Antimalarial activity of phytol derivatives: in vitro and in vivo study

Phytol exerts sedative-like effects and modulates the diazepam and flumazenil's action, possibly through the GABAA receptor interaction pathway

This study aimed at the evaluation of the sedative effect of phytol (PHY) with possible molecular mechanisms through in vivo and in silico studies. For this, adult male mice were randomly divided into six individual groups, namely control (vehicle), two standards (DZP: diazepam at 2 m/kg, FLU: flumazenil at 0.1 mg/kg), three test groups (PHY at 25, 50, and 75 mg/kg), and three combined groups with the DZP-2 and/or FLU-0.1 with PHY-75 mg/kg. After thirty minutes, each animal was treated with thiopental sodium (TS) at 40 mg/kg to produce sedation and observed for latency and duration of sleep up to 4 h. In silico studies were performed with the 6X3X protein of the GABAA receptor α1 and β2 subunits. The results demonstrate that PHY dose-dependently enhanced sleep duration in animals. However, it produced an insignificant sleep duration compared to the control and standard groups. It also significantly (p < 0.05) decreased the latency and increased the duration of sleep with DZP-2, while reducing these parameters with FLU-0.1. In in silico studies, DZP and FLU exhibited binding affinities with 6X3X by -6.8 and -6.9 kcal/mol, respectively, while PHY exhibited -6.9 kcal/mol. Taken together, PHY may exert a sedative-like effect in TS-induced sleeping mice and modulate the effects of DZP and FLU, possibly through interacting with the 6X3X protein of the GABAA receptor. PHY may be one of the good candidates for the management of sleep disturbances, such as insomnia.

New Phytol Derivatives with Increased Cosmeceutical Potential

Natural compounds are widely incorporated into cosmetic products for many purposes. Diterpenes often function as fragrances, enhancing the sensory experience of these formulations. However, current trends in cosmetic science aim to develop multifunctional products, where compounds traditionally used for texture or fragrance also possess biological activities that contribute to the product's efficacy. In this context, this study focuses on synthesizing derivatives of phytol-a compound already presents in cosmetic formulations-to enhance its anti-aging properties. The derivatives were synthesized through esterification with substituted benzoic and cinnamic acids, known for their antioxidant and enzyme inhibition properties. Reaction yields ranged from 91.0% to 5.2%, depending on the substituents in acid derivatives. The structures of the synthesized compounds were confirmed through NMR and MS techniques. Both the natural and newly synthesized derivatives were evaluated for their cosmeceutical potential using antioxidant assays and inhibition assays for tyrosinase, elastase, collagenase, and hyaluronidase. This work presents the first report of the synthesis and cosmetic evaluation of several of these derivatives. Comparing with phytol (1), which presented an IC50 of 77.47 µM, four of the derivatives presented improved tyrosinase inhibitory activity, with phytyl 4-methoxybenzoate being the most active (IC50 = 27.9 µM), followed by phytyl benzoate with an IC50 of 34.73 µM. Substitutions at other positions on the aromatic ring were less effective. Molecular docking studies confirmed that the modifications potentiated a stronger interaction between the synthesized compounds and tyrosinase.

Phytochemical composition, bioactive properties, and toxicological profile of Tetrapleura tetraptera

The use of medicinal plants has gained renewed wide popularity in Africa, Asia, and most parts of the world because of the decreasing efficacy of synthetic drugs. Thus, natural products serve as a potent source of alternative remedy. Tetrapleura tetraptera is a medicinal plant with cultural and traditional significance in West Africa. In addition to the plant being commonly used as a spice in the preparation of traditional spicy food for postpartum care it is also widely used to constitute herbal concoctions and decoctions for treatment of diseases. This review aimed to provide an up-to-date information on the ethnomedicinal uses, pharmacological activities and phytoconstituents of T. tetraptera. Preclinical studies regarding the plant's toxicity profile were also reviewed. For this updated review, literature search was done on PubMed, Science Direct, Wiley, and Google Scholar databases using the relevant keywords. The review used a total of 106 papers that met the inclusion criteria from January 1989 - February 2022 and summarised the bioactivities that have been reported for the rich phytoconstituents of T. tetraptera studied using various chemical methods. Considering the huge report, the review focused on the antimicrobial and antiinflammatory activities of the plant extracts and isolated compounds. Aridan, aridanin and several bioactive compounds of T. tetraptera have shown pharmacological activities though their mechanisms of action are yet to be fully understood. This study also highlighted the influence of plant parts and extraction solvents on its biological activities. It also presented data on the toxicological profile of the plant extracts using different models. From cultural uses to modern pharmacological research the bioactive compounds of T. tetraptera have proved effective in infectious disease management. We hope that this paper provided a robust summary of the biological activities and toxicological profile of T. tetraptera, thus calling for more research into the pharmacological and pharmacokinetic activities of natural products to help combat the growing threat of drug resistance and provide guidelines for their ethnomedicinal uses.

Ameliorative Effects of Dietary Ellagic Acid Against Severe Malaria Pathogenesis by Reducing Cytokine Storms and Oxidative Stress

Ellagic acid (EA), a fruit- and vegetable-derived flavonoid, has been reported for multiple pharmacological activities, which encouraged us to examine its useful effect in severe malaria pathogenesis, especially malaria-induced cytokine storms and oxidative stress linked to damage in major organs. Malaria was induced by injecting Plasmodium berghei–infected RBCs intraperitoneally into the mice. EA was given orally (5, 10, and 20 mg/kg) following Peter’s 4-day suppression test. EA exhibited the suppression of parasitemia, production of inflammatory cytokine storms and oxidative stress marker level quantified from vital organs significantly and an increase in hemoglobin, blood glucose, and mean survival time compared to the vehicle-treated infected group. EA administration also restored the blood–brain barrier integrity evidenced through Evans blue staining. Furthermore, we demonstrated the protecting effect of EA in LPS-induced inflammatory cytokine storms and oxidative stress in glial cells. The present study conclude that ellagic acid is able to alleviate severe malaria pathogenesis by reducing cytokine storms and oxidative stress–induced by malarial parasites. It also attributed promising antimalarial activity and afforded to improve the blood glucose and hemoglobin levels in treated mice. These research findings suggested the suitability of ellagic acid as a useful bioflavonoid for further study for the management of severe malaria pathogenesis.

Coumarin-1,2,3-triazole Hybrid Molecules: An Emerging Scaffold for Combating Drug Resistance

Undoubtedly, antibiotics have saved billions of lives, but lack of novel antibiotics, development of resistance mechanisms in almost all clinical isolates of bacteria, and recurrent infections caused by persistent bacteria hamper the successful treatment of the infections. Due to the widespread emergence of resistance, even the new families of anti-microbial agents have a short life expectancy. Drugs acting on a single target often lead to drug resistance and are associated with various side effects. For overcoming this problem, either multidrug therapy, or a single drug acting on multiple targets may be used. The latter is called 'hybrid molecules,' which are formed by clubbing two biologically active pharmacophores together, with or without an appropriate linker. In this rapidly evolving era, the development of natural product-based hybrid molecules may be a super-alternative to multidrug therapy, for combating drug resistance caused by various bacterial and fungal strains. Coumarins (benzopyran-2-one) are one of the earliest reported plant secondary metabolites having a clinically proven diverse range of pharmacological properties. On the other hand, 1,2,3-triazole is a common pharmacophore in many drugs responsible for polar interactions, improving the solubility and binding affinity to biomolecular targets. In this review, we discuss recent advances in Coumarin-1,2,3-triazole hybrids as potential anti-bacterial agents, aiming to provide a useful platform for the exploration of new leads with a broader spectrum, more effectiveness and less toxicity with multiple modes of action for the development of cost-effective and safer drugs in the future.

In vitro, in vivo and in silico Antihyperglycemic Activity of Some Semi-synthetic Phytol Derivatives

BACKGROUND

Due to the prevalence of type-2 diabetes across the globe, there is unmet need to explore new molecular targets for the development of cost-effective and safer antihyperglycemic agents.

OBJECTIVE

Structural modification of phytol and evaluation of in vitro, in vivo and in silico antihyperglycemic activity of derivatives establishing the preliminary structure activity relationship (SAR).

METHODS

The semi-synthetic derivatives of phytol were prepared following previously described methods. The antihyperglycemic potential was measured in vitro in terms of increase in 2-deoxyglucose (2-DG) uptake by L-6 rat skeletal muscle cells as well as in vivo in sucrose-loaded (SLM) and streptozotocin (STZ)-induced diabetic rat models. The blood glucose profile was measured at 30, 60, 90, 120, 180, 240, 300 and 1440 min post administration of sucrose in rats. The in silico docking was performed on peroxisome proliferator-activated receptor gamma (PPARγ) as anti-diabetic target along with absorption, distribution, metabolism, excretion and toxicity (ADMET) studies.

RESULTS

Nine semi-synthetic ester derivatives: acetyl (1), lauroyl (2), palmitoyl (3), pivaloyl (4), trans-crotonyl (5), benzoyl (6), m-anisoyl (7), 3,4,5-trimethoxy benzoyl (8) cinnamoyl (9) along with bromo derivative (10) of phytol were prepared. The derivatives 9, 8 and 2 caused 4.5, 3.2 and 2.7 times more in vitro uptake of 2-DG respectively than rosiglitazone (ROSI). The derivatives showed significant improvement on oral glucose tolerance both in SLM (29.6-21%) as well as STZ-induced diabetic (30.8-19.0%) rats. The in silico ADMET, docking studies showed non-toxicity and high binding affinity with PPARγ.

CONCLUSION

The potent antihyperglycemic activity with favorable pharmacokinetics supports phytol derivatives as suitable antidiabetic lead.