Anti-bacterial properties and GC-MS analysis of extracts and essential oils of selected plant product

Abstract

Nyambe MM. 2018. Phytochemical and antibacterial analysis of indigenous chewing sticks, Diospyros lyciodes and Euclea divinorum of Namibia. Biofarmasi 16: 29-43. The purpose of this study was to ascertain the phytochemical and antibacterial properties of Diospyros lycioides and Euclea divinorum and correlate the results obtained to their ethnomedicinal uses as chewing sticks. Fractions of powdered leaves, twigs, and roots were obtained from crude extracts using vacuum liquid chromatography with solvents of increasing polarity. Antimicrobial activities of the crude extracts and fractions were assessed using the agar overlay, disc diffusion, and agar dilution methods against the oral pathogens, Streptococcus mutans and Streptococcus sanguinis. In addition, the effect of fractions on the attachment of oral pathogens to tooth surface were also analyzed using saliva-coated hydroxyapatite beads (S-HA) as a model. Phytochemical screen tests revealed the presence of the following secondary metabolites in the twigs and roots of both plants: anthraquinones, cardenolides, saponins, tannins, polyphenols, and terpenoids. Alkaloids were detected only in the roots of both plants. Root fractions from both plants displayed higher antibacterial activity than twig fractions. This supports the preference of roots over twigs by stick users. D. lycioides root fraction displayed minimum inhibitory concentrations (MICs) of 0.625 mg/mL and 1.25 mg/mL against S. sanguinis and S. mutans, respectively. E. divinorum root fraction showed MICs of 1.25 mg/mL and 2.5 mg/mL against the aforementioned organisms. Adherence of the bacteria to S-HA was reduced more by root fractions from D. lycioides while twig fractions from both plants also showed significant anti-adhesive properties. Since fractions from both plants inhibited the growth of bacteria and reduced attachment to S-HA, it is an indication that these plants are potential sources of antibacterial and anti-adhesive agents and their use should be encouraged. The anti-adhesive activity of extracts from these plants has not yet being reported. Further research on isolation and characterization of the active compounds from fractions that showed antibacterial and anti-adhesive activity is recommended.

Antifungal Activity of Euclea divinorum Root and Study of its Ethnobotany and Phytopharmacology

“…Euclea divinorum Hiern (Ebenaceae) is a famous plant in the ethnomedicine of Soqotra Island, the root bark is used mostly as a toothbrush or as powder for cleaning of the teeth by rubbing on the teeth and chewing or rubbing to dye the lips and mouth red. Similar traditional uses of Euclea divinorum root were found in the ethnobotany of Namibia and Kenya [5,7,8]. However, in the ethnomedicine systems of some African countries, the roots of different Euclea species were reported in use as medicines, such as Euclea undulata roots that are used to relieve toothache in Botswana [9], and E. natalensis to clean teeth in Zanzibar [10], while Euclea pseudebenus roots are used to clean teeth on the southwest coast of Africa [11].…”

“…Toothbrush and/or chewing pieces (miswak) are the most frequently traditional modes prepared from the plant parts and used for teeth and mouth problems. These used parts can be classified into: (a) plant toothbrush with colouring properties such as such as Euclea divinorum [3], Euclea natalensis [4] and Diospyros lyciodes [5]; (b) plant toothbrush without colouring agents such as Salvadora persica [6].…”

“…Preliminary phytochemical investigations identified previously secondary bioactive metabolites in different parts of E. divinorum. Methanol and aqueous extracts of the E. divinorum root have been reported to contain polyphenols, saponins, tannins, flavonoids, steroids, terpenoids, glycosides and alkaloids [5,16]. Polyphenols and glycosides have been identified in the methanol extracts of leaves, stems and fruits [5,17].…”

“…Methanol and aqueous extracts of the E. divinorum root have been reported to contain polyphenols, saponins, tannins, flavonoids, steroids, terpenoids, glycosides and alkaloids [5,16]. Polyphenols and glycosides have been identified in the methanol extracts of leaves, stems and fruits [5,17]. Some triterpenoids including lupeol, botulin and lupene [13,18] and naphthoquinones including methyljuglone, mamegakinone, diospyrin and isodiospyrin [13,18,19] have been previously identified and isolated as main constituents of the non-polar chloroform extract of the E. divinorum root [13,18,19].…”

“…The cytotoxic, antibacterial, oxytocic, and diuretic activity of the root of E. divinorum have been demonstrated [3,5,14,16] (Table 1). Moreover, different biological and pharmacological investigations of the other parts of E. divinorum including leaves, fruits and barks of the plant were previously studied and reported, which are presented in Table 1.…”