ANTIBACTERIAL EFFECTS OF Chrysophyllum albidum EXTRACTS ON BACTERIAL ISOLATES FROM URINARY CATHETERS
Indwelling urinary catheters are standard medical devices utilized in both hospitals and nursing home settings to relieve urinary retention and urinary incontinence (CDCP, 1992). The most common urinary catheter in use is the Foley indwelling urethral catheter, a closed sterile system that comprise of a tube inserted through the urethra and held in place by an inflatable balloon to allow urinary drainage of the bladder. Due to the frequent, hospital application motive and catheter placement skill on the part of medical personnel, the use of indwelling catheters during hospitalisation, 21-50% of patients are placed at risk for complications associated with the use of these devices (Liedberg et al, 1990).
In patients with indwelling urinary catheter, microorganisms may be introduced into the bladder; (i) at the time the catheter is inserted, (ii) due to the ascent of microorganisms through the catheter lumen from a contaminated drainage system, and (iii) migration of microorganisms present in the urethra around the catheter (Kass, et al 1957).
The definition of Catheter-Associated Urinary Tract Infection (CAUTI) varies among published studies and the terms “bacteriuria” and “urinary tract infection” (UTI) are frequently used indistinctly (Kunin, 1997). Bacteriuria or funguria levels >103 colony- forming units (CFU) have been shown to be highly predictive of CAUTI, given that these levels increase to 105 CFU within 24 to 48 hours (Stark, et al 1984). Other specialists consider CAUTI to be present when there is predominant pathogen growth equal to or greater than 102 CFU, especially when associated with piuria (Stamm, 1998). Signs and symptoms associated with CAUTI such as fever, disuria, urgency, flank pain and leukocytosis have also been shown to have a low positive predictive value for CAUTI diagnosis since 90 percent of them are asymptomatic. This is most likely due to the fact that a urinary tract catheter continually eases bladder compression, thus avoiding urgency and pollakiuria associated with
inflamed bladder distension. A catheter in the urethra also prevents continuous urethral exposure to large numbers of organisms in the infected urine, averting urethritis, and consequently, urgency and disuria (Tambyah, et al 2000). Millions of urinary tract catheterizations are carried out worldwide for purposes of control, repair, diagnosis and treatment. The risk of infection per procedure is from 1 to 2 percent. This risk increases to 3 to 7 percent per catheterization day in such a way that nearly all patients will present with bacteriuria after 30days of urethral catheterization (Nagy, 2004).
The risk per day average is 5 percent. Other studies have stated that more than half the number of patients with permanent catheters will develop bacteriuria after 5 days of use and that the infection risk per day is 2.7 percent for chronic use as opposed to 0.14 percent for intermittent use (Blumstein, 2001; Warren, 1997). Fifteen to twenty percent of hospitalized patients require urinary catheter while four percent of patients receiving at-home care use permanent urinary catheters (Zimakoff, 1993). It has also been reported that extra-hospital urinary infections are associated with the use of vesical catheters in 16.3 percent of patients (Nagy, 2004). The conventional cut-off point for distinguishing between short and long-term catheterization is 30 days (Esclarin, et al 2000).
A study carried out in Great Britain from 1996 to 2001 reported that there was a significant change in both the bacterial spectrum and antimicrobial resistance. A greater incidence of polymicrobial infection was also observed resulting in important clinical implications. CAUTIs could become more difficult to treat, especially while the catheter was in situ, since it would be necessary to determine the indicated antibiotic or antibiotics to combat the bacteria present (Trautner, et al 2001).
Chronic vesical catheter use is a very common condition in medical practice due to a large variety of pathologies. Infection risk in permanent catheter use is variable and depends on the population, hospital application motive and catheter placement skill on the part of medical personnel. Urinary infection is not the only problem related to catheter use. Urethral stenosis in the male, urethrorrhagia, catheter obstruction, vesicoureteral reflux, bacteremia, false pathways and even stone formation are all possible resulting problems (Cormio, et al 1996; Salyer, et al 1994, Zimmerli, et al 1982).
Indiscriminate antibiotic use in patients with temporary or chronic urinary catheter has led to the creation of bacterial resistance to one or to multiple drugs. This has provoked the development of severe and difficult-to-treat urinary infections. Inadequate, insufficient and inopportune medical treatment can result in treatment complications for the patient.
Catheter-associated urinary tract infections (CAUTIs) representing over 40% of the most common type of nosocomial infections, are a major health concern due to the complications and frequent recurrence, which constitute 80% of all nosocomial UTIs (Stamm, 1991). These UTIs are often caused by Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa and Staphylococcus aureus (Stamm, 1998). Gram-negative bacterial species that cause CAUTIs like E. coli express a number of virulence factors associated with adhesions, motility, biofilm formation, immunoaviodance, and nutrient acquisition as well as factors that cause damage to the host. Studies have shown that despite the imminent threat of infections from these potent opportunistic nosocomial multiresistant strains, most cases of catheter-associated bacteriuria are asymptomatic. But where an episode of CAUTIs becomes symptomatic, the resulting effect can range from mild fever, urethritis and cystitis to severe acute pyelonephritis, renal scarring, calculus formation, and bacteremia. If
these infections are left untreated, they could be fatal (Budin, Itay; Devaraj, Neal; 2009).
Medical devices are responsible for a large portion of nosocomial infections, particularly in critically ill patients. Device-associated infections can cause major medical and economic sequel. Bacterial colonization of the indwelling devices can be a prelude to both infection and malfunctioning of the device. The pathogenesis of device-associated infection centres around the multifaceted interaction among the bacteria, the device, and the host. Bacterial factors are probably the most important in pathogenesis of infection, whereas device factors are the most amenable to modification with the objective of preventing infection. Some, but not all, of the studied bacterial receptors satisfy the proposed “adherence/infection” version of Koch’s postulates (Rabih et al, 2001). Traditional surface-modifying preventive approach have largely focused on antimicrobial coating of devices and resulted in variable clinical success in preventing device-associated infections (CDCP, 1992).
Medicinal plants are plants which contain substances that could be used for therapeutic purposes or which are precursors for the synthesis of useful drugs (Abolaji et al., 2007). Medicinal plants, for many years in the past, have been used in the treatment of many kinds of diseases. Over 5000 plants are known to be in use for medicinal purposes in Africa, but only a few have been described or studied (Taylor et al., 2001). Natural products from plants can be another potent source for the discovery of excellent biological activities, that is: anticancer and antioxidant activities (Adebayo et al., 2010).
This study investigates the use of Chrysophyllum albidium in the Southern part of Nigeria in the treatment of urinary tract infections. It is true that scientists are not relenting in their fight against these drug- resistant bacteria but there are reasons why people especially in the rural
areas have resorted to traditional medicine as alternative. These reasons include; (i) the high cost of broad-spectrum antibiotics, which is not affordable by people in rural areas, (ii) the unavailability of such drugs in this locality, (iii) the nearness of traditional doctors to them, and the low cost of these herbs used in traditional medicine. Also, people who reside in the urban centres and who can afford the cost of antibiotics often resort to traditional medicine due to the resistance of some bacteria to these antimicrobial drugs. The incessant strike action by the health-care workers also force the urban dwellers to go for traditional medicine. Chrysophyllum albidium is used in traditional medicine for the treatment of urinary associated problems. Hence, the purpose of this study is to find out the efficacy of Chrysophyllum albidum plant part extracts on isolated bacteria from urinary catheters.
The objectives of this study is, therefore, to identify the microorganisms present in patients with urinary tract catheters, to determine the sensitivity and resistance of the bacteria present to commonly used antibiotics and finally, to test the efficacy of a medicinal plant parts – Chrysophyllum albidium on these microorganisms especially on the resistant ones.
STATEMENT OF PROBLEMS
· The passage of urine is supposed to be natural and under control, but due to its retention in the bladder and incontinence on the patient, use of catheter is recommended.
· The use of the catheter then introduces infectious microorganisms; (i) at the time the catheter is inserted, (ii) due to the ascent of microorganisms through the catheter lumen from a contaminated drainage system, and (iii) migration of microorganisms present in the urethra around the catheter.
· Long time catheterisation and the frequent use of antibiotics, which makes the target organism, become resistant to these antibiotics.
· The difficulty in treating catheter associated urinary tract infections (CAUTIs) due to the presence of mixed colonies and biofilm formation.
OBJECTIVES OF THE STUDY
The objectives of this study are;
· to identify the microorganisms present in the urinary tract of patients with urinary catheters,
· to determine the susceptibility or sensitivity and resistance of the bacteria identified to commonly used antimicrobial drugs and finally,
· to test the efficacy of – Chrysophyllum albidum medicinal plant part extracts (root, leaves and cotyledon) on these identified bacteria.
⦁ Long Term Urethral Catheters
A long-term catheter requires catheterisation for a long period of time above three months or throughout life and may be attached to a drainage bag to collect the urine. A situation where long time catherization is required is where there is damage to the bladder, urinary incontinence due to old age and other types of diseases. Persons with spinal cord anomalies from birth defects like myelomeningocele, or spinal cord injury suffer from a “neurogenic bladder” whereby the bladder does not empty completely, can be on a long-term catheter (Blumstein, 2001). There are 2 types of drainage bags. One type is a leg bag, which is a smaller drainage device that attaches by elastic bands to the leg. A leg bag is usually worn during the day since it fits discreetly under pants or skirts, and is easily emptied into the toilet. The other type of drainage bag is a larger drainage device (down drain) that may be used during the night. This device is usually hung on the bed or placed on the floor. Catheters come in a large variety of sizes, materials (latex, silicone, Teflon) and types (Foley catheter, straight catheter, coude tip catheter). For example, a Foley catheter is a soft plastic or rubber tube that is inserted into the bladder to drain the urine. Experts recommend that the smallest possible catheter be used. Some people may require larger catheters to control leakage of urine around the catheter or if the urine is thick and bloody or contains large amounts of sediment. However, larger catheters are more likely to cause damage to the urethra. Some people have developed allergies or sensitivity to latex after long-term latex catheter use. These people are advised to use the silicone or Teflon catheters (Foley, 1931).
⦁ Suprapubic Catheters
A suprapubic catheter is basically an indwelling catheter that is placed directly into the bladder through the abdomen. The catheter is inserted above the pubic bone. This catheter must be placed by a urologist during an outpatient surgery or office procedure. The insertion site (opening on the abdomen) and the tube must be cleansed daily with soap and water and covered with dry gauze.
Qualified medical personnel usually change these catheters. The catheter may be attached to the standard drainage bags as described above. A suprapubic catheter may be recommended for people who require long- term catheterization, after some gynecological surgeries, and in people with urethral injury or obstruction. Complications of suprapubic catheter use may include: urinary tract or kidney infections, blood infections (septicemia), urine leakage around the catheter, skin breakdown, bladder stones, and blood in the urine (hematuria). After many years of catheter use, bladder cancer may also develop (Rabih, 2001).
⦁ Short Term Urethral Catheters
Some people may only require catheterization on an occasional basis, called intermittent catheterization. These people can be taught to catheterize themselves to drain the bladder when needed without having to constantly wear an external device. People who may benefit from intermittent catheterization include people with neurological disorders, women after certain gynecological surgeries, men with large prostates, and anyone who is unable to properly empty their bladder. The process is similar to the above described procedures except the balloon inflation is not performed and the catheter is removed after the flow of urine has stopped.
VARIOUS NEEDS FOR USE OF URINARY CATHETER Urinary catheters are sometimes recommended as a way to manage urinary incontinence and urinary retention in both men and women. There are several different types of catheters, which may be used for a variety of different reasons.
Urinary catheters may be used to drain the bladder. This is most likely due to the fact that a urinary tract catheter continually eases bladder compression, thus avoiding urgency and pollakiuria associated with inflamed bladder distension. A catheter in the urethra also prevents continuous urethral exposure to large numbers of organisms in the infected urine, averting urethritis, and consequently, urgency and disuria (Tambyah, et al 2000). Millions of urinary tract catheterizations are carried out worldwide for purposes of control, repair, diagnosis and treatment. This is often a last resort because of the possible complications associated with continuous catheter usage. (Kunin & McCormark, 1966). Short-term catheters are also used during the following: (i) on patients who are anaesthetized or sedated for surgery or other medical care; (ii) on comatose patients; (iii) due to urethral surgeries; (iv) due to ureterectomy;
(v) to ripen the cervix during induction in labour; and (vi) on patients with kidney disease whose urine output must be constantly and accurately measured. Long-term catheters could be used on patients with permanent paralysis or physical injury to use either standard toilet facilities or urinals.
A health care provider may recommend use of a catheter for short-term use or long-term use. Long-term use catheters are called indwelling catheters.
INFECTIONSASSOCIATEDWITHTHEUSEOF URINARY CATHETERS
The host proteins deposited from urine may facilitate attachment to the catheter by uropathogens. Escherichia coli and related gram-negative organisms have hairlike projections that bind to the Tamm-Horsfall protein. In the bloodstream, blood flow at the catheter tip is rapid, whereas in a catheterized urinary tract some stasis is usually present. Stasis, of course, predisposes to high levels of bacterial colonization. Additionally, while an intravascular catheter must pass through a skin wound, urinary catheters pass through a natural orifice. Thus, implementing sterile urinary catheter insertion techniques probably plays a lesser role in the prevention of catheter associated urinary tract infections (CAUTI), particularly in the case of long-term urinary catheters. In contrast to the relatively low numbers of skin flora present at the insertion site of a vascular catheter, contamination of the periurethral area with high numbers of bowel flora is very common. The most frequent causative agents of nosocomial CAUTI come from the patient's colonic flora or from the hands of health care personnel. These organisms include E coli, Enterococci, Pseudomonas, Klebsiella, Enterobacter, or Candida. The enteric gram-negative organisms found in the catheterized urinary tract are those that are commonly associated with multidrug resistance (Kunin & Steele, 1985). Although most intravascular catheters remain in place for days to weeks, many patients wear indwelling urinary catheters for years, even for the duration of their lives. Thus, the difficulties of preventing CAUTI are compounded by catheter location, duration of catheter placement, numbers of organisms, and types of organisms typically contaminating the catheterized urinary tract.
Vascular catheters, as well as urinary catheters can become colonized through several routes. Extraluminal colonization may occur by direct inoculation when the catheter is inserted, or it may occur later by organisms ascending in the mucus film between the catheter and the urethra. Intraluminal colonization occurs by reflux of organisms from a contaminated drainage bag or by a break in the closed drainage system. Once organisms gain access to the catheterized urinary tract, the level of bacteriuria usually increases to more than 105 cfu/mL within 24 to 48 hours in the absence of antimicrobial therapy. Apparently the presence of the urinary catheter alters the physiology of the urinary tract and predisposes the individual to infection. This is the case, because studies in healthy, noncatheterized women show that introduction of organisms into the bladder rarely leads to high-level bacteriuria. However, in the presence of an indwelling urethral catheter, the rate of acquisition of high-level bacteriuria is approximately 5% per day. It is worthy to note that, bacteriuria, or the presence of bacteria in the urine, is frequently asymptomatic and is not synonymous with symptomatic urinary tract infections (Cormio, et al, 1996).
In the normal, noncatheterized bladder, the two main host defence mechanisms against urinary tract infections (UTI) are mechanical clearance of organisms by voiding and the intrinsic antibacterial activity of the bladder wall itself. Proposed mechanisms for the increased risk of bacteriuria in catheterized individuals include the presence of residual urine in the bladder, ischemic damage to the bladder mucosa through overdistention, mechanical irritation from the presence of the catheter, and the presence of a foreign body to support biofilm formation. A systematic evaluation of urine specimens from chronically catheterized patients revealed that 98% of weekly urine specimens from such patients contained more than 105 cfu/mL of bacteria, and over 77% of the
specimens were polymicrobial (Kunin, 1997). Complications of catheter use may include: urinary tract or kidney infections, blood infections (septicemia), urethral injury, skin breakdown, bladder stones, and blood in the urine (hematuria). After many years of catheter use, bladder cancer may also develop (Cormio et al, 1996). All of these mechanisms involved in the pathogenesis of colonization and infection of the colonized urinary tract combine to make CAUTI very difficult to prevent in individuals wearing urinary catheters for longer than two weeks.
BIOLOGY OF SOME BACTERIA THAT COLONIZE URINARY CATHETERS
The biology of some bacteria that colonize urinary catheters are as stated below.
⦁ Staphylococcus spp – Staphylococci are classified into slime producers and non-slime producers. This ability to produce slime has been proposed as a marker for pathogenic strains of staphylococci. Slime is a viscous, extracellular glycoconjugate that allows these bacteria to adhere to smooth surfaces such as prosthetic medical devices and catheters.
Staphylococci produce disease through their ability to multiply and spread widely in tissues and through their production of many virulence factors. Some of these factors are exotoxins, leukocidins, toxic shock syndrome toxins, exfoliative toxins, enterotoxins and other enzymes like hyaluronidase, proteinases, lipases and b-lactamase (Crinch & Maki, 2002; Darouiche, 2001).
⦁ ADHESION OF Staphylococcus spp. TO URINARY CATHETERS
Staphylococcus epidermidis – Adherence of S. epidermidis to the surface of the device is not a one-time phenomenon but rather an evolving
process. Initially, there is a rapid attachment of bacteria to the surface of the device that is mediated either by non-specific factors (such as surface tension, hydrophobicity, and electrostatic forces) or by specific adhesions (Crinch & Maki, 2002). This initial phase of S. epidermidis adherence is followed by an accumulative phase during which bacteria adhere to each other and form a biofilm, a process that is mediated by the polysaccharide intercellular adhesins (PIA) encoded by the ica operon (Darouiche, 2001).
Staphylococcus aureus – The adherence of S. aureus is more dependent on the presence of host-tissue ligands, including fibrinonectins, fibrinogens, and collagens (Greene et al, 1995). S. aureus adheres to such host-tissue ligands via genetically defined microbial surface proteins commonly referred to as “microbial surface components recognizing adhesive matrix molecules” (MSCRAMM) (Darouiche et al 1997).
⦁ ADHESION OF Escherichia coli TO URINARY CATHETERS Escherichia coli – E.coli isolates that causes long-term (³ 12weeks) bacteriuria expressed type I fimbriae more than did isolates that cause short-term (£ 1 week) bacteriuria (Cormio et al, 1996). Studies have shown that E. coli strains with P fimbriae adhere to urethral stents more avidly than do strains that lack P fimbriae (Anderson et al 1996). These observations suggests that adherence of E. coli to urological devices may be dependent on the location of the device and local predominance of certain bacterial strains, given that E. coli strains that express type I fimbriae prevail in the bladder, whereas E. coli strains that express P fimbriae usually infect the kidney (CDRH, 1998).
⦁ ADHESION OF Proteus spp TO URINARY CATHETERS Proteus spp – Proteus spp. forms layers on the catheter surface, underlying encrustations of struvite and hydroxyapatite that partially or
completely occluded the catheter lumen. Encrustation was also apparent on catheters colonized by P. mirabilis plus other species, but was rarely seen on catheters colonized by non-urease-producing species. These observations support the hypothesis that catheter encrustation is brought about by the activity of urease-producing biofilms and confirms that the main target in the control of catheter encrustation should be P. mirabilis. The problem stems from infection of the catheterized urinary tract by urease-producing bacteria, particularly Proteus mirabilis (Mobley and Warren 1987; Kunin 1989). These organisms colonize the catheter surfaces, forming biofilm communities embedded in a polysaccharide matrix. The bacterial urease generates ammonia from urea and elevates the pH of the urine and the biofilm. Under these alkaline conditions, crystals of magnesium ammonium phosphate (struvite) and calcium phosphate (hydroxyapatite) are formed and become trapped in the organic matrix which surrounds the cells. The continued development of these encrustations eventually blocks the catheter lumen (Pourchez, et al 1989).
⦁ ADHESION OF Klebsiella spp TO URINARY CATHETERS
Klebsiella spp. – Klebsiella spp. uses type 1 and type 3 pili to mediate the colonization of inert surfaces. High adherence and biofilm formation were positively correlated with bacterial surface hydrophobicity, type 3 fimbriae expression but not with type 1 pili expression and were not dependent upon the strain's origin (Mobley and Warren 1987). The recombinant pFK10 plasmid carrying the mrk gene cluster results in type
3 fimbriae expression, increased surface hydrophobicity, increased adherence to abiotic surfaces and biofilm formation. Thus, type 3 pili constitute the main K. pneumoniae adhesive factor, facilitating adherence and biofilm formation on abiotic surfaces of strains of different origins (Consterton et al, 1999).
⦁ ADHESION OF Providencia stuartii TO URINARY CATHETERS
Providencia stuartii – P. stuartii is more prevalent in the urinary tract of patients with long-term bladder catheters than it is in catheter-free patients. Persistent adherence of P. stuartii to urinary catheters is thought to be mediated by type III fimbriae (Ng et al, 2010).
⦁ ADHESION OF Pseudomonas aeruginosa TO URINARY CATHETERS
Pseudomonas aeruginosa - Pseudomonas aeruginosa has been shown to form biofilms on a number of surfaces, including the tissues of the cystic fibrosis lung (Swem, et al 2009) and on abiotic surfaces such as contact lenses and catheter lines. This ubiquitous organism is also the cause of nosocomial infections in immunocompromised patients and individuals with severe burns (Donlan, 2002).
Biofilms of P. aeruginosa (and other microorganisms) are formed from individual planktonic cells in a complex and presumably highly regulated developmental process. Planktonic cells are thought to initiate interactions with a surface in response to various signals, including the nutritional status of the environment. The fully developed surface- attached community can be highly structured with distinct architectural and physical/chemical properties (Costerton et al., 1999). These biofilm- grown cells are thought to be markedly different from their planktonic counterparts, based on a number of lines of evidence. For example, P. aeruginosa growing on a surface has increased expression of algC, a gene required for the synthesis of extracellular polysaccharides (Davies et al., 1993; Davies and Geesey, 1995). Biofilm-grown P. aeruginosa has also been shown to acquire increased resistance to antibiotics (Costerton, 1991). Type IV pili have been shown to be important for the adherence to
and colonization of eukaryotic cell surfaces and are thought to play a role in pathogenesis.
DEVICE FACTORS TO BACTERIAL ADHESION TO URINARY CATHETERS
The presence of the device can, in and of itself enhances bacterial adherence and virulence. Analysis of the data on bacterial adherence and surface modification of the device is found to yield the following five major principles;
i. different bacteria may adhere differently to the same device material;
ii. the same bacteria may adhere differently to the same device material;
iii. the same bacteria may adhere differently to the same device material placed under different circumstances, including the medium in which the device is placed (hydrophobic vs hydrophilic), type of flow (dynamic vs stationary), and temperature;
iv. in vitro inhibition of bacterial colonization of the device does not ensure anti-effective efficacy in vivo; and
v. the clinical benefit of a particular surface-modifying approach may vary from one application to another (Zimmerli et al, 1982; Boelen et al, 2000).
Other device related factors that may affect bacterial adherence to the device include; sources of the device material, surface of the device and shape of the device.
HOSTFACTORSTOBACTERIALADHESIONTO URINARY CATHETERS
Host factors that are known to affect bacterial adherence to the device includes tissue ligands that mediate adherence of the “microbial surface
components recognizing adhesive matrix molecules” (MSCRAMM) positive bacteria to a variety of medical device. Also, the host factors that can either promote or inhibit the persistence of already adherent bacteria on the surface of the device. Studies have indicated that S. aureus binds more to the surface of vascular catheters and E. coli binds more to biliary stents that had been explanted from patients or animals (and therefore contains host-tissue ligands to bacterial adherence). This was further supported by the demonstration that S. aureus binds more to catheters coated with fibrinonectin or fibrinogen than to uncoated catheters (Salyers et al, 1994).
Chrysophyllum albidum (Udara in Ibo) Kingdom: Plantae
Chrysophyllum albidum is a small to medium buttressed tree species, up to 25-37m in height with a mature girth varying from 1.5 to 2m. The bole (trunk) is usually fluted, frequently free of branches for 21m above the ground. Its bark is thin, pale brownish-green, with slash exuding white, gummy latex. The leaves are simple, dark green above, pale tawny below when young and silver-white below when mature, oblong-elliptic to elongate obovate elliptic, 12-30cm long, 3.8-10cm broad; apex shortly
acuminate, base cuneate; primary lateral nerves widely spaced, 9-14cm on each side of the midrib; secondary lateral nerves indistinct or invisible; petiole 1.7-4.2cm long. The flowers are shortly pedicellate, in dense clusters in the leaf axils or from above the scars of fallen leaves; calyx 5- lobed, 3mm long, rusty pubescent outside, creamy white, the lobes equalling the tube in length. The flowers are small (3–8mm), purplish white and have a sweet fragrant smell; they are clustered several together, and are hermaphroditic (self fertile). The fruits are almost spherical, slightly pointed at the tip, about 3.2 cm in diameter, greenish-grey when immature, turning orange-red, yellow-brown or yellow, sometimes with speckles, 5 celled, with 5 brown seeds in yellowish, pleasantly acid pulp. The seeds are about 1-1.5 x 2cm, beanlike, shiny when ripe, compressed, with one sharp edge and a star-shaped arrangement in the fruit. The seed coats are hard, bony, shiny, and dark brown, and when broken reveal white-coloured cotyledons. The generic name is based on Greek words for ‘gold’ and ‘leaf’ and refers to the leaves of some species that are often covered with golden hairs underneath (Adewusi, 1997; Adisa, 2000; Madubuike & Ogbonnaya, 2000) (Plate 1).
Plate 1 – Chrysophyllum albidum Plant
Chrysophyllum albidum PLANT PARTS
Chrysophyllum albidum LEAVES
The leaves of Chrysophyllum albidum are simple, dark green above, pale tawny below when young and silver-white below when mature, oblong- elliptic to elongate obovate elliptic, 12-30cm long, 3.8-10cm broad; apex shortly acuminate, base cuneate; primary lateral nerves widely spaced, 9- 14cm on each side of the midrib; secondary lateral nerves indistinct or invisible; petiole 1.7-4.2cm long. The generic name is based on Greek words for ‘gold’ and ‘leaf’ and refers to the leaves of some species that are often covered with golden hairs underneath (Madubuike and Ogbonnaya, 2003) (Plate 2).
In Ethno-medicine, the leaves are used as emollients and for the treatment of skin eruptions, diarrhoea and stomachache, which are as a result of infections and inflammatory reactions (Adewusi, 1997).
In Cuba, the decocted leaves are administered as a cancer remedy and as pectoral (Morton, 1987).
Plate 2 – Front and back view of Chrysophyllum albidum leaves
Front view Back view
Chrysophyllum albidum SEED COTYLEDONS
The seeds of Chrysophyllum albidum are about 1-1.5 x 2cm, beanlike, shiny when ripe, compressed, with one sharp edge and a star-shaped arrangement in the fruit. The seed coats are hard, bony, shiny, and dark brown, and when broken reveal white-coloured cotyledons.
The cotyledons from the seeds of C. albidum are used as ointments in the treatment of vaginal and dermatological infections in Western Nigeria (Adewusi, 1997; Adisa, 2000; Madubuike & Ogbonnaya, 2000).
In Venezuela, the bitter pulverized seed is taken as a tonic, diuretic, febrifuge and in the treatment of diarrhoea (Morton, 1987) (Plate 3).
Plate 3 – Seeds of Chrysophyllum albidum Plant
Chrysophyllum albidum ROOT
The roots of Chrysophyllum albidum is located deep into the soil. When uprooted, the outermost covering is brownish in colour and when wounded, white gelatinous exudates are seen. The bark of the root is glossy, smooth, thin and leathery and adheres tightly to the inner rind (6 –
12.5 mm) thick.
In the Southern Nigeria, the roots and stem barks are employed in urinary related infections.
A decoction of the rind is taken as a pectoral and the tannin-rich, astringent root bark is used as a tonic and stimulant, and is taken to halt diarrhea, dysentery and hemorrhages, and as a treatment of gonorrhea and “catarrh of the bladder” (Morton, 1987) (Plate 4).
Plate 4 – Root bark of Chrysophyllum albidum plant
ECOLOGY OF PLANT AND DISTRIBUTION
Chrysophyllum albidum is a dominant canopy tree of lowland mixed rainforest, sometimes riverine. It is widely distributed from West Africa to the Sudan with an eastern limit in Kakamega forest, Kenya. C. albidum, from the Sapotaceae family, is commonly found in the Central, Eastern and Western Africa (Amusan et al., 2003). They are distributed in Nigeria, Uganda, Niger, Cameroun and Cote d’ Ivoire (Adewusi, 1997). It is often called the white star apple and distributed throughout the southern part of Nigeria (Idowu et al., 2006). In South-western Nigeria, the fruit is called “agbalumo” and popularly referred to as “udara” in South-eastern Nigeria. C. albidum is a popular tropical fruit tree and widely distributed in the low land rain forest zones and frequently found in villages (Madubuike and Ogbonnaya, 2003). The roots, barks and leaves of C. albidum have been employed in folk medicine for the treatment of diseases. The bark is used for the treatment of yellow fever and malaria, while the leaf is used as an emollient and for the treatment of skin eruption, stomachache and diarrhea (Adisa, 2000; Idowu et al., 2006). The cotyledons from the seeds of C. albidum are used as ointments in the treatment of vaginal and dermatological infections in Western Nigeria. The fruit pulp is rich in vitamin C and iron and an excellent source of raw material for industries (Adisa, 2000; Akubugwo and Ugbogu, 2007). In the South, the roots and stem barks are employed in urinary related infections. Tannins, flavonoids, terpenoids, proteins, carbohydrates and resins are the phytochemicals that have been reported in C. albidum (Akaneme, 2008).
Propagation is mainly by seedlings, wildings and direct sowing. Seedlings require good tending and shade until well established.
FUNCTIONAL USES OF THE PLANT
⦁ As Food: The fruit of C. albidum has immense economic potential, especially following the report that jams that could compete with raspberry jams and jellies could be made from it (Adisa, 2000). The fleshy fruit pulp is suitable for jams and is eaten especially as snack by both young and old (Amusa et.al., 2003) .The fruit has been found to have the highest content of ascorbic acid per 100g of edible fruit or about 100 times that of oranges and 10 times that of guava or cashew (Idowu, 2006). It is reported as an excellent source of vitamins, irons, flavours to diets (Adisa, 2000). In addition, its seeds are a source of oil, which is used for diverse purposes. The fleshy and juicy fruits, which are popularly eaten, are the potential source of a soft drink (Iwu, 1999).
⦁ In Timber production: The bole (trunk) is brownish-white, soft, coarse and open in grain, very perishable in contact with the ground. Its wood is easy to saw and plane, nails well, take a fine polish, and therefore are suitable for construction work, tool handles and similar purposes. The fruits also contain 90% anacadic acid, which is used industrially in protecting wood and as source of resin, while several other components of the tree including the roots, stem barks and leaves are used for medicinal purposes (Adewusi, 1997).
⦁ In Alcohol production: The fruits can be fermented and distilled for the production of wine and spirits.
Medicinal uses: The Bark of Chrysophyllum albidum is used as a remedy for yellow fever and malaria, while the leaves (Plate 2) are used as emollients and for the treatment of skin eruptions, diarrhea and stomach- ache, which are as a result of infections and inflammatory reactions (Adewusi, 1997). It is also reported that in the South-Eastern part of Nigeria, the stem barks and roots (Plate 4) are used for the treatment of
urinary tract infections (UTI’s). A decoction of the rind is taken as a pectoral and the tannin-rich, astringent root bark is used as a tonic and stimulant, and is taken to halt diarrhea, dysentery and hemorrhages, and as a treatment of gonorrhea and “catarrh of the bladder”. In Venezuela, the bitter pulverized seeds (Plate 3) is taken as a tonic, diuretic, febrifuge and in the treatment of diarrhoea (Morton, 1987). Its rich sources of natural antioxidants have been established to promote health by acting against oxidative stress related disease such infections as; diabetes, cancer and coronary heart diseases (Burits & Bucar, 2002). Studies have shown a diminished risk of chronic diseases in populations consuming diets high in fruits and vegetables and it has been suggested that antioxidants found in large quantities in fruits and vegetables may be responsible for this protective effect (Harnifi & Amrani, 2007). Generally, food antioxidants act as reducing agents, reversing oxidation by donating electrons and hydrogen ions. Much attention has been focused on natural antioxidants and some antioxidants isolated from natural sources with high activity have been reported by Olorunnisola et al. (2008)..