Psidium guajava bioactive product chemical analysis and heavy metal toxicity reduction

Guava (Psidium guajava) leaf extract enhances immunity, growth, and resistance against Vibrio parahaemolyticus in white shrimp Penaeus vannamei

This study investigated the effects of guava leaf extract (GLE) on immune responses, growth performance, and resistance to Vibrio parahaemolyticus in white shrimp (Penaeus vannamei). To examine the effect of GLE on the immune response of white shrimps, they were treated with various concentrations of GLE on hemocyte (in vitro) and were orally administered (in vivo) feed containing various concentrations of 0, 1, 5, and 10 g kg^-1 GLE (control, GLE1, GLE5, and GLE10, respectively) for 28 days. Furthermore, their growth performance was evaluated for 56 days. In a separate experiment, the shrimps were challenged with V. parahaemolyticus injection after 7 days of culture. In vitro experiments indicated that GLE is nontoxic and can activate immune response. In vivo experiments revealed that the GLE5 led to the highest total hemocyte count, phenoloxidase activity, phagocytic activity, and superoxide anion production and the highest upregulation of lipopolysaccharide, β-1,3-glucan-binding protein, peroxinectin, lysozyme, crustin, penaeidin 2, penaeidin 3, clotting protein, superoxide dismutase, and glutathione peroxidase. Moreover, better growth performance was observed in the GLE groups, with GLE5 exhibiting the highest specific growth rate, weight gain, and feed conversion rate. In addition, GLE5 enhanced resistance to V. parahaemolyticus, with a survival rate of 72.27%. In conclusion, GLE was found to be effective in enhancing nonspecific immune response and growth performance and in reducing V. parahaemolyticus infection in white shrimp.

Medicinal Plants to Strengthen Immunity during a Pandemic

The development of new effective anti-coronavirus drugs and therapies is important, but it requires significant human, financial and, most importantly, time expenditures. The current pandemic is neither the first nor the last. Humanity has already accumulated considerable survival experience. We cannot do without prevention and epidemiological protection measures. This study reviews medicinal plants that grow in Northeast Asia and whose antioxidant, antiviral, anti-inflammatory and immunomodulatory characteristics are already known, also in the framework of the prevention and treatment of pneumonia of various etiologies. The need for a comprehensive approach to maintaining immunodefences, including functional foods and positive emotions, is emphasized. In the period of pandemics, it is important to research various areas that allow to us accumulate a critical mass of information and cope with the next global disease.