Physalis peruviana as an antioxidant

Physalis peruviana Linnaeus (abbreviated as P. peruviana further in text) is a perennial belonging to Solanaceae family – nightshades. It grows up to 1,5 meters, branching into an herbaceous plant similar to a tomato. It develops a round, amber-colored fruit, thickened with a thin wax layer, with a diameter of 1-2 cm. The fruit is sheltered with a thin paper-like husk which forms the shape of a lantern. The insides of this luscious fruit are filled with 100-200 smaller seeds.

The original habitat of this exotic plant is South America, i.e. tropical areas. Regardless of the conditions in its primary habitat, Physalis peruviana was spread throughout the world owing to its scarce growth conditions: P. peruviana can thrive in areas up to 3000 meters in altitude, the optimal temperature for its growth is 18 C (although it can survive in temperatures to zero degrees.); it only requires frequent illumination and wet soil, which does not have to be high in quality. The most common name for Physalis Peruviana is groundcherry, but it was also given many other names, such as: Andean strawberry, Incan berry, Chinese lantern, Jerusalem strawberry.

Nutritional use

Considering that every other part of this plant besides fruit bears toxicity due to solanines and other solanine alkaloids, the fruits are the only part safe for consumption. Due to its sweet-sour taste, it is primarily advised to consume fresh P. Peruviana by incorporating it to fruit salads, although it can as well be used in combination with vegetables. Dried fruit can also be consumed. Groundcherry is used in cuisine and confectionery throughout the world, comprising various meat and seafood sauces and toppings, and pastries as well. It is frequently used as an ornament in food, salads, and desserts. When ripe, the nectar of this exotic berry is rich in pectinase, an enzyme that is key to produce jam.

Significance in medicine

P.peruviana achieves its medicinal merit through the antioxidant capacity of polyphenols found in the fruit. By examining the extracted fruit skin and pulp oils of P. Peruviana, a high concentration of phytosterols – compounds that contribute to anti-inflammatory, antitumor, antibacterial and antifungal processes in the organism. The most abundant of phytosterols in the extracted oil is campesterol, followed by beta-sitosterol and stigmasterol that lower cholesterol levels. P. Peruviana fruit is rich in polyunsaturated fatty acids, vitamins A, B,C,E AND K1, phytosterols, withanolides and physalines. So, aside from good nutritional characteristics, it posseses biologically active compounds as well.

When it comes to mineral species, unexpectedly elevated levels of phosphorus were determined. Aside from phosphorus, P. peruviana fruit is rich in iron, potassium, and zinc. Zinc is non-enzymatic antioxidant that prevents oxidative cell damage.

Vitamin A (beta-carotene, carotenoids) gives this fruit a specific yellow-orange color, but more importantly it possesses antioxidative properties by inactivating free radicals generated in the body tissues.

Vitamin C (Ascorbic acid) reduces harmful effects of reactive oxygen species and reactive nitrogen species that otherwise lead to the damage of lipides, DNA and proteins, all of which are linked to cardiovascular diseases, neurodegenerative illnesses, and cancer growth.

Vitamin E, most potent as α-tocoferol isomer, with the aid of lipide antioxidants decreases the levels of lipide peroxides that cause free-radical mediated cell-membrane damage.

One of the compound classes unique to this species are physalins – biologically active compounds comprised by physalin A,B,D and F (and other glycosides) that are prominent for their anticancer effect. Physalins B and F potentially have a suppressive effect, manifested through the proliferation of lymphocytes, inhibition of excretion proinflammatory cytokines and inhibition of macrophage activation. The full-scale effect of physalins can be described with one word – immunosuppression that results with the decrease in both inflammation and fibrosis.

The second compound class unique for this species are withanolides – steroid lactones with many properties: antimicrobial, anticancer, anti-inflammatory, hepatoprotective, immunomodulatory and antiparasitic.  Up to 17 withanolides have been found in P. Peruviana, with four of them (fiperunolide A, 4-β-hydroxywithanolide E, withanolide E i withanolide C) exhibiting a cytotoxic effect on tumor cells in lung, breast and liver cancer.

Antidiabetic effect was also scientifically proven. With research conducted on youth population, it has been ascertained that the respondents who regularly ate P. peruviana fruit for a certain period of time had lower postprandial glucose levels, i.e. a higher hypoglycemic effect was proven. At the same time, the daily consumption of maximum of five fruits is advised.

Translated by: Dominik Šutalo