Lipase activity inhibited by aloenin A: Glycoside from Aloe vera (L.) Burm. f.-In vitro and molecular docking studies

Deciphering the ameliorative effect of Aloe vera (L.) burm. F. extract on histopathological alterations in Streptozotocin-induced WNIN/GR-ob rats

ETHNOPHARMACOLOGICAL RELEVANCE

Natural products have emerged as a novel source in the management of non-communicable diseases, more so in diabetes mellitus and its comorbidities. Aloe vera is widely recognized for its anti-hyperglycemic and anti-hyperlipidemic properties and numerous researchers have identified component (s) from Aloe vera attributing to these therapeutic effects.

AIM OF THE STUDY

The current work was undertaken to gain insight into the protective effect of Aloe vera (L.) Burm. f. extract to study the cytoarchitecture/histopathological alterations in the target organs in mutant Obese WNIN/GR-Ob rats that were made frank diabetic with streptozotocin.

MATERIALS AND METHODS

Rats were divided into five groups. 1)WNIN-GR-Ob/control group 2)WNIN-GR-Ob treated with STZ 3)WNIN-GR-Ob + STZ + Sitagliptin 4)WNIN-GR-Ob + STZ + Aloe vera 5)WNIN-GR-Ob/control group + Aloe vera. Histopathological analysis of the pancreas, kidney, liver, and adipocytes was done after 4 weeks of treatment.

RESULTS

The histopathological examination of STZ-induced diabetic rats revealed significant changes in all the vital organs including cell infiltration, degeneration, and necrosis. Treatment with A. vera negated most of the histopathological changes seen in STZ induced rats. Sitagliptin-which served as a positive control in the present study-reversed the alterations seen in streptozotocin rats.

CONCLUSION

Considering the hypoglycaemic and hypolipidemic activities of Aloe vera that have been previously demonstrated by us, the present study further re-instates the therapeutic efficacy of Aloe vera towards vital organs. It was able to restore islet cells and reduce β-cell damage. In addition, it was also able to aid in kidney tubular regeneration and reverse the degenerative changes brought on by streptozotocin on liver. Further, Aloe vera treated group exhibited moderate hyperplasia with decreased size of adipocytes and reduced macrophage infiltration. Thus, our findings advocate its application as an important nutraceutical in the therapeutic management of diabetes mellitus and associated complications.

Characterization, Anti-glycation, Anti-inflammation, and Lipase Inhibitory Properties of Rauvolfia vomitoria Leaf Extract: In Vitro and In Silico Evaluations for Obesity Treatment

Pancreatic lipase (PLP) is an enzyme responsible for the catalytic hydrolysis of fats and its inhibition is relevant for obesity management. Side effects linked with orthodox inhibitors have, however, paved the way for an increased search for safe natural sources. The present study investigated the anti-glycation, anti-inflammatory, and anti-lipase properties of Rauvolfia vomitoria aqueous (ARV), ethanolic (ERV), and methanolic (MRV) leaf extracts coupled with the molecular interactions of selected bioactive compounds with PLP using in vitro and in silico techniques. Phytochemical constituents were characterized using spectroscopic techniques. Drug-likeness and chemical reactivity profile of selected bioactive compounds were analyzed using SwissADME and quantum chemical calculations. FT-IR and GC-MS affirmed the presence of phenolic compounds including 3-phenyl-2-ethoxypropylphthalimide and 5-methyl-2-phenyl-1H-indole. All extracts showed moderate anti-glycation, anti-inflammatory, and lipase inhibitory capacities relative to standard controls. However, MRV exhibited the highest lipase inhibition (IC50, 0.17 ± 0.01 mg/mL), using a mixed-inhibition pattern. MRV interaction with PLP resulted in decreased secondary structure components of PLP (α-sheet, β-turn). MRV compounds (MCP20, MCP28, etc.) exhibited low chemical hardness, EHOMO-ELUMO energy gap, and high chemical reactivity. Foremost MRV compounds obeyed Lipinski's rule of five for drug-likeness and interacted with PHE-78 amongst others at PLP catalytic domain with high binding affinity (≥ - 9.3 kcal/mol). Pi-alkyl hydrophobic interaction and hydrogen bonding were predominantly involved. Our findings provide scientific insights into the ethnotherapeutic uses of R. vomitoria extracts for the management of obesity and related complications, plus useful information for optimizable drug-like candidates against obesity.

Aloe vera-An Extensive Review Focused on Recent Studies

Since ancient times, Aloe vera L. (AV) has attracted scientific interest because of its multiple cosmetic and medicinal properties, attributable to compounds present in leaves and other parts of the plant. The collected literature data show that AV and its products have a beneficial influence on human health, both by topical and oral use, as juice or an extract. Several scientific studies demonstrated the numerous biological activities of AV, including, for instance, antiviral, antimicrobial, antitumor, and antifungal. Moreover, its important antidepressant activity in relation to several diseases, including skin disorders (psoriasis, acne, and so on) and prediabetes, is a growing field of research. This comprehensive review intends to present the most significant and recent studies regarding the plethora of AV's biological activities and an in-depth analysis exploring the component/s responsible for them. Moreover, its morphology and chemical composition are described, along with some studies regarding the single components of AV available in commerce. Finally, valorization studies and a discussion about the metabolism and toxicological aspects of this "Wonder Plant" are reported.

Synthesis and Characterization of Short α and β-Mixed Peptides with Excellent Anti-Lipase Activities

Obesity is a source of significant pathologies and deadly diseases, including heart disease, diabetes, and cancer. One of the most intriguing strategies in the hunt for new anti-obesity medications is the inhibition of pancreatic lipase (PL). This study presents a novel application of short α and β-mixed peptides as pancreatic lipase inhibitors. These peptides were synthesized in the solution phase and characterized using FTIR and 1H-NMR. L-proline is present in a high percentage of natural anti-lipase peptides and was used as a β-amino acid in this study to enhance anti-lipase activity and proteolytic stability. Moreover, L-α-proline was converted to β-amino acid derivatives using the Arndt-Eistert method with the advantage of stereo control at the α-carbon. The synthesized peptides with anti-lipase activity are N-Boc-β-Pro-Gly-OBz (93%), N-Boc-O-Bz-Tyr-β-Pro-β-Pro-Gly-OBz (92%), N-Boc-O-Bz-Tyr-β-Pro-COOH (91%), N-Boc-Phe-β-Pro-OCH3 (90%), and N-Boc-O-Bz-Tyr-β-Pro-OCH3 (89%). These peptides may function as lead molecules for further modification to more significant molecules, which can help control obesity.

Methodologies for Assessing Pancreatic Lipase Catalytic Activity: A Review

Obesity is a disease of epidemic proportions with a concerning increasing trend. Regarded as one of the main sources of energy, lipids can also represent a big part of an unnecessary intake of calories and be, therefore, directly related to the problem of obesity. Pancreatic lipase is an enzyme that is essential in the absorption and digestion of dietary fats and has been explored as an alternative for the reduction of fat absorption and consequent weigh loss. Literature describes a great variability of methodologies and experimental conditions used in research to evaluate the in vitro inhibitory activity of compounds against pancreatic lipase. However, in an attempt to choose the best approach, it is necessary to know all the reaction conditions and understand how these can affect the enzymatic assay. The objective of this review is to understand and summarize the methodologies and respective experimental conditions that are mainly used to evaluate pancreatic lipase catalytic activity. 156 studies were included in this work and a detailed description of the most commonly used UV/Vis spectrophotometric and fluorimetric instrumental techniques are presented, including a discussion regarding the differences found in the parameters used in both techniques, namely enzyme, substrate, buffer solutions, kinetics conditions, temperature and pH. This works shows that both UV/Vis spectrophotometry and fluorimetry are useful instrumental techniques for the evaluation of pancreatic lipase catalytic activity, presenting several advantages and limitations, which make the choice of parameters and experimental conditions a crucial decision to obtain the most reliable results.