110.86 ± 2.97, and 160.53 ± 2.48 (μg/g), respectively. Twenty-four metabolites were identified using UPLC-qTOF/MS. Oral administration of SCPLE (150 mg/kg) in thrombocytopenic rats exhibited significant (p < 0.01) increase in thrombocytes (1014.83 × 10 cells/mm), DTH response (0.16 ± 0.004), and phagocytic index (63.15% increase) as compared to CP-induced thrombocytopenia group. Histopathological studies showed minimal fibrosis in spleen histology.

DISCUSSION AND CONCLUSIONS

Results suggest CPL can mediate the release of platelets providing the means for the treatment and prevention of dengue.