Investigation of alpha amylase inhibitors from Bidens pilosa L. by in silico and in vitro studies

Bidens pilosa L. has been traditionally used as an anti-diabetic herbal medicine; however, its mechanism of action remains elusive. In this study, the potential role of B. pilosa compounds on alpha-amylase inhibition and regulation of multiple pathways was investigated via computational and experimental studies. The phytocompounds were retrieved from plant databases and published literature. The druggability profile of these compounds was predicted using MolSoft. The probable targets of these phytocompounds were predicted using BindingDB (similarity index ≥ 0.7). Further, compound-gene set-pathway and functional enrichment analysis were performed using STRING and KEGG pathway databases. The network between compound-protein-pathway was constructed using Cytoscape. Molecular docking was performed using AutoDock Vina, executed through the POAP pipeline. The stability of the best docked complex was subjected to all-atom molecular dynamics (MD) simulation for 100 ns to investigate their structural stabilities and intermolecular interactions using GROMACS software. Finally, B. pilosa hydroalcoholic extract was subjected to LC-MS and tested for dose- and time-dependent alpha-amylase inhibitory activity. Out of 31 bioactive compounds, 13 were predicted to modulate the human pancreatic alpha-amylase (AMY2A) and 12 pathways associated with diabetes mellitus. PI3K-Akt signaling pathway (hsa04151) scored the lowest false discovery rate by triggering 15 genes. Further intermolecular interaction analysis of the docked complex revealed that Brassidin had the highest active site interaction and lowest binding energy compared to standard acarbose, and MD reveals the formation of a stable complex throughout 100 ns production run. LC-MS analysis revealed the presence of 13 compounds (targeting AMY2A) in B. pilosa hydroalcoholic extract, which showed potent AMY2A inhibition by in vitro studies that corroborate in silico findings for its anti-diabetic activity. Based on these findings, enriched fractions/pure compounds inhibitory activity that can be performed in future for drug discovery.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40203-023-00187-9.

Unraveling snake venom phospholipase A2: an overview of its structure, pharmacology, and inhibitors

Snake bite is a neglected disease that affects millions of people worldwide. WHO reported approximately 5 million people are bitten by various species of snakes each year, resulting in nearly 1 million deaths and an additional three times cases of permanent disability. Snakes utilize the venom mainly for immobilization and digestion of their prey. Snake venom is a composition of proteins and enzymes which is responsible for its diverse pharmacological action. Snake venom phospholipase A2 (SvPLA2) is an enzyme that is present in every snake species in different quantities and is known to produce remarkable functional diversity and pharmacological action like inflammation, necrosis, myonecrosis, hemorrhage, etc. Arachidonic acid, a precursor to eicosanoids, such as prostaglandins and leukotrienes, is released when SvPLA2 catalyzes the hydrolysis of the sn-2 positions of membrane glycerophospholipids, which is responsible for its actions. Polyvalent antivenom produced from horses or lambs is the standard treatment for snake envenomation, although it has many drawbacks. Traditional medical practitioners treat snake bites using plants and other remedies as a sustainable alternative. More than 500 plant species from more than 100 families reported having venom-neutralizing abilities. Plant-derived secondary metabolites have the ability to reduce the venom's adverse consequences. Numerous studies have documented the ability of plant chemicals to inhibit the enzymes found in snake venom. Research in recent years has shown that various small molecules, such as varespladib and methyl varespladib, effectively inhibit the PLA2 toxin. In the present article, we have overviewed the knowledge of snake venom phospholipase A2, its classification, and the mechanism involved in the pathophysiology of cytotoxicity, myonecrosis, anticoagulation, and inflammation clinical application and inhibitors of SvPLA2, along with the list of studies carried out to evaluate the potency of small molecules like varespladib and secondary metabolites from the traditional medicine for their anti-PLA2 effect.

Three finger toxins of elapids: structure, function, clinical applications and its inhibitors

The WHO lists snakebite as a "neglected tropical disease". In tropical and subtropical areas, envenoming is an important public health issue. This review article describes the structure, function, chemical composition, natural inhibitors, and clinical applications of Elapids' Three Finger Toxins (3FTX) using scientific research data. The primary venomous substance belonging to Elapidae is 3FTX, that targets nAChR. Three parallel β-sheets combine to create 3FTX, which has four or five disulfide bonds. The three primary types of 3FTX are short-chain, long-chain, and nonconventional 3FTX. The functions of 3FTX depend on the specific toxin subtype and the target receptor or ion channel. The well-known effect of 3FTX is probably neurotoxicity because of the severe consequences of muscular paralysis and respiratory failure in snakebite victims. 3FTX have also been studied for their potential clinical applications. α-bungarotoxin has been used as a molecular probe to study the structure and function of nAChRs (Nicotinic Acetylcholine Receptors). Acid-sensing ion channel (ASIC) isoforms 1a and 1b are inhibited by Mambalgins, derived from Black mamba venom, which hinders their function and provide an analgesic effect. α- Cobra toxin is a neurotoxin purified from Chinese cobra (Naja atra) binds to nAChR at the neuronal junction and causes an analgesic effect for moderate to severe pain. Some of the plants and their compounds have been shown to inhibit the activity of 3FTX, and their mechanisms of action are discussed.

Pharmacognostic and In-vitro Antioxidant Antimicrobial potentials of Jayanti Veda (Tridax procumbens L.)

Ayurveda is one of the oldest holistic traditional systems of medicine. Tridax procumbens known as “Jayanti Veda” which is weed found throughout India. It shows number of pharmacological activities like Hepatoprotective, Anti-inflammatory, Wound healing, Antioxidant, Antimicrobial, Antidiabetic. The present study was carried out to evaluate antioxidant and antimicrobial activity of hydroalcoholic extract and fractions of Tridax procumbens in order to find possible sources for future novel pharmaceutical formulations. The plant material was subjected for extraction and the extract was further fractionated. Hydroalcoholic extract and fractions were analyzed for different phytocomponents. Fraction 2 was analyzed for phenolic content, Fraction 3 was analyzed for its antimicrobial activity. Fraction 4 was analyzed for its flavonoid content, and antioxidant potentials. The crude extract showed the presence of various phytocompounds whereas F1 contains lipids & waxes. F2 contains phenolics, terpenes & sterols. F3 contains alkaloids. F4 contains flavonoids. The total flavonoid contents of F4 was compared with crude extract (51.19±0.412 and 45±0.073 respectively), antioxidant activity of F4 was compared with crude extract (IC50 - 22.7795±0.8208 and 23.247±0.7344 respectively), total phenolic contents of F2 was compared with crude extract (82.24±0.871 and 47.43±0.37 respectively) and antimicrobial activity of F3 [IZD- 1.0cm- (S. aureus), 0.9cm (E.coli) and crude-0.6cm- (S, aureus), 0.5cm (E.coli)] Results were found significantly higher for all the fractions as compared to crude extract. The present results revealed that the Tridax procumbens acts as a powerful antioxidant and antimicrobial agent. 

The introduction of a new contraceptive; two years experience with Norplant

OBJECTIVE

To determine the uptake, acceptability and continuation rates of a new contraceptive implant, Norplant.

DESIGN

Review of case notes of all acceptors during the two years following the introduction of the implant.

SETTING

A large family planning clinic in Edinburgh.

SUBJECTS

All women choosing Norplant.

RESULTS

508 women chose Norplant, many as an alternative to sterilisation or because they had experienced problems with other methods of contraception. 9% of women were lost to follow-up. Of the remainder continuation rates were 84% at one year and 80% after 18 months of use. 43% of women gave bleeding problems as the reason for removal. However the combination of weight gain, mood swings, depression and headache was frequently reported as unwanted side effects by women seeking removal. No major problems were experienced with either insertion or removal of Norplant.

CONCLUSIONS

Norplant is an effective method of contraception which many women find attractive. The incidence of erratic bleeding is high but many women tolerate this problem because the method is easy to use and lasts five years. Careful counselling is essential for high continuation rates.