Larvicidal, pupicidal and insecticidal activities of Cosmos bipinnatus, Foeniculum vulgare and Tagetes minuta against Culex quinquefasciatus mosquitoes

Purpose: To evaluate the larvicidal, pupicidal and insecticidal activities of Cosmos bipinnatus, Foenuculum vulgare and Tagetes minuta leaf extracts against Culex quinquefasciatus mosquitoes.Methods: The leaves of the plants were extracted with distilled water, ethanol (95 %), and hexane and the extracts screened for their phytochemical profile. While larvicidal and pupicidal activities were assayed at concentrations ranging from 0.1 - 10 mg/mL, insecticidal property was tested at varying amounts (0.25 - 2 g) of the plant sample. The respective larval mortality was thereafter evaluated using Probit analysis.Results: Saponins, terpenoids, flavonoids and steroids were detected in the plant extracts. The ethanol extracts of F. vulgare, T. minuta and C. bipinnatus exhibited larvicidal activity half-maximal lethal concentration (LC50) of 0.10, 1.17 and 1.18 mg/mL, followed by hexane extracts with LC50 value of 1.03, 1.01 and 1.27 mg/mL, respectively, against the larvae of C. quinquefasciatus mosquito. Hexane extracts displayed pupicidal activity with LC50 of 1.07, 1.12 and 1.16 mg/mL against F. vulgare, T. minuta and C. bipinnatus, respectively, while the ethanol extracts of T. minuta, C. bipinnatus and F. vulgare displayed pupicidal activity at LC50 of 1.11, 1.14 and 1.31 mg/mL respectively, against pupa of C. quinquefasciatus mosquito. The aqueous extracts had no (p > 0.05) lethal effects on both larvae and pupa of C. quinquefasciatus at all evaluated concentrations. F. vulgare had the highest (p < 0.05) half-maximal knock-down effect (KD50 = 7.52 min-1), followed by T. minuta (KD50 = 8.64 min-1) on adult C. quinquefasciatus mosquitoes after 6 h of exposure. F. vulgare and T. minuta killed all evaluated mosquito adults within 12 h with LD99 = 0.25 g/air, while the leaves of C. bipinnatus had no (p > 0.05) knock-down or lethal effects on the adult mosquito.Conclusion: C. bipinnatus, F. vulgare and T. minuta possess larvicidal and pupicidal properties against C. quinquefasciatus, whereas only F. vulgare and T. minuta displayed insecticidal properties. Consequent upon these findings, all the plants can be considered naturally potent larvicidal and pupicidal agents against C. quinquefasciatus.Keywords: Cosmos bipinnatus, Culex quinquefasciatus, Botanical insecticides, Knock-down effect, Larvicidal, Pupicidal, Insecticidal, Foeniculum vulgare, Tagetes minut

Anti-nephrolithiatic potential and the protective role of saponin-rich extract of Dianthus basuticus against acetaminophen-induced damage in HEK293 cells

Saponins have found ethnomedicinal applications against a number of diseases including oxidative stress, urinary and kidney ailments. This study investigated antioxidant, anti-nephrolithiatic and nephroprotective properties of saponin-rich extract of Dianthus basuticus in vitro. While nephroprotective activity was demonstrated against acetaminophen-mediated toxicity in HEK293 cells using the MTT method, its inhibition of calcium oxalate (CaOx) nucleation was evaluated in the anti-nephrolithiatic study. The antioxidant effect was demonstrated against OH and lipid peroxide radicals. The significant (p <0.05) acetaminophen-induced reduction of viable cells in the nephrotoxic cells following 24 hours incubation was reverted and cell mortality dropped from 81.98 to 13.15 % at 125 µg/mL dose of the extract.  The extract significantly inhibited CaOx nucleation crystals in a dose-related manner with the highest dose being 51.11 % potent. The inhibitory effect of the extract had an overall IC50 of 1.03 µg/mL (R2= 0.9698) which is corroborated by the degree of turbidity of the treated crystals solutions. The overall effects elicited by the extract may be attributed to its antioxidant activity which was concentration-related with the highest dose exhibiting the most potent effect (IC50: 0.45–0.63 µg/mL) when compared with vitamin C (IC50: 0.49–0.69 mg/mL). Hence, D. basuticus is potentially a new lead agent in the management of nephrolithiasis and renal disorders

Toxicopathological Evaluation of Hydroethanol Extract of Dianthus basuticus

Background. Dianthus basuticus is a commonly used medicinal plant in Basotho traditional medicine for the treatment of diabetes, but there is no report on its safety or toxicity. Therefore, we evaluated the toxicity profile of the hydroethanol whole plant extract of Dianthus basuticus in Wistar rats. Methods. Acute toxicity test was performed with single oral administration of 100–3200 mg/kg body weight of D. basuticus extract to rats and the animals were observed for 14 days for signs of toxicity. The subacute toxicity experiment was conducted by oral administration of graded doses (200, 400, and 800 mg/kg) of D. basuticus extract daily for 28 days. Behavioural changes as well as haematological, biochemical, and histological parameters were then evaluated. Results. There was no observable sign of toxicity in the acute toxicity test. There were significant decreases (P<0.05) in the feed and water intake as well as total cholesterol and triglycerides of the D. basuticus extract-treated rats in subacute toxicity study. There were no treatment related differences in the haematological, biochemical, and histopathological evaluations. Conclusions. Administration of hydroethanol extract of D. basuticus may be safe at the dosages tested in this study but its continuous usage can cause anorexia

Biological Activities of three Nigerian Spices - Laurus nobilis Linn, Murraya koenigii (L) Spreng and Thymus vulgaris Linn

Purpose: To evaluate the biological properties of polyphenol extracts of three spices – Laurus nobilis (bay), Murayya koenigii (curry) and Thymus vulgaris (thyme) from Lagos, Nigeria.Methods: Acetone extracts of these spices were subjected to bovine serum albumin (BSA)-glucose antiglycation, 1, 1-diphenyl-2 picrylhydrazyl (DPPH) and superoxide anion radical scavenging assays. Brine-shrimp lethality and phytotoxicity tests were also performed on the extracts (10 – 1000 μg/mL).Results: The extract of T. vulgaris had the highest antiglycation effect with 50 % inhibitory concentration (IC50) of 0.02 mg/mL, as well as antioxidant potential with IC50 of 0.10 and 0.06 mg/mL for DPPH and superoxide anion radical scavenging assays, respectively (p &lt; 0.05). On the other hand, all the extracts exhibited weak cytotoxicity with 50 % lethal dose (LD50) ranging from 1000 – 2000 μg/mL, and for phytotoxicity, LD50 ranged from 640 – 1640 μg/mL).Conclusion: Acetone extracts of bay, curry and thyme displayed good antiglycation as well as antioxidant potential and are safe for consumption. However, of all the spices, thyme exhibited the best activity as an antioxidant and antiglycation agent.Keywords: Glycation, Hyperglycemia, Polyphenols, Spices, Bay, Curry, Thym

In vitro comparative assessment of the inhibitory effects of single and combined spices against glucose-synthesizing enzymes

Purpose: To assess the individual and synergistic inhibitory activities of five (5) tropical spices, viz, Zingiber officinale Rosc., Xylopia aethiopica (Dun.) A. Rich, Piper guineense Schum &amp; Thonn, Myristica fragrans Houtt. and Allium sativum L. against glucose hydrolysing enzymes.Methods: In vitro assessment of the alpha-amylase and alpha-glucosidase inhibitory activities of cold water, hot water, ethanol and aqueous-ethanol extracts of each of the five spices and their combination was investigated using enzymatic protocols. Acarbose was used as the standard.Results: Only four extracts showed strong inhibition against alpha-glucosidase and weak inhibition against alpha-amylase. Going by their half-maximal inhibitory concentrations (IC50), the combined spices exhibited the best concurrent inhibitory activity against both hydrolysing enzymes (665.83 ± 27.50 μg/mL for alpha-glucosidase) and (1166.86 ± 14.70 μg/mL for alpha-amylase).Conclusion: The findings from this study demonstrate the enhanced antihyperglycemic potentials of the combined spices compared to the individual spices for the management of diabetes. Keywords: Hyperglycemia, Diabetes, Alpha-amylase, Alpha-glucosidase, Zingiber officinale, Xylopia aethiopica, Piper guineense, Myristica fragrans, Allium sativum, Spice

Pharmacological Potentials of Ginger

Zingiber officinale, belonging to the family Zingiberaceae, is a popular spice and herb used as delicacy and to manage numerous diseases such as diabetes, hypertension, cancer, ulcer, diarrhea, cold, cough, spasm, vomiting, etc. in folk medicine from China, India, and Arabia Peninsula to other continents of the world including Africa (Nigeria, Egypt, and so on). Though this review is aimed at summarizing the pharmacological potentials of this well-endowed spice, interestingly, we found out that these reported ethnobotanical uses are attributed to a number of inherent chemical constituents including gingerol, 6-, 8-, 10-gingerol, 6-shogaol, 6-hydroshogaol, oleoresin, etc., eliciting various pharmacological effects, not limited to antioxidant, antitumor/anticancer, anti-inflammatory, antihyperglycemic, antihypertensive, anticholesterolemic, antibiotic/antimicrobial, neuroprotective, antiulcer/gastroprotective, antiemetic, hepatoprotective, and antiplatelet aggregation, safety profiles established through a number of studies (in vitro, in vivo, and cell lines), though some of these potentials are yet to be explored. Sadly, even few of these established effects are yet to be experimented in clinical trials, and only until these are intensified would there be prospect toward drug development for preventive and curative treatments. In conclusion, we are able to highlight and sum up the therapeutic implications of ginger and its related derivatives in the management of ailments confronting humanity

The purview of phytotherapy in the management of kidney disorders: a systematic review on Nigeria and South Africa

Background: The kidney is tasked with a number of metabolic functions in the body. In its role as a detoxifier and primary eliminator of xenobiotics, it becomes vulnerable to developing injuries. Currently, over 1 million people in the world are living on renal replacement therapies (RRTs). The case in sub-Sahara African countries like Nigeria and South Africa is not any better than the global trend.Materials and Methods: A systematic review of medicinal plants used in the treatment of kidney disorders was conducted. Information were gathered from published scientific journals, books, reports from national, regional and international institutions, conference proceedings and other high profile intellectual resources. MeSH words like ‘prevalence of kidney disorders in Africa’, ‘renal replacement therapy’, ‘nephrotoxins or nephrotoxicants’, ‘nephroprotective plants’, ‘nephroprotective plants in Nigeria or South Africa’ and ‘nephroprotective phytocompounds’ were used to retrieve information from online databases (Google, Pubmed, MEDLINE, Science Direct, Scopus and SID).Results: Interestingly, our findings revealed that phytotherapy has emerged and is being employed to protect renal functions and delay progression of renal pathological conditions into end episodes where the last resort is RRT. In fact, in recent times, Phytotherapists are not only interested in developing relatively safe, more affordable, easily accessible and potent nephroprotective formulations but also increasing awareness on the prevalence of the disease and educating the populace on the probable preventive measures. More importantly, efforts at scientifically elucidating the pharmacological efficacy of the identified nephroprotective plants yet to be validated must be intensified through informed expert opinions. Till date, there is paucity of information on the concept of nephroprotection in most developing countries where kidney disorder is a major threat. Although, the concept is just emerging in South Africa, evidences have given credence to its application in complementary and alternative system of medicine in Nigeria.Conclusion: This review, therefore, reawaken researchers’ consciousness in the continuous search for auspicious nephroprotective plants that could potentially be excellent candidates in developing new lead drugs to manage and treat renal disorders.Keywords: Bioactive principles, Nephroprotective, Nephrotoxic, Renal replacement therapy, Silent kille

Kinetics of modulatory role of Cyperus esculentus L. on the specific activity of key carbohydrate metabolizing enzymes

Background: The continuous search for new lead compounds as viable inhibitors of specific enzymes linked to carbohydrate metabolism has intensified. Cyperus esculentus L. is one of the therapeutically implicated botanicals against several degenerative diseases including diabetes mellitus.Materials and Methods: This study evaluated the antioxidant and mechanism(s) of inhibitory potential of aqueous extract of C. esculentus on α-amylase and α-glucosidase in vitro. The extract was investigated for its radical scavenging and hypoglycaemic potentials using standard experimental procedures. Lineweaver-Burke plot was used to predict the manner in which the enzymes were inhibited.Results: The data obtained revealed that the extract moderately and potently inhibited the specific activities of α-amylase and α-glucosidase, respectively. The inhibition was concentration-related with respective IC50 values of 5.19 and 0.78 mg/mL relative to that of the control (3.72 and 3.55 mg/mL). The extract also significantly scavenged free radicals and the effects elicited could be ascribed to its phytoconstituents.Conclusion: The respective competitive and non-competitive mode of action of the extract is due to its inhibitory potentials on the activities of α-amylase and α-glucosidase. Going forward, in addition to completely characterize the exact compound(s) responsible for the elicited activity in this study, pertinent attention will be given to the in vivo evaluation of the identified constituents.Keywords: Acarbose, Antioxidant, Diabetes, Enzyme kinetics, Vma

Antidiabetic Medicinal Plants Used by the Basotho Tribe of Eastern Free State: A Review

Diabetes mellitus (DM) belongs to the group of five leading important diseases causing death globally and remains a major health problem in Africa. A number of factors such as poverty, poor eating habit, and hormonal imbalance are responsible for the occurrence of the disease. It poses a major health challenge in Africa continent today and the prevalence continues to increase at an alarming rate. Various treatment options particularly the usage of herbs have been effective against diabetes because they have no adverse effects. Interestingly, South Africa, especially the Basotho tribe, is blessed with numerous medicinal plants whose usage in the treatment of DM has been effective since the conventional drugs are expensive and often unaffordable. The present study attempted to update the various scientific evidence on the twenty-three (23) plants originating from different parts of the world but widely used by the Sotho people in the management of DM. Asteraceae topped the list of sixteen (16) plant families and remained the most investigated according to this review. Although limited information was obtained on the antidiabetic activities of these plants, it is however anticipated that government parastatals and scientific communities will pay more attention to these plants in future research

The Purview of Phytotherapy in the Management of Gastric Ulcer

Stomach/gastric ulcer is a debilitating disease affecting more than 10% of the global population. Sufferers often have chronic pains with life-threatening gastrointestinal haemorrhage or perforation. Since the first diagnosis of stomach ulcer (SU) in the 19th century, excessive gastric juice that eroded the mucosa of the stomach was opined as its major cause. Efforts were channelled toward effective control of the resulting acid build-up through the use of antiulcer medications and reduction in stress-induced activities, which may aggravate gastric hyperacidity. An intense treatment option involved vagotomy (surgically severing the nerves surrounding an ulcer) to prevent hyperacidity and further perforation of the stomach epithelium. Despite these interventions, SU disease remained an impediment to clinical practice. Literatures revealed that many botanicals have been used to treat SU and this is hinged on their being endowed with antiulcerogenic phytonutrients of therapeutic significance. In this review, attempts have been made to highlight the main mechanisms of action and limitations of the conventional antiulcerogenic drugs, various antiulcerogenic experimental models, as well as compile selected medicinal plants and their implicated phytonutrients that will ultimately and eventually present effective and globally competitive exciting opportunities for the development of new lead therapeutics for the management of SU disorders