Humarain: a new dimeric gallic acid glycoside from Punica granatum L. bark

In Vitro Anti-HIV-1 Reverse Transcriptase and Integrase Properties of Punica granatum L. Leaves, Bark, and Peel Extracts and Their Main Compounds

In a search for natural compounds with anti-HIV-1 activity, we studied the effect of the ethanolic extract obtained from leaves, bark, and peels of Punica granatum L. for the inhibition of the HIV-1 reverse transcriptase (RT)-associated ribonuclease H (RNase H) and integrase (IN) LEDGF-dependent activities. The chemical analyses led to the detection of compounds belonging mainly to the phenolic and flavonoid chemical classes. Ellagic acid, flavones, and triterpenoid molecules were identified in leaves. The bark and peels were characterized by the presence of hydrolyzable tannins, such as punicalins and punicalagins, together with ellagic acid. Among the isolated compounds, the hydrolyzable tannins and ellagic acid showed a very high inhibition (IC50 values ranging from 0.12 to 1.4 µM and 0.065 to 0.09 µM of the RNase H and IN activities, respectively). Of the flavonoids, luteolin and apigenin were found to be able to inhibit RNase H and IN functions (IC50 values in the 3.7-22 μM range), whereas luteolin 7-O-glucoside showed selective activity for HIV-1 IN. In contrast, betulinic acid, ursolic acid, and oleanolic acid were selective for the HIV-1 RNase H activity. Our results strongly support the potential of non-edible P. granatum organs as a valuable source of anti-HIV-1 compounds.

Anthelmintic activity of pomegranate peel extract (Punica granatum) and synthetic anthelmintics against gastrointestinal nematodes in cattle, sheep, goats, and buffalos: in vivo study

Parasitic gastroenteritis (PGE) is one of the most important parasitic diseases that causes economic losses and health problems in ruminants. PGE causes a drop in milk, meat, and wool production in addition to decreasing animal fertility and sometimes leading to animal death. Conventional anthelmintics used for animal treatment are expensive, especially for farmers in developing countries. Moreover, the concern of anthelmintic resistance to these synthetic drugs is rising. Therefore, this study aimed to evaluate the anthelmintic activity of plant extract pomegranate (Punica granatum L) peel extract (PPE) against PGE infestations among ruminants. A total of 120 ruminants of different species (20 cattle, 12 buffalos, 68 sheep, and 20 goats) were examined for PGE eggs in their fecal samples. The animals under experiment were divided into four groups: the first group (negative control) was not given any drugs, the second group was given ivermectin (0.5 ml/25 kg bwt) (positive control 1), the third group was given albendazole (2.5 mg active principle/kg bwt) (positive control 2), and the fourth group was given PPE (200 mg/kg bwt). Fecal egg count (FEC) was performed on day 0 prior to the 1st dose of treatment. On day 15, an additional treatment (with the same doses) was administered and FEC was performed on days 7 and 21. Our results showed that on the 7th day of the experiment, there was an increase in FEC in the negative control group by 5%, while in the second, third, and fourth groups, there was a decrease in FEC with 95%, 90%, and 85% respectively. On the 21st day (7 days from the second dose), there was an increase in FEC in the control group by a 10% and 100% reduction in FEC in both the second and third groups. While in the fourth group, there was a decrease in FEC by 97%. In conclusion, PPE could be used as a safe, cheap, and effective natural anthelmintic against PGE.

A Critical Review of Phenolic Compounds Extracted from the Bark of Woody Vascular Plants and Their Potential Biological Activity

Polyphenols are one of the largest and most widespread groups of secondary metabolites in the plants world. These compounds are of particular interest due to their occurrence and the properties they possess. The main sources of phenolic compounds are fruits and vegetables, but lately, more and more studies refer to woody vascular plants, especially to bark, as an important source of phenolic compounds with a potential biological effect. This study aims to bring together information on the phenolic compounds present in the bark of woody vascular plants by discussing extraction methods, the chemical composition of the extracts and potential biological effects. The literature data used in this paper were collected via PubMed (2004⁻2019). Search terms were: bark, rhytidome, woody vascular plant, polyphenols, phenolic compounds, biologic activity, antioxidant, immunostimulatory, antimutagenic, antibacterial, anti-inflammatory, and antitumoral. This paper intends to highlight the fact that the polyphenolic extracts obtained from the bark of woody vascular plants represent sources of bioactive compounds with antioxidant, immunostimulatory, antimutagenic, antibacterial properties, etc. Future research directions should be directed towards identification and isolation of bioactive compounds. Consequently, biologically active compounds obtained from the bark of woody plants could be exploited on an industrial scale.

Comparative Evaluation of Anthelmintic Activity of Edible and Ornamental Pomegranate Ethanolic Extracts against Schistosoma mansoni

Due to the development of praziquantel (PZQ) schistosomes resistant strains, the discovery of new antischistosomal agents is of high priority in research. This work reported the in vitro and in vivo effects of the edible and ornamental pomegranate extracts against Schistosoma mansoni. Leaves and stem bark ethanolic extracts of both dried pomegranates were prepared at 100, 300, and 500 μg/mL for in vitro and 600 and 800 mg/kg for in vivo. Adult worms Schistosoma mansoni in RPMI-1640 medium for in vitro and S. mansoni infected mice for in vivo tests were obtained from Theodor Bilharz Research Institute, Cairo, Egypt. In vitro activity was manifested by significant coupled worms separation, reduction of motor activity, lethality, and ultrastructural tegumental alterations in adult worms. In vivo activity was manifested revealed by significant reduction of hepatic granulomas number and diameter, decreased number of bilharzial eggs in liver tissues, lowered liver inflammatory infiltration, decreased hepatic fibrosis, and inducible nitric oxide synthase (iNOS) expression. Ethanolic stem bark extract of edible pomegranate exhibited highest antischistosomal activities both in vitro and in vivo. Therefore, pomegranate showed a good potential to be used as a promising new candidate for the development of new schistosomicidal agents.