Aspergillus population diversity and its role in aflatoxin contamination of cashew nuts from coastal Kenya.

Cashew nuts are among the main cash crops in coastal Kenya, due in large part to their high nutritional value. Unfortunately, they also make them highly susceptible to mold contamination, resulting in biodeterioration of the nutritional value and potential contamination with toxic secondary metabolites, such as aflatoxins, that cause them to be rejected for sale at the market. We determined the population diversity of the Aspergillus species and their role in aflatoxin contamination in cashew nuts in selected coastal regions of Kenya. Fifty raw cashew nut samples were collected from post-harvest storage facilities across three counties in Kenya's coastal region and examined for moisture content and the presence of Aspergillus fungi. About 63 presumptive isolates were recovered from the cashew nuts. ITS and 28S rDNA regions were sequenced. The aflD, aflM and aflR genes were amplified to identify the potentially aflatoxigenic from the Aspergillus isolates. The Aflatoxins' presence on the isolates was screened using UV and the ammonia vapour test on coconut milk agar and validated using ELISA assay. A comparison of cashew moisture content between the three counties sampled revealed a significant difference. Sixty-three isolates were recovered and identified to section based on morphological characters and their respective ITS regions were used to obtain species identifications. Three sections from the genus were represented, Flavi and Nigri, and Terrei with isolates from the section Nigri having slightly greater abundance (n = 35). The aflD, aflM and aflR genes were amplified for all isolates to assess the presence of the aflatoxin biosynthesis pathway, indicating the potential for aflatoxin production. Less than half of the Aspergillus isolates (39.68%) contained the aflatoxin pathway genes, while 22.22% isolates were aflatoxigenic, which included only the section Flavi isolates. Section Flavi isolates identification was confirmed by calmodulin gene. The presence of species from Aspergillus section Flavi and section Nigri indicate the potential for aflatoxin or ochratoxin in the cashew nuts. The study established a foundation for future investigations of the fungi and mycotoxins contaminating cashew nuts in Kenya, which necessitates developing strategies to prevent infection by mycotoxigenic fungi, especially during the storage and processing phases.

In Vitro Hypoglycemic and Antioxidant Activities of Dichloromethane Extract of Xerophyta spekei.

Diabetes mellitus is a chronic metabolic disorder which has greatly led to an increase in morbidity and mortality globally. Although Xerophyta spekei is widely used for the management of diabetes among the Embu and Mbeere communities in Kenya, it has never been empirically evaluated for its hypoglycemic activity. This study was carried out to verify the hypoglycemic activity of dichloromethane (DCM) extract of Xerophyta spekei as well as its antioxidant activity using various in vitro techniques. Phytochemicals associated with its antioxidant activity were identified through GC-MS. Data were subjected to descriptive statistics and expressed as mean ± standard error of the mean (X̄ ± SEM). Comparison between various variables was performed by using unpaired Student's t-test and one-way analysis of variance (ANOVA), followed by Tukey's post-hoc test. The confidence interval was set at 95%. The obtained results were presented in tables and graphs. Results showed that there was no difference in α-amylase inhibition activity between the plant extract and the standard (IC50 525.9 ± 12.34 and 475.1 ± 9.115, respectively; p > 0.05). Besides, the glucose adsorption activity of the extract increased with an increase in glucose concentration (from 5.89 to 32.64 mg/dl at 5 mmol and 30 mmol of glucose, respectively; p < 0.05). The extract also limited the diffusion of glucose more than the negative control (7.49 and 17.63 mg/dl, respectively; p < 0.05). It also enhanced glucose uptake by yeast cells. In addition, the studied plant extract showed notable antioxidant activities. The therapeutic effects exhibited by this plant in managing diabetes mellitus and other ailments could be due to its antioxidant as well as its hypoglycemic activity. The study recommends the evaluation of X. spekei for in vivo hypoglycemic and antioxidant activities. Besides, the isolation of bioactive phytochemicals from the plant may lead to the development of new hypoglycaemic agents.

Hemoglobin Precipitation: An Index of In Vitro Vasoconstrictive Activities of Methanol Leaf Extracts of Croton megalocarpus Hutch and Lantana camara Linn.

The function of innate hemostasis aids the body in bleeding control, preventing the loss of excessive amounts of blood following low-degree injuries. However, injuries of a higher degree may require extrinsic intervention to stop life-threatening blood loss. Astringent agents' actions result in mechanical constriction of small blood vessels and shrinkage of body tissues, thereby stopping blood loss. This enhances the primary phase of hemostasis, where vasoconstriction is the main mechanism at play during the initial response to injury. The effects of plant extracts on protein precipitation have been linked to blood vessel vasoconstriction. Traditionally, the leaves of Croton megalocarpus Hutch and Lantana camara Linn plants are used by communities living in Makueni County, Kenya, for peripheral bleeding control. However, the effects of extracts of both plants on hemoglobin precipitation have not been evaluated scientifically. In the current study, the activities of methanol extracts of C. megalocarpus (H.) and L. camara (L.) on blood protein precipitation were investigated. The leaves were harvested, cleaned, air-dried, milled, and extracted in absolute methanol before being concentrated into dry powders. A qualitative phytochemical screen revealed the presence of terpenoids, steroids, tannins, phenols, flavonoids, reducing sugars, cardiac glycosides, and carbohydrates in the methanol extract of C. megalocarpus (H.). The methanol extracts of L. camara (L.) contained cardiac glycosides, saponins, tannins, phenols, terpenoids, reducing sugars, and carbohydrates. The hemoglobin precipitation ability of various concentrations of extracts using mice samples was presented as relative astringency following the tannic acid external standard method. Methanol extracts C. megalocarpus (H.) and L. camara (L.) had significantly higher relative astringency compared with the normal control, indicating a protein precipitating activity. The relative astringency observed in both plant extracts is linked to the activity of tannins, phenols, flavonoids, and saponins detected during preliminary phytochemical screening.

Anti-inflammatory potential of dichloromethane leaf extracts of Eucalyptus globulus (Labill) and Senna didymobotrya (Fresenius) in mice.

BACKGROUND: Inflammation is an immune response characterized by swelling, redness, pain and heat. Inflammation is mainly managed using conventional medicines that are associated with many side effects. Plant-based remedies are considerably better alternative therapies for they have fewer side effects. OBJECTIVE: This study aimed at determining the anti-inflammatory potential of dichloromethane (DCM) leaf extracts of Eucalyptus globulus and Senna didymobotrya in mice. METHODS: Fresh leaves of these plants were harvested from Embu County, Kenya. Quantitative phytochemical analysis was done using Gas Chromatography-Mass Spectrometry (GC-MS). Anti-inflammatory test comprised nine groups of five animals each: normal, negative, positive controls and 6 experimental groups. Inflammation was induced with Carrageenan. One hour post-treatment, the different groups were intraperitoneally administered with the reference drug, diclofenac, 3% DMSO and six DCM leaf extracts at doses of 25, 50, 100, 150, 200 and 250mg/kgbw. RESULTS: GC-MS results revealed α-phellandrene, camphene, terpinolene, and limonene among others. Anti-inflammatory effects showed that extract doses of 100,150,200 and 250mg/kg bw significantly reduced the inflamed paw. Doses of 200 and 250mg/kgbw in both plants were more potent and compared with diclofenac. E. globulus extract dose of 250mg kg bw reduced inflamed paw in the 1st, 2nd, 3rd and 4th hours, by 2.27,6.52,9.09 and 10.90% respectively while S.didymobotrya at similar dose ranges, inflamed paw reduced by 2.41, 5.43, 8.31 and 9.05% respectively. CONCLUSION: E. globulus and S. didymobotrya have potent anti-inflammatory activities, attributed to their constituent phytochemicals. This study confirms the traditional use of these plants in treating inflammation.

Anti-obesity effects of dichloromethane leaf extract of Gnidia glauca in high fat diet-induced obese rats.

BACKGROUND: Obesity is a chronic metabolic disorder characterized by increased adipose tissue mass due to positive energy balance. Prescription of anti-obesity drugs can be useful adjuncts to diet and exercise for obese patients who have failed to achieve weight loss. However, these drugs are ineffective and are associated with adverse effects. In recent times, medicinal plants have drawn a sharp focus owing to their biocompatibility and effectiveness. Attempts to determine the therapeutic effects and identification of bio-active principles from herbal prescriptions have become the prime focus in the validation of their folkloric usage and in drug discovery programs. Therefore, the present study aimed to determine the anti-obesity effects of Dichloromethane leaf extract of Gnidia glauca in high-fat-diet-induced obese rats. METHODS: Obesity was induced experimentally in white albino Wistar rats by feeding them with prepared high-fat-diet and water ad libitum for a period of 12 weeks. The in-vivo anti-obesity effects were determined by oral administration of Gnidia glauca at dosage levels of 200, 250 and 300 mg/kg body weight from the 6th to 12th week of study. Phytochemical analysis of Gnidia glauca was conducted using gas chromatography linked to mass spectrophotometer. RESULTS: The results indicated that Gnidia glauca exhibited potent anti-obesity effects. It significantly reduced the body weight, organ weights, organo-somatic indices, anthropometric indices, the total fat content, adiposity index, atherogenic index as well as various lipid profiles. It also decreased the total feed intake. However, it significantly increased levels of high-density lipoproteins and rectal body temperature of rats. Quantitative phytochemical analysis also revealed the presence of various phytocompounds that have shown to be associated with anti-obesity effects. CONCLUSION: The anti-obesity effects of Gnidia glauca maybe attributed to the phytochemicals present. The present study, therefore, scientifically validates the traditional use of Gnidia glauca as a potential candidate for the synthesis of new effective anti-obesity supplement.

Antipyretic potential of dichloromethane leaf extract of Eucalyptus globulus (Labill) and Senna didymobotrya (Fresenius) in rats models.

INTRODUCTION: Fever is managed using synthetic drugs such as aspirin, paracetamol among others. Synthetic drugs are associated with many side effects. Herbal medicines form alternative therapy since they possess fewer side effects and are readily available. This study aimed to determine antipyretic potential of DCM extracts of E. globulus and S. didymobotrya in Swiss albino rats. MATERIALS AND METHODS: The plant leaves samples were obtained from Embu County, Kenya. Dichloromethane solvent was used to extract bioactive constituents from the plant samples. Three grams of DCM leaf extracts of Eucalyptus globulus (Labill) and Senna didymobotrya (Fresenius) samples were obtained and analyzed to determine quantitative phytochemical composition at ICIPE laboratory using GC-MS. Albino rats were used in the antipyretic activity study. Nine groups of five experimental animals were used in each test: Positive control, normal control, negative control and experimental (25, 50, 100, 150, 200 and 250 mg/kg body weight extracts) groups. Pyrexia was induced by injection of turpentine in albino rats intraperitoneally. One hour later, the pyretic animals received the leaf extracts at various dose levels, reference drug (aspirin100 mg/kg body) or the vehicle (DMSO). RESULTS: Results of antipyretic in vivo bioscreening revealed that E. globulus and S. didymobotrya possess potent antipyretic activity which was comparable to that of the reference drug aspirin. Both extracts exhibited highest antipyretic activity at a dose of 250 mg/kg bw. Results of the GC-MS revealed that these plants possess bio-compounds such as Terpinolene, Alpha-pinene, Borneol, Globulol and Terpineols that are associated with antipyretic activity. CONCLUSIONS: In conclusion, this study revealed that these plants are endowed with bioactive compounds such as terpenoids, and flavonoids that possess antipyretic activity in rats.

In Vitro Antioxidant Properties of Dichloromethanolic Leaf Extract of Gnidia glauca (Fresen) as a Promising Antiobesity Drug.

The acquisition of ethnobotanical information from traditional practitioners remains an empirical aspect of understanding the ethnopharmacology research. However, integration of information on chemical composition of plant extracts and their pharmacological activities forms a key resource for synthesis of new and effective therapeutics. In traditional African medicine, Gnidia glauca has folkloric remedies against obesity and its associated oxidative stress-mediated complications. However, the upsurge in its use has not been accompanied with scientific validations to support these claims. The present study aimed to determine the antioxidant potential of G glauca as a promising antiobesity agent. The antioxidant effects of the extract were assessed against 1,1-diphenyl-2-picrylhydrazyl, hydroxyl, hydrogen peroxide, nitric oxide, and superoxide radicals as well as lipid peroxidation, iron-chelating effect, and ferric-reducing power. Phytochemical analysis was conducted using gas chromatography linked to mass spectrophotometry. The results revealed that G glauca exhibited scavenging activities against all radicals formed. Besides, the extract showed iron chelation and ferric reducing abilities. The extract indicated a lower half maximal inhibitory concentration value than the standards used. For instance, the extract inhibited 50% of the formation of 2,2-diphenyl-1-picrylhydrazine at the concentration of 1.33 ± 0.03 mg/mL relative to 1.39 ± 0.06 mg/mL of the standard, vitamin C at 1% confidence limit. Similarly, the extract scavenged 50% of hydroxyl radical at 204.34 ± 10.64 µg/mL relative to 210.05 ± 8.80 µg/mL of gallic acid. The extract also contained various phytochemicals that have been associated with antiobesity effects. The synergistic effects of these phytocompounds increase their bioavailability and action on multiple molecular targets thereby correcting obesity-induced oxidative stress.

Modulation of Cognition: The Role of Gnidia glauca on Spatial Learning and Memory Retention in High-Fat Diet-Induced Obese Rats.

Chronic exposures to high-fat diets are linked to neuropathological changes that culminate in obesity-related cognitive dysfunction and brain alteration. Learning, memory performance, and executive function are the main domains affected by an obesogenic diet. There are limited effective therapies for addressing cognitive deficits. Thus, it is important to identify additional and alternative therapies. In African traditional medicine, Gnidia glauca has putative efficacy in the management of obesity and associated complications. The use of Gnidia glauca is largely based on its long-term traditional use. Its therapeutic application has not been accompanied by sufficient scientific evaluation to validate its use. Therefore, the current study sought to explore the modulatory effects of dichloromethane leaf extracts of Gnidia glauca on cognitive function in the high-fat diet- (HFD-) induced obese rats. Obesity was induced by feeding the rats with prepared HFD and water ad libitum for 6 weeks. The in vivo antiobesity effects were determined by oral administration of G. glauca at dosage levels of 200, 250, and 300 mg/kg body weight in HFD-induced obese rats from the 6th to the 12th weeks. The Lee obesity index was used as a diagnostic criterion of obesity. The Morris water maze was employed to test spatial learning and memory retention in rats. The results indicated that Gnidia glauca showed potent antiobesity effects as indicated in the reduction of body weight and obesity index in extract-treated rats. Moreover, Gnidia glauca exhibited cognitive-enhancing effects in obese rats. The positive influences on cognitive functions might be attributed to the extracts' phytochemicals that have been suggested to confer protection against obesity-induced oxidative damage, reduction of central inflammation, and increased neurogenesis. The therapeutic effects observed suggest that Gnidia glauca might be an alternative to current medications for the symptomatic complications of obesity, such as learning and memory loss. Further studies are therefore needed to establish its toxicity profiles.

Effects of DCM Leaf Extract of Gnidia glauca (Fresen) on Locomotor Activity, Anxiety, and Exploration-Like Behaviors in High-Fat Diet-Induced Obese Rats.

Obesity is the main component of metabolic syndromes involving distinct etiologies that target different underlying behavioral and physiological functions within the brain structures and neuronal circuits. An alteration in the neuronal circuitry stemming from abdominal or central obesity stimulates a cascade of changes in neurochemical signaling that directly or indirectly mediate spontaneously emitted behaviors such as locomotor activity patterns, anxiety, and exploration. Pharmacological agents available for the treatment of neurologic disorders have been associated with limited potency and intolerable adverse effects. These have necessitated the upsurge in the utilization of herbal prescriptions due to their affordability and easy accessibility and are firmly embedded within wider belief systems of many people. Gnidia glauca has been used in the management of many ailments including obesity and associated symptomatic complications. However, its upsurge in use has not been accompanied by empirical determination of these folkloric claims. The present study, therefore, is aimed at determining the modulatory effects of dichloromethane leaf extract of Gnidia glauca on locomotor activity, exploration, and anxiety-like behaviors in high-fat diet-induced obese rats in an open-field arena. Obesity was experimentally induced by feeding the rats with prepared high-fat diet and water ad libitum for 6 weeks. The in vivo antiobesity effects were determined by oral administration of G. glauca at dosage levels of 200, 250, and 300 mg/kg body weight in high-fat diet-induced obese rats from the 6th to 12th week. Phytochemical analysis was done using gas chromatography linked to mass spectroscopy. Results indicated that Gnidia glauca showed anxiolytic effects and significantly increased spontaneous locomotor activity and exploration-like behaviors in HFD-induced obese rats. The plant extract also contained phytocompounds that have been associated with amelioration of the main neurodegenerative mediators, viz., inflammation and oxidative stress. These findings provide "qualified leads" for the synthesis of new alternative therapeutic agents for the management of neurologic disorders. However, there is a need to conduct toxicity studies of Gnidia glauca to establish its safety profiles.

Herbal therapy: A review of emerging pharmacological tools in the management of diabetes mellitus in Africa.

BACKGROUND: Diabetes mellitus is a chronic physiological glucose metabolic disorder. It has affected millions of people all over the world thereby having a significant impact on quality of life. The management of diabetes includes both nonpharmacological and conventional interventions. Drawbacks in conventional therapy have led to seeking alternative therapy in herbal medicine. Therefore, the need to review, elucidate and classify their mode of action in therapy for diabetes disease arises. MATERIALS AND METHODS: Comprehensive literature reports were used to review all conventional agents and herbal therapy used in the management of diabetes. An online database search was conducted for medicinal plants of African origin that have been investigated for their antidiabetic therapeutic potentials. RESULTS: The results showed that of the documented sixty five plants used, fourteen inhibit intestinal absorption of glucose, three exhibit insulin-mimetic properties, seventeen stimulate insulin secretion from pancreatic beta cells, twelve enhance peripheral glucose uptake, one promotes regeneration of beta-cell of islets of Langerhans, thirteen ameliorate oxidative stress and twenty induces hypoglycemic effect (mode of action is still obscure). Thirteen of these plants have a duplicate mode of actions while one of them has three modes of actions. These agents have a similar mechanism of action as the conventional drugs. CONCLUSION: In conclusion, antidiabetic activities of these plants are well established; however, the molecular modulation remains unknown. It is envisaged that the use of herbal therapy will promote good health and improve the status of diabetic patients.

Preliminary Phytochemical Screening and Biological Activities of Bulbine abyssinica Used in the Folk Medicine in the Eastern Cape Province, South Africa.

Bulbine abyssinica A. Rich. is used in traditional medicine to treat rheumatism, dysentery, bilharzia, cracked lips, back pain, infertility, diabetes mellitus, and gastrointestinal, vaginal, and bladder infections. Therefore, preliminary phytochemical screening, antioxidant, anti-inflammatory, and antibacterial properties of the whole plant (acetone and aqueous extracts) were determined using standard procedures. The in vitro antioxidant model assays revealed that the plant possesses free radical scavenging potential varying with free radical species. The species showed significant protein denaturation inhibitory activity with good protection against erythrocyte membrane lysis indicating anti-inflammatory potential. The results also showed that the species was active against the growth of all the selected eight diabetic status opportunistic bacteria except one. Moreover, the species is characterized by appreciable amounts of total phenols, flavonoids, flavanols, proanthocyanidins, and alkaloids. Traces amounts of saponins and tannins were also observed. Amongst the identified phytochemicals present, empirical searches identified them being antioxidant, anti-inflammatory, and antimicrobial agents. The identification of these phytochemical constituents with their known pharmacological properties indicates that this plant is a good source of the free radical scavenging, anti-inflammatory, and antimicrobial agents. These findings also account for the multipharmacological use of B. abyssinica in fork medicine.