Purpose: The objective of this study was to determine the effect of aqueous extracts of Garcinia indica whole dried fruit and semidried pulp against TV infectivity at 37°C over six hours.
Methods: TV (200 μl) at approximately seven log PFU/ml was mixed with equal volumes of Garcinia fruit and pulp aqueous extracts (50 and 100 mg/ml) or phosphate-buffered saline (PBS, pH 7.2, as control) for 2, 3, and 6 hours at 37°C. After each time interval, treatments were stopped in cell culture media containing 10% fetal bovine serum (FBS) and serially diluted in media containing 2% FBS. Infectivity was determined using standard plaque assays on confluent LLC-MK2 cells in six-well plates in duplicate. Each treatment was replicated thrice and recovered titers were compared to PBS controls.
Results: Garcinia pulp extract (100 mg/ml) resulted in TV reductions of 1.7, 2.4, and ~3 log PFU/ml after 2, 3, and 6 h, respectively, while 50 mg/ml showed only ~1.2, 2.1, and 2.2 log PFU/ml reduction after 2, 3, and 6 h, respectively. The dried fruit extract at 100 mg/ml showed 1.1, 1.9, and ~2 log PFU/ml reduction, while 50 mg/ml showed 0.74, 1.7 and 1.9 log PFU/ml reduction after 2, 3, and 6 h, respectively.
Significance: The results indicate that Garcinia fruit and pulp aqueous extracts show antiviral effects against TV that are concentration and time-dependent. This study shows the need for further exploration of the potential health benefits of the underutilized Garcinia fruit.