Rauwolfia polysaccharide can inhibit the progress of ulcerative colitis through NOS2-mediated JAK2/STAT3 pathway

BACKGROUND

Ulcerative colitis (UC) is an inflammatory disease of the digestive tract. Rauwolfia polysaccharide (Rau) has therapeutic effects on colitis in mice, but its mechanism of action needs to be further clarified. In the study, we explored the effect of Rau on the UC cell model induced by Lipopolysaccharide (LPS).

METHODS

We constructed a UC cell model by stimulating HT-29 cells with LPS. Dextran sodium sulfate (DSS) was used to induce mice to construct an animal model of UC. Subsequently, we performed Rau administration on the UC cell model. Then, the therapeutic effect of Rau on UC cell model and was validated through methods such as Cell Counting Kit-8 (CCK8), Muse, Quantitative real‑time polymerase chain reaction (RT-qPCR), Western blotting, and Enzyme-linked immunosorbent assay (ELISA).

RESULTS

The results showed that Rau can promote the proliferation and inhibit the apoptosis of the HT-29 cells-induced by LPS. Moreover, we observed that Rau can inhibit the expression of NOS2/JAK2/STAT3 in LPS-induced HT-29 cells. To further explore the role of NOS2 in UC progression, we used siRNA technology to knock down NOS2 and search for its mechanism in UC. The results illustrated that NOS2 knockdown can promote proliferation and inhibit the apoptosis of LPS-induced HT-29 cells by JAK2/STAT3 pathway. In addition, in vitro and in vivo experiments, we observed that the activation of the JAK2/STAT3 pathway can inhibit the effect of Rau on DSS-induced UC model.

CONCLUSION

In short, Rauwolfia polysaccharide can inhibit the progress of ulcerative colitis through NOS2-mediated JAK2/STAT3 pathway. This study provides a theoretical clue for the treatment of UC by Rau.

Alkaloids and Lignans from the Aerial Parts of Rauvolfia tetraphylla Inhibit NO Production in LPS-activated RAW 264.7 Cells

Three previously undescribed compounds named rauvolphyllas A-C (1-3), along with thirteen known compounds, 18β-hydroxy-3-epi-α-yohimbine (4), yohimbine (5), α-yohimbine (6), 17-epi-α-yohimbine (7), (E)-vallesiachotamine (8), (Z)-vallesiachotamine (9), 16S-E-isositsirikine (10), Nb -methylisoajimaline (11), Nb -methylajimaline (12), ajimaline (13), (+)-lyoniresinol 3α-O-β-D-glucopyranoside (14), (+)-isolarisiresinol 3α-O-β-D-glucopyranoside (15), and (-)-lyoniresinol 3α-O-β-D-glucopyranoside (16) were isolated from the aerial parts of Rauvolfia tetraphylla L. Their chemical structures were elucidated based on the extensive spectroscopic interpretation of HR-ESI-MS, 1D and 2D NMR spectra. The absolute configurations of 2 and 3 were determined by experimental ECD spectra. Compounds 5, 6, 7, and 11-13 exhibited nitric oxide production inhibition activity in LPS-activated RAW 264.7 cells with the IC50 values of 79.10, 44.34, 51.28, 33.54, 37.67, and 28.56 μM, respectively, compared to that of the positive control, dexamethasone, which showed IC50 value of 13.66 μM. The other isolates were inactive with IC50 values over 100 μM.

Green synthesis of MnO2-embedded Rauvolfia tetraphylla leaves (MnO2@RTL) for crystal violet dye removal and as an antibacterial agent

The application of green synthesized nanocomposites for the prevention of environmental pollution is increasing nowadays. Here, a green composite has been synthesized by embedding MnO2 on Rauvolfia tetraphylla leaves using its leaf extract hereinafter termed as MnO2@RTL, and demonstrated for crystal violet (CV) dye removal from simulated and real wastewater. The surface properties of the material were determined by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), Fourier transform infrared spectra (FTIR), X-ray diffraction (XRD), and Brunauer-Emmet-Teller (BET) surface area, pHZPC, and zeta potential. The material exhibits a remarkable adsorption capacity of 61.162 mg/g at 328 K and pH 7. The adsorption was best fitted with Pseudo-second-order kinetic (R2 = 0.998) and a combination of Langmuir and Freundlich isotherm model (R2 = 0.994-0.999). The thermodynamic study revealed spontaneous (ΔG values =  - 2.988 to - 4.978 kJ/mol) and endothermic (ΔH values = 6.830 to 11.018 kJ/mol) adsorption. After adsorption, 80% regeneration occurred with 50% methanol, and recycled up to five times. Advantageously, the material was able to remove CV dye in the presence of coexistent ions and from industrial wastewater, confirming field applicability. The adsorption capacity of the material is superior to previously reported materials. The standard deviation and relative standard deviations have been evaluated to be 0.000422-0.000667 and 0.473-0.749%, which suggests the reliability of the experiments. The exhausted material, after recycling, was pyrolyzed to overcome the disposal problem. It was established as a secondary adsorbent with 73% efficiency which makes the material win-win. The material showed antibacterial properties with Staphylococcus aureus bacteria with a zone of inhibition 5 mm.

Chemical composition, antioxidant, and enzyme inhibitory properties of Rauwolfia vomitoria extract

OBJECTIVES

Rauwolfia vomitoria is one ethno-botanicals in Nigeria used by traditional health practitioners in managing several human diseases. However, necessary information regarding its effect on enzymes implicated in the development and progression of erectile dysfunction is missing in the literature. Thus, this study investigated the antioxidant property and impact of Rauwolfia vomitoria extract on erectile dysfunction-related enzymes in vitro.

METHODS

High performance liquid chromatography was used to identify and quantify Rauwolfia vomitoria's phenolic components. Then, utilizing common antioxidant assays, the extract's antioxidant properties were evaluated and finally the effect of the extract on some enzymes (AChE, arginase and ACE) implicated in erectile dysfunction was investigated in vitro.

RESULTS

The results showed that the extract inhibited AChE (IC50=388.72 μg/mL), arginase (IC50=40.06 μg/mL) and ACE (IC50=108.64 μg/mL) activities. In addition, phenolic rich extract of Rauvolfia vomitoria scavenged radicals and chelated Fe2+ in concentration dependent manner. Furthermore, rutin, chlorogenic acid, gallic acid, and kaempferol were found in large quantities by HPLC analysis.

CONCLUSIONS

Therefore, one of the potential reasons driving Rauwolfia vomitoria's use in folk medicine for the treatment of erectile dysfunction could be its antioxidant and inhibitory activities on several enzymes linked to erectile dysfunction in vitro.

Anti-fouling potential and in-silico analysis of carotenoid and fatty acids from Rauvolfia tetraphylla L

Study investigated the antifouling potential ofRauvolfia tetraphyllaL. fruit, leaf and stem extracts against the marine fouling organisms throughin-vitroand in-silicoapproach. Methanolic crude extract of R. tetraphylla L.leaf exhibited maximum antibacterial potential against six fouling organisms isolated from Parangipettai coast and was further taken up for column fractionation. Twenty-four fractions were obtained, among which five fractions showed inhibitory efficiency against microfoulers of Bacillus megaterium. The active compounds present in the bioactive fraction were identified by FTIR, GC-MS and NMR (13C; 1H). The bioactive compounds that exhibited maximum antifouling activity were identified as Lycopersene (80%), Hexadecanoic acid; 1, 2-Benzenedicarboxylic acid, dioctyl ester; Heptadecene - (8) - carbonic acid - (1) and Oleic acid. Molecular docking studies of the potent anti-fouling compounds Lycopersene, Hexadecanoic acid, 1, 2-Benzenedicarboxylic acid, dioctyl ester and Oleic acid showed the binding energy of 6.6, - 3.8, -5.3 and -5.9 (Kcal/mol) and hence these compounds will act as a potential biocide to control the aquatic foulers. Moreover, further studies need to carry out in terms of toxicity, field assessment and clinical trial in order to take these biocides for a patent.

Genus Rauvolfia: A review of its ethnopharmacology, phytochemistry, quality control/quality assurance, pharmacological activities and clinical evidence

ETHNOPHARMACOLOGICAL RELEVANCE

The plants are from the genus Rauvolfia Plum. ex L. (Apocynaceae), which is represented by 74 species with many synonyms, and distributed worldwide, especially in the Asian, and African continents. Traditionally, some of them are used for the treatment of various disorders related to the central nervous system (CNS), cardiovascular diseases (CVD), and as an antidote due to the presence of monoterpene indole alkaloids (MIAs) such as ajmaline (144), ajmalicine (164) serpentine (182), yohimbine (190) and reserpine (214).

AIM

The present review provides comprehensive summarization and critical analysis of the traditional to modern applications of Rauvolfia species, and the major focus was to include traditional uses, phytochemistry, quality control, pharmacological properties, as well as clinical evidence that may be useful in the drug discovery process.

MATERIALS AND METHODS

Information related to traditional uses, chemical constituents, separation techniques/analytical methods, and pharmacological properties of the genus Rauvolfia were obtained using electronic databases such as Web of Science, Scopus, SciFinder, PubMed, PubChem, ChemSpider, and Google Scholar between the years 1949-2021. The scientific name of the species and its synonyms were checked with the information of The Plant List.

RESULTS

A total of seventeen Rauvolfia species have been traditionally explored for various therapeutic applications, out of which the roots of R. serpentina and R. vomitoria are used most commonly for the treatment of many diseases. About 287 alkaloids, seven terpenoids, nine flavonoids, and four phenolic acids have been reported in different parts of the forty-three species. Quality control (QC)/quality assurance (QA) of extracts/herbal formulations of Rauvolfia species was analyzed by qualitative and quantitative methods based on the major MIAs such as compounds 144, 164, 182, 190, and 214 using HPTLC, HPLC, and HPLC-MS. The various extracts of different plant parts of thirteen Rauvolfia species are explored for their pharmacological properties such as antimicrobial, antioxidant, antiprotozoal, antitrypanosomal, antipsychotic, cardioprotective, cholinesterase inhibitory, and hepatoprotective. Of which, clinical trials of herbal formulations/extracts of R. serpentina and MIAs have been reported for CVD, CNS, antihypertensive therapy, antidiabetic effects, and psoriasis therapy, while the extracts and phytoconstituents of remaining Rauvolfia species are predominantly significant, owning them to be additional attention for further investigation under clinical trials and QC/QA.

CONCLUSION

The present communication has provided a comprehensive, systematic, and critically analyzed vision into the traditional uses, phytochemistry, and modern therapeutic applications of the genus Rauvolfia are validated by scientific evidence. In addition, different plant parts from this genus, especially raw and finished herbal products of the roots of R. serpentina have been demonstrated for the QC/QA.

Antioxidant and haematinic effects of methanolic and aqueous methanolic roots extracts of Rauwolfia serpentina Benth in type 2 diabetic mice

Present investigation was carried out to evaluate the antioxidant and haematinic effects of methanolic (MREt) and aqueous methanolic (AqMREt) root extracts of R. serpentina in mice model of type 2 diabetes (T2D). Experimental mice were divided into nine groups (six per group) as: fructose-induced (T2D) diabetic group (distilled water 1ml/kg), negative control (0.05% DMSO 1ml/kg), positive control (pioglitazone 15mg/kg) and six test groups (MREt 10, 30 & 60mg/kg & AqMREt 50, 100 & 150mg/kg). Whereas tenth group was served as normal control (1ml/kg distilled water). All test doses of MREt & AqMREt significantly (p<0.05) decreases the percent inhibition of catalase (CAT) and superoxide dismutase (SOD) when compared with diabetic controls. Treatment with both extracts also improved the total hemoglobin (Hb), red blood cell (RBC), white blood cell (WBC) counts, packed cell volume (PCV), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) in test groups. Fourier transform infrared (FTIR) spectral analysis revealed the presence of phenols moiety in both extracts. Findings suggested that AqMREt possesses more antioxidant and haematinic potential while the MREt of R. serpentina moderately possesses the same activities, which might be due to the high content of phenols present in AqMREt.

Therapeutic role of Rauwolfia serpentina in minimizing the risk of glycosylation and associated biomarkers in experimentally induced type 1 diabetic mice

Present work investigates the effects of hydro-methanolic roots extract (HyMREt) of Rauwolfia serpentina in type 1 diabetic mice. Mice were divided into normal, diabetic, negative and positive controls (I-IV) and three test (HyMREt doses) groups (V-VII - 50, 100, &150mg/kg). Allocated treatment of each group was given orally for 14 days in overnight fasted state. Percent change in fasting blood glucose (FBG), body weights, body tissue weights, hepatic glycogen, total lipids, glycosylated hemoglobin (HbA_1c), complete blood profile and antioxidant enzymes including catalase (CAT) and superoxide dismutase (SOD) were estimated. HyMREt doses produced meaningful (p<0.0001) reduction (-39 to -53%) in FBG. Hemoglobin (Hb) levels were raised, HbA1c were considerably decreased (4.5-3.77%) and glycosylation (HbA_1c to Hb) ratio was expressively (p<0.0001) improved in test groups. Dose-wise improvement (p< 0.05) in total glycogen and decrement (p<0.05) in lipids were observed in livers of test groups. HyMREt significantly decreased (p<0.05) percent inhibition of SOD and CAT. HyMREt doses progressively (p<0.05) improved RBC and other hematological parameters while decrement was only noticed in leucocyte counts. Administration of test doses of HyMREt were significantly reduced the glycosylation, oxidative stress and anemia caused by alloxan intoxication in mice.

Monoterpene indole alkaloids with diverse skeletons from the stems of Rauvolfia vomitoria and their acetylcholinesterase inhibitory activities

Nine undescribed monoterpene indole alkaloids, rauvomitorine A-I, including an unprecedented C-9-methoxymethylene-sarpagine framework alkaloid, two rare suaveoline framework type alkaloids, and six yohimbine framework type alkaloids, as well as eleven known alkaloids, were isolated from the stems of Rauvolfia vomitoria Afzel. (Apocynaceae). The structures of the unreported alkaloids were elucidated by extensive spectroscopic analysis and single-crystal X-ray diffraction analysis with Cu Kα radiation. Rauvomitorine A with an unreported framework type represents the first example of C-9-methoxymethylene-sarpagine alkaloids and its plausible biosynthetic pathway was proposed. All the isolated alkaloids were evaluated their acetylcholinesterase inhibitory (AChE) activities and cytotoxicity against five cancer cell lines and some of them exhibited potential anti-AChE activities with IC₅₀ values ranging from 49.76 to 186.62 μM. Importantly, this is the first report of the AChE inhibitory activities on suaveoline framework type alkaloids, suggesting this type of alkaloids may be valuable sources for the discovery of AChE inhibitory agents. A preliminary structure-activity relationship for AChE inhibitory activities of the isolated alkaloids is also discussed, providing some clues to designing lead compounds for AChE inhibitors.

Reflexin A, a new indole alkaloid from Rauvolfia reflexa induces apoptosis against colon cancer cells

One new indole alkaloid, reflexin A (1), and two known indoles, macusine B (2) and vinorine (3), were isolated from the bark of Rauvolfia reflexa. Their structures were elucidated by 1D and 2D NMR, UV, IR, and MS spectroscopic analyses. Compound 1 displayed anticancer activity against HCT-116 colon cancer cells with an IC₅₀ value of 30.24 ± 0.75 µM. The results implied that the newly isolated 1 induced apoptosis in HCT-116 cells, suggesting its possible role as an anticancer agent. In vivo acute toxicity study was performed on compound 1 to evaluate its safety profile.

Cerebellar neurohistology and behavioural effects of gongronema latifolium and Rauwolfia vomitoria in mice

Rauwolfia vomitoria and Gongronema latifolium are medicinal herbs used for the treatment of hypertension, malaria, mental and intestinal disorders. G. latifolium is known to prevent the side effects reported for R. vomitoria. Therefore we decided to investigate what effects a combination treatment of G. latifolium and R. vomitoria would have on mice. Thirty male mice weighing 15-26 g were divided into 4 groups of 6 mice each. Groups 2, 3 and 4 were the treatment groups, and were treated with 150 mg/kg of R. vomitoria root bark extract, 200 mg/kg of G. latifolium leaf extract, and combination of both extracts, respectively. The control group received 0.5 mL of 20% Tween. The treatments were by oral gavages and lasted for 7 days. The open field maze neurobehavioural test was performed on day 8 to ascertain locomotion, exploration and anxiety, and the animals were immediately sacrificed. Results indicate lower body weights, though no difference was seen in the brain weights and behavioural test parameters in the treatment groups compared with the control group. Neurohistology of the cerebellum showed slight hypertrophy of Purkinje cells, with brain matrix loss in treatment groups 2 and 3, but group 4 showed no apparent histopathology. The cellular population was higher, while the cellular sizes and total cellular areas were lower in all the treatment groups. This study showed that R. vomitoria root bark and G. latifolium leaf extracts may individually cause cerebellar cytoarchitecture changes, which may be prevented with the combination of both remedies.

Formulation and comparative evaluation of poly herbal anti-acne face wash gels

CONTEXT

Rauvolfia serpentina (L). Benth. ex Kurz. (Apocynaceae) possessing antibacterial properties are widely used in modern herbal medicines. Curcuma longa L. (Zingiberaceae), a readily available antiseptic, possess antioxidant, antibacterial, blood purifying and antiinflammatory properties and used in various skin creams. Azadirachta indica A. Juss. (Meliaceae) possess astringent, antiviral, discutient, stimulant and antibacterial properties and works excellently well against acne and keeps the skin healthy.

OBJECTIVE

Acne is the common skin problem that 85% of the teenagers face today. In this study, poly herbal anti-acne face wash gels were prepared using two polymers Carbopol and hydroxy propyl methyl cellulose (HPMC) along with the extracts of plants Rawvolfia serpentina, Curcuma longa, and Azadiracta indica.

MATERIALS AND METHODS

The gel formulations were prepared in four different concentrations of 50, 100, 200 mg/ml as Gel-CRB 100, Gel-HPMC 50, Gel-HPMC 100, Gel-HPMC 200, respectively. The formulations were tested for the anti-acne activity by turbidimetric method.

RESULTS

RESULTS showed that the gels were non-irritant, stable and posses anti-acne activity. The efficacy when tested with a standard was almost same to that of Clindamycin gel.

DISCUSSION AND CONCLUSION

From this study, Gel-HPMC 100 was proved to be stable and considered as an effective herbal formulation for acne treatment.

Alkaloids of the leaves of Rauwolfia vomitoria Afz

Leaves of Rauwolfia vomitoria, collected in Nigeria, contained at least six alkaloids, three are indole derivatives (aricine, tetrahydroalstonine, isoreserpiline) and three are isomers of α-oxindole type (carapanaubine, rauvoxine, rauvoxinine). Rauvoxine and rauvoxinine are new alkaloids. The leaves contained no reserpine.

African Rauwolfia Species

A substitute or adulterant for the roots of R. vomitoria Afz. is R. mombasiana Stapf, an East African shrub with a high reserpine yield. The anatomy of the root and stem is described and illustrated, and compared with published data about other African species.

African Rauwolfia Species: Part I. The Structure of the Root and Stem ofRauwolfia volkensii Stapf

A possible substitute or adulterant for the roots of R. vomitoria Afz. is the shrubby East African species R. volkensii Stapf. The anatomy of the roots and stems is described and illustrated, and compared with published data about other African species

THE DISTRIBUTION OF ALKALOIDS IN RAUWOLFIA CAFFRA SOND. AND RELATED SPECIES

In its content of reserpine, Rauwolfia caffra root-bark compares favourably with other species. The highest proportion of reserpine is found in the inner phloem whereas the ajmaline group of alkaloids, except for their absence in the cork, are more evenly distributed. The alkaloid content of thin bark exceeds that of thick bark and is very low in the wood of stem and root.

[Recent additions to the biography of the Augsburg physician and Orient traveler Leonhard Rauwolf (1535?-1596)]

The Augsburg physician Leonhard Rauwolf is known to the history of Western sciences for describing the exotic flora of the Near East in his travelogue "Aigentliche Beschreibung der Raiss [...] inn die Morgenländer" (Lauingen 1582). It has been asserted that little is known about his life before and after this journey. This paper summarizes his biography from previous biographical sketches and adds new archival findings from sources at Augsburg and Linz: Leonhard Rauwolf was the son of the Augsburg iron trader and councilman Sixt Rauwolf (1557) and his wife Agatha née Eggelhof (1583). He had several surviving brothers, Hans (or Johann), Georg, Sixt the younger, Matthäus, Ulrich, and a sister, Agatha. Sixt and Leonhard Rauwolf's "middle class" financial situation is analyzed by means of Augsburg tax records. Professional conditions of Leonhard Rauwolf in service of three cities in Germany and Austria are verified from the sources. Four letters, written to colleagues and friends are, along with two of his letters of approbation, edited here for the first time: they illustrate his lasting strong interest in botany and his attempts to build up a professional network. Further his political fate at Augsburg is examined that was shattered by the ongoing of religious conflicts in this biconfessional town and finally caused him to remove to Linz. At last, a look is taken at his later life at Linz and the circumstances of his death which he met in Hungary during the war against the Turks.

Rustom Jal Vakil and the saga of Rauwolfia serpentina

Dr Rustom Jal Vakil was India's pioneer in cardiology. He introduced the discipline of cardiology in his country. His mixture of clinical acumen, research and writing has survived him. Through his work with an ancient Indian folk remedy, Rauwolfia serpentina, he ushered in the modern era of effective pharmacotherapy of hypertension. His work was particularly significant since it galvanized other workers into finding more effective agents for the treatment of hypertension. He is remembered fondly by his acquaintances as an unassuming man in whom a multitude of choicest qualities blended seamlessly with each other.

[Milestones of cardiovascular therapy. IV. Reserpine]

Reserpine, the purified alkaloid of Rauwolfia serpentina, was the first potent drug widely used in the long-term treatment of hypertension. Rauwolfia serpentina is a tropical woody plant of the Apocyanaceae family ingenious to Asia, South America and Africa. Extracts of its different parts and of plants resembling to rauwolfia were used in Hindu medicine for snakebite, insomnia, insanity and many other diseases and complaints. In Europe, Georg Eberhard Rumpf first reported about rauwolfia in his Herbarium amboinense, 1755. The first modern paper about therapeutic applications of the whole root of rauwolfia was published in 1931 in the Indian Medical Journal by Sen and Bose, and many papers dealing with botanics, chemistry and pharmacology then appeared in Indian and European periodics. In 1949, Vakil published the first report of the antihypertensive effect of rauwolfia in the British Heart Journal. In the Ciba laboratories in Basel, Switzerland, Mueller, Schlittler and Bein analysed various rauwolfia alkaloids and published in 1952 the first complete report about their chemistry and pharmacology. In the same year, reserpine was introduced under the name Serpasil in the treatment of hypertension, tachycardia and thyreotoxicosis. The combination of reserpine, dihydroergocristine and a diuretic is still on the market (Brinerdin, Crystepin). In psychiatry, reserpine was prescribed as a tranqulizing agent until modem synthetic antidepressant and antipsychotic drugs were introduced. The author also briefly summarizes the chemistry, pharmacology and clinical use of reserpine.

Tissue lipid lowering-effect of a traditional Nigerian anti-diabetic infusion of Rauwolfia vomitoria foilage and Citrus aurantium fruit

The toxicity and anti-diabetic properties of an aqueous plant extract made by boiling Rauwolfia vomitoria foilage and Citrus aurantium fruits were evaluated in mice. A single dosage corresponding to 70x the human-daily-dose was non-toxic when administered to 6-week-old NMRI lean mice or 6- or 11-week-old C57BL/6J lean mice. Daily treatment of 11-week-old C57BL/KsBom-db (db/db) genetic diabetic mice with a dose corresponding to 10x human-daily-dose for 6 weeks facilitated a significant weight loss as compared to the untreated controls. During treatment, the db/db mice were maintained on the carbohydrate-deficient Altromin C1009 diet. Although the food intake in the treated mice was not statistically significant from that in the controls, the treated animals had significantly higher serum triglyceride contents, suggesting that the treatment induced lipid mobilization from internal stores. Moreover, the fatty acid profile of the eyes from the treated animals showed a significant reduction in total fatty acid content accompanied by a 33% reduction in estimated Stearoyl-CoA desaturase activity (p = 0.039) as compared with controls. The fatty acid mobilization and a protection of the brittle C57BL/KsBom-db pancreas were observed 5 weeks after cessation of treatment when the treated animals were maintained on the poorer Altromin C1009 diet.

Rustom Jal Vakil: his contributions to cardiology

Rustom Jal Vakil returned to India in 1938 after earning his medical degree from the University of London and focused on the treatment of heart ailments at a time when cardiology was not a distinct subspecialty in India. In 1949, after years of scrupulous collation and analysis of data, he published a watershed paper on the antihypertensive properties of Rauwolfia serpentina and effected a paradigm shift in the management of hypertension. Rauwolfia was the world's 1st successful blood-pressure-lowering agent, and its acceptance encouraged research scientists to pursue the development of other hypotensive drugs. Vakil was a prolific researcher whose contributions to Indian cardiovascular epidemiology--and to the whole of medical literature--were enormous. He was also a fine clinician with a remarkable gift for communication, be it with his patients, students, peers, or the lay public. All of this came together to make him the embodiment of a medically competent India.

A newly-detected reductase from Rauvolfia closes a gap in the biosynthesis of the antiarrhythmic alkaloid ajmaline

A new enzyme, 1,2-dihydrovomilenine reductase (E.C. 1.3.1), has been detected in Rauvolfia cell suspension cultures. The enzyme specifically converts 2beta( R)-1,2-dihydrovomilenine through an NADPH-dependent reaction into 17-O-acetylnorajmaline, a close biosynthetic precursor of the antiarrhythmic alkaloid ajmaline from Rauvolfia. A five-step purification procedure using SOURCE 30Q chromatography, hydroxyapatite chromatography, 2',5'-ADP Sepharose 4B affinity chromatography and ion exchange chromatography on DEAE Sepharose and Mono Q delivered an approximately 200-fold enriched enzyme in a yield of approximately 6%. SDS-PAGE showed an M r for the enzyme of approximately 48 kDa. Optimum pH and optimum temperature of the reductase were at pH 6.0 and 37 degrees C. The enzyme shows a limited distribution in cell cultures expressing ajmaline biosynthesis, and is obviously highly specific for the ajmaline pathway.

Isolation and structure elucidation of a new indole alkaloid from Rauvolfia serpentina hairy root culture: the first naturally occurring alkaloid of the raumacline group

A new monoterpenoid indole alkaloid, 10-hydroxy- N(alpha)-demethyl-19,20-dehydroraumacline ( 1), was isolated as a mixture of E- and Z-isomers from hairy root culture of Rauvolfia serpentina Benth. ex Kurz (Apocynaceae) and the structure was determined by 1D and 2D NMR analyses. The new indole alkaloid represents the first naturally occurring alkaloid of the raumacline group and its putative biosynthetical pathway is discussed.

The pharmacognosy of the root of Rauwolfia ligustrina Roem. and Schult

The morphological and anatomical characters of Rauwolfia ligustrina roots are described and compared with those of other Rauwolfia species. The characters of the stem, particularly in so far as they concern its detection when mixed with root, are recorded. Analytical studies on individual plants indicate that reserpine is confined almost entirely to the root-bark, the concentration rapidly decreasing towards the crown and becoming negligible in the stems. Samples of root from different localities may vary greatly in reserpine content.

Effect of Ajmaloon on the baroreceptor-heart rate reflex in anaesthetized rabbits and monkeys

The effects of a herbal drug, Ajmaloon (Hamdard, India), on the arterial blood pressure, heart rate (HR) and baroreceptor-heart rate reflex were studied in anesthetized rabbits and monkeys. Intravenously administered Ajmaloon produced a dose-dependent hypotensive response in both the species without any significant effect on the heart rate. Only in high doses (200 mg/kg or more). Ajmaloon produced a bradycardia response in rabbits. Even the highest dose (300 mg/kg) of Ajmaloon used in the present investigation did not cause arrhythmia or any other conduction disorder or respiratory distress. Baroreflex SAP-HR curve was shifted to the left of the control following treatment with 100 mg/kg intravenous Ajmaloon in both the species. Loss of tachycardia response to fall in arterial pressure in Ajmaloon treated animals indicated the drug induced suppression of normally existing sympathetic excitatory influence in response to hypotension. Baroreflex regulatory HR response to hypertension remains intact after intravenous administration of 100 mg/kg Ajmaloon, a dose much higher than the prescribed highest oral dose for humans. Intact baroreflex regulation of arterial blood pressure in response to hypertension in Ajmaloon treated mammals suggests that in patients besides lowering the blood pressure. Ajmaloon might not interfere with the normal blood pressure regulatory mechanism through arterial baroreceptors during hypertension.

[Antiarrhythmic activity of ajmaline obtained from Rauwolfia serpentina biomass grown in tissue culture]

The conventional experimental techniques showed that ajmaline derived from Rouwolfia serpentina Benth. biomass grown in tissue culture was effective in arresting canine ventricular arrhythmias induced by coronary occlusion, strophanthin and epinephrine, displaying antiarrhythmic effects in aconitine-induced intoxication of rats and substantially elevating the threshold of ventricular fibrillations in cats. The antiarrhythmic activity of ajmaline produced by the biotechnological technique was identical to that of ajmaline derived from the natural root of Rauwolfia serpentina Benth, which allows one to recommend that the agent in question should be clinically tested as an antiarrhythmic.

Rauwolfia use and breast cancer: a case-control study

Breast cancer risk among 1,362 cases and 1,250 controls participating in a large multicenter screening program was examined in relation to hypertension and the use of rauwolfia derivatives. A previous diagnosis of hypertension, reported by 22% of the cases and 23% of the controls, was not associated with an increased risk of breast cancer [odds ratio (OR) = 0.9]; nor was there any excess risk for long-term hypertensives. In addition, there was no significant increase in risk associated with use of either rauwolfia derivatives (OR = 1.2), thiazide preparations (OR = 1.2), or methyldopa (OR = 1.1). However, there were significant excess risks among long-term users and those with extended intervals since first use of rauwolfia. Rauwolfia users of 10 or more years' duration or those whose initial use occurred greater than or equal to 10 years before diagnosis had risk ratios of 4.5 (95% Cl, 1.2-19.8) and 3.8 (95% Cl, 2.3-11.6), respectively. These results suggest that women exposed to long-term rauwolfia use have an elevated risk of developing breast cancer, although the results fail to support previous observations of a generalized adverse effect.