The discovery of new pharmaceutical identities, particularly anti-infective agents, represents an urgent need due to the increase in immunocompromised patients and the ineffectiveness/toxicity of the drugs currently used. The scientific community has recognized in the last decades the importance of the plant kingdom as a huge source of novel molecules which could act against different type of infections or illness. However, the great diversity of plant species makes it difficult to select them with probabilities of success, adding to the fact that existing information is difficult to find, it is atomized or disordered. Persicaria and Polygonum constitute two of the main representatives of the Polygonaceae family, which have been extensively used in traditional medicine worldwide. Important and structurally diverse bioactive compounds have been isolated from these genera of wild plants; among them, sesquiterpenes and flavonoids should be remarked. In this article, we firstly mention all the species reported with pharmacological use and their geographical distribution. Moreover, a number of tables which summarize an update detailing the type of natural product (extract or isolated compound), applied doses, displayed bioassays and the results obtained for the main bioactivities of these genera cited in the literature during the past 40 years. Antimicrobial, antioxidant, analgesic and anti-inflammatory, antinociceptive, anticancer, antiviral, antiparasitic, anti-diabetic, antipyretic, hepatoprotective, diuretic, gastroprotective and neuropharmacological activities were explored and reviewed in this work, concluding that both genera could be the source for upcoming molecules to treat different human diseases.

Persicaria acuminata (Polygonaceae) is a perennial herb that grows in the central area of Argentina and it is commonly used by native populations to heal infected wounds and other conditions related to fungal infections. In this article, we explored the in vitro antifungal activity of its ethyl acetate extract against a panel of three fruit phytopathogenic fungi including: Penicillium digitatum, P. italicum, and Monilinia fructicola. The sesquiterpenes isolated from the extract were also evaluated against these strains, demonstrating that the dialdehyde polygodial was the responsible for this activity. In order to encourage the use of the extract rather than the pure compound, we displayed ex vivo assays using fresh oranges and peaches inoculated with P. digitatum and M. fructicola, respectively, and subsequently treated by immersion with an extract solution of 250 and 62.5 µg/mL, respectively. There were no statistically significant differences between the treatments with commercial fungicides and the extract over the control of both fruit rots. The concentration of the active compound present in the extract used on fruit experiments was determined by Gas Chromatography-Mass Spectroscopy. Finally, cytotoxicity evaluation against Huh7 cells showed that P. acuminata extract was less cytotoxic than the commercial fungicides at the assayed concentrations. After these findings we could conclude that a chemically characterized extract of P. acuminata should be further developed to treat fungal diseases in fruits from an agro-ecological model.

Background: One of the main problems that fruit health has gone through in recent years is the difficult eradication of their fungal pathogens during crops or the post-harvest stage. This concerns the whole world because it represents huge production losses, fruit export restrictions and consumer distrust. Consequently, new alternatives are sought to avoid the increasing use of fungicides that cause important damage to fruit consumers and to the environment. One of the alternatives to solve this problem could be the exploration of plants and their active compounds applied to the treatment of fruit health. Materials and methods: This article describes peach production worldwide and particularly in Argentina, in addition to the main fungal rot that causes the greatest economic losses. Furthermore, experimental in-vitro studies of 69 extracts obtained from 18 plants growing in the central region of Argentina were displayed against the devastating fungus Monilinia fructicola, which greatly affects stone fruits. A simple and effective method developed in agar plate was applied to evaluate a large number of samples in a short time. Results: Results showed that approximately 36% of the samples tested were strongly active against this pathogen, 12% were moderately active and 52% demonstrated to be inactive. Conclusion: These findings support the possible use of natural products for fruit health and the importance of deepening in this field of science.

Postharvest fungal infections, particularly by Botrytis cinerea, can cause up to 50% losses in fruits and vegetables, and the overuse of synthetic fungicides has led to resistant pathogen strains. We hypothesized that hexane (Hex) and methanolic (MeOH) extracts from peanut (P) and pecan nut (PN) shells possess antifungal properties effective against B. cinerea in strawberries. To test this, we conducted both in vitro and ex vivo assays using strawberries inoculated with B. cinerea, comparing two controls (T0: water; T1: commercial synthetic fungicide) with four treatments—Hex-P, MeOH-P, Hex-PN, and MeOH-PN—at 1000 and 2000 ppm (in vitro) and 4000 ppm (ex vivo). Total phenolic content (TPC) and antioxidant activity (AA) were also measured. MeOH-P and Hex-PN extracts at 2000 ppm significantly inhibited fungal mycelial growth in vitro. In ex vivo assays, MeOH-P reduced both disease incidence and severity comparably to the synthetic fungicide. MeOH-PN exhibited the highest TPC and AA. These findings support the potential use of MeOH-P extract as a natural alternative to synthetic fungicides for controlling B. cinerea in strawberries during postharvest storage.

Natural products obtained from plants constitute an alternative to chemically synthesized fungicides, whose improper use might have caused the development of resistant fungal strains. In the present work, 40 products obtained from 20 native Argentinean plant species were tested against three citrus postharvest pathogens: Penicillium digitatum, Penicillium italicum, and Geotrichum citri-aurantii. Natural products were obtained by classical solvent extraction methods and the fungicidal evaluation was carried out by agar diffusion tests using commercial fungicides as negative controls and dimethyl sulfoxide as a positive one. The inhibition percentages were determined 7 and 14 days post inoculation of each fungus. Most of the products tested showed inhibition percentages higher than 50% for G. citri-aurantii, but only 20% of them were active against P. digitatum and P. italicum. The most promising products which inhibited (100%) the growth of at least one of the three phytopathogens were extracted from the following plants: Orthosia virgata, Petiveria alliacea, Funastrum clausum, Solanum caavurana, and Solanum pilcomayense. These products were tested over inoculated oranges and there were no statistically significant differences between the treatments with a commercial fungicide and the methanolic extract in the control of fruit rot. The products extracted from native plants have fungicide potential, but further studies are required.