CONTEXT:The pepino fruit Solanum muricatum Ait. (Solanaceae) is commonly known as melon pear and sweet cucumber grown in South America, New Zealand, and India. Traditionally, the fruits are used in the treatment of diabetes and cancer. AIM:The objective of present study is to explore the immunomodulatory, anticancer, and anti-inflammatory activities of the methanol extract of S. muricatum fruits in experimental mice models. MATERIALS AND METHODS:Immunomodulatory activity of S. muricatum fruits was evaluated by assessing the relative organ weight, bone marrow cellularity, α-esterase activity, and by studying the phagocytic activity by carbon clearance test. The anti-tumor activity of the fruit extract was studied against Dalton's lymphoma ascites (DLA) cell line induced solid and ascites tumor models. The anti-inflammatory activity of the fruit extract was evaluated using carrageenan and formaldehyde models. STATISTICAL ANALYSIS:The results were expressed as mean (±SD). Statistical analyses were performed using a one-way analysis of variance (ANOVA) followed by Dunnett's test using GraphPad Instat software. P values less than 0.05 were considered statistically significant. RESULTS:S. muricatum treatment could not only stimulate the immune system but also significantly (P < 0.01) inhibit the growth of transplantable tumor. The serum glutathione and γ-glutamyl transpeptidase (GGT) levels were found to be significantly decreased compared with tumor-bearing control animals. The increased tumor necrosis factor (TNF)-α level in tumor control (802.6 ± 12.0) was significantly (P < 0.01) decreased to 175.2 ± 16.5 after S. muricatum treatment. The TNF-α level in normal animals was found to be 21.0 ± 3.5 pg/ml. An increase in life span was observed after S. muricatum treatment. The extract also inhibited the edema induced by carrageenan and formaldehyde, respectively. CONCLUSION:The results showed that the S. muricatum fruit extract has potent immunomodulatory, anticancer, and anti-inflammatory activities.