Utilisation of Mangifera indica plant extracts and parts in antimicrobial formulations and as a pharmaceutical excipient: a review.

Background: Antimicrobial resistance and the environmental threat posed by some synthetic antimicrobial agents necessitate more research into development of novel pharmaceutical products that are environmentally friendly. Also, the use of plant derived excipients is growing and opening up new avenue to solve current drug delivery issues in the pharmaceutical industry. Main body: This review summarizes studies related to the antimicrobial property of Mangifera indica extracts, possible mechanisms of antimicrobial action and antimicrobial formulations from the plant and overview of researches relating to the use of M. indica as a pharmaceutical excipient. Electronic searches were conducted on databases such as Pub Med, Wiley Online Library (WOL) and Google Scholar with focus on published articles relating to M. indica. Inclusion and exclusion criteria include publications relating to antimicrobial properties of M. indica extracts, its antimicrobial formulations and its use as a pharmaceutical excipient. The electronic searches yielded about 190 articles. From the studies reviewed, the mechanisms of action of phytochemicals described corroborate the antimicrobial activity exhibited by M. indica extracts and its selected formulations. In addition, mango pectin was observed to possess potential as a pharmaceutical excipient. Very few previous review articles based their focus on incorporating mechanism of action of phytochemicals with antimicrobial activity.This review examined antimicrobial properties of M. indica extracts and formulations, major phytochemicals in the plant parts and their possible modes of action. In addition, the study assessed the use of natural polymer derived from mango plant as excipients in pharmaceutical and pharmacological preparations. Conclusion: The study concluded that effective antimicrobial activity of mango plant extracts and formulations requires synergy of actions among various phytochemical constituents of the extract or formulation. It is recommended that more researches focused on discovery of new phytochemicals in M. indica, their mechanisms of action and effective utilization of the plant in the pharmaceutical industry should be further explored.

Design and evaluation of the antimicrobial properties of ackee seed extract silver nanoparticle film formulations.

BACKGROUND: Plant-extract-reduced metal nanoparticles provide means of overcoming microbial resistance. Incorporating them into appropriate pharmaceutical formulations will enhance their portability and ease of administration. OBJECTIVES: To synthesize silver nanoparticles using methanol extracts of the seeds of Blighia sapida as capping agents and formulating the products in antimicrobial films. MATERIAL AND METHODS: Phytochemical screening of the methanol extract of Blighia sapida K.D. Koenig (ackee) seeds was performed and its antioxidant properties were determined using DPPH (1,1-diphenyl-2-picrylhydrazyl) assay. The green synthesis of ackee seed extract silver nanoparticles (ASAgNPs) was accomplished with reacting 1 mM of aqueous silver nitrate (AgNO3) and the methanol extract in a flask; the bioreduction was performed at 37°C for 72 h. The resulting nanoparticles were lyophilized and characterized using UV-visible spectrophotometry, Fourier-transform infrared spectroscopy (FTIR) and photomicrography. The nanoparticles were further formulated into films using starch and carboxymethyl cellulose using the solvent evaporation method. The extract, biosynthesized nanoparticles and film formulations were screened for antimicrobial activity against several pathogens using the agar well diffusion method. RESULTS: The methanol seed extracts of the ackee fruit contained saponins, tannins, flavonoids, terpenoids, and anthraquinones. The extract exhibited significant antioxidant properties. The nanoparticles and film formulations had a broader range of activity against microbes than the plant extract, exhibiting significant activity against Escherichia coli ATCC 700728, Salmonella typhi ATCC 14028, Staphylococcus aureus ATCC 29213, and Pseudomonas aeruginosa ATCC 27853. Activity was also observed with Candida krusei, C. albicans, and Penicillium sp. It is noteworthy that this last organism showed resistance to fluconazole. CONCLUSIONS: Ackee seed extract silver nanoparticles exhibited a synergistic antimicrobial activity against several pathogens. Film formulations of the nanoparticles retained this antimicrobial activity and allowed the product to be presented in a consumer-ready form.

Clinicopathological evaluation of Newcastle disease virus vaccination using gums from Cedrela odorata and Khaya senegalensis as delivery agents in challenged chickens.

Following previous studies on delivery potential and immune response of chickens given Newcastle disease vaccine with gums, this study was conducted to evaluate the protective ability of vaccines delivered with plant gums against clinicopathological features of Newcastle disease (ND). Processed gums from incised trunks of Cedrela odorata and Khaya senegalensis trees were combined with ND vaccine in ratio 2:2:1 and administered at 21 days to white leghorn cockerels after weaning of maternal antibodies. The birds were grouped into gum-vaccine-oral (GVOR), vaccine-oral (VOR), gum-vaccine-ocular (GVOC), vaccine-ocular (VOC), gum-oral (GOR), gum-ocular (GOC), no-gum-no-vaccine/challenged (NGNV/C), no-gum-no-vaccine/unchallenged (NGNV/U). Vaccination was boosted with the same preparation at day 42 while birds were challenged with live ND virus (KUDU strain) at day 84. Clinical signs (Dullness, Diarrhoea, Paralysis, Torticollis) Post infection (Pi), terminal weakness, gross and histology lesions were scored on a severity scale from absent (0-), mild (1+) to moderate (2+) and severe (3+). Scores were assigned a quantitative score of 0, 10, 20, 30 respectively. Clinical signs scores for the 5 week Pi were subjected to Friedman test to assess the significance of severity among the groups. The test was significant at 1% significance level which implies that the clinical signs ranked highest in the NGNV/C, followed by the Gum alone groups, the vaccine alone groups and the gum-vaccine groups irrespective of route. Moribund birds subsequently euthanized were seen in the GOR and GOC group at 21% each and at 57% in NGNV/C group alone. No signs were seen in the NVNG/U group. Grossly, mild to moderate lesions were seen in all groups except GVOR and NGNV/U. At histology, pulmonary congestion, acute pneumonia, cecal tonsilar haemorrhages, gliosis and neuronophagia were present at different proportions in all groups except the GVOR and NGNV/U. Overall, lesion severity was least in the gum-vaccine groups while the oral groups had less lesion score compared to the ocular. From this study, phytogenic mucoadhesives polymers used hold immense potential as a delivery agent capable of improving protection against clinicopathologic features of Newcastle disease in previously vaccinated birds.

Ex-vivo evaluation of the mucoadhesive properties of Cedrela odorata and Khaya senegalensis gums with possible applications for veterinary vaccine delivery.

BACKGROUND: Few studies have investigated the interaction of bioadhesives with biologic tissues for veterinary application. Hence, this study evaluates the mucoadhesive property and vaccine delivery properties of polymers from phytogenic origin. Gums from Cedrela odorata and Khaya senegalensis were harvested, purified, dried and compressed into 500 mg tablets individually and in combined ratios. The time taken for these tablets, placed on freshly excised (5 × 5 cm) trachea and duodenal tissues of cattle, chicken, pig, sheep and goat and fastened to the basket end of a tablet dissolution machine probe set at 50 rev/min in a phosphate buffer 6.8 pH at 37 °C, to fall off the tissue was the peak adhesion time (PAT). Gum with best PAT was combined with Newcastle disease vaccine and the procedure repeated. Haemagglutination assay (HA) was conducted on the gum polymer-vaccine mix with gum and vaccine individually as controls. RESULTS: On intestinal and trachea tissues, Cedrela gum polymer averagely had prolonged PAT (≈1 h 30 min and 1 h respectively) while average PAT values of Khaya gums followed the same trend but too transient PAT (≈6 and 0.3 min respectively). However on combination, Cedrela-Khaya polymer mix (1:1) was best on chicken, cattle and sheep trachea and intestinal tissues (PAT of 1 h 30 min and 2 h 24 min respectively). On combination with vaccine, the PAT of the gums reduced slightly on cattle and sheep tissues while other animal tissue showed varied results. The HA results showed the gum polymer boosted the HA property of the vaccine (Log 10(5)), when compared to vaccine alone (Log 10(4)). CONCLUSION: Hence, mucoadhesives from phytogenic sources have potential for non-invasive vaccine application.

RELEASE AND MUCOADHESION PROPERTIES OF DICLOFENAC MATRIX TABLETS FROM NATURAL AND SYNTHETIC POLYMER BLENDS.

The delayed release and mucoadhesive properties of Cedrela gum and hydroxypropylmethylcellulose blend in diclofenac sodium tablet formulations were evaluated. Tablets were prepared by direct compression and the crushing strength and detachment force were found to increase from 74.49 ± 1.22 to 147.25 ± 2.57 N and 0.302 ± 0.36 to 1.141 ± 0.05 N from low to high level of polymers, respectively. The release kinetics followed Korsmeyer-Peppas release and the n varied between 0.834 and 1.273, indicating that the release mechanism shifts from Fickian to super case I (anomalous release). The drug release profile fits a pulsatile-release pattern characterized by a lag time followed by a more or less rapid and complete drug release. The Cedrela gum-hydroxypropylmethylcelluse blend tablets delayed diclofenac release for 2 h and sustained the release for 12 h. The polymer blend delayed drug release in the 0.1 M HCl simulating gastric environment and subsequent release pH 6.8 phosphate buffer.

EFFECT OF FORMULATION AND PROCESS VARIABLES ON THE RELEASE, MECHANICAL AND MUCOADHESIVE PROPERTIES OF IBUPROFEN TABLET FORMULATIONS.

A 2(4) full factorial analysis was used to study the individual and interactive effects of binder type, X1; binder concentration, X2; relative density, X3 and tabletting technique, X4, on disintegration time (DT), brittle fracture index (BFI), tensile strength (TS) and mucoadhesion time (MT) of ibuprofen tablets formulated by direct compression (DC) and wet granulation (WG), and containing Entandophragnia angolense gum (ENTA) as binder, in comparison with hydroxypropylcellulose. The result of the FTIR and UV peaks suggests the absence of any interaction between ENTA and ibuprofen. Interactions between the polymers and ibuprofen were determined using FTIR and UV determinations. The ranking of the individual effects on DT and BFI was X2 > X3 > X1 > X4, on TS; X3 > X2> X1 > X4 and on MT; X2> X > X4 > X3. The effects of changing the binder from hydroxypropylcellulose to ENTA led to an increase in DT and decrease in TS, BFI and MT. Changing X2 and X3 to higher values increased the DT and TS. The interaction between X1 and X2 had the highest influence on BEI and MT, while interaction between "X3 and X4", and "X2 and X3" had the highest influence on DT and TS, respectively. Ibuprofen tablets prepared by wet granulation method and containing Entandophragma angolense gum showed lower capping/lamination tendencies and better mucoadhesive drug release profiles.

In vitro and in vivo antimicrobial evaluation of alkaloidal extracts of Enantia chlorantha stem bark and their formulated ointments.

The in vitro and in vivo antimicrobial evaluation of the formulated ointment of alkaloidal extract of Enantia chlorantha Oliv. (Annonaceae) was the concern of this study. The alkaloidal fraction of the stem bark extract was formulated into simple ointment using British Pharmacopoeia formula for preparation of simple ointment. Agar diffusion and agar dilution methods were used for the in vitro antimicrobial studies. Ketoconazole 4000 µg/mL and tioconazole cream 1% were used as reference standards while normal saline was used as control. The fungicidal activity kinetics of the plant extract was carried out using selected concentrations of the plant extract against the most sensitive organism (Candida albicans). For the in vivo studies, 25 albino rats weighing between 180-200 g were divided into 5 groups, anesthesized (thiopental sodium 50 mg/kg), infected with overnight culture of Candida albicans and incubated at 37 degrees C for three days to allow for growth of the microorganisms. Each of the five groups was treated on the third day of incubation with different concentrations of the formulated simple ointment (200 mg/mL, 100 mg/kg, 50 mg/mL), tioconazole cream 1% (reference standard) and normal saline control, respectively. The alkaloidal extract exhibited greater zones of inhibition with Candida glabrata and Trichophyton tonsurans while Candida albicans and Trichophyton interdigitali also showed some sensitivity. There was no surviving organism at the end of 240 min at 100 mg/mL concentration with 10(-4) dilution factor. Treatment of the infected rats with the formulated simple ointments (200, 100 and 50 mg/mL) showed that 50 mg/mL ointment had a better percentage reduction in the fungal loads at the end of the experiment when compared with the 200 mg/mL simple ointment as well as the standard tioconazole 1% cream and normal saline treated rats, respectively. The alkaloidal fraction of Enantia chlorantha stem bark as well as the formulated ointment exhibited significant in vitro and in vivo antifungal activities against different species of Candida, dermatophytes and plant fungi.

A influência da goma de Cissus nas propriedades mecânicas e de liberação de comprimidos de paracetamol - uma análise fatorial / The influence of cissus gum on the mechanical and release properties of paracetamol tablets ? a factorial analysis

The quantitative effects of a new gum, used as a binder, on the mechanical and release properties of paracetamol tablet formulations were analyzed in a 23 full factorial experiment. Cissus gum extracted from Cissus populnea Guill. & Perr. (Vitaceae) was compared with official gelatin. The individual and interaction effects of type of binder, concentration of binder and packing fraction on the friability, tensile strength, brittle fracture index, disintegration time and drug release profile of tablets were determined. Changing the binder from gelatin to cissus gum led to an increase in friability and a decrease in tensile strength, brittle fracture index (BFI) and drug release variables. Increasing binder concentration from 2.0w/w to 4.0%w/w, and increasing relative density from 0.80 to 0.90, led to increases in lamination tendency and release rate of the formulations. Tablets containing gelatin had higher tensile strength, lower friability, longer disintegration time and a greater tendency to laminate than those with cissus gum. Hence, care must be taken in choosing a suitable binder for tablet formulations, with respect to their mechanical and release characteristics. The study suggests that cissus gum should be preferred to gelatin in tablet formulations that tend to cap or laminate or in formulations meant for rapid drug release

Os efeitos quantitativos de uma nova goma como agente agregante nas propriedades mecânicas e de liberação de formulações de comprimidos de paracetamol foram avaliados utilizando um modelo fatorial 23 experimental. A goma foi obtida de Cissus populnea Guill. & Perr. (Vitaceae) e comparada com a gelatina oficial. Os efeitos individuais e de interação do tipo de agregante, concentração de agregante, porcentagem de friabilidade, resistência à tração, índice de fratura e tempo de desintegração e liberação do fármaco dos comprimidos foram determinados. A mudança do agente agregante de gelatina para goma de cissus levou a um aumento da friabilidade e a uma diminuição na resistência à tração, no índice de fratura e nos parâmetros de liberação do fármaco. O aumento da concentração do agregante de 2,0% p/p para 4,0% p/p e da densidade relativa de 0,80 a 0,90 levou a um aumento na tendência de laminação e na taxa de liberação das formulações. Comprimidos contendo gelatina apresentaram maior resistência à tração com menor friabilidade e maior tempo de desintegração e dissolução com maior tendência para laminado, quando comparados com a goma de cissus. Por isso, cuidados devem ser tomados na escolha de um agente agregante para formulações de comprimidos no que diz respeito às características mecânicas e de liberação. O estudo sugere que a goma de cissus pode ser empregada ao invés de gelatina em formulações de comprimidos que apresentam tendência de formar laminado ou decapeamento ou em formulações para liberação controlada de fármacos.