Exploring the potentials of some compounds from Garcinia kola seeds towards identification of novel PDE-5 inhibitors in erectile dysfunction therapy

Computational Investigation of the Therapeutic Potential of Detarium senegalense in the Management of Erectile Dysfunction

Erectile dysfunction (ED) is a multifactorial social problem affecting men worldwide. While phosphodiesterase type 5 inhibitors (PDE5) like sildenafil are commonly used, they often present side effects, underscoring the need for alternative therapies. Therefore, this study investigated the potential of phytochemicals from Detarium senegalense in the management of ED. A library of phytochemicals from Detarium senegalense was generated, prepared, and interacted with six key enzymes implicated in ED, including PDE5, using the Schrödinger Maestro suite. The results identified catechin, epicatechin, and gallic acid as the leading compounds with significant binding affinities for the targeted enzymes. Catechin and epicatechin (-9.877 and -11.408 kcal/mol, respectively) exhibited comparable binding affinities to sildenafil (-11.926 kcal/mol) on PDE5. The MD simulation results also revealed superior stability and ability to maintain interaction with key amino acids at the active site of PDE5 over the entire simulation period for these compounds. These compounds also demonstrated favorable ADMET profiles over sildenafil, including high gastrointestinal absorption and no violation of Lipinski's rule, indicating good bioavailability and drug likeness. These findings suggest that flavonoids from Detarium senegalense, especially catechin and epicatechin, have potential in the management of ED by interacting with multiple targets involved in its pathogenesis.

Insights into bioactive constituents of onion (Allium cepa L.) waste: a comparative metabolomics study enhanced by chemometric tools

BACKGROUND

Onion waste was reported to be a valuable source of bioactive constituents with potential health-promoting benefits. This sparked a surge of interest among scientists for its valorization. This study aims to investigate the chemical profiles of peel and root extracts of four onion cultivars (red, copper-yellow, golden yellow and white onions) and evaluate their erectogenic and anti-inflammatory potentials.

METHODS

UPLC-QqQ-MS/MS analysis and chemometric tools were utilized to determine the chemical profiles of onion peel and root extracts. The erectogenic potential of the extracts was evaluated using the PDE-5 inhibitory assay, while their anti-inflammatory activity was determined by identifying their downregulating effect on the gene expression of IL-6, IL-1β, IFN-γ, and TNF-α in LPS-stimulated WBCs.

RESULTS

A total of 103 metabolites of diverse chemical classes were identified, with the most abundant being flavonoids. The organ's influence on the chemical profiles of the samples outweighed the influence of the cultivar, as evidenced by the close clustering of samples from the same organ compared to the distinct separation of root and peel samples from the same cultivar. Furthermore, the tested extracts demonstrated promising PDE-5 and anti-inflammatory potentials and effectively suppressed the upregulation of pro-inflammatory markers in LPS-stimulated WBCs. The anti-inflammatory activities exerted by peel samples surpassed those of root samples, highlighting the importance of selecting the appropriate organ to maximize activity. The main metabolites correlated with PDE-5 inhibition were cyanidin 3-O-(malonyl-acetyl)-glucoside and quercetin dimer hexoside, while those correlated with IL-1β inhibition were γ-glutamyl-methionine sulfoxide, γ-glutamyl glutamine, sativanone, and stearic acid. Taxifolin, 3'-hydroxymelanettin, and oleic acid were highly correlated with IL-6 downregulation, while quercetin 4'-O-glucoside, isorhamnetin 4'-O-glucoside, and p-coumaroyl glycolic acid showed the highest correlation to IFN-γ and TNF-α inhibition.

CONCLUSION

This study provides a fresh perspective on onion waste as a valuable source of bioactive constituents that could serve as the cornerstone for developing new, effective anti-PDE-5 and anti-inflammatory drug candidates.

Exploring the Multifaceted Potential of Sildenafil in Medicine

Phosphodiesterase type 5 (PDE5) is pivotal in cellular signalling, regulating cyclic guanosine monophosphate (cGMP) levels crucial for smooth muscle relaxation and vasodilation. By targeting cGMP for degradation, PDE5 inhibits sustained vasodilation. PDE5 operates in diverse anatomical regions, with its upregulation linked to various pathologies, including cancer and neurodegenerative diseases. Sildenafil, a selective PDE5 inhibitor, is prescribed for erectile dysfunction and pulmonary arterial hypertension. However, considering the extensive roles of PDE5, sildenafil might be useful in other pathologies. This review aims to comprehensively explore sildenafil's therapeutic potential across medicine, addressing a gap in the current literature. Recognising sildenafil's broader potential may unveil new treatment avenues, optimising existing approaches and broadening its clinical application.

Catechin from Anonna senegalensis is a Potential Inhibitor of Erectile Dysfunction: Implication for Its Use in Male Sexual Enhancement

Erectile dysfunction (ED) is a major challenge for men. The drugs for its treatment are associated with side effects. Hence, in phytomedicinal research, where Anonna senegalensis (A. senegalensis) is a candidate with abundant phytochemicals possessing various pharmacological properties, but the sex-enhancing phytochemical is elusive in the literature. This study aimed to understand the molecular interaction of its potent molecule mediating male sexual enhancement. A library of 69 compounds from A. senegalensis was docked against the ED-targeted proteins. Sildenafil citrate was used as the reference standard. Thereafter, the lead compound was screened for drug-likeness by applying the Lipinski rule of 5 (RO5), pharmacokinetic properties, and bioactivity using SwissADME and Molinspiration web servers, respectively. The results show catechin as the lead phytochemical compound with a stronger binding affinity for most of the proteins of ED. Also, catechin demonstrates good compliance with the RO5, great pharmacokinetic profiles, and could be said to be a polypharmacological molecule with good bioactivity scores. The research findings unravel the potential of catechin (a phytochemical belonging to the flavonoids class) from A. senegalensis leaf as a potential male sexual enhancement molecule via its high binding affinity for most erectile dysfunction-targeted proteins. They may require further toxicity and therapeutic evaluations in vivo.

Garcinia kola: a critical review on chemistry and pharmacology of an important West African medicinal plant

Garcinia kola Heckel (Clusiaceae) is a tree indigenous to West and Central Africa. All plant parts, but especially the seeds, are of value in local folklore medicine. Garcinia kola is used in treatment of numerous diseases, including gastric disorders, bronchial diseases, fever, malaria and is used to induce a stimulating and aphrodisiac effect. The plant is now attracting considerable interest as a possible source of pharmaceutically important drugs. Several different classes of compounds such as biflavonoids, benzophenones, benzofurans, benzopyran, vitamin E derivatives, xanthones, and phytosterols, have been isolated from G. kola, of which many appears to be found only in this species, such as garcinianin (found in seeds and roots), kolanone (fruit pulp, seeds, roots), gakolanone (stem bark), garcinoic acid, garcinal (both in seeds), garcifuran A and B, and garcipyran (all in roots). They showed a wide range of pharmacological activities (e.g. analgesic, anticancer, antidiabetic, anti-inflammatory, antimalarial, antimicrobial, hepatoprotective and neuroprotective effects), though this has only been confirmed in animal models. Kolaviron is the most studied compound and is perceived by many studies as the active principle of G. kola. However, its research is associated with significant flaws (e.g. too high doses tested, inappropriate positive control). Garcinol has been tested under better conditions and is perhaps showing more promising results and should attract deeper research interest (especially in the area of anticancer, antimicrobial, and neuroprotective activity). Human clinical trials and mechanism-of-action studies must be carried out to verify whether any of the compounds present in G. kola may be used as a lead in the drug development.

Therapeutic potential of rutin in male infertility: A mini review

Male infertility has become a problem worldwide, and recent research has emphasized the development of more effective therapy options. Among natural compounds, rutin has been widely studied for its potential to treat dysfunction related to male infertility, including a reduction in sperm quality, spermatogenesis disruption and structural disruption in the testis. A thorough review of scientific literature published in several databases, including Google Scholar, PubMed/MEDLINE and Scopus, was used to synthesize the present state of research on the role of rutin in male reproductive health. Rutin has been shown to possess antiapoptotic, antioxidant and anti-inflammatory activities, among others, which are crucial in the management of male infertility. Numerous investigations have shown that rutin protects against male infertility and have explored the underlying mechanisms involved. The present review, therefore, assesses the therapeutic mechanisms involved in male infertility treatment using rutin. Rutin was able to mitigate the induced oxidative stress, apoptosis, inflammation, and related physiological processes that can cause testicular dysfunction. Please cite this article as: Rotimi DE, Elebiyo TC, Ojo OA. Therapeutic potential of rutin in male infertility: a mini review. J Integr Med. 2022; Epub ahead of print.

A Review on the Pharmacological Importance of PDE5 and Its Inhibition to Manage Biomedical Conditions

Phosphodiesterase type 5 (PDE5) is a cyclic GMP (cGMP) specific protein. It hydrolyzes the phosphodiesterase linkage and catalyzes the conversion of cGMP to 5’ GMP, which controls different physiological activities of the body. PDE5 is associated with biomedical conditions like neurological disorders, pulmonary arterial hypertension, cardiomyopathy, cancer, erectile dysfunction, and lower urinary tract syndrome. Inhibition of PDE5 has now been proven pharmaceutically effective in a variety of therapeutic conditions. Avanafil, tadalafil, sildenafil, and vardenafil are the most commonly used PDE5 inhibitors (PDE5i) today which are often used for the management of erectile dysfunction, lower urinary tract syndromes, malignancy, and pulmonary arterial hypertension. However, these synthetic PDE5i come with a slew of negative effects. Some of the most common side effects include mild headaches, flushing, dyspepsia, altered color vision, back discomfort, priapism, melanoma, hypotension and dizziness, non-arteritic anterior ischemic optic neuropathy (NAION), and hearing loss. In light of the potential negative effects of this class of medications, there is a lot of room for new, selective PDE5 inhibitors to be discovered. We have found 25 plant botanical compounds effectively inhibiting PDE5 which might be useful in treating a variety of disorders with minimal or no adverse effects.

Pharmacological action of quercetin against testicular dysfunction: A mini review

The testis is an immune-privileged organ susceptible to oxidative stress and inflammation, two major factors implicated in male infertility. A reduction in the concentration and activities of testicular function biomarkers has been shown to correlate with impaired hypothalamic-pituitary-testicular axis and oxidative stress. However, the use of natural products to ameliorate these oxidative stress-induced changes may be essential to improving male reproductive function. Quercetin possesses several pharmacological activities that may help to combat cellular reproduction-related assaults, such as altered sperm function and reproductive hormone dysfunction, and dysregulated testicular apoptosis, oxidative stress, and inflammation. Studies have shown that quercetin ameliorates testicular toxicity, largely by inhibiting the generation of reactive oxygen species, with the aid of the two antioxidant pharmacophores present in its ring structure. The radical-scavenging property of quercetin may alter signal transduction of oxidative stress-induced apoptosis, prevent inflammation, and increase sperm quality in relation to the hormonal concentration. In this review, the therapeutic potential of quercetin in mediating male reproductive health is discussed.