Cytotoxicity study and antioxidant activity of crude extracts and SPE fractions from Carica papaya leaves

Carica papaya L. Leaves: Deciphering Its Antioxidant Bioactives, Biological Activities, Innovative Products, and Safety Aspects

The prevalence of viral infections, cancer, and diabetes is increasing at an alarming rate around the world, and these diseases are now considered to be the most serious risks to human well-being in the modern period. There is a widespread practice in Asian countries of using papaya leaves (C. papaya L.) as herbal medicine, either alone or in combination with prescribed medications, to treat a variety of ailments. The importance of conducting the necessary descriptive studies in order to determine the safety of papaya leaf consumption is also emphasized in the context of their application in the healthcare sector. Electronic databases such as Google Scholar, Scopus, and PubMed were used to gather information on papaya leaves, their therapeutic potential, and clinical evidence-based studies. The literature was gathered from publications on papaya leaves, their therapeutic potential, and clinical evidence-based studies. The antidengue, anticancer, antidiabetic, neuroprotective, and anti-inflammatory effects of papaya leaves discussed in this article are supported by evidence from preclinical, in vivo, in vitro, and clinical trial studies, as well as from other sources. Leaves have been investigated for their mechanism of action as well as their potential to be used in the development of novel herbal products for the health business. According to the reports gathered, only a small number of research demonstrated that leaf extract at high concentrations was hazardous to certain organs. The collective literature reviewed in this review provides insights into the use of papaya leaves as a cure for epidemic diseases, highlighting the phytochemical composition and pharmacological attributes of papaya leaves, as well as the results of various preclinical and clinical studies that have been conducted so far on the subject. The review clearly demonstrates the successful medical evidence for the use of papaya leaf extracts in the healthcare system as a supplemental herbal medication in a variety of clinical settings.

A DPPH· Kinetic Approach on the Antioxidant Activity of Various Parts and Ripening Levels of Papaya (Carica papaya L.) Ethanolic Extracts

Papaya fruits (Carica papaya L.) are valuable both as food, including concentrates and mixed beverages and in traditional medicine. The goal of the study was to evaluate the antioxidant activity of various parts of unripe and ripe papaya fruit from the DPPH· kinetics point of view. Peel, pulp, seed, and seed-pulp of unripe and ripe papaya fruits (¼ and >¾ level of ripening) were extracted with ethanol and monitored at 517 nm in the presence of DPPH·. The radical scavenging capacity (RSC) at various time ranges and DPPH· reaction rates for specific time intervals were determined. The highest RSC values were obtained for papaya pulp extracts, consistently higher for the ripe samples in comparison with the unripe ones (86.4% and 41.3%). The DPPH· rates significantly differ for the unripe and ripe papaya extracts, especially for the first time range. They are more than double for the ripe papaya. These values were 2.70, 4.00, 3.25, 2.75 μM/s for the peel, pulp, seed, seed-pulp extracts from the ripe papaya and only 1.00, 1.65, 1.40, 1.80 μM/s for the unripe samples. DPPH· kinetic approach can be useful for a fast and simple evaluation of the overall antioxidant properties of fruit extracts.

Potential SARS-CoV-2 3CLpro inhibitors from chromene, flavonoid and hydroxamic acid compound based on FRET assay, docking and pharmacophore studies

This present study reports some natural products and one hydroxamic acid synthetic compound which were previously reported as matrix metalloproteinase-9 (MMP-9) inhibitors to be evaluated for their inhibition toward severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) 3-chymotrypsin-like protease (3CLpro). This enzyme is one of the proteins responsible for this coronaviral replication. Two herbal methanolic extracts i.e., Averrhoa carambola leaves and Ageratum conyzoides aerial part demonstrate >50% inhibition at 1000 µg/mL. Interestingly, apigenin, one of flavonoids, demonstrates 92% inhibition at 250 µg/mL (925 µM) as well as hydroxamic acid compound, N-isobutyl-N-(4-methoxyphenylsulfonyl)glycyl hydroxamic acid (NNGH), which shows 69% inhibition at 100 µM. The in vitro results are supported by the docking studies revealing that the binding mode of both compounds is mainly by interacting with GLU166 residue in the hydrophobic pocket of the 3CLpro. Pharmacophore mapping further supported the results by confirming that the in vitro activities of both compounds are due to their pharmacophore features employing hydrogen bond acceptor (HBA), hydrogen bond donor (HBD) and hydrophobic. Gas Chromatography-Mass Spectrometry (GC-MS) analysis reported chromene compounds in Ageratum conyzoides aerial part methanolic extract are potential to be this enzyme inhibitor candidate. These all results reflect their potencies to be SARS-CoV-2 inhibitors through 3CLpro inhibition mechanism.