weds test

 

1.      Define the following terminologies;                                                                                         5marks

Drug, Crude drugs , Natural Product, Ethnobotany , Ethnopharmacology

·         Drug

§  Is a natural or synthetic substance used in the treatment, cure, prevention, or diagnosis of disease or used to otherwise enhance physical or mental wellbeing

§  Drugs should be included in the official pharmacopoeia

·         Crude drugs

§  Are harvested (i.e. dried) plant or animal sources which pharmaceutically or medicinally useful products, and before they undergo extensive processing or modification

·         Natural Product

§  It is a chemical compound or substance produced by a living organism found in nature that usually has a pharmacological or biological activity for use in pharmaceutical drug discovery and drug design.

·         Ethnobotany

§  Is the study of the relationship between people and plants, field includes studying plants as medicines, alternative methods for healing, as wild foods, as agricultural crops; modes of transportation; as clothing and in the religious ceremonies.

·         Ethnopharmacology

§  Ethnopharmacology is the scientific study correlating ethnic groups, their health, and how it relates to their physical habits and methodology in creating and using medicines

2.      Outline three ways on how knowledge of medicinal properties of plants was acquired 3marks

a.      By guesswork or trial and error while searching food.

b.      By superficial resemblance between plant parts and affected organs.

c.       By accidental discovery

3.      List five cells, which makes complex tissues                                                    5marks

                                                  i.      Tracheids

                                                 ii.      Vessels or tracheae,

                                               iii.      Xylem fibres and

                                               iv.      Xylem parenchyma

                                                 v.      Sieve elements,

                                               vi.      Companion cells,

                                             vii.      Phloem parenchyma and

                                           viii.      Phloem fibres

4.      Regarding anatomy of the root, give five concentric rings of differen tissues                                                5marks

The Rhizodermis or Epiblema

The Cortex

Endodermis

The Pericycle

The Vascular Tissues

5.      Write down five sources of active principals from medicinal plant                                       5marks

Leaf, bark, flower, fruits, root, stem

6.      Mention three uses of yellow bees wax on the plant                                                    3 marks

§  as stiffening agents in yellow ointments

§  as a base in plasters

§  in the manufacture of candles and cosmetics and polish

7.      Give definition of three types of plant breeding methods                                                    3marks

Selective Breeding

Individual plants showing the most desirable characteristics are chosen and interbred

Hybridisation

Mating of different species or varieties to produce a hybrid progeny, different from both parents (incorporating desired characteristics). E.g.  Mentha piperita and M. spicata are naturally occurring hybrids

Transgenic Medicinal Plants

Genetic Engineering: Recombinant DNA

                                                                                                  i.      Transfer DNA sequences from the chromosomes of 1 plant to another

                                                                                                 ii.      Lead to the artificial transfer of a particular character from one organism to another

8.      With at least three points, describe Vacuum Drying                                                               3marks

It is also done in oven, but at low temperature

Low pressure ensures rapid and complete drying

It is an expensive method and thus reserved for expensive drugs or drugs which cannot be sufficiently dried by other methods

 

9.      Write the differences between two types of adulteration                                                     2marks

a.      Deliberate adulteration

                                                                                      i.      This is intentional and normally commercial mainly for enhancement of profits

b.      Accidental adulteration -unintentional

10.  Outline three ways in which admixture of medicinal plant can occur                                 3marks

                                            i.      Poor collection due to unskilled labour

                                           ii.      Presence of plant parts other than those allowed by the definition

                                         iii.      Collection of foreign material (stones, dirt)

11.  Write four uses of  Linseed  oil                                                                                                   4marks

a.      Used in lowering blood cholesterol levels (due to presence of ALA), control blood pressure

b.      Used in treatment of inflammation associated with gout

c.       Controls constipation

d.      It is an important drying oil in the paint and varnish industry

12.  Mention four Uses of Atropine                                                                                                4marks

                                                  i.      Stimulant on CNS

                                                 ii.      Dilates eye pupils

                                               iii.      Decreases sweating

                                               iv.      Produces stomach acid and saliva and relaxes smooth muscle (asthma and colic)

13.  Outline two therapeutic uses of Rhubarb                                                                                2marks

a.      Rhubarb can be used as a strong laxative

b.      Rhubarb has an astringent effect on the mucous membranes of the mouth and the nasal cavity

14.  Mention six therapeutic uses of cinnamon oil                                                                                     6marks

aromatic, carminative, flavouring agent, analgesic, antiseptic, antirheumatic, antispasmodic,demulcent, digestive, expectorant, stomachic, diaphoretic

antibacterial, antifungal                                                        

15.  What do you understand by term: Protoxylem, Metaxylem                                              2marks

§  Protoxylem is the earlier formed xylem elements

§  Metaxylem is the later formed xylem elements

 

16.  Write the botanical plant of the following: Clove oil, Anise oil, Eucalyptus oil, Dill Oil 4marks

Anise oil - Pimpenella anisum   

Clove oil -Eugenia caryophyllus (or Syzygium aromaticum)

Eucalyptus oil -Eucalyptus globlus     

Dill oil -Anethum graveolens                  

 

17.  outline three kinds of curare depending on their containers and chemical characteristics

                                                                                                                                                             3marks

§  Tube-curare

§  Packed in bamboo tubes (Brazil and Peru)

§  The alkaloid was then named “tubocurarine”

§  Calabash-curare

§  Packed in gourds (Guiana, Venezuela and Columbia)

§  Pot-curare

§  Packed in earthenware pots

18.  Mention five characteristics of third zone of cortex of dicot stem                                       5marks

a.      Consists of parenchyma cells

b.      The innermost layer of the cortex is the endodermis

c.       Made of barrel shaped cells arranged compactly without intercellular spaces

d.      Rich in starch grains, hence “starch sheath”

e.      In most dicot stems no casparian strips

 

19.  Write the Natural Sources, Constituents and Uses of Nux vomica                                       9marks

 

·         Definition

§  Nux vomica are dried, ripe seeds of Strychnous nux-vomica, family Loganiaceae

·         Constituents

§  The Main indole alkaloids are;

§  Strychnine

§  Brucine

·         Strychnine is more physiologically active than brucine

·         Strychnine is present in the inner part of the endosperm while brucine is in the outer layers

§  Other alkaloids are:

·         α-colubrine, β-colubrine, vomicine, pseudostrychnine and isostrychnine

§  The drug also contains 3% fixed oils, glycoside - loganin

·         Uses

§  It stimulates peristalsis in chronic constipation and is often combined with cascara and other laxatives

§  Bitter stomachich and tonic (increases gastric juice to improve appetite and digestion)

§  Improves the pulse and raises blood pressure

§  At higher doses it is a lethal poison

§  Brucine is used commercially as an alcohol denaturant (as it is extremely bitter)

 

20.  A. Describe the following method of extraction of volatile oils

a.      Soxhlet extraction                                                                                                        5marks

§  In this method; the fine ground crude drug is placed in a porous bag (Thimble), which is placed in the chamber of the soxhlet extractor.

§  The extracting solvent in the flask is heated and its vapors condense in condenser.

§  The condensed drops of solvent fall in the porous bag (thimble), dissolving out the desired component from a solid mixture.

§  When the siphon tube fills to overflowing, it initiates a siphoning action into the flask. This process is continuous/repeated and is carried out until a drop of solvent from the siphon tube does not leave residue when evaporated.

b.      Enfleurage (hot or cold)                                                                                                 5marks

In this a fatty layer is prepared using lard and the flower petals are spreaded over it, after the imbibitions is over the fatty layer is replaced with fresh petals. After the saturation of fatty layer the odorous principles are removed by treating with alcohol and a triple extract then prepared.

 

c.       Maceration                                                                                                                       5marks

The lard or oil is heated over a water bath, a charge of flowers added and the mixture stirred continuously for some time.

The exhausted flowers are removed, pressed, the expressed fluid returned to the

hot fat, fresh flowers, added and the process continued until defined weights of flowers and solvent have been used.

Again, a triple extract is prepared by extracting the perfumed lard or oil with alcohol

d.      by supercritical gases                                                                                                      5marks

It is the process of separating one component (the extractant) from another (matrix) using supercritical fluids as the extracting solvents

The system must contain a pump for CO2, a pressure cell that contains the  sample ,a mean of maintaining pressure in the system and a collecting vessel

                                                                                      i.      The liquid is pumped to heated zone, where it is heated to supercritical conditions

                                                                                    ii.      It then passed into extraction vessel. Here it diffuses in the solid matrix and dissolves the material to be extracted

                                                                                  iii.      The dissolved material is taken out from extraction vessel into a separator at low pressure

 

B. Give explanation on four important process of extraction of fixed oils and fats          4marks

§   Decortication –crushing to remove seed coat

§  Expression - kernels are placed onto the oil presses and subjected to pressure with or without application of heat

§  Filtration - separates oil from other matters and may be done several times to attain purity.

§  Steaming -at high temperature to inactivate proteins and other materials e.g. castor oil requires steaming