Update on the species of the genus Stephania in Cambodia : systematic, phytochemical and pharmacological studies

L’objectif de la thèse est une mise au point des espèces de Stephania répertoriées au Cambodge par l’étude systématique, phytochimique et pharmacologique. Du point de vue systématique, les travaux ont permis de répertorier sept espèces et deux variétés de Stephania au Cambodge : S. cambodica, S. japonica var. discolor et var. timoriensis, S. oblata, S. pierrei, S. rotunda (espèce-type), S. suberosa, et S. venosa. La clef de détermination établie lors de ce travail de thèse permet d’identifier ces espèces. D’après les résultats phylogénétiques, seul S. pierrei est monophylétique, ce qui représente moins de 10% des espèces de Stephania. L’étude chimique de cinq espèces a été réalisée par des méthodes chromatographiques (CLHP, UCLHP) et des méthodes spectroscopiques. Différents alcaloïdes ont été proposés comme marqueurs : la palmatine, la roémérine et la tétrahydropalmatine pour S. cambodica et S. rotunda, la cépharanthine, la tétrahydropalmatine et la xylopinine pour S. suberosa, la cépharanthine pour S. pierrei, la crébanine, et la tétrahydropalmatine pour S. venosa. Neuf alcaloïdes ont été isolés à partir du tubercule de S. cambodica, dont un nouveau composé dénommé «angkorwatine ». Une méthode d’éco-extraction des alcaloïdes assistée par ultrasons a été mise au point et optimisée par un plan d’expérience pour cette espèce. Une méthode analytique par UCLHP a été développée et validée pour le contrôle qualité de S. cambodica. Les résultats montrent que les extraits hydroéthanoliques obtenus par macération à partir du tubercule de S. suberosa, S. venosa et S. rotunda présentent une activité anti-inflammatoire importante (in vitro) avec un ratio anti-inflammatoire élevé.The thesis aims to provide update on species of the genus Stephania recorded in Cambodia by systematic, phytochemical and pharmacological studies.The systematic study allowed to list seven species and two varieties of Stephania in Cambodia: S. cambodica, S. japonica var. discolor and var. timoriensis, S. oblata, S. pierrei, S. rotunda (type species), S. suberosa and S. venosa. The presence of S. japonica var. timoriensis and S. oblata is reported for the first time in Cambodia. According to the phylogenetic results, only S. pierrei is monophyletic, which represents less than 10% of species in the genus Stephania. Chemical studies on the tubers of five species were carried out using chromatographic methods (HPLC, UHPLC) and spectroscopic methods. Different isolated alkaloids have been proposed as markers: palmatine, roemerine and tetrahydropalmatine for S. cambodica and S. rotunda, cepharanthine, tetrahydropalmatine, and xylopinine for S. suberosa, cepharanthine for S. pierrei, crebanine, and tetrahydropalmatine for S. venosa. Nine alkaloids belonging to five classes were isolated from the tuber of S. cambodica and a new compound namely "angkorwatine" was described. Ultrasound assisted extraction of alkaloids was developed and optimized by Design of Experiment for this species. This innovative extraction is a good alternative to conventional methods. An analytical UHPLC method was developed and validated for the quality control of S. cambodica. Results show that hydroethanolic extracts obtained by maceration of S. suberosa, S. rotunda and S. venosa exhibit significant anti-inflammatory activity with high anti-inflammatory ratio (selectivity index)

Lecto- and epitypification of Stephania rotunda (Menispermaceae)

The plant genus Stephania Loureiro (1790: 608–609) (Menispermaceae) comprises about 60 species distributed in tropical and subtropical Asia, tropical Africa, and Oceania (Lo et al. 2008). Species of this genus are commonly used in folk medicine for the treatment of asthma, tuberculosis, dysentery, hyperglycemia, cancer, fever, and malaria (Semwal et al. 2010). Currently, active pharmacological research is being conducted on S. rotunda Loureiro (1790: 608), and particularly on its tubers. This species shows in addition to antioxidant and cytotoxic activities, a significant antiplasmodial activity (Bun et al. 2009, Baghdikian et al. 2013). Floral traits are seldom used for infrageneric determination purposes in Stephania. Rather, vegetative traits show a better taxonomical discriminating power to determine species. According to the original description of the Portuguese botanist João de Loureiro (1790), Stephania rotunda is characterized by subrounded or triangular-suborbicular peltate leaves and twining stems. No type was designated in the protologue; however Loureiro specified that the species habitat was the Cochin-Chinese forest. Two specimens collected by Loureiro, housed at the Herbarium of The Natural History Museum (BM), correspond to the type location: Loureiro s.n., BM000554372 and BM000554373 (Fig. 1A, B). The most complete specimen (the first one cited here) is now designated as the lectotype, and the other considere

Pilot implementation of HIV self-testing delivery in private pharmacies combined to a Respondent Driven Sampling method to improve HIV testing for MSM and TGW in Phnom Penh – ANRS 0100s: a prospective feasibility study (Preprint)

BACKGROUND Regular testing is recognized as a key strategy for HIV control. The 2023 Integrated Biological and Behavioral Survey (IBBS) in Cambodia revealed that nearly one third of men who have sex with men (MSM) and one fourth of transgender women (TGW) were never tested for HIV or since more than 12 months. The majority of MSM and TGW were tested at Community-based organizations (CBO) facilities and by CBO outreach workers while private facilities are poorly used for HIV testing (6% for MSM and 9% for TGW). Private pharmacies could be able to deliver HIV self-testing (HIVST) kits giving the advantage of confidentiality, anonymity and time-saving, in particular for those reluctant to visit CBOs. The recruitment of participants by respondent driven sampling (RDS) method could give the opportunity to reach MSM and TGW outside the network of CBOs. OBJECTIVE This pilot study aims to evaluate the feasibility of HIVST delivery by a private pharmacy combined with RDS method to improve HIV testing among MSM and TGW in Phnom Penh, Cambodia. METHODS The study design is a mixed qualitative and quantitative approaches. MSM and TGW aged more than 18 years old will be recruited via a Respondent Driven Sampling (RDS) method with seeds recruited at hotspots and on social networks. The seeds will then distribute electronic and paper coupons to their networks physically and via social media, messaging and calling applications. Each recruited peer will bring the coupon to receive direct and free access to one HIVST kit at partner pharmacies as well as the 10 additional coupons to recruit the members of their networks. After 6 months, a qualitative assessment will be conducted among users to evaluate the acceptability and appropriateness of the strategy and among pharmacists to identify the barriers and facilitators. RESULTS Data collection will be conducted between September 2024 and December 2025. The initial results are expected to be published in February, 2026. CONCLUSIONS This public-private partnership intervention could allow to reach and test hidden population of MSM and TGW in Phnom Penh. CLINICALTRIAL ClinicalTrials.gov NCT05745168; https://clinicaltrials.gov/study/NCT0574516

Optimisation de l'extraction assistée par ultrasons des alcaloïdes bioactifs de Stephania cambodica par la méthodologie des surfaces de réponses

International audiencePalmatine Roemerine Scanning electron microscopy Tetrahydropalmatine UHPLC Ultrasound a b s t r a c t An ultrasound-assisted extraction (UAE) was optimized for the extraction of three bioac-tive alkaloids, namely, palmatine, roemerine, and tetrahydropalmatine from the tuber of Stephania cambodica. The performance of UAE and microwave-assisted extraction (MAE) was compared with that of percolation. UAE and MAE are also more environmentally friendly and use less toxic chemicals. MAE was as efficient as UAE for the extraction of tetrahydropalmatine; however, UAE significantly enhanced extraction yields of palmatine and roemerine. The influence of effective variables viz. liquidesolid ratio, percentage of ethanol, and time on UAE was then investigated using response surface methodology. The optimal UAE conditions were found to be ethanol 52%, time 9 min, and liquidesolid ratio 26.6:1 mL/g. Structural change was conducted by scanning electron microscopy. These findings suggest that UAE is a practical extractive procedure for preparation of alkaloid-rich extract for pharmacological investigation and for analytical control of S. cambodica tuber.L'extraction assistée par ultrasons (UAE) a été optimisée pour extraire trois alcaloïdes bioactifs : palmatine, roémérine et tétrahydropalmatine du tubercule de Stephania cambodica. L'efficacité de l'extraction assistée par ultrasons et par micro-ondes (MAE) a été comparée à celle de la percolation. La MAE est plus efficace que l'UAE pour l'extraction de la tétrahydropalmatine, mais l'UAE a augmenté significativement le rendement de la palmatine et de la roémérine. Les effets des variables indépendantes : ratio liquide/solide, pourcentage d'éthanol et temps d'extraction ont été etudiés par la méthodologie des surfaces de réponses. Les conditions d'extraction optimales suivantes ont été déterminées : éthanol, 52%, temps, 9 min, et ratio liquide/solide 26.6:1 mL/g. Le changement structural a été examiné par microscopie électronique à balayage. D'après les résultats de ce travail, l'UAE est une méthode d'extraction pratique pour la préparation d'extraits riches en alcaloïdes et le contrôle qualité de cette plante

The world checklist of Stephania (Menispermaceae), with notes on types

International audienc

Chemical profiling of the tuber of <i>Stephania cambodica</i> Gagnep. (Menispermaceae) and analytical control by UHPLC-DAD

International audienceA new aporphine glycoside (1), named " angkorwatine " , and eight known alkaloids: oblongine (2), stepharine (3), asimilobine-β-D-glucopyranoside (4), isocorydine (5), tetrahydropalmatine (THP) (6), jatrorrhizine (7), palmatine (PAL) (8) and roemerine (ROE) (9) were simultaneously isolated from the tuber of Stephania cambodica. The development and validation of UHPLC-DAD method was carried out for the quantification of marker compounds (PAL, ROE, THP) of S. cambodica. In addition to good selectivity and linearity (r 2 >0.997), trueness, precision, and accuracy of the method did not exceed the acceptance limit of ±10% for ROE, THP and ±20% for PAL. Consequently, this method is able to provide accurate results between 1.39−4.18 µg/mL, 2.01−30.72 µg/mL and 4.29−64.42 µg/mL for PAL, ROE, and THP, respectively. This study shows that the validated UHPLC method is a rapid, innovative and effective analytical approach to control quality of tubers of S. cambodica and to regulate the usage of this plant in traditional medicine