Identification and Functional Characterization of Oxidosqualene Cyclases from Medicinal Plant Hoodia gordonii.

Oxidosqualene cyclases (OSCs) are the key enzymes accountable for the cyclization of 2,3-oxidosqualene to varied triterpenoids and phytosterols. Hoodia gordonii (from the family Apocynaceae), a native of the Kalahari deserts of South Africa, Namibia, and Botswana, is being sold as a prevalent herbal supplement for weight loss. The appetite suppressant properties are attributed to P57AS3, an oxypregnane steroidal glycoside. At the molecular level, the enzymes involved in the biosynthesis of triterpenes and phytosterols from H. gordonii have not been previously reported. In the current study, predicted transcripts potentially encoding oxidosqualene cyclases were recognized first by searching publicly available H. gordonii RNA-seq datasets. Two OSC-like sequences were selected for functional analysis. A monofunctional OSC, designated HgOSC1 which encodes lupeol synthase, and HgOSC2, a multifunctional cycloartenol synthase forming cycloartenol and other products, were observed through recombinant enzyme studies. These studies revealed that distinct OSCs exist for triterpene formation in H. gordonii and provided opportunities for the metabolic engineering of specific precursors in producing phytosterols in this plant species.

Effect of South African Herb Hoodia gordonii on Liver Glucolipid Metabolism and PI3K/Akt/FoxO1 Signalling Pathway in db/db Mice / 中国实验方剂学杂志

ObjectiveTo observe the effects of the South African herb Hoodia gordonii （HG） on glucolipid metabolism in diabetic db/db mice and explore the possible mechanisms of HG on the liver of db/db mice based on the phosphoinositide-3 kinase （PI3K）/protein kinase B （Akt）/factor forkhead protein O1 （FoxO1） signaling pathway. MethodA total of 30 db/db mice were randomly divided into five groups according to fasting blood glucose： model group， metformin group （0.195 g·kg-1）， and low dose （0.39 g·kg-1）， medium dose （0.78 g·kg-1）， and high dose （1.56 g·kg-1） HG groups， with six m/m mice in each group， and another six m/m mice were set as normal group. The mice in the normal and model groups were given saline of 9 mL·kg-1 by gavage. Body weight， water intake， and fasting blood glucose of the mice in each group were measured weekly. After six weeks of continuous administration， serum insulin （FINS）， low-density lipoprotein cholesterol （LDL）， total cholesterol （TC）， triglyceride （TG）， alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， urea， and creatinine （CREA） were measured， and liver sections were embedded and stained with hematoxylin-eosin （HE）， periodic acid-Schiff （PAS）， and oil red O. Protein expression of PI3K p85， p-Akt， and p-FoxO1 in liver was detected by immunohistochemistry. The mRNA expression of PI3K， Akt， and FoxO1 in liver tissue was detected by real-time polymerase chain reaction （Real-time PCR）. ResultAfter six weeks of administration intervention， it was found that fasting blood glucose was significantly downregulated in mice in the three HG groups （P<0.05）. The level of islet resistance index was significantly reduced in both the low and medium dose HG groups （P<0.05）. The expression levels of TC， TG， and LDL were reduced in all HG groups （P<0.05， P<0.01）. Pathologically， HG could alleviate hepatocyte steatosis， reduce the volume and content of lipid droplets in liver， and increase the distribution of glycogen granules in liver to some extent in mice. Immunohistochemical assays revealed that PI3K p85 protein expression was significantly increased in the low， medium， and high dose HG groups compared with the model group （P<0.01）. p-Akt protein expression was significantly increased in the medium and high dose HG groups （P<0.05， P<0.01）. p-FoxO1 protein expression was significantly increased in the low， medium， and high dose HG groups （P<0.05， P<0.01）. Compared with the model group， PI3K mRNA was increased in low dose， medium dose， and high dose HG groups （P<0.05）， and Akt mRNA was increased in high dose HG group （P<0.05）. FoxO1 mRNA was decreased in low dose， medium dose， and high dose HG groups （P<0.05）. ConclusionHG can ameliorate the disorder of glucolipid metabolism in db/db mice， which may be related to its activation of the hepatic PI3K/Akt/FoxO1 signaling pathway.

Oral Administration of Hoodia parviflora Alleviates Insulin Resistance and Nonalcoholic Steatohepatitis.

Metabolic syndrome is recognized as a proinflammatory condition leading to hepatic steatosis and nonalcoholic steatohepatitis (NASH). We tested the effects of a succulent species Hoodia parviflora N.E. Br., of the genus Hoodia sweetex Dence, on animal models of NASH and insulin resistance (ob/ob mouse and the sand rat Psammomys obesus). IL6 secretion was evaluated by ELISA and hepatic signal transducer and activator of transcription 3 by Western blot. We followed liver enzymes, weight, glucose, hepatic histology, hepatic triglycerides (TGs), and total fat and serum insulin. Oral administration of extracts derived from H. parviflora alleviated the insulin resistance manifested by improved glucose tolerance tests. Treatment alleviated the liver injury noted by a decrease in liver enzyme levels, improved intrahepatic TG content, total hepatic fat, and improved hepatic histology. Similarly, treatment with H. parviflora reduced hepatic inflammation in mice with Concanavalin A-induced hepatitis. These effects were independent of food consumption and weight. H. parviflora was associated with alleviated insulin resistance, hepatic steatosis, and liver injury. The data support its use as a liver protector.

POLITICS OF BIOPIRACY: AN ADVENTURE INTO HOODIA/XHOBA PATENTING IN SOUTHERN AFRICA.

BACKGROUND: Africa is being described as the wretched of the earth, despite this, the continent is endowed with natural resources, dynamic ecosystem, and different species of plants and animals, and species derivatives. This paper area of departure is to focus on Hoodia, a plant that is being a source of food, medicine and water for the San and Khoe indigenous peoples before the advent of Europeans into southern Africa. South African Council for Scientific and Industrial Research (CSIR) dubiously patented Hoodia without observing the basic indices of geographical indications (GIs), indigenous knowledge (IK), novelty, access sharing benefit (ASB), prior informed consent (PIC) and sustainability of ecosystem before the rights was sold to Phytopharm pharmaceutical company. MATERIALS AND METHODS: This article adopts neoliberal thesis with emphasis on complex interdependence theory of organic linkages between developing and developed countries. Secondary sources of information taken into account of qualitative and critical discuss content analyses dominate this paper. RESULT: The paper recommends a linkage between developed and developing states based on endowment theory and comparative advantage with the notion of adhering to the Convention on Biological Diversity (CBD) which has three objectives: the conservation of biodiversity; the sustainable utilisation of indigenous biological resources (IBR); and fair and equitable benefit sharing. CONCLUSION: The paper recommends that there is a need to follow CBD and other relevant international regimes that promote equal exchange in exploitation of Africa resources as against the present skewed arrangement that is in favour of multinational corporations (MNCs).

Safety of dried aerial parts of Hoodia parviflora as a novel food pursuant to Regulation (EC) No 258/97.

Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver a scientific opinion on the dried aerial parts of Hoodia parviflora as a novel food (NF) submitted pursuant to Regulation (EC) No 258/97. The information provided on the composition, the specifications, the production process, the batch-to-batch variability and the stability of the NF is sufficient and does not raise safety concerns. The applicant intends to use the NF in a number of energy-reduced/sugar-free/no-added-sugar foods in quantities of up to 15 mg per serving. The applicant also proposes to provide the NF as a food supplement. The target population proposed by the applicant is adults. The highest intake estimates were found in the group of elderly (≥ 65 years) individuals, with a high intake of 1.0 mg/kg body weight (bw) per day. One 90-day toxicity study in rodents was provided from which a benchmark dose lower confidence limit (BMDL 05) of 53.5 mg/kg bw per day was derived for effects of the NF on bodyweight. The Panel concludes that the addition of the NF to foods as a food ingredient at the uses and use levels as proposed by the applicant would exceed intake levels considered safe in humans. The Panel considers that the NF is safe to be used as a food supplement at a maximum dose of 9.4 mg/day. The target population is adults.

In vitro anti-HIV and antioxidant activity of Hoodia gordonii (Apocynaceae), a commercial plant product.

BACKGROUND: Hoodia gordonii products are widely commercialized for anti-obesity purposes; however, minimal research is available on the other health properties demonstrated by this popular herbal plant. METHODS: H. gordonii crude extracts (ethanol and ethyl acetate) were assayed for in vitro anti-HIV-1 protease (PR), reverse transcriptase (RT) and integrase activity. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) and reducing power assays were used for the antioxidant analysis. In addition, qualitative and quantitative phytochemical analyses of the extracts were determined using standard methods. RESULTS: H. gordonii extract demonstrated good inhibition against HIV RT with IC50 values of 73.55 ± 0.04 and 69.81 ± 9.45 µg/mL for ethanol and ethyl acetate extracts, respectively. Both extracts also demonstrated inhibitory activity against HIV PR with IC50 values of 97.29 ± 0.01 and 63.76 ± 9.01 µg/mL for ethanol and ethyl acetate extracts. In addition, H. gordonii also showed good antioxidant activity with IC50 values of 124.6 ± 11.3 and 126.2 ± 3.15 µg/mL obtained for ethanol and ethyl acetate extracts, respectively. The reducing power of H. gordonii extracts increased as the concentration increased which confirmed the presence of antioxidants (reductants) in the extracts. Phytochemical screening of H. gordonii revealed the presence of phenolics, alkaloids, terpenes, steroids, cardiac glycosides and tannins in the ethanolic extract, while the ethyl acetate extract only showed the presence of phenolics, cardiac glycosides and steroids. The total phenolic content was 420 ± 0.17 and 319.9 ± 0.2 mg GAE/g for the ethanol and ethyl acetate extracts, respectively. The ethanol extract, which revealed the presence of tannins, had a tannin content of 330 ± 0.2 mg TAE/g extract. CONCLUSION: This data suggests that H. gordonii has good in vitro inhibition against selected HIV-1 enzymes as well as antioxidant properties, suggesting new potential uses for this commercial plant.

Antidepressant-like effect of Hoodia gordonii in a forced swimming test in mice: evidence for involvement of the monoaminergic system

Hoodia gordonii is a plant species used traditionally in southern Africa to suppress appetite. Recently, it has been associated with a significant increase in blood pressure and pulse rate in women, suggesting sympathomimetic activity. The present study investigated the possible antidepressant-like effects of acute and repeated (15 days) administration of H. gordonii extract (25 and 50 mg/kg, po) to mice exposed to a forced swimming test (FST). Neurochemical analysis of brain monoamines was also carried out to determine the involvement of the monoaminergic system on these effects. Acute administration of H. gordonii decreased the immobility of mice in the FST without accompanying changes in general activity in the open-field test during acute treatment, suggesting an antidepressant-like effect. The anti-immobility effect of H. gordonii was prevented by pretreatment of mice with PCPA [an inhibitor of serotonin (5-HT) synthesis], NAN-190 (a 5-HT1A antagonist), ritanserin (a 5-HT2A/2C antagonist), ondansetron (a 5-HT3A antagonist), prazosin (an α1-adrenoceptor antagonist), SCH23390 (a D1 receptor antagonist), yohimbine (an α2-adrenoceptor antagonist), and sulpiride (a D2 receptor antagonist). A significant increase in 5-HT levels in the striatum was detected after acute administration, while 5-HT, norepinephrine and dopamine were significantly elevated after chronic treatment. Results indicated that H. gordonii possesses antidepressant-like activity in the FST by altering the dopaminergic, serotonergic, and noradrenergic systems.

Efficacy and acceptance of a commercial Hoodia parviflora product for support of appetite and weight control in a consumer trial.

Species of Hoodia Sweet ex Decne., family Apocynaceae, a southern African succulent plant, have been recognized for their appetite suppressing properties. Products that support appetite and weight control have been developed in Israel from locally cultivated Hoodia spp. To study consumer acceptance, efficacy of, and tolerance for a frozen product based on whole aerial parts of Hoodia parviflora N.E. Br., we initiated and conducted this single-blind, randomized, placebo-controlled consumer trial. Volunteer participants ingested flavored 3 g frozen Hoodia or placebo cubes for 40 days. Subjects were weighed and measured and baseline body-mass index was determined. Adverse events were monitored and eight mild, transient, possible treatment-emergent events were reported. No moderate, severe, or chronic events were reported. On days 1, 10, and 40, subjects self-reported their perceptions of food consumption, hunger development, incidence and control of food cravings, and efficacy of the product. On day 40, the treatment group demonstrated a statistically significant decrease in measured quantitative parameters against the placebo and reported a positive perception of the product.

Eficácia e toxicidade do pó comercial de Hoodia gordonii (Masson) swet ex decne utilizado no tratamento da obesidade / Efficacy and toxicity of Hoodia gordonii commercial powder used to combat obesity

A obesidade é atualmente o principal problema de saúde em países desenvolvidos e em desenvolvimento. Diversos recursos terapêuticos têm sido empregados para o tratamento da obesidade destacando-se os fitoterápicos, consagrados pelo conhecimento popular. Nesse contexto, a planta Hoodia gordonii tem despertado atualmente grande interesse mundial, principalmente pelas recentes descobertas e comprovações científicas da inibição do apetite e da sede pelo glicosídeo ativo P57 isolado de espécies da planta. Apesar disso, tais efeitos ainda não foram avaliados e comprovados em amostras comerciais do pó de H. gordonii (PHG), não existindo evidências científicas que garantam a sua eficácia e segurança. Portanto, o objetivo deste trabalho foi realizar ensaios biológicos com ratos para avaliar a atividade farmacológica e a toxicidade de amostras comerciais do pó de H. gordonii. As amostras foram administradas por gavagem em doses equivalentes a 20 vezes as recomendadas para humanos em ratas Wistar durante 4 semanas sendo avaliados os parâmetros indicadores do efeito terapêutico. Após as 4 semanas, os animais foram sacrificados, e amostras de sangue e órgãos foram coletados e submetidos à avaliação dos indicadores metabólicos, endócrinos, hematológicos e histopatológicos. Os resultados demonstraram que para todos os parâmetros avaliados não houve diferenças significativas entre o grupo controle que recebeu somente solução salina estéril e os grupos tratados com PHG indicando que os mesmos, apesar de não apresentarem quaisquer indícios de toxicidade, são incapazes de produzir os supostos efeitos de inibição de apetite e consequente tratamento da obesidade.

Obesity is currently the main health problem in developed and developing countries. Several therapeutic methods have been employed for the treatment of obesity, especially herbal medicines, highlighted by popular knowledge. In this context, the plant Hoodia gordonii has currently aroused great interest worldwide, especially for recent discoveries and scientific proof of inhibition of appetite and thirst by the active glycoside P57 isolated from plant species. Nevertheless, such effects have not been evaluated and proven for commercial samples of H. gordonii powder (PHG), with no scientific evidence to ensure its effectiveness and safety. Therefore, the aim of this study was to conduct biological tests with rats to evaluate the pharmacological activity and toxicity of commercial samples of H. gordonii powder. The samples were administered through gavage, at doses equivalent to 20 times those recommended for humans, in female Wistar rats during 4 weeks for evaluation of the parameters indicative of therapeutic efficacy. After 4 weeks, the animals were sacrificed and blood and organ samples were collected and subjected to the evaluation of metabolic, endocrine, hematological and histopathological indicators. Results showed that for all evaluated parameters, there were no significant differences between the control group that only received sterile saline solution and the groups treated with PHG, indicating that the latter, although presenting no evidence of toxicity, are unable to produce the alleged effects of appetite inhibition and subsequent obesity treatment.