Abstract
Purpose: In the Encyclopedia of Brazilian Medicinal Plants (1996) by Goro Hashimoto, Passiflora quadrangularis (hereinafter P. quadrangularis) is generally described as having a sedative effect, and quadranguloside, a cycloartane-type triterpenoid saponin, is described as a component of the leaves. The author speculates that this compound is closely related to the sedative effect of P. quadrangularis. In this study, the author collected literature on the phytochemical components and pharmacological and biological activity of P. quadrangularis. From the knowledge gained from the literature survey, the author considered the mental and neurological effects of P. quadrangularis, such as anxiolytic and sedative effects, shown in the Encyclopedia of Brazilian Medicinal Plants through phytochemical components and brain neurochemistry. The author examined whether P. quadrangularis is suitable for Passiflora preparations and their combinations in the formulation design of future psychotropic and neurological drugs.
Methods: The author searched the Web for reports on P. quadrangularis. From these, the author extracted research papers on the phytochemical components and pharmacological and biological activity effects of P.quadrangularis.
Results: Recent literature survey results showed that the main components isolated and identified from aqueous and aqueous alcoholic extracts of the leaves or peel of P. quadrangularis were C-glycosyl flavonoids. Among them, all reports stated that the main C-glycosyl flavonoid was vitexin-2-O-xyloside. Gazola, et al. (2018) initially considered apigenin, an aglycone of C-glycosyl flavonoid, as the causative agent of the sedative effect of aqueous extracts from the peel of P. quadrangularis. They demonstrated the potential involvement of GABAA receptors in mediating the sedative effect of apigenin. However, when the estimated amount of apigenin was administered alone, some samples did not show a sedative effect. Therefore, it was thought that other compounds may have contributed to the cause. Furthermore, the sedative effect of apigenin was observed after oral administration to mice. Therefore, it was speculated that not only apigenin but also other metabolites generated after in vivo metabolism may regulate GABAA receptors in vivo. Recently, Gopika, et al. (2024) confirmed the presence of quercetin 3,7-O-dirhamnoside and kaempferol 3-O-rhamnoside 7-O-xyloside in the hydroalcoholic extract of P. quadrangularis using LCMS analysis. On the other hand, from this literature survey, the author could not find any research papers that demonstrated the psychopharmacological effects of quadranguloside, a cycloartane-type triterpenoid saponin, such as anxiolytic, sedative, or antidepressant effects.
Conclusion: It is thought that the aglycones of C-glycosyl flavonoids (apigenin, ruteorin, etc.) contained in P.quadrangularis and their metabolites act as a community dividing them into their respective GABAA receptor binding sites. Based on these comprehensive results, it is believed that P. quadrangularis exerts anxiolytic, sedative and mild tranquilizing effects. Through this literature survey, it is believed that with regard to Nerbenl-Forte, a botanical sedative containing valerian, passiflora, hops and potentilla, the ingredients contained in the herbal medicines of valerian, passiflora and hops act as GABAA receptor positive allosteric modulators and exert their anxiolytic, sedative and mild tranquilizing effects through a synergistic.
