Antidiarrhoeal activity ofHypoxis hemerocallideaFisch. & C. A. Mey. (Hypoxidaceae) Corm (‘African potato’) aqueous extract in rodents

Synergistic broad-spectrum antibacterial activity of Hypoxis hemerocallidea-derived silver nanoparticles and streptomycin against respiratory pathobionts

Respiratory tract infections arise due to the introduction of microbes into the airway, disrupting the normal, healthy, complex interdependent microbiome. The selective disruption of this community can be either beneficial or dangerous. Nanoparticles are a potential tool for modifying this population. Coated silver nanoparticles (AgNPs) were synthesized using ethanolic extracts of Hypoxis hemerocallidea (EEHH), a Southern African plant used extensively in traditional medicine and the source of many bioactive secondary metabolites. The room temperature reaction between silver nitrate and EEHH forms largely spherical AgNPs with an average diameter of 6-20 nm. These nanoparticles show similar levels of antibacterial activity as the broad-spectrum antibiotic streptomycin against Bacillus cereus, Streptococcus pneumonia, Escherichia coli, Pseudomonas aeuroginosa, and Moraxella catarrhalis. However, the AgNPs synergistically increase the antibacterial activity of streptomycin when they are applied in combination (30-52%). AgNPs are reiterated to be promising dual-function antibiotics, synergistically enhancing activity while also acting as delivery agents for small molecules.

African potato (Hypoxis hemerocallidea): a systematic review of its chemistry, pharmacology and ethno medicinal properties

BACKGROUND

African Potato (hypoxis hemerocallidea), is used for enhancing immune system in Southern Africa. It is among the plants of intense commercial and scientific interest; hence, the aim of this study was to describe its chemistry and pharmacology.

METHODS

PubMed, Cochrane Controlled Trials Register (CENTRAL) and Google Scholar were searched independently for relevant literature. The last search occurred in October 2018. Other research material was obtained from Google. The following search terms were used, but not limited to: "African Potato", "hypoxis", "hemerocallidea", "rooperol." Articles that were explaining the chemistry and pharmacology of hypoxis hemerocallidea were included.

RESULTS

Thirty articles from PubMed, Cochrane and Google Scholar were eligible. Three webpages were included from Google. Results showed that the tuberous rootstock (corm) of African Potato is used traditionally to treat wasting diseases, testicular tumours, insanity, barrenness, impotency, bad dreams, intestinal parasites, urinary infection, cardiac disease and enhancing immunity. The plant contains hypoxoside, which is converted rapidly to a potent antioxidant, rooperol in the gut. The corm contains sterols, sterol glycosides, stanols, terpenoids, saponins, cardiac glycosides, tannins and reducing sugars. A dose of 15 mg/kg/day of hypoxoside is reportedly therapeutic. Preclinical studies of African Potato have shown immunomodulation, antioxidant, antinociceptive, hypoglycaemic, anti-inflammatory, anticonvulsant, antibacterial, uterolytic, antimotility, spasmolytic and anticholinergic effects. The common side effects of African Potato are nausea and vomiting, which subside over time. In vitro, African Potato demonstrated inhibitory effects on CYP1A2, 2C9, 2D6, 3A4, 3A5, CYP19-metabolism and induction of P-glycoprotein. In vivo, it did not alter the pharmacokinetics of efavirenz or lopinavir/ritonavir.

CONCLUSION

African Potato is mainly used as an immunostimulant. The exact mechanisms of action for all the pharmacological actions are unknown. More research is required to substantiate claims regarding beneficial effects. There are many research gaps that require investigation including pharmacokinetic interactions with conventional drugs, especially those used in HIV/AIDS.

Histo-morphological and seminal evaluation of testicular parameters in diabetic rats under antiretroviral therapy: interactions with Hypoxis hemerocallidea

OBJECTIVES

Broad range of metabolic changes associated with highly active antiretroviral therapy (HAART) has been reported over decades including reproductive perturbations. The current study aimed at investigating the role of Hypoxis hemerocallidea (Hyp) in the seminal and morphometric alterations in the testes of streptozotocin-nicotinamide-induced diabetic rats under HAART.

MATERIALS AND METHODS

Sixty-two adult male Sprague-Dawley rats were divided into A-H groups, containing 6 rats in the control group A and 8 rats in the treatment groups B-H. Diabetes was induced by intraperitoneal injection of nicotinamide (110 mg/kg BW) followed by streptozotocin (45 mg/kg BW). The animals were then subjected to various treatments with HAART, Hyp, and melatonin.

RESULTS

weights (body and testicular), histological, histochemical, seminal fluid, and morphometric analyses were carried out. Sperm count and motility were reduced in HAART (P<0.05/0.003) and Hyp200 (P<.003) groups compared with normal and diabetic controls, respectively. Sperm count was higher (P<.003) in HAART+ Mel and HAART+Hyp100 groups. Morphometry showed the reduction in germinal epithelium height and basement membrane thickness (P<.003) in the Hyp100 group compared with diabetic controls. Adjuvant use of Hyp and melatonin with HAART did not significantly raise these indices (P>.05). Histological slides showed gross distortions in HAART, diabetic and HAART +Hyp groups with marked atrophy in tubules, germ cell loss and areas of focal depletion of the cell. PAS staining revealed detached basement membrane in diabetic groups with strong PAS-stain.

CONCLUSION

The use of Hyp or melatonin does not ameliorate the testicular damages in diabetic animals under antiretroviral therapy.

Hepatic histomorphological and biochemical changes following highly active antiretroviral therapy in an experimental animal model: Does Hypoxis hemerocallidea exacerbate hepatic injury?

As the roll-out of antiretroviral therapy continues to drive downwards morbidity and mortality in people living with HIV/AIDS (PLWHAs), organ toxicities (especially the liver) are frequently becoming a major concern for researchers, scientists and healthcare planners.

This study was conducted to investigate the possible protective effect of Hypoxis hemerocallidea (AP) against highly active antiretroviral therapy (HAART)-induced hepatotoxicity. A total of 63 pathogen-free adult male Sprague-Dawley rats were divided into 9 groups and treated according to protocols.

While no mortality was reported, animals treated with adjuvant HAART and AP recorded least% body weight gain. Significant derangements in serum lipid profiles were exacerbated by treatment of with AP as LDL (increased p < 0.03), triglycerides (increased p < 0.03) with no change in total cholesterol levels. Adjuvant AP with HAART caused reduction in LDL (p < 0.05 and 0.03), increased HDL (p < 0.05) and TG (p < 0.05 and 0.001 for AP₁₀₀ and AP₂₀₀ doses respectively). Markers of liver injury assayed showed significant increase (p < 0.003, 0.001) in AST in AP alone as well as HAART+ vitamins C and E groups respectively. Adjuvant HAART and AP and vitamins C and E also caused significant declines in ALT and ALP levels. Serum GGT was not markedly altered. Disturbances in histopathology ranged from severe hepatocellular distortions, necrosis and massive fibrosis following co-treatment of HAART with vitamins C and E as well as HAART alone. These results warrant caution on the adjuvant use of AP with HAART by PLWHAs as implications for hepatocellular injuries are suspect with untoward cardiometabolic changes.

Antidiarrheal activity of ethanolic extract of Manihot esculenta Crantz leaves in Wistar rats

Background:

Use of Manihot esculenta Crantz (MEC) plant has been mentioned in literature of Food and Agriculture Organization of United Nations, Central Tuber Crops Research Institute and many others. It is also known commonly as tapioca, continues to be a crop of food security for the millions of people, especially in the developing countries of the globe including India. Medicinal uses of this plant including diarrhea have been mentioned in literature, but scientific evidence is lacking.

Objective:

The objective was to study antidiarrheal activity of ethanolic leaf extract of MEC in Wistar rats.

Materials and Methods:

Ethanolic extract of MEC leaves in the doses of 50 mg/kg, 100 mg/kg and 200 mg/kg were used in Wistar rats of either sex. Experimental models used were castor oil-induced intestinal fluid accumulation and charcoal passage test. Loperamide and atropine sulfate were the standard drugs used in these models respectively.

Results:

MEC extracts decreased intestinal fluid volume in dose dependent manner no extract group was comparable with standard drug loperamide (5 mg/kg). MEC extracts also significantly inhibited gastrointestinal motility in dose dependent manner. MEC (100 mg/kg) and MEC (200 mg/kg) were comparable with standard drug atropine sulfate (5 mg/kg) in this aspect. <0.05 were considered to be significant.

Conclusions:

Ethanolic extract of MEC leaves exhibited significant antidiarrheal activity by decreasing intestinal fluid accumulation and the gastrointestinal motility in Wistar rats.

The potential of Hypoxis hemerocallidea for herb-drug interaction

CONTEXT

Aqueous decoction of Hypoxis hemerocallidea Fisch. & C.A. Mey. (Hypoxidaceae) (Hypoxis) is widely consumed in Southern Africa by people living with HIV/AIDS, some of whom are on ARV and other medications.

OBJECTIVE

The aim of this study was to investigate the potential of the crude aqueous extracts of Hypoxis to inhibit major forms of CYP450 and transport proteins.

MATERIALS AND METHODS

Corms of Hypoxis were water-extracted and incubated (in graded concentrations: 1-100 µg/mL) with human liver microsomes (20 min) to monitor the effects on phenacetin O-deethylation, coumarin 7-hydroxylation, bupropion hydroxylation, paclitaxel 6α-hydroxylation, diclofenac 4'-hydroxylation, S-mephenytoin 4'-hydroxylation, bufuralol 1'-hydroxylation, chlorzoxazone 6-hydroxylation, midazolam 1'-hydroxylation and testosterone 6β-hydroxylation as markers for the metabolic activities of CYP1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1 and 3A4/5, respectively. The generation of metabolites were monitored and quantified with the aid of LC-MS/MS. The potential of the extracts to inhibit human ATP-binding cassette transporter activity was assessed using recombinant MDCKII and LLC-PK1 cells over-expressing human breast cancer resistant protein and human P-glycoprotein , respectively (with Ko143 and cyclosporin A as positive controls). Similar assessment was performed with human organic anion transporting polypeptide (OATP1B1 and OATP1B3) using recombinant HEK293 cells over-expressing OATP1B1 and OATP1B3, respectively (with rifamycin and 10 µM atorvastatin as positive controls).

RESULTS

Extracts of Hypoxis inhibited the production of the metabolites of the substrates of the following enzymes (as compared to controls) with the indicated IC50 values (µg/mL): CYP1A2 (120.6), CYP2A6 (210.8), CYP2B6 (98.5), CYP2C8 (195.2), CYP2C9 (156) and CYP3A4/5 (185.4). The inhibition of the uptake activity of OATP1B1 and OATP1B3 were also observed with IC50 values of 93.4 and 244.8 μg/mL, respectively.

DISCUSSION

Extract concentrations higher than the estimated IC50 values are achievable in the gastrointestinal tract when traditional doses of Hypoxis are considered. This may have profound effects on presystemic metabolism of the drug substrates. If absorbed, systemic inhibition of metabolic enzymes/transporters by Hypoxis may be expected.

CONCLUSION

The result suggests that there is the potential for HDI between Hypoxis and the substrates of the affected enzymes/transporters, if sufficient in vivo concentration of Hypoxis extracts is attained.

Garcinia buchananii bark extract is an effective anti-diarrheal remedy for lactose-induced diarrhea

ETHNOPHARMACOLOGICAL RELEVANCE

The extract from the stem bark of Garcinia buchananii trees is used as an anti-diarrhea remedy in sub-Saharan Africa. We tested the hypothesis that G. buchananii bark extract and its anti-motility fractions are effective treatments against lactose-induced diarrhea.

MATERIALS AND METHODS

A high-lactose (35%) diet was used to induce diarrhea in Wistar rats, which were then treated with either G. buchananii bark extract (0.1, 0.5, 1.0 and 5.0 g bark powder), and its anti-motility fractions isolated using preparative thin layer chromatography; termed PTLC1 (15 mg) and PTLC5 (3.8 mg) or loperamide (8.4 mg). Drug preparations were dissolved in 1L except PTCL1 and PTLC5 that were dissolved in 100mL tap water. Numerous parameters were measured in each condition including consistency, fluid and mucus content of feces, body weight, water and food consumption, urine production and bloating.

RESULTS

Diarrheic rats produced watery or loose, mucuoid, sticky, feces. Fluids constituted 86% of stool mass compared with only 42% for control rats fed standard chow. Compared with controls, diarrheic rats produced more urine, lost weight and had bloated ceca and colons. All doses of the extract, its anti-motility fractions and loperamide individually stopped diarrhea within 6-24 h of administration, whilst significantly reducing mucus and fecal fluid content, urine production and intestinal bloating. Rats treated with 0.1g extract, PTLC1 and PTLC5 gained weight, whilst PTLC5 also increased water intake.

CONCLUSIONS

Garcinia buchananii extract and its anti-motility fractions are effective remedies against lactose-induced diarrhea. The extract contains compounds that reverse weight loss, promote food and water intake, supporting the notion that characterization of the compounds could lead to new therapies against diarrheal diseases.

Investigation into the genotoxicity of water extracts from Hypoxis species and a commercially available Hypoxis preparation

We performed an in vitro evaluation of the genotoxic potential of water extracts from four Hypoxis species (Hypoxis hemerocallidea, H. colchicifolia, H. rigidula, H. acuminata) and a commercial preparation thereof using the neutral red uptake (NRU) assay, the alkaline comet assay and the cytome assay in human hepatoma HepG2 cells. The relative cytotoxicity of these samples was established by determining their NI50 values (50% inhibition of NRU), and these results were used for dose-finding in genotoxicity tests. None of the tested extracts were identified as genotoxic in both the alkaline comet assay and cytome assay.

Antidiarrhoeal activity of an ethanol extract of the stem bark of Piliostigma reticulatum (Caesalpiniaceae) in rats

Piliostigma reticulatum (Caesalpiniaceae) is used in Africa as a traditional medicine for the treatment of many diseases, such as malaria, tuberculosis and diarrhoea. We investigated the antidiarrhoeal properties of a crude ethanol extract from the stem bark of Piliostigma reticulatum (EEPR) in Wistar albino rats to substantiate its traditional use and to determine its phytochemical constituents. The antidiarrhoeal activity of the plant extract was evaluated in a castor oil-induced diarrhoea model in rats and compared with loperamide. The effect of the extract on gastrointestinal motility was also determined by the oral administration of charcoal meal and castor oil-induced intestinal fluid accumulation (enteropooling). EEPR showed remarkable dose-dependent antidiarrhoeal activity evidenced by a reduction of defecation frequency and change in consistency. Extracts at 250, 500 and 1000 mg/kg body weight significantly reduced diarrhoeal faeces. EEPR also significantly inhibited gastrointestinal motility and castor oil-induced enteropooling at 500 and 1000 mg/kg, similar to the inhibition obtained in control rats treated by atropine. Phytochemical screening revealed the presence of tannins, flavonoids, polyphenols and reducing sugars in the stem bark of P. reticulatum. No mortality or visible signs of general weakness were observed in the rats following administration of the crude extract in doses up to 6000 mg/kg body weight in an acute toxicity study. Our results show that the stem bark of P. reticulatum possesses antidiarrhoeal activity and strongly suggest that its use in traditional medicine practice could be justified.