Yohimbine 5mg tablets

A natural compound derived from the Pausinystalia yohimbe tree-yohimbine, has a rich history of use in traditional medicine and is currently being explored for its potential therapeutic applications. This indole alkaloid primarily acts as an antagonist of α2-adrenergic receptors. Initially recognized for its purported aphrodisiac properties, yohimbine has been investigated for a wide range of applications, including sports or the treatment of erectile dysfunction and metabolic disorders. However, toxicological concerns exist, particularly at higher doses. Ongoing researches help to fully assess yohimbine's efficacy and safety profile and to explore strategies for enhancing its bioavailability and reducing toxicity. This review examines the multifaceted nature of yohimbine, delving into both its promising therapeutic potential and the associated risks.

Abstract licence: CC BY

Xylazine is a common veterinary drug used for sedation, anesthesia, muscle relaxation and analgesia. Berberine (C20H18NO4+) is an alkaloid compound found in different plant species with a wide range of biological and pharmacological activities. To date, no studies have examined the effects of berberine on acute hyperglycemia. Therefore, the present study was designed to investigate the effects of berberine on acute hyperglycemia and low insulin levels caused by ketamine/xylazine (K/X) administration. To clarify the involved mechanism, yohimbine (C21H26N2O3, an α2-adrenergic receptor antagonist) was used. To further elucidate the underlying mechanisms, insulin concentration, SOD activity, TAC, MDA, TNF-α, and IL-1β levels in serum were also determined. Berberine (1.25, 5, and 20 mg/kg) and yohimbine (0.5 and 2 mg/kg) were injected intraperitoneally (IP) 25 and 20 min before acute hyperglycemia induction, respectively. IP administration of a cocktail of ketamine (100 mg/kg) and xylazine (10 mg/kg) caused acute hyperglycemia. The tail blood glucose levels and their average (30–120 min) were measured. After the last blood glucose level measurement, blood samples were taken, and the serum insulin concentration, total antioxidant capacity (TAC), superoxide dismutase (SOD), malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) levels were evaluated. K/X significantly (P < 0.05) increased blood glucose at 30, 60, 90, and 120 min, decreased insulin levels, and induced oxidative stress, which was accompanied by an increase in pro-inflammatory cytokines. Berberine (5 and 20 mg/kg) and yohimbine (2 mg/kg) significantly reduced blood glucose and increased insulin levels. Berberine (5 and 20 mg/kg) treatment also improved the decreased TAC content and SOD activity and restored the increased serum levels of MDA, TNF-α and IL-1β. Furthermore, coadministration of ineffective doses of berberine (1.25 mg/kg) and yohimbine (0.5 mg/kg) significantly prevented hyperglycemia and hypoinsulinemia. The synergic effect between berberine and yohimbine was observed. Overall, berberine helps counteract K/X-induced hyperglycemia and hypoinsulinemia. Anti-hyperglycemic synergy between berberine and yohimbine suggests that berberine works partly by blocking α2 adrenergic receptors. In addition, oxidative stress and pro-inlammatory mediators reduction and anti-oxidative activity elevation might be involved in these metabolic effects of berberine.

Abstract licence: CC BY-NC-ND

Alzheimer’s disease (AD) involves progressive cognitive decline and neuropsychiatric symptoms that are strongly linked to neuroinflammation and aberrant hippocampal neurogenesis. We examined whether dexmedetomidine (Dex), a clinically used selective α 2 -adrenergic agonist, could mitigate Aβ 1–42 –induced pathology in mice. After intracerebroventricular Aβ 1–42 injection, animals were treated with Dex (25 or 50 μg/kg/day) for 7 days; a subgroup additionally received the α 2 antagonist Yohimbine. Behavioral tests showed improved memory performance across recognition and spatial paradigms, accompanied by reduced anxiety-like behavior in exploratory assays. Histological analyses with Nissl and doublecortin (DCX) staining indicated preserved neuronal integrity, fewer degenerating cells, and normalization of pathological neurogenesis. At the molecular level, Dex suppressed the expression of pro-inflammatory and apoptotic genes (CXCL2, IL-1β, iNOS, SPHK1) and lowered hippocampal malondialdehyde, consistent with reduced oxidative stress and improved cellular resilience. Yohimbine partly reversed these effects, supporting α 2 -adrenergic involvement but leaving open the possibility of additional pathways contributing to the response. Overall, our results suggest that Dex protects against Aβ-driven injury through coordinated regulation of neuroinflammation, oxidative stress, and neurogenesis, underscoring its promise as a molecularly targeted candidate for early therapeutic strategies in AD management.

Abstract licence: CC BY

The inversion of C3 stereochemistry in monoterpenoid indole alkaloids (MIAs), derived from the central precursor strictosidine (3S), is essential for producing pharmacologically important 3 R MIAs and spirooxindoles such as reserpine. While early MIA biosynthesis preserves the 3S configuration, the mechanism underlying C3 inversion has remained unresolved. Here, we identify and biochemically characterize a conserved oxidase-reductase pair in Gentianales: heteroyohimbine/yohimbine/corynanthe C3-oxidase (HYC3O) and C3-reductase (HYC3R), which together invert the 3S stereochemistry to 3 R across diverse substrates. HYC3O and HYC3R are encoded within biosynthetic gene clusters in Rauvolfia tetraphylla and Catharanthus roseus, homologous to a geissoschizine synthase (GS) cluster also uncovered. Comparative genomics indicate that the GS cluster originated at the base of Gentianales (~135 Mya), coinciding with the evolution of the strictosidine synthase cluster, whereas the reserpine cluster arose later. These findings uncover the genomic and biochemical basis of key events driving MIA diversification beyond canonical vinblastine and ajmaline pathways. Inversion of C3 stereochemistry of monoterpenoid indole alkaloids (MIAs) has to occur at some point during their biosynthesis; however, the mechanism has remained unresolved. Here, the authors report an oxidase–reductase enzyme pair encoded within a gene cluster and demonstrate their collaborative role in inverting MIA C3 stereochemistry.

Abstract licence: CC BY-NC-ND